Adds Snowbridge to Rococo runtime (#2522)

# Description

Adds Snowbridge to the Rococo bridge hub runtime. Includes config
changes required in Rococo asset hub.

---------

Co-authored-by: Alistair Singh <alistair.singh7@gmail.com>
Co-authored-by: ron <yrong1997@gmail.com>
Co-authored-by: Vincent Geddes <vincent.geddes@hey.com>
Co-authored-by: claravanstaden <Cats 4 life!>

Cargo.toml

@@ -36,6 +36,20 @@ members = [
 	"bridges/primitives/test-utils",
 	"bridges/primitives/xcm-bridge-hub",
 	"bridges/primitives/xcm-bridge-hub-router",
+	"bridges/snowbridge/parachain/pallets/ethereum-beacon-client",
+	"bridges/snowbridge/parachain/pallets/inbound-queue",
+	"bridges/snowbridge/parachain/pallets/outbound-queue",
+	"bridges/snowbridge/parachain/pallets/outbound-queue/merkle-tree",
+	"bridges/snowbridge/parachain/pallets/outbound-queue/runtime-api",
+	"bridges/snowbridge/parachain/pallets/system",
+	"bridges/snowbridge/parachain/pallets/system/runtime-api",
+	"bridges/snowbridge/parachain/primitives/beacon",
+	"bridges/snowbridge/parachain/primitives/core",
+	"bridges/snowbridge/parachain/primitives/ethereum",
+	"bridges/snowbridge/parachain/primitives/router",
+	"bridges/snowbridge/parachain/runtime/rococo-common",
+	"bridges/snowbridge/parachain/runtime/runtime-common",
+	"bridges/snowbridge/parachain/runtime/tests",
 	"cumulus/client/cli",
 	"cumulus/client/collator",
 	"cumulus/client/consensus/aura",

bridges/snowbridge/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
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+      "You" (or "Your") shall mean an individual or Legal Entity
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+
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+      not limited to compiled object code, generated documentation,
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+
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+      of this License, Derivative Works shall not include works that remain
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+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
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+
+      (c) You must retain, in the Source form of any Derivative Works
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+
+      (d) If the Work includes a "NOTICE" text file as part of its
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+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
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+   Copyright [yyyy] [name of copyright owner]
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+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

bridges/snowbridge/README.md

@@ -0,0 +1,127 @@
+# Snowbridge ·
+[![codecov](https://codecov.io/gh/Snowfork/snowbridge/branch/main/graph/badge.svg?token=9hvgSws4rN)]
+(https://codecov.io/gh/Snowfork/snowbridge)
+![GitHub](https://img.shields.io/github/license/Snowfork/snowbridge)
+
+Snowbridge is a trustless bridge between Polkadot and Ethereum. For documentation, visit https://docs.snowbridge.network.
+
+## Components
+
+### Parachain
+
+Polkadot parachain and our pallets. See [parachain/README.md](https://github.com/Snowfork/snowbridge/blob/main/parachain/README.md).
+
+### Contracts
+
+Ethereum contracts and unit tests. See [contracts/README.md](https://github.com/Snowfork/snowbridge/blob/main/contracts/README.md)
+
+### Relayer
+
+Off-chain relayer services for relaying messages between Polkadot and Ethereum. See
+[relayer/README.md](https://github.com/Snowfork/snowbridge/blob/main/relayer/README.md)
+
+### Local Testnet
+
+Scripts to provision a local testnet, running the above services to bridge between local deployments of Polkadot and
+Ethereum. See [web/packages/test/README.md](https://github.com/Snowfork/snowbridge/blob/main/web/packages/test/README.md).
+
+### Smoke Tests
+
+Integration tests for our local testnet. See [smoketest/README.md](https://github.com/Snowfork/snowbridge/blob/main/smoketest/README.md).
+
+## Development
+
+We use the Nix package manager to provide a reproducible and maintainable developer environment.
+
+After [installing nix](https://nixos.org/download.html) Nix, enable [flakes](https://nixos.wiki/wiki/Flakes):
+
+```sh
+mkdir -p ~/.config/nix
+echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf
+```
+
+Then activate a developer shell in the root of our repo, where
+[`flake.nix`](https://github.com/Snowfork/snowbridge/blob/main/flake.nix) is located:
+
+```sh
+nix develop
+```
+
+Also make sure to run this initialization script once:
+```sh
+scripts/init.sh
+```
+
+### Support for code editors
+
+To ensure your code editor (such as VS Code) can execute tools in the nix shell, startup your editor within the
+interactive shell.
+
+Example for VS Code:
+
+```sh
+nix develop
+code .
+```
+
+### Custom shells
+
+The developer shell is bash by default. To preserve your existing shell:
+
+```sh
+nix develop --command $SHELL
+```
+
+### Automatic developer shells
+
+To automatically enter the developer shell whenever you open the project, install
+[`direnv`](https://direnv.net/docs/installation.html) and use the template `.envrc`:
+
+```sh
+cp .envrc.example .envrc
+direnv allow
+```
+
+### Upgrading the Rust toolchain
+
+Sometimes we would like to upgrade rust toolchain. First update `parachain/rust-toolchain.toml` as required and then
+update `flake.lock` running
+```sh
+nix flake lock --update-input rust-overlay
+```
+
+## Troubleshooting
+
+Check the contents of all `.envrc` files.
+
+Remove untracked files:
+```sh
+git clean -idx
+```
+
+Ensure that the current Rust toolchain is the one selected in `scripts/init.sh`.
+
+Ensure submodules are up-to-date:
+```sh
+git submodule update
+```
+
+Check untracked files & directories:
+```sh
+git clean -ndx | awk '{print $3}'
+```
+After removing `node_modules` directories (eg. with `git clean above`), clear the pnpm cache:
+```sh
+pnpm store prune
+```
+
+Check Nix config in `~/.config/nix/nix.conf`.
+
+Run a pure developer shell (note that this removes access to your local tools):
+```sh
+nix develop -i --pure-eval
+```
+
+## Security
+
+The security policy and procedures can be found in SECURITY.md.

bridges/snowbridge/parachain/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

bridges/snowbridge/parachain/README.md

@@ -0,0 +1,155 @@
+# Parachain modules
+
+## Configuration
+
+Note: This section is not necessary for local development, as there are scripts to auto-configure the parachain in the
+[test directory](https://github.com/Snowfork/snowbridge/blob/main/web/packages/test).
+
+For a fully operational chain, further configuration of the initial chain spec is required. The specific configuration will
+depend heavily on your environment, so this guide will remain high-level.
+
+After completing a release build of the parachain, build an initial spec for the snowbase runtime:
+
+```bash
+target/release/snowbridge build-spec --chain snowbase --disable-default-bootnode > spec.json
+```
+
+Now edit the spec and configure the following:
+1. Recently finalized ethereum header and difficulty for the ethereum light client
+2. Contract addresses for the Ether, Erc20, and Dot apps.
+3. Authorized principal for the basic channel
+
+For an example configuration, consult the [setup script](https://github.com/Snowfork/snowbridge/blob/main/web/packages/test/scripts/start-services.sh)
+for our local development stack. Specifically the `start_polkadot_launch` bash function.
+
+## Tests
+
+To run the parachain tests locally, use `cargo test --workspace`. For the full suite of tests, use
+`cargo test --workspace --features runtime-benchmarks`.
+
+Optionally exclude the top-level and runtime crates:
+
+```bash
+cargo test --workspace \
+        --features runtime-benchmarks \
+        --exclude snowbridge \
+        --exclude snowbridge-runtime \
+        --exclude snowblink-runtime \
+        --exclude snowbase-runtime
+```
+
+### Updating test data for inbound channel unit tests
+
+To regenerate the test data, use a test with multiple `submit` calls in `ethereum/test/test_basic_outbound_channel.js`, eg.
+"should increment nonces correctly".
+
+Add the following preamble:
+
+```javascript
+const rlp = require("rlp");
+const contract = BasicOutboundChannel;
+const signature = 'Message(address,address,uint64,uint64,bytes)';
+```
+
+For each encoded log you want to create, find a transaction object `tx` returned from a `submit` call and run this:
+
+```javascript
+const rawLog = tx.receipt.rawLogs[0];
+const encodedLog = rlp.encode([rawLog.address, rawLog.topics, rawLog.data]).toString("hex");
+console.log(`encodedLog: ${encodedLog}`);
+const iface = new ethers.utils.Interface(contract.abi);
+const decodedEventLog = iface.decodeEventLog(
+  signature,
+  rawLog.data,
+  rawLog.topics,
+);
+console.log(`decoded rawLog.data: ${JSON.stringify(decodedEventLog)}`);
+```
+
+Place the `encodedLog` string in the `message.data` field in the test data. Use the `decoded rawLog.data` field to
+update the comments with the decoded log data.
+
+## Generating pallet weights from benchmarks
+
+Build the parachain with the runtime benchmark flags for the chosen runtime:
+
+```bash
+runtime=snowbase
+cargo build \
+    --release \
+    --no-default-features \
+    --features "$runtime-native,rococo-native,runtime-benchmarks,$runtime-runtime-benchmarks" \
+    --bin snowbridge
+```
+
+List available pallets and their benchmarks:
+
+```bash
+./target/release/snowbridge benchmark pallet --chain $runtime --list
+```
+
+Run a benchmark for a pallet, generating weights:
+
+```bash
+target/release/snowbridge benchmark pallet \
+  --chain=$runtime \
+  --execution=wasm \
+  --wasm-execution=compiled \
+  --pallet=basic_channel_inbound \
+  --extra \
+  --extrinsic=* \
+  --repeat=20 \
+  --steps=50 \
+  --output=pallets/basic-channel/src/inbound/weights.rs \
+  --template=templates/module-weight-template.hbs
+```
+
+## Generating beacon test fixtures and benchmarking data
+
+### Minimal Spec
+
+To generate `minimal` test data and benchmarking data, make sure to start the local E2E setup to spin up a local beacon
+node instance to connect to:
+
+```bash
+cd web/packages/test
+./scripts/start-services.sh
+```
+
+Wait for output `Testnet has been initialized`.
+
+In a separate terminal, from the `snowbridge` directory, run:
+
+```bash
+mage -d relayer build && relayer/build/snowbridge-relay generate-beacon-data --spec "minimal" && cd parachain &&
+cargo +nightly fmt -- --config-path rustfmt.toml && cd -
+```
+
+### Mainnet Spec
+
+We only use the mainnet spec for generating fixtures for pallet weight benchmarks.
+
+To generate the data we can connect to the Lodestar Goerli public node. The script already connects to the Lodestar node,
+so no need to start up additional services. In the event of the Lodestar node not being available, you can start up your
+own stack with these commands:
+
+```bash
+cd web/packages/test
+./scripts/start-goerli.sh
+```
+
+From the `snowbridge` directory, run:
+
+```bash
+mage -d relayer build && relayer/build/snowbridge-relay generate-beacon-data --spec "mainnet" && cd parachain &&
+cargo +nightly fmt -- --config-path rustfmt.toml && cd -
+```
+
+### Benchmarking tests
+
+To run the benchmark tests
+
+```bash
+cd parachain/pallets/ethereum-beacon-client
+cargo test --release --features runtime-benchmarks
+```

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/Cargo.toml

@@ -0,0 +1,95 @@
+[package]
+name = "snowbridge-ethereum-beacon-client"
+description = "Snowbridge Beacon Client Pallet"
+version = "0.0.1"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+serde = { version = "1.0.188", optional = true }
+serde_json = { version = "1.0.96", optional = true }
+codec = { version = "3.6.1", package = "parity-scale-codec", default-features = false, features = ["derive"] }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+ssz_rs = { version = "0.9.0", default-features = false }
+ssz_rs_derive = { version = "0.9.0", default-features = false }
+byte-slice-cast = { version = "1.2.1", default-features = false }
+rlp = { version = "0.5.2", default-features = false }
+hex-literal = { version = "0.4.1", optional = true }
+log = { version = "0.4.20", default-features = false }
+
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking", default-features = false, optional = true }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false, optional = true }
+
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+snowbridge-ethereum = { path = "../../primitives/ethereum", default-features = false }
+primitives = { package = "snowbridge-beacon-primitives", path = "../../primitives/beacon", default-features = false }
+static_assertions = { version = "1.1.0", default-features = false }
+bp-runtime = { path = "../../../../../bridges/primitives/runtime", default-features = false }
+pallet-timestamp = { path = "../../../../../substrate/frame/timestamp", default-features = false, optional = true }
+
+[dev-dependencies]
+rand = "0.8.5"
+sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
+serde_json = "1.0.96"
+hex-literal = "0.4.1"
+pallet-timestamp = { path = "../../../../../substrate/frame/timestamp" }
+sp-io = { path = "../../../../../substrate/primitives/io" }
+serde = "1.0.188"
+
+[features]
+default = ["std"]
+fuzzing = [
+	"hex-literal",
+	"pallet-timestamp",
+	"serde",
+	"serde_json",
+	"sp-io",
+]
+std = [
+	"bp-runtime/std",
+	"byte-slice-cast/std",
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"pallet-timestamp/std",
+	"primitives/std",
+	"rlp/std",
+	"scale-info/std",
+	"serde",
+	"snowbridge-core/std",
+	"snowbridge-ethereum/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"ssz_rs/std",
+	'frame-benchmarking/std',
+]
+runtime-benchmarks = [
+	"beacon-spec-mainnet",
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"hex-literal",
+	"pallet-timestamp?/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-timestamp?/try-runtime",
+	"sp-runtime/try-runtime",
+]
+beacon-spec-mainnet = []

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/benchmark.md

@@ -0,0 +1,88 @@
+# Motivation
+Demonstrate that
+[FastAggregateVerify](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-bls-signature-04#section-3.3.4) is the most
+expensive call in ethereum beacon light client, though in [#13031](https://github.com/paritytech/substrate/pull/13031)
+Parity team has wrapped some low level host functions for `bls-12381` but adding a high level host function specific
+for it is super helpful.
+
+# Benchmark
+We add several benchmarks
+[here](https://github.com/Snowfork/snowbridge/blob/8891ca3cdcf2e04d8118c206588c956541ae4710/parachain/pallets/ethereum-beacon-client/src/benchmarking/mod.rs#L98-L124)
+as following to demonstrate
+[bls_fast_aggregate_verify](https://github.com/Snowfork/snowbridge/blob/8891ca3cdcf2e04d8118c206588c956541ae4710/parachain/pallets/ethereum-beacon-client/src/lib.rs#L764)
+is the main bottleneck. Test data
+[here](https://github.com/Snowfork/snowbridge/blob/8891ca3cdcf2e04d8118c206588c956541ae4710/parachain/pallets/ethereum-beacon-client/src/benchmarking/data_mainnet.rs#L553-L1120)
+is real from goerli network which contains 512 public keys from sync committee.
+
+## sync_committee_period_update
+Base line benchmark for extrinsic [sync_committee_period_update](https://github.com/Snowfork/snowbridge/blob/8891ca3cdcf2e04d8118c206588c956541ae4710/parachain/pallets/ethereum-beacon-client/src/lib.rs#L233)
+
+## bls_fast_aggregate_verify
+Subfunction of extrinsic `sync_committee_period_update` which does what
+[FastAggregateVerify](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-bls-signature-04#section-3.3.4) requires.
+
+## bls_aggregate_pubkey
+Subfunction of `bls_fast_aggregate_verify` which decompress and instantiate G1 pubkeys only.
+
+## bls_verify_message
+Subfunction of `bls_fast_aggregate_verify` which verify the prepared signature only.
+
+
+# Result
+
+## hardware spec
+Run benchmark in a EC2 instance
+```
+cargo run --release --bin polkadot-parachain --features runtime-benchmarks -- benchmark machine --base-path /mnt/scratch/benchmark
+
++----------+----------------+-------------+-------------+-------------------+
+| Category | Function       | Score       | Minimum     | Result            |
++===========================================================================+
+| CPU      | BLAKE2-256     | 1.08 GiBs   | 1.00 GiBs   | ✅ Pass (107.5 %) |
+|----------+----------------+-------------+-------------+-------------------|
+| CPU      | SR25519-Verify | 568.87 KiBs | 666.00 KiBs | ❌ Fail ( 85.4 %) |
+|----------+----------------+-------------+-------------+-------------------|
+| Memory   | Copy           | 13.67 GiBs  | 14.32 GiBs  | ✅ Pass ( 95.4 %) |
+|----------+----------------+-------------+-------------+-------------------|
+| Disk     | Seq Write      | 334.35 MiBs | 450.00 MiBs | ❌ Fail ( 74.3 %) |
+|----------+----------------+-------------+-------------+-------------------|
+| Disk     | Rnd Write      | 143.59 MiBs | 200.00 MiBs | ❌ Fail ( 71.8 %) |
++----------+----------------+-------------+-------------+-------------------+
+```
+
+## benchmark
+
+```
+cargo run --release --bin polkadot-parachain \
+--features runtime-benchmarks \
+-- \
+benchmark pallet \
+--base-path /mnt/scratch/benchmark \
+--chain=bridge-hub-rococo-dev \
+--pallet=snowbridge_ethereum_beacon_client \
+--extrinsic="*" \
+--execution=wasm --wasm-execution=compiled \
+--steps 50 --repeat 20 \
+--output ./parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/snowbridge_ethereum_beacon_client.rs
+```
+
+### [Weights](https://github.com/Snowfork/cumulus/blob/ron/benchmark-beacon-bridge/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/snowbridge_ethereum_beacon_client.rs)
+
+|extrinsic       | minimum execution time benchmarked(us) |
+| --------------------------------------- |----------------------------------------|
+|sync_committee_period_update | 123_126                                |
+|bls_fast_aggregate_verify| 121_083                                |
+|bls_aggregate_pubkey | 90_306                                  |
+|bls_verify_message | 28_000                                  |
+
+- [bls_fast_aggregate_verify](#bls_fast_aggregate_verify) consumes 98% execution time of [sync_committee_period_update](#sync_committee_period_update)
+
+- [bls_aggregate_pubkey](#bls_aggregate_pubkey) consumes 75% execution time of [bls_fast_aggregate_verify](#bls_fast_aggregate_verify)
+
+- [bls_verify_message](#bls_verify_message) consumes 23% execution time of [bls_fast_aggregate_verify](#bls_fast_aggregate_verify)
+
+# Conclusion
+
+A high level host function specific for
+[bls_fast_aggregate_verify](https://github.com/Snowfork/snowbridge/blob/8891ca3cdcf2e04d8118c206588c956541ae4710/parachain/pallets/ethereum-beacon-client/src/lib.rs#L764)
+is super helpful.

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/benchmarking/mod.rs

@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+mod fixtures;
+mod util;
+
+use crate::Pallet as EthereumBeaconClient;
+use frame_benchmarking::v2::*;
+use frame_system::RawOrigin;
+
+use fixtures::{
+	make_checkpoint, make_execution_header_update, make_finalized_header_update,
+	make_sync_committee_update,
+};
+
+use primitives::{
+	fast_aggregate_verify, prepare_aggregate_pubkey, prepare_aggregate_signature,
+	verify_merkle_branch,
+};
+use util::*;
+
+#[benchmarks]
+mod benchmarks {
+	use super::*;
+
+	#[benchmark]
+	fn force_checkpoint() -> Result<(), BenchmarkError> {
+		let checkpoint_update = make_checkpoint();
+		let block_root: H256 = checkpoint_update.header.hash_tree_root().unwrap();
+
+		#[extrinsic_call]
+		_(RawOrigin::Root, Box::new(*checkpoint_update));
+
+		assert!(<LatestFinalizedBlockRoot<T>>::get() == block_root);
+		assert!(<FinalizedBeaconState<T>>::get(block_root).is_some());
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn submit() -> Result<(), BenchmarkError> {
+		let caller: T::AccountId = whitelisted_caller();
+		let checkpoint_update = make_checkpoint();
+		let finalized_header_update = make_finalized_header_update();
+		let block_root: H256 = finalized_header_update.finalized_header.hash_tree_root().unwrap();
+		EthereumBeaconClient::<T>::process_checkpoint_update(&checkpoint_update)?;
+
+		#[extrinsic_call]
+		submit(RawOrigin::Signed(caller.clone()), Box::new(*finalized_header_update));
+
+		assert!(<LatestFinalizedBlockRoot<T>>::get() == block_root);
+		assert!(<FinalizedBeaconState<T>>::get(block_root).is_some());
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn submit_with_sync_committee() -> Result<(), BenchmarkError> {
+		let caller: T::AccountId = whitelisted_caller();
+		let checkpoint_update = make_checkpoint();
+		let sync_committee_update = make_sync_committee_update();
+		EthereumBeaconClient::<T>::process_checkpoint_update(&checkpoint_update)?;
+
+		#[extrinsic_call]
+		submit(RawOrigin::Signed(caller.clone()), Box::new(*sync_committee_update));
+
+		assert!(<NextSyncCommittee<T>>::exists());
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn submit_execution_header() -> Result<(), BenchmarkError> {
+		let caller: T::AccountId = whitelisted_caller();
+		let checkpoint_update = make_checkpoint();
+		let finalized_header_update = make_finalized_header_update();
+		let execution_header_update = make_execution_header_update();
+		let execution_header_hash = execution_header_update.execution_header.block_hash;
+		EthereumBeaconClient::<T>::process_checkpoint_update(&checkpoint_update)?;
+		EthereumBeaconClient::<T>::process_update(&finalized_header_update)?;
+
+		#[extrinsic_call]
+		_(RawOrigin::Signed(caller.clone()), Box::new(*execution_header_update));
+
+		assert!(<ExecutionHeaders<T>>::contains_key(execution_header_hash));
+
+		Ok(())
+	}
+
+	#[benchmark(extra)]
+	fn bls_fast_aggregate_verify_pre_aggregated() -> Result<(), BenchmarkError> {
+		EthereumBeaconClient::<T>::process_checkpoint_update(&make_checkpoint())?;
+		let update = make_sync_committee_update();
+		let participant_pubkeys = participant_pubkeys::<T>(&update)?;
+		let signing_root = signing_root::<T>(&update)?;
+		let agg_sig =
+			prepare_aggregate_signature(&update.sync_aggregate.sync_committee_signature).unwrap();
+		let agg_pub_key = prepare_aggregate_pubkey(&participant_pubkeys).unwrap();
+
+		#[block]
+		{
+			agg_sig.fast_aggregate_verify_pre_aggregated(signing_root.as_bytes(), &agg_pub_key);
+		}
+
+		Ok(())
+	}
+
+	#[benchmark(extra)]
+	fn bls_fast_aggregate_verify() -> Result<(), BenchmarkError> {
+		EthereumBeaconClient::<T>::process_checkpoint_update(&make_checkpoint())?;
+		let update = make_sync_committee_update();
+		let current_sync_committee = <CurrentSyncCommittee<T>>::get();
+		let absent_pubkeys = absent_pubkeys::<T>(&update)?;
+		let signing_root = signing_root::<T>(&update)?;
+
+		#[block]
+		{
+			fast_aggregate_verify(
+				&current_sync_committee.aggregate_pubkey,
+				&absent_pubkeys,
+				signing_root,
+				&update.sync_aggregate.sync_committee_signature,
+			)
+			.unwrap();
+		}
+
+		Ok(())
+	}
+
+	#[benchmark(extra)]
+	fn verify_merkle_proof() -> Result<(), BenchmarkError> {
+		EthereumBeaconClient::<T>::process_checkpoint_update(&make_checkpoint())?;
+		let update = make_sync_committee_update();
+		let block_root: H256 = update.finalized_header.hash_tree_root().unwrap();
+
+		#[block]
+		{
+			verify_merkle_branch(
+				block_root,
+				&update.finality_branch,
+				config::FINALIZED_ROOT_SUBTREE_INDEX,
+				config::FINALIZED_ROOT_DEPTH,
+				update.attested_header.state_root,
+			);
+		}
+
+		Ok(())
+	}
+
+	impl_benchmark_test_suite!(
+		EthereumBeaconClient,
+		crate::mock::mainnet::new_tester(),
+		crate::mock::mainnet::Test
+	);
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/benchmarking/util.rs

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{
+	decompress_sync_committee_bits, Config, CurrentSyncCommittee, Pallet as EthereumBeaconClient,
+	Update, ValidatorsRoot, Vec,
+};
+use primitives::PublicKeyPrepared;
+use sp_core::H256;
+
+pub fn participant_pubkeys<T: Config>(
+	update: &Update,
+) -> Result<Vec<PublicKeyPrepared>, &'static str> {
+	let sync_committee_bits =
+		decompress_sync_committee_bits(update.sync_aggregate.sync_committee_bits);
+	let current_sync_committee = <CurrentSyncCommittee<T>>::get();
+	let pubkeys = EthereumBeaconClient::<T>::find_pubkeys(
+		&sync_committee_bits,
+		(*current_sync_committee.pubkeys).as_ref(),
+		true,
+	);
+	Ok(pubkeys)
+}
+
+pub fn absent_pubkeys<T: Config>(update: &Update) -> Result<Vec<PublicKeyPrepared>, &'static str> {
+	let sync_committee_bits =
+		decompress_sync_committee_bits(update.sync_aggregate.sync_committee_bits);
+	let current_sync_committee = <CurrentSyncCommittee<T>>::get();
+	let pubkeys = EthereumBeaconClient::<T>::find_pubkeys(
+		&sync_committee_bits,
+		(*current_sync_committee.pubkeys).as_ref(),
+		false,
+	);
+	Ok(pubkeys)
+}
+
+pub fn signing_root<T: Config>(update: &Update) -> Result<H256, &'static str> {
+	let validators_root = <ValidatorsRoot<T>>::get();
+	let signing_root = EthereumBeaconClient::<T>::signing_root(
+		&update.attested_header,
+		validators_root,
+		update.signature_slot,
+	)?;
+	Ok(signing_root)
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/config/mainnet.rs

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+pub const SLOTS_PER_EPOCH: usize = 32;
+pub const SECONDS_PER_SLOT: usize = 12;
+pub const EPOCHS_PER_SYNC_COMMITTEE_PERIOD: usize = 256;
+pub const SYNC_COMMITTEE_SIZE: usize = 512;
+pub const SYNC_COMMITTEE_BITS_SIZE: usize = SYNC_COMMITTEE_SIZE / 8;
+pub const SLOTS_PER_HISTORICAL_ROOT: usize = 8192;
+pub const IS_MINIMAL: bool = false;
+pub const BLOCK_ROOT_AT_INDEX_DEPTH: usize = 13;

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/config/minimal.rs

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+pub const SLOTS_PER_EPOCH: usize = 8;
+pub const SECONDS_PER_SLOT: usize = 6;
+pub const EPOCHS_PER_SYNC_COMMITTEE_PERIOD: usize = 8;
+pub const SYNC_COMMITTEE_SIZE: usize = 32;
+pub const SYNC_COMMITTEE_BITS_SIZE: usize = SYNC_COMMITTEE_SIZE / 8;
+pub const SLOTS_PER_HISTORICAL_ROOT: usize = 64;
+pub const IS_MINIMAL: bool = true;
+pub const BLOCK_ROOT_AT_INDEX_DEPTH: usize = 6;

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/config/mod.rs

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use primitives::merkle_proof::{generalized_index_length, subtree_index};
+use static_assertions::const_assert;
+
+pub mod mainnet;
+pub mod minimal;
+
+#[cfg(not(feature = "beacon-spec-mainnet"))]
+pub use minimal::*;
+
+#[cfg(feature = "beacon-spec-mainnet")]
+pub use mainnet::*;
+
+// Generalized Indices
+
+// get_generalized_index(BeaconState, 'block_roots')
+pub const BLOCK_ROOTS_INDEX: usize = 37;
+pub const BLOCK_ROOTS_SUBTREE_INDEX: usize = subtree_index(BLOCK_ROOTS_INDEX);
+pub const BLOCK_ROOTS_DEPTH: usize = generalized_index_length(BLOCK_ROOTS_INDEX);
+
+// get_generalized_index(BeaconState, 'finalized_checkpoint', 'root')
+pub const FINALIZED_ROOT_INDEX: usize = 105;
+pub const FINALIZED_ROOT_SUBTREE_INDEX: usize = subtree_index(FINALIZED_ROOT_INDEX);
+pub const FINALIZED_ROOT_DEPTH: usize = generalized_index_length(FINALIZED_ROOT_INDEX);
+
+// get_generalized_index(BeaconState, 'current_sync_committee')
+pub const CURRENT_SYNC_COMMITTEE_INDEX: usize = 54;
+pub const CURRENT_SYNC_COMMITTEE_SUBTREE_INDEX: usize = subtree_index(CURRENT_SYNC_COMMITTEE_INDEX);
+pub const CURRENT_SYNC_COMMITTEE_DEPTH: usize =
+	generalized_index_length(CURRENT_SYNC_COMMITTEE_INDEX);
+
+// get_generalized_index(BeaconState, 'next_sync_committee')
+pub const NEXT_SYNC_COMMITTEE_INDEX: usize = 55;
+pub const NEXT_SYNC_COMMITTEE_SUBTREE_INDEX: usize = subtree_index(NEXT_SYNC_COMMITTEE_INDEX);
+pub const NEXT_SYNC_COMMITTEE_DEPTH: usize = generalized_index_length(NEXT_SYNC_COMMITTEE_INDEX);
+
+//  get_generalized_index(BeaconBlockBody, 'execution_payload')
+pub const EXECUTION_HEADER_INDEX: usize = 25;
+pub const EXECUTION_HEADER_SUBTREE_INDEX: usize = subtree_index(EXECUTION_HEADER_INDEX);
+pub const EXECUTION_HEADER_DEPTH: usize = generalized_index_length(EXECUTION_HEADER_INDEX);
+
+pub const MAX_EXTRA_DATA_BYTES: usize = 32;
+pub const MAX_LOGS_BLOOM_SIZE: usize = 256;
+pub const MAX_FEE_RECIPIENT_SIZE: usize = 20;
+
+pub const MAX_BRANCH_PROOF_SIZE: usize = 20;
+
+/// DomainType('0x07000000')
+/// <https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/beacon-chain.md#domain-types>
+pub const DOMAIN_SYNC_COMMITTEE: [u8; 4] = [7, 0, 0, 0];
+
+pub const PUBKEY_SIZE: usize = 48;
+pub const SIGNATURE_SIZE: usize = 96;
+
+const_assert!(SYNC_COMMITTEE_BITS_SIZE == SYNC_COMMITTEE_SIZE / 8);

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/functions.rs

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::config::{
+	EPOCHS_PER_SYNC_COMMITTEE_PERIOD, SLOTS_PER_EPOCH, SYNC_COMMITTEE_BITS_SIZE,
+	SYNC_COMMITTEE_SIZE,
+};
+
+/// Decompress packed bitvector into byte vector according to SSZ deserialization rules. Each byte
+/// in the decompressed vector is either 0 or 1.
+pub fn decompress_sync_committee_bits(
+	input: [u8; SYNC_COMMITTEE_BITS_SIZE],
+) -> [u8; SYNC_COMMITTEE_SIZE] {
+	primitives::decompress_sync_committee_bits::<SYNC_COMMITTEE_SIZE, SYNC_COMMITTEE_BITS_SIZE>(
+		input,
+	)
+}
+
+/// Compute the sync committee period in which a slot is contained.
+pub fn compute_period(slot: u64) -> u64 {
+	slot / SLOTS_PER_EPOCH as u64 / EPOCHS_PER_SYNC_COMMITTEE_PERIOD as u64
+}
+
+/// Compute epoch in which a slot is contained.
+pub fn compute_epoch(slot: u64, slots_per_epoch: u64) -> u64 {
+	slot / slots_per_epoch
+}
+
+/// Sums the bit vector of sync committee participation.
+pub fn sync_committee_sum(sync_committee_bits: &[u8]) -> u32 {
+	sync_committee_bits.iter().fold(0, |acc: u32, x| acc + *x as u32)
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/impls.rs

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use snowbridge_core::inbound::{
+	VerificationError::{self, *},
+	*,
+};
+use snowbridge_ethereum::Receipt;
+
+impl<T: Config> Verifier for Pallet<T> {
+	/// Verify a message by verifying the existence of the corresponding
+	/// Ethereum log in a block. Returns the log if successful. The execution header containing
+	/// the log should be in the beacon client storage, meaning it has been verified and is an
+	/// ancestor of a finalized beacon block.
+	fn verify(event_log: &Log, proof: &Proof) -> Result<(), VerificationError> {
+		log::info!(
+			target: "ethereum-beacon-client",
+			"💫 Verifying message with block hash {}",
+			proof.block_hash,
+		);
+
+		let header = <ExecutionHeaderBuffer<T>>::get(proof.block_hash).ok_or(HeaderNotFound)?;
+
+		let receipt = match Self::verify_receipt_inclusion(header.receipts_root, proof) {
+			Ok(receipt) => receipt,
+			Err(err) => {
+				log::error!(
+					target: "ethereum-beacon-client",
+					"💫 Verification of receipt inclusion failed for block {}: {:?}",
+					proof.block_hash,
+					err
+				);
+				return Err(err)
+			},
+		};
+
+		log::trace!(
+			target: "ethereum-beacon-client",
+			"💫 Verified receipt inclusion for transaction at index {} in block {}",
+			proof.tx_index, proof.block_hash,
+		);
+
+		event_log.validate().map_err(|_| InvalidLog)?;
+
+		// Convert snowbridge_core::inbound::Log to snowbridge_ethereum::Log.
+		let event_log = snowbridge_ethereum::Log {
+			address: event_log.address,
+			topics: event_log.topics.clone(),
+			data: event_log.data.clone(),
+		};
+
+		if !receipt.contains_log(&event_log) {
+			log::error!(
+				target: "ethereum-beacon-client",
+				"💫 Event log not found in receipt for transaction at index {} in block {}",
+				proof.tx_index, proof.block_hash,
+			);
+			return Err(LogNotFound)
+		}
+
+		log::info!(
+			target: "ethereum-beacon-client",
+			"💫 Receipt verification successful for {}",
+			proof.block_hash,
+		);
+
+		Ok(())
+	}
+}
+
+impl<T: Config> Pallet<T> {
+	/// Verifies that the receipt encoded in `proof.data` is included in the block given by
+	/// `proof.block_hash`.
+	pub fn verify_receipt_inclusion(
+		receipts_root: H256,
+		proof: &Proof,
+	) -> Result<Receipt, VerificationError> {
+		let result = verify_receipt_proof(receipts_root, &proof.data.1).ok_or(InvalidProof)?;
+
+		match result {
+			Ok(receipt) => Ok(receipt),
+			Err(err) => {
+				log::trace!(
+					target: "ethereum-beacon-client",
+					"💫 Failed to decode transaction receipt: {}",
+					err
+				);
+				Err(InvalidProof)
+			},
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/lib.rs

@@ -0,0 +1,841 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Ethereum Beacon Client
+//!
+//! A light client that verifies consensus updates signed by the sync committee of the beacon chain.
+//!
+//! # Extrinsics
+//!
+//! ## Governance
+//!
+//! * [`Call::force_checkpoint`]: Set the initial trusted consensus checkpoint.
+//! * [`Call::set_operating_mode`]: Set the operating mode of the pallet. Can be used to disable
+//!   processing of conensus updates.
+//!
+//! ## Consensus Updates
+//!
+//! * [`Call::submit`]: Submit a finalized beacon header with an optional sync committee update
+//! * [`Call::submit_execution_header`]: Submit an execution header together with an ancestry proof
+//!   that can be verified against an already imported finalized beacon header.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod config;
+pub mod functions;
+pub mod impls;
+pub mod types;
+pub mod weights;
+
+#[cfg(any(test, feature = "fuzzing"))]
+pub mod mock;
+
+#[cfg(all(test, not(feature = "beacon-spec-mainnet")))]
+mod tests;
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+
+use frame_support::{
+	dispatch::DispatchResult, pallet_prelude::OptionQuery, traits::Get, transactional,
+};
+use frame_system::ensure_signed;
+use primitives::{
+	fast_aggregate_verify, verify_merkle_branch, verify_receipt_proof, BeaconHeader, BlsError,
+	CompactBeaconState, CompactExecutionHeader, ExecutionHeaderState, ForkData, ForkVersion,
+	ForkVersions, PublicKeyPrepared, SigningData,
+};
+use snowbridge_core::{BasicOperatingMode, RingBufferMap};
+use sp_core::H256;
+use sp_std::prelude::*;
+pub use weights::WeightInfo;
+
+use functions::{
+	compute_epoch, compute_period, decompress_sync_committee_bits, sync_committee_sum,
+};
+pub use types::ExecutionHeaderBuffer;
+use types::{
+	CheckpointUpdate, ExecutionHeaderUpdate, FinalizedBeaconStateBuffer, SyncCommitteePrepared,
+	Update,
+};
+
+pub use pallet::*;
+
+pub use config::SLOTS_PER_HISTORICAL_ROOT;
+
+pub const LOG_TARGET: &str = "ethereum-beacon-client";
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[derive(scale_info::TypeInfo, codec::Encode, codec::Decode, codec::MaxEncodedLen)]
+	#[codec(mel_bound(T: Config))]
+	#[scale_info(skip_type_params(T))]
+	pub struct MaxFinalizedHeadersToKeep<T: Config>(PhantomData<T>);
+	impl<T: Config> Get<u32> for MaxFinalizedHeadersToKeep<T> {
+		fn get() -> u32 {
+			// Consider max latency allowed between LatestFinalizedState and LatestExecutionState is
+			// the total slots in one sync_committee_period so 1 should be fine we keep 2 periods
+			// here for redundancy.
+			const MAX_REDUNDANCY: u32 = 2;
+			config::EPOCHS_PER_SYNC_COMMITTEE_PERIOD as u32 * MAX_REDUNDANCY
+		}
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+		#[pallet::constant]
+		type ForkVersions: Get<ForkVersions>;
+		/// Maximum number of execution headers to keep
+		#[pallet::constant]
+		type MaxExecutionHeadersToKeep: Get<u32>;
+		type WeightInfo: WeightInfo;
+	}
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		BeaconHeaderImported {
+			block_hash: H256,
+			slot: u64,
+		},
+		ExecutionHeaderImported {
+			block_hash: H256,
+			block_number: u64,
+		},
+		SyncCommitteeUpdated {
+			period: u64,
+		},
+		/// Set OperatingMode
+		OperatingModeChanged {
+			mode: BasicOperatingMode,
+		},
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		SkippedSyncCommitteePeriod,
+		/// Attested header is older than latest finalized header.
+		IrrelevantUpdate,
+		NotBootstrapped,
+		SyncCommitteeParticipantsNotSupermajority,
+		InvalidHeaderMerkleProof,
+		InvalidSyncCommitteeMerkleProof,
+		InvalidExecutionHeaderProof,
+		InvalidAncestryMerkleProof,
+		InvalidBlockRootsRootMerkleProof,
+		HeaderNotFinalized,
+		BlockBodyHashTreeRootFailed,
+		HeaderHashTreeRootFailed,
+		SyncCommitteeHashTreeRootFailed,
+		SigningRootHashTreeRootFailed,
+		ForkDataHashTreeRootFailed,
+		ExpectedFinalizedHeaderNotStored,
+		BLSPreparePublicKeysFailed,
+		BLSVerificationFailed(BlsError),
+		InvalidUpdateSlot,
+		/// The given update is not in the expected period, or the given next sync committee does
+		/// not match the next sync committee in storage.
+		InvalidSyncCommitteeUpdate,
+		ExecutionHeaderTooFarBehind,
+		ExecutionHeaderSkippedBlock,
+		Halted,
+	}
+
+	/// Latest imported checkpoint root
+	#[pallet::storage]
+	#[pallet::getter(fn initial_checkpoint_root)]
+	pub(super) type InitialCheckpointRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Latest imported finalized block root
+	#[pallet::storage]
+	#[pallet::getter(fn latest_finalized_block_root)]
+	pub(super) type LatestFinalizedBlockRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Beacon state by finalized block root
+	#[pallet::storage]
+	#[pallet::getter(fn finalized_beacon_state)]
+	pub(super) type FinalizedBeaconState<T: Config> =
+		StorageMap<_, Identity, H256, CompactBeaconState, OptionQuery>;
+
+	/// Finalized Headers: Current position in ring buffer
+	#[pallet::storage]
+	pub(crate) type FinalizedBeaconStateIndex<T: Config> = StorageValue<_, u32, ValueQuery>;
+
+	/// Finalized Headers: Mapping of ring buffer index to a pruning candidate
+	#[pallet::storage]
+	pub(crate) type FinalizedBeaconStateMapping<T: Config> =
+		StorageMap<_, Identity, u32, H256, ValueQuery>;
+
+	#[pallet::storage]
+	#[pallet::getter(fn validators_root)]
+	pub(super) type ValidatorsRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Sync committee for current period
+	#[pallet::storage]
+	pub(super) type CurrentSyncCommittee<T: Config> =
+		StorageValue<_, SyncCommitteePrepared, ValueQuery>;
+
+	/// Sync committee for next period
+	#[pallet::storage]
+	pub(super) type NextSyncCommittee<T: Config> =
+		StorageValue<_, SyncCommitteePrepared, ValueQuery>;
+
+	/// Latest imported execution header
+	#[pallet::storage]
+	#[pallet::getter(fn latest_execution_state)]
+	pub(super) type LatestExecutionState<T: Config> =
+		StorageValue<_, ExecutionHeaderState, ValueQuery>;
+
+	/// Execution Headers
+	#[pallet::storage]
+	pub type ExecutionHeaders<T: Config> =
+		StorageMap<_, Identity, H256, CompactExecutionHeader, OptionQuery>;
+
+	/// Execution Headers: Current position in ring buffer
+	#[pallet::storage]
+	pub type ExecutionHeaderIndex<T: Config> = StorageValue<_, u32, ValueQuery>;
+
+	/// Execution Headers: Mapping of ring buffer index to a pruning candidate
+	#[pallet::storage]
+	pub type ExecutionHeaderMapping<T: Config> = StorageMap<_, Identity, u32, H256, ValueQuery>;
+
+	/// The current operating mode of the pallet.
+	#[pallet::storage]
+	#[pallet::getter(fn operating_mode)]
+	pub type OperatingMode<T: Config> = StorageValue<_, BasicOperatingMode, ValueQuery>;
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		#[pallet::call_index(0)]
+		#[pallet::weight(T::WeightInfo::force_checkpoint())]
+		#[transactional]
+		/// Used for pallet initialization and light client resetting. Needs to be called by
+		/// the root origin.
+		pub fn force_checkpoint(
+			origin: OriginFor<T>,
+			update: Box<CheckpointUpdate>,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			Self::process_checkpoint_update(&update)?;
+			Ok(())
+		}
+
+		#[pallet::call_index(1)]
+		#[pallet::weight({
+			match update.next_sync_committee_update {
+				None => T::WeightInfo::submit(),
+				Some(_) => T::WeightInfo::submit_with_sync_committee(),
+			}
+		})]
+		#[transactional]
+		/// Submits a new finalized beacon header update. The update may contain the next
+		/// sync committee.
+		pub fn submit(origin: OriginFor<T>, update: Box<Update>) -> DispatchResult {
+			ensure_signed(origin)?;
+			ensure!(!Self::operating_mode().is_halted(), Error::<T>::Halted);
+			Self::process_update(&update)?;
+			Ok(())
+		}
+
+		#[pallet::call_index(2)]
+		#[pallet::weight(T::WeightInfo::submit_execution_header())]
+		#[transactional]
+		/// Submits a new execution header update. The relevant related beacon header
+		/// is also included to prove the execution header, as well as ancestry proof data.
+		pub fn submit_execution_header(
+			origin: OriginFor<T>,
+			update: Box<ExecutionHeaderUpdate>,
+		) -> DispatchResult {
+			ensure_signed(origin)?;
+			ensure!(!Self::operating_mode().is_halted(), Error::<T>::Halted);
+			Self::process_execution_header_update(&update)?;
+			Ok(())
+		}
+
+		/// Halt or resume all pallet operations. May only be called by root.
+		#[pallet::call_index(3)]
+		#[pallet::weight((T::DbWeight::get().reads_writes(1, 1), DispatchClass::Operational))]
+		pub fn set_operating_mode(
+			origin: OriginFor<T>,
+			mode: BasicOperatingMode,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			OperatingMode::<T>::set(mode);
+			Self::deposit_event(Event::OperatingModeChanged { mode });
+			Ok(())
+		}
+	}
+
+	impl<T: Config> Pallet<T> {
+		/// Forces a finalized beacon header checkpoint update. The current sync committee,
+		/// with a header attesting to the current sync committee, should be provided.
+		/// An `block_roots` proof should also be provided. This is used for ancestry proofs
+		/// for execution header updates.
+		pub(crate) fn process_checkpoint_update(update: &CheckpointUpdate) -> DispatchResult {
+			let sync_committee_root = update
+				.current_sync_committee
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::SyncCommitteeHashTreeRootFailed)?;
+
+			// Verifies the sync committee in the Beacon state.
+			ensure!(
+				verify_merkle_branch(
+					sync_committee_root,
+					&update.current_sync_committee_branch,
+					config::CURRENT_SYNC_COMMITTEE_SUBTREE_INDEX,
+					config::CURRENT_SYNC_COMMITTEE_DEPTH,
+					update.header.state_root
+				),
+				Error::<T>::InvalidSyncCommitteeMerkleProof
+			);
+
+			let header_root: H256 = update
+				.header
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+
+			// This is used for ancestry proofs in ExecutionHeader updates. This verifies the
+			// BeaconState: the beacon state root is the tree root; the `block_roots` hash is the
+			// tree leaf.
+			ensure!(
+				verify_merkle_branch(
+					update.block_roots_root,
+					&update.block_roots_branch,
+					config::BLOCK_ROOTS_SUBTREE_INDEX,
+					config::BLOCK_ROOTS_DEPTH,
+					update.header.state_root
+				),
+				Error::<T>::InvalidBlockRootsRootMerkleProof
+			);
+
+			let sync_committee_prepared: SyncCommitteePrepared = (&update.current_sync_committee)
+				.try_into()
+				.map_err(|_| <Error<T>>::BLSPreparePublicKeysFailed)?;
+			<CurrentSyncCommittee<T>>::set(sync_committee_prepared);
+			<NextSyncCommittee<T>>::kill();
+			InitialCheckpointRoot::<T>::set(header_root);
+			<LatestExecutionState<T>>::kill();
+
+			Self::store_validators_root(update.validators_root);
+			Self::store_finalized_header(header_root, update.header, update.block_roots_root)?;
+
+			Ok(())
+		}
+
+		pub(crate) fn process_update(update: &Update) -> DispatchResult {
+			Self::cross_check_execution_state()?;
+			Self::verify_update(update)?;
+			Self::apply_update(update)?;
+			Ok(())
+		}
+
+		/// Cross check to make sure that execution header import does not fall too far behind
+		/// finalised beacon header import. If that happens just return an error and pause
+		/// processing until execution header processing has caught up.
+		pub(crate) fn cross_check_execution_state() -> DispatchResult {
+			let latest_finalized_state =
+				FinalizedBeaconState::<T>::get(LatestFinalizedBlockRoot::<T>::get())
+					.ok_or(Error::<T>::NotBootstrapped)?;
+			let latest_execution_state = Self::latest_execution_state();
+			// The execution header import should be at least within the slot range of a sync
+			// committee period.
+			let max_latency = config::EPOCHS_PER_SYNC_COMMITTEE_PERIOD * config::SLOTS_PER_EPOCH;
+			ensure!(
+				latest_execution_state.beacon_slot == 0 ||
+					latest_finalized_state.slot <
+						latest_execution_state.beacon_slot + max_latency as u64,
+				Error::<T>::ExecutionHeaderTooFarBehind
+			);
+			Ok(())
+		}
+
+		/// References and strictly follows <https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#validate_light_client_update>
+		/// Verifies that provided next sync committee is valid through a series of checks
+		/// (including checking that a sync committee period isn't skipped and that the header is
+		/// signed by the current sync committee.
+		fn verify_update(update: &Update) -> DispatchResult {
+			// Verify sync committee has sufficient participants.
+			let participation =
+				decompress_sync_committee_bits(update.sync_aggregate.sync_committee_bits);
+			Self::sync_committee_participation_is_supermajority(&participation)?;
+
+			// Verify update does not skip a sync committee period.
+			ensure!(
+				update.signature_slot > update.attested_header.slot &&
+					update.attested_header.slot >= update.finalized_header.slot,
+				Error::<T>::InvalidUpdateSlot
+			);
+			// Retrieve latest finalized state.
+			let latest_finalized_state =
+				FinalizedBeaconState::<T>::get(LatestFinalizedBlockRoot::<T>::get())
+					.ok_or(Error::<T>::NotBootstrapped)?;
+			let store_period = compute_period(latest_finalized_state.slot);
+			let signature_period = compute_period(update.signature_slot);
+			if <NextSyncCommittee<T>>::exists() {
+				ensure!(
+					(store_period..=store_period + 1).contains(&signature_period),
+					Error::<T>::SkippedSyncCommitteePeriod
+				)
+			} else {
+				ensure!(signature_period == store_period, Error::<T>::SkippedSyncCommitteePeriod)
+			}
+
+			// Verify update is relevant.
+			let update_attested_period = compute_period(update.attested_header.slot);
+			let update_has_next_sync_committee = !<NextSyncCommittee<T>>::exists() &&
+				(update.next_sync_committee_update.is_some() &&
+					update_attested_period == store_period);
+			ensure!(
+				update.attested_header.slot > latest_finalized_state.slot ||
+					update_has_next_sync_committee,
+				Error::<T>::IrrelevantUpdate
+			);
+
+			// Verify that the `finality_branch`, if present, confirms `finalized_header` to match
+			// the finalized checkpoint root saved in the state of `attested_header`.
+			let finalized_block_root: H256 = update
+				.finalized_header
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+			ensure!(
+				verify_merkle_branch(
+					finalized_block_root,
+					&update.finality_branch,
+					config::FINALIZED_ROOT_SUBTREE_INDEX,
+					config::FINALIZED_ROOT_DEPTH,
+					update.attested_header.state_root
+				),
+				Error::<T>::InvalidHeaderMerkleProof
+			);
+
+			// Though following check does not belong to ALC spec we verify block_roots_root to
+			// match the finalized checkpoint root saved in the state of `finalized_header` so to
+			// cache it for later use in `verify_ancestry_proof`.
+			ensure!(
+				verify_merkle_branch(
+					update.block_roots_root,
+					&update.block_roots_branch,
+					config::BLOCK_ROOTS_SUBTREE_INDEX,
+					config::BLOCK_ROOTS_DEPTH,
+					update.finalized_header.state_root
+				),
+				Error::<T>::InvalidBlockRootsRootMerkleProof
+			);
+
+			// Verify that the `next_sync_committee`, if present, actually is the next sync
+			// committee saved in the state of the `attested_header`.
+			if let Some(next_sync_committee_update) = &update.next_sync_committee_update {
+				let sync_committee_root = next_sync_committee_update
+					.next_sync_committee
+					.hash_tree_root()
+					.map_err(|_| Error::<T>::SyncCommitteeHashTreeRootFailed)?;
+				if update_attested_period == store_period && <NextSyncCommittee<T>>::exists() {
+					let next_committee_root = <NextSyncCommittee<T>>::get().root;
+					ensure!(
+						sync_committee_root == next_committee_root,
+						Error::<T>::InvalidSyncCommitteeUpdate
+					);
+				}
+				ensure!(
+					verify_merkle_branch(
+						sync_committee_root,
+						&next_sync_committee_update.next_sync_committee_branch,
+						config::NEXT_SYNC_COMMITTEE_SUBTREE_INDEX,
+						config::NEXT_SYNC_COMMITTEE_DEPTH,
+						update.attested_header.state_root
+					),
+					Error::<T>::InvalidSyncCommitteeMerkleProof
+				);
+			}
+
+			// Verify sync committee aggregate signature.
+			let sync_committee = if signature_period == store_period {
+				<CurrentSyncCommittee<T>>::get()
+			} else {
+				<NextSyncCommittee<T>>::get()
+			};
+			let absent_pubkeys =
+				Self::find_pubkeys(&participation, (*sync_committee.pubkeys).as_ref(), false);
+			let signing_root = Self::signing_root(
+				&update.attested_header,
+				Self::validators_root(),
+				update.signature_slot,
+			)?;
+			// Improvement here per <https://eth2book.info/capella/part2/building_blocks/signatures/#sync-aggregates>
+			// suggested start from the full set aggregate_pubkey then subtracting the absolute
+			// minority that did not participate.
+			fast_aggregate_verify(
+				&sync_committee.aggregate_pubkey,
+				&absent_pubkeys,
+				signing_root,
+				&update.sync_aggregate.sync_committee_signature,
+			)
+			.map_err(|e| Error::<T>::BLSVerificationFailed(e))?;
+
+			Ok(())
+		}
+
+		/// Reference and strictly follows <https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#apply_light_client_update
+		/// Applies a finalized beacon header update to the beacon client. If a next sync committee
+		/// is present in the update, verify the sync committee by converting it to a
+		/// SyncCommitteePrepared type. Stores the provided finalized header.
+		fn apply_update(update: &Update) -> DispatchResult {
+			let latest_finalized_state =
+				FinalizedBeaconState::<T>::get(LatestFinalizedBlockRoot::<T>::get())
+					.ok_or(Error::<T>::NotBootstrapped)?;
+			if let Some(next_sync_committee_update) = &update.next_sync_committee_update {
+				let store_period = compute_period(latest_finalized_state.slot);
+				let update_finalized_period = compute_period(update.finalized_header.slot);
+				let sync_committee_prepared: SyncCommitteePrepared = (&next_sync_committee_update
+					.next_sync_committee)
+					.try_into()
+					.map_err(|_| <Error<T>>::BLSPreparePublicKeysFailed)?;
+
+				if !<NextSyncCommittee<T>>::exists() {
+					ensure!(
+						update_finalized_period == store_period,
+						<Error<T>>::InvalidSyncCommitteeUpdate
+					);
+					<NextSyncCommittee<T>>::set(sync_committee_prepared);
+				} else if update_finalized_period == store_period + 1 {
+					<CurrentSyncCommittee<T>>::set(<NextSyncCommittee<T>>::get());
+					<NextSyncCommittee<T>>::set(sync_committee_prepared);
+				}
+				log::info!(
+					target: LOG_TARGET,
+					"💫 SyncCommitteeUpdated at period {}.",
+					update_finalized_period
+				);
+				Self::deposit_event(Event::SyncCommitteeUpdated {
+					period: update_finalized_period,
+				});
+			};
+
+			if update.finalized_header.slot > latest_finalized_state.slot {
+				let finalized_block_root: H256 = update
+					.finalized_header
+					.hash_tree_root()
+					.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+				Self::store_finalized_header(
+					finalized_block_root,
+					update.finalized_header,
+					update.block_roots_root,
+				)?;
+			}
+
+			Ok(())
+		}
+
+		/// Validates an execution header for import. The beacon header containing the execution
+		/// header is sent, plus the execution header, along with a proof that the execution header
+		/// is rooted in the beacon header body.
+		pub(crate) fn process_execution_header_update(
+			update: &ExecutionHeaderUpdate,
+		) -> DispatchResult {
+			let latest_finalized_state =
+				FinalizedBeaconState::<T>::get(LatestFinalizedBlockRoot::<T>::get())
+					.ok_or(Error::<T>::NotBootstrapped)?;
+			// Checks that the header is an ancestor of a finalized header, using slot number.
+			ensure!(
+				update.header.slot <= latest_finalized_state.slot,
+				Error::<T>::HeaderNotFinalized
+			);
+
+			// Checks that we don't skip execution headers, they need to be imported sequentially.
+			let latest_execution_state: ExecutionHeaderState = Self::latest_execution_state();
+			ensure!(
+				latest_execution_state.block_number == 0 ||
+					update.execution_header.block_number ==
+						latest_execution_state.block_number + 1,
+				Error::<T>::ExecutionHeaderSkippedBlock
+			);
+
+			// Gets the hash tree root of the execution header, in preparation for the execution
+			// header proof (used to check that the execution header is rooted in the beacon
+			// header body.
+			let execution_header_root: H256 = update
+				.execution_header
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::BlockBodyHashTreeRootFailed)?;
+
+			ensure!(
+				verify_merkle_branch(
+					execution_header_root,
+					&update.execution_branch,
+					config::EXECUTION_HEADER_SUBTREE_INDEX,
+					config::EXECUTION_HEADER_DEPTH,
+					update.header.body_root
+				),
+				Error::<T>::InvalidExecutionHeaderProof
+			);
+
+			let block_root: H256 = update
+				.header
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+
+			match &update.ancestry_proof {
+				Some(proof) => {
+					Self::verify_ancestry_proof(
+						block_root,
+						update.header.slot,
+						&proof.header_branch,
+						proof.finalized_block_root,
+					)?;
+				},
+				None => {
+					// If the ancestry proof is not provided, we expect this header to be a
+					// finalized header. We need to check that the header hash matches the finalized
+					// header root at the expected slot.
+					let state = <FinalizedBeaconState<T>>::get(block_root)
+						.ok_or(Error::<T>::ExpectedFinalizedHeaderNotStored)?;
+					if update.header.slot != state.slot {
+						return Err(Error::<T>::ExpectedFinalizedHeaderNotStored.into())
+					}
+				},
+			}
+
+			Self::store_execution_header(
+				update.execution_header.block_hash,
+				update.execution_header.clone().into(),
+				update.header.slot,
+				block_root,
+			);
+
+			Ok(())
+		}
+
+		/// Verify that `block_root` is an ancestor of `finalized_block_root` Used to prove that
+		/// an execution header is an ancestor of a finalized header (i.e. the blocks are
+		/// on the same chain).
+		fn verify_ancestry_proof(
+			block_root: H256,
+			block_slot: u64,
+			block_root_proof: &[H256],
+			finalized_block_root: H256,
+		) -> DispatchResult {
+			let state = <FinalizedBeaconState<T>>::get(finalized_block_root)
+				.ok_or(Error::<T>::ExpectedFinalizedHeaderNotStored)?;
+
+			ensure!(block_slot < state.slot, Error::<T>::HeaderNotFinalized);
+
+			let index_in_array = block_slot % (SLOTS_PER_HISTORICAL_ROOT as u64);
+			let leaf_index = (SLOTS_PER_HISTORICAL_ROOT as u64) + index_in_array;
+
+			ensure!(
+				verify_merkle_branch(
+					block_root,
+					block_root_proof,
+					leaf_index as usize,
+					config::BLOCK_ROOT_AT_INDEX_DEPTH,
+					state.block_roots_root
+				),
+				Error::<T>::InvalidAncestryMerkleProof
+			);
+
+			Ok(())
+		}
+
+		/// Computes the signing root for a given beacon header and domain. The hash tree root
+		/// of the beacon header is computed, and then the combination of the beacon header hash
+		/// and the domain makes up the signing root.
+		pub(super) fn compute_signing_root(
+			beacon_header: &BeaconHeader,
+			domain: H256,
+		) -> Result<H256, DispatchError> {
+			let beacon_header_root = beacon_header
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+
+			let hash_root = SigningData { object_root: beacon_header_root, domain }
+				.hash_tree_root()
+				.map_err(|_| Error::<T>::SigningRootHashTreeRootFailed)?;
+
+			Ok(hash_root)
+		}
+
+		/// Stores a compacted (slot and block roots root (hash of the `block_roots` beacon state
+		/// field, used for ancestry proof)) beacon state in a ring buffer map, with the header root
+		/// as map key.
+		fn store_finalized_header(
+			header_root: H256,
+			header: BeaconHeader,
+			block_roots_root: H256,
+		) -> DispatchResult {
+			let slot = header.slot;
+
+			<FinalizedBeaconStateBuffer<T>>::insert(
+				header_root,
+				CompactBeaconState { slot: header.slot, block_roots_root },
+			);
+			<LatestFinalizedBlockRoot<T>>::set(header_root);
+
+			log::info!(
+				target: LOG_TARGET,
+				"💫 Updated latest finalized block root {} at slot {}.",
+				header_root,
+				slot
+			);
+
+			Self::deposit_event(Event::BeaconHeaderImported { block_hash: header_root, slot });
+
+			Ok(())
+		}
+
+		/// Stores the provided execution header in pallet storage. The header is stored
+		/// in a ring buffer map, with the block hash as map key. The last imported execution
+		/// header is also kept in storage, for the relayer to check import progress.
+		pub(crate) fn store_execution_header(
+			block_hash: H256,
+			header: CompactExecutionHeader,
+			beacon_slot: u64,
+			beacon_block_root: H256,
+		) {
+			let block_number = header.block_number;
+
+			<ExecutionHeaderBuffer<T>>::insert(block_hash, header);
+
+			log::trace!(
+				target: LOG_TARGET,
+				"💫 Updated latest execution block at {} to number {}.",
+				block_hash,
+				block_number
+			);
+
+			LatestExecutionState::<T>::mutate(|s| {
+				s.beacon_block_root = beacon_block_root;
+				s.beacon_slot = beacon_slot;
+				s.block_hash = block_hash;
+				s.block_number = block_number;
+			});
+
+			Self::deposit_event(Event::ExecutionHeaderImported { block_hash, block_number });
+		}
+
+		/// Stores the validators root in storage. Validators root is the hash tree root of all the
+		/// validators at genesis and is used to used to identify the chain that we are on
+		/// (used in conjunction with the fork version).
+		/// <https://eth2book.info/capella/part3/containers/state/#genesis_validators_root>
+		fn store_validators_root(validators_root: H256) {
+			<ValidatorsRoot<T>>::set(validators_root);
+		}
+
+		/// Returns the domain for the domain_type and fork_version. The domain is used to
+		/// distinguish between the different players in the chain (see DomainTypes
+		/// <https://eth2book.info/capella/part3/config/constants/#domain-types>) and to ensure we are
+		/// addressing the correct chain.
+		/// <https://eth2book.info/capella/part3/helper/misc/#compute_domain>
+		pub(super) fn compute_domain(
+			domain_type: Vec<u8>,
+			fork_version: ForkVersion,
+			genesis_validators_root: H256,
+		) -> Result<H256, DispatchError> {
+			let fork_data_root =
+				Self::compute_fork_data_root(fork_version, genesis_validators_root)?;
+
+			let mut domain = [0u8; 32];
+			domain[0..4].copy_from_slice(&(domain_type));
+			domain[4..32].copy_from_slice(&(fork_data_root.0[..28]));
+
+			Ok(domain.into())
+		}
+
+		/// Computes the fork data root. The fork data root is a merkleization of the current
+		/// fork version and the genesis validators root.
+		fn compute_fork_data_root(
+			current_version: ForkVersion,
+			genesis_validators_root: H256,
+		) -> Result<H256, DispatchError> {
+			let hash_root = ForkData {
+				current_version,
+				genesis_validators_root: genesis_validators_root.into(),
+			}
+			.hash_tree_root()
+			.map_err(|_| Error::<T>::ForkDataHashTreeRootFailed)?;
+
+			Ok(hash_root)
+		}
+
+		/// Checks that the sync committee bits (the votes of the sync committee members,
+		/// represented by bits 0 and 1) is more than a supermajority (2/3 of the votes are
+		/// positive).
+		pub(super) fn sync_committee_participation_is_supermajority(
+			sync_committee_bits: &[u8],
+		) -> DispatchResult {
+			let sync_committee_sum = sync_committee_sum(sync_committee_bits);
+			ensure!(
+				((sync_committee_sum * 3) as usize) >= sync_committee_bits.len() * 2,
+				Error::<T>::SyncCommitteeParticipantsNotSupermajority
+			);
+
+			Ok(())
+		}
+
+		/// Returns the fork version based on the current epoch. The hard fork versions
+		/// are defined in pallet config.
+		pub(super) fn compute_fork_version(epoch: u64) -> ForkVersion {
+			Self::select_fork_version(&T::ForkVersions::get(), epoch)
+		}
+
+		/// Returns the fork version based on the current epoch.
+		pub(super) fn select_fork_version(fork_versions: &ForkVersions, epoch: u64) -> ForkVersion {
+			if epoch >= fork_versions.capella.epoch {
+				return fork_versions.capella.version
+			}
+			if epoch >= fork_versions.bellatrix.epoch {
+				return fork_versions.bellatrix.version
+			}
+			if epoch >= fork_versions.altair.epoch {
+				return fork_versions.altair.version
+			}
+
+			fork_versions.genesis.version
+		}
+
+		/// Returns a vector of public keys that participated in the sync committee block signage.
+		/// Sync committee bits is an array of 0s and 1s, 0 meaning the corresponding sync committee
+		/// member did not participate in the vote, 1 meaning they participated.
+		/// This method can find the absent or participating members, based on the participant
+		/// parameter. participant = false will return absent participants, participant = true will
+		/// return participating members.
+		pub fn find_pubkeys(
+			sync_committee_bits: &[u8],
+			sync_committee_pubkeys: &[PublicKeyPrepared],
+			participant: bool,
+		) -> Vec<PublicKeyPrepared> {
+			let mut pubkeys: Vec<PublicKeyPrepared> = Vec::new();
+			for (bit, pubkey) in sync_committee_bits.iter().zip(sync_committee_pubkeys.iter()) {
+				if *bit == u8::from(participant) {
+					pubkeys.push(*pubkey);
+				}
+			}
+			pubkeys
+		}
+
+		/// Calculates signing root for BeaconHeader. The signing root is used for the message
+		/// value in BLS signature verification.
+		pub fn signing_root(
+			header: &BeaconHeader,
+			validators_root: H256,
+			signature_slot: u64,
+		) -> Result<H256, DispatchError> {
+			let fork_version = Self::compute_fork_version(compute_epoch(
+				signature_slot,
+				config::SLOTS_PER_EPOCH as u64,
+			));
+			let domain_type = config::DOMAIN_SYNC_COMMITTEE.to_vec();
+			// Domains are used for for seeds, for signatures, and for selecting aggregators.
+			let domain = Self::compute_domain(domain_type, fork_version, validators_root)?;
+			// Hash tree root of SigningData - object root + domain
+			let signing_root = Self::compute_signing_root(header, domain)?;
+			Ok(signing_root)
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/mock.rs

@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate as ethereum_beacon_client;
+use frame_support::parameter_types;
+use pallet_timestamp;
+use primitives::{Fork, ForkVersions};
+use sp_core::H256;
+use sp_runtime::traits::{BlakeTwo256, IdentityLookup};
+
+#[cfg(not(feature = "beacon-spec-mainnet"))]
+pub mod minimal {
+	use super::*;
+
+	use crate::config;
+	use hex_literal::hex;
+	use primitives::CompactExecutionHeader;
+	use snowbridge_core::inbound::{Log, Proof};
+	use sp_runtime::BuildStorage;
+	use std::{fs::File, path::PathBuf};
+
+	type Block = frame_system::mocking::MockBlock<Test>;
+
+	frame_support::construct_runtime!(
+		pub enum Test {
+			System: frame_system::{Pallet, Call, Storage, Event<T>},
+			Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},
+			EthereumBeaconClient: ethereum_beacon_client::{Pallet, Call, Storage, Event<T>},
+		}
+	);
+
+	parameter_types! {
+		pub const BlockHashCount: u64 = 250;
+		pub const SS58Prefix: u8 = 42;
+	}
+
+	impl frame_system::Config for Test {
+		type BaseCallFilter = frame_support::traits::Everything;
+		type OnSetCode = ();
+		type BlockWeights = ();
+		type BlockLength = ();
+		type DbWeight = ();
+		type RuntimeOrigin = RuntimeOrigin;
+		type RuntimeCall = RuntimeCall;
+		type RuntimeTask = RuntimeTask;
+		type Hash = H256;
+		type Hashing = BlakeTwo256;
+		type AccountId = u64;
+		type Lookup = IdentityLookup<Self::AccountId>;
+		type RuntimeEvent = RuntimeEvent;
+		type BlockHashCount = BlockHashCount;
+		type Version = ();
+		type PalletInfo = PalletInfo;
+		type AccountData = ();
+		type OnNewAccount = ();
+		type OnKilledAccount = ();
+		type SystemWeightInfo = ();
+		type SS58Prefix = SS58Prefix;
+		type MaxConsumers = frame_support::traits::ConstU32<16>;
+		type Nonce = u64;
+		type Block = Block;
+	}
+
+	impl pallet_timestamp::Config for Test {
+		type Moment = u64;
+		type OnTimestampSet = ();
+		type MinimumPeriod = ();
+		type WeightInfo = ();
+	}
+
+	parameter_types! {
+		pub const ExecutionHeadersPruneThreshold: u32 = 10;
+		pub const ChainForkVersions: ForkVersions = ForkVersions{
+			genesis: Fork {
+				version: [0, 0, 0, 1], // 0x00000001
+				epoch: 0,
+			},
+			altair: Fork {
+				version: [1, 0, 0, 1], // 0x01000001
+				epoch: 0,
+			},
+			bellatrix: Fork {
+				version: [2, 0, 0, 1], // 0x02000001
+				epoch: 0,
+			},
+			capella: Fork {
+				version: [3, 0, 0, 1], // 0x03000001
+				epoch: 0,
+			},
+		};
+	}
+
+	impl ethereum_beacon_client::Config for Test {
+		type RuntimeEvent = RuntimeEvent;
+		type ForkVersions = ChainForkVersions;
+		type MaxExecutionHeadersToKeep = ExecutionHeadersPruneThreshold;
+		type WeightInfo = ();
+	}
+
+	// Build genesis storage according to the mock runtime.
+	pub fn new_tester() -> sp_io::TestExternalities {
+		let t = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+		let mut ext = sp_io::TestExternalities::new(t);
+		let _ = ext.execute_with(|| Timestamp::set(RuntimeOrigin::signed(1), 30_000));
+		ext
+	}
+
+	fn load_fixture<T>(basename: &str) -> Result<T, serde_json::Error>
+	where
+		T: for<'de> serde::Deserialize<'de>,
+	{
+		let filepath: PathBuf =
+			[env!("CARGO_MANIFEST_DIR"), "tests", "fixtures", basename].iter().collect();
+		serde_json::from_reader(File::open(filepath).unwrap())
+	}
+
+	pub fn load_execution_header_update_fixture() -> primitives::ExecutionHeaderUpdate {
+		load_fixture("execution-header-update.minimal.json").unwrap()
+	}
+
+	pub fn load_checkpoint_update_fixture(
+	) -> primitives::CheckpointUpdate<{ config::SYNC_COMMITTEE_SIZE }> {
+		load_fixture("initial-checkpoint.minimal.json").unwrap()
+	}
+
+	pub fn load_sync_committee_update_fixture(
+	) -> primitives::Update<{ config::SYNC_COMMITTEE_SIZE }, { config::SYNC_COMMITTEE_BITS_SIZE }> {
+		load_fixture("sync-committee-update.minimal.json").unwrap()
+	}
+
+	pub fn load_finalized_header_update_fixture(
+	) -> primitives::Update<{ config::SYNC_COMMITTEE_SIZE }, { config::SYNC_COMMITTEE_BITS_SIZE }> {
+		load_fixture("finalized-header-update.minimal.json").unwrap()
+	}
+
+	pub fn load_next_sync_committee_update_fixture(
+	) -> primitives::Update<{ config::SYNC_COMMITTEE_SIZE }, { config::SYNC_COMMITTEE_BITS_SIZE }> {
+		load_fixture("next-sync-committee-update.minimal.json").unwrap()
+	}
+
+	pub fn load_next_finalized_header_update_fixture(
+	) -> primitives::Update<{ config::SYNC_COMMITTEE_SIZE }, { config::SYNC_COMMITTEE_BITS_SIZE }> {
+		load_fixture("next-finalized-header-update.minimal.json").unwrap()
+	}
+
+	pub fn get_message_verification_payload() -> (Log, Proof) {
+		(
+			Log {
+				address: hex!("ee9170abfbf9421ad6dd07f6bdec9d89f2b581e0").into(),
+				topics: vec![
+					hex!("1b11dcf133cc240f682dab2d3a8e4cd35c5da8c9cf99adac4336f8512584c5ad").into(),
+					hex!("00000000000000000000000000000000000000000000000000000000000003e8").into(),
+					hex!("0000000000000000000000000000000000000000000000000000000000000001").into(),
+				],
+				data: hex!("0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000004b000f000000000000000100d184c103f7acc340847eee82a0b909e3358bc28d440edffa1352b13227e8ee646f3ea37456dec701345772617070656420457468657210574554481235003511000000000000000000000000000000000000000000").into(),
+			},
+			Proof {
+				block_hash: hex!("05aaa60b0f27cce9e71909508527264b77ee14da7b5bf915fcc4e32715333213").into(),
+				tx_index: 0,
+				data: (vec![
+					hex!("cf0d1c1ba57d1e0edfb59786c7e30c2b7e12bd54612b00cd21c4eaeecedf44fb").to_vec(),
+					hex!("d21fc4f68ab05bc4dcb23c67008e92c4d466437cdd6ed7aad0c008944c185510").to_vec(),
+					hex!("b9890f91ca0d77aa2a4adfaf9b9e40c94cac9e638b6d9797923865872944b646").to_vec(),
+				], vec![
+					hex!("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").to_vec(),
+					hex!("f851a0b9890f91ca0d77aa2a4adfaf9b9e40c94cac9e638b6d9797923865872944b646a060a634b9280e3a23fb63375e7bbdd9ab07fd379ab6a67e2312bbc112195fa358808080808080808080808080808080").to_vec(),
+					hex!("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").to_vec(),
+				]),
+			}
+		)
+	}
+
+	pub fn get_message_verification_header() -> CompactExecutionHeader {
+		CompactExecutionHeader {
+			parent_hash: hex!("04a7f6ab8282203562c62f38b0ab41d32aaebe2c7ea687702b463148a6429e04")
+				.into(),
+			block_number: 55,
+			state_root: hex!("894d968712976d613519f973a317cb0781c7b039c89f27ea2b7ca193f7befdb3")
+				.into(),
+			receipts_root: hex!("cf0d1c1ba57d1e0edfb59786c7e30c2b7e12bd54612b00cd21c4eaeecedf44fb")
+				.into(),
+		}
+	}
+}
+
+#[cfg(feature = "beacon-spec-mainnet")]
+pub mod mainnet {
+	use super::*;
+
+	type Block = frame_system::mocking::MockBlock<Test>;
+	use sp_runtime::BuildStorage;
+
+	frame_support::construct_runtime!(
+		pub enum Test {
+			System: frame_system::{Pallet, Call, Storage, Event<T>},
+			Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},
+			EthereumBeaconClient: ethereum_beacon_client::{Pallet, Call, Storage, Event<T>},
+		}
+	);
+
+	parameter_types! {
+		pub const BlockHashCount: u64 = 250;
+		pub const SS58Prefix: u8 = 42;
+	}
+
+	impl frame_system::Config for Test {
+		type BaseCallFilter = frame_support::traits::Everything;
+		type OnSetCode = ();
+		type BlockWeights = ();
+		type BlockLength = ();
+		type DbWeight = ();
+		type RuntimeOrigin = RuntimeOrigin;
+		type RuntimeCall = RuntimeCall;
+		type RuntimeTask = RuntimeTask;
+		type Hash = H256;
+		type Hashing = BlakeTwo256;
+		type AccountId = u64;
+		type Lookup = IdentityLookup<Self::AccountId>;
+		type RuntimeEvent = RuntimeEvent;
+		type BlockHashCount = BlockHashCount;
+		type Version = ();
+		type PalletInfo = PalletInfo;
+		type AccountData = ();
+		type OnNewAccount = ();
+		type OnKilledAccount = ();
+		type SystemWeightInfo = ();
+		type SS58Prefix = SS58Prefix;
+		type MaxConsumers = frame_support::traits::ConstU32<16>;
+		type Nonce = u64;
+		type Block = Block;
+	}
+
+	impl pallet_timestamp::Config for Test {
+		type Moment = u64;
+		type OnTimestampSet = ();
+		type MinimumPeriod = ();
+		type WeightInfo = ();
+	}
+
+	parameter_types! {
+		pub const ChainForkVersions: ForkVersions = ForkVersions{
+			genesis: Fork {
+				version: [0, 0, 16, 32], // 0x00001020
+				epoch: 0,
+			},
+			altair: Fork {
+				version: [1, 0, 16, 32], // 0x01001020
+				epoch: 36660,
+			},
+			bellatrix: Fork {
+				version: [2, 0, 16, 32], // 0x02001020
+				epoch: 112260,
+			},
+			capella: Fork {
+				version: [3, 0, 16, 32], // 0x03001020
+				epoch: 162304,
+			},
+		};
+		pub const ExecutionHeadersPruneThreshold: u32 = 10;
+	}
+
+	impl ethereum_beacon_client::Config for Test {
+		type RuntimeEvent = RuntimeEvent;
+		type ForkVersions = ChainForkVersions;
+		type MaxExecutionHeadersToKeep = ExecutionHeadersPruneThreshold;
+		type WeightInfo = ();
+	}
+
+	// Build genesis storage according to the mock runtime.
+	pub fn new_tester() -> sp_io::TestExternalities {
+		let t = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+		let mut ext = sp_io::TestExternalities::new(t);
+		let _ = ext.execute_with(|| Timestamp::set(RuntimeOrigin::signed(1), 30_000));
+		ext
+	}
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/types.rs

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+pub use crate::config::{
+	SLOTS_PER_HISTORICAL_ROOT, SYNC_COMMITTEE_BITS_SIZE as SC_BITS_SIZE,
+	SYNC_COMMITTEE_SIZE as SC_SIZE,
+};
+use frame_support::storage::types::OptionQuery;
+use snowbridge_core::RingBufferMapImpl;
+
+// Specialize types based on configured sync committee size
+pub type SyncCommittee = primitives::SyncCommittee<SC_SIZE>;
+pub type SyncCommitteePrepared = primitives::SyncCommitteePrepared<SC_SIZE>;
+pub type SyncAggregate = primitives::SyncAggregate<SC_SIZE, SC_BITS_SIZE>;
+pub type CheckpointUpdate = primitives::CheckpointUpdate<SC_SIZE>;
+pub type Update = primitives::Update<SC_SIZE, SC_BITS_SIZE>;
+pub type NextSyncCommitteeUpdate = primitives::NextSyncCommitteeUpdate<SC_SIZE>;
+
+pub use primitives::ExecutionHeaderUpdate;
+
+/// ExecutionHeader ring buffer implementation
+pub type ExecutionHeaderBuffer<T> = RingBufferMapImpl<
+	u32,
+	<T as crate::Config>::MaxExecutionHeadersToKeep,
+	crate::ExecutionHeaderIndex<T>,
+	crate::ExecutionHeaderMapping<T>,
+	crate::ExecutionHeaders<T>,
+	OptionQuery,
+>;
+
+/// FinalizedState ring buffer implementation
+pub(crate) type FinalizedBeaconStateBuffer<T> = RingBufferMapImpl<
+	u32,
+	crate::MaxFinalizedHeadersToKeep<T>,
+	crate::FinalizedBeaconStateIndex<T>,
+	crate::FinalizedBeaconStateMapping<T>,
+	crate::FinalizedBeaconState<T>,
+	OptionQuery,
+>;

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/src/weights.rs

@@ -0,0 +1,68 @@
+//! Autogenerated weights for ethereum_beacon_client
+//!
+//! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
+//! DATE: 2022-09-27, STEPS: `10`, REPEAT: 10, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("/tmp/snowbridge/spec.json"), DB CACHE: 1024
+
+// Executed Command:
+// ./target/release/snowbridge
+// benchmark
+// pallet
+// --chain
+// /tmp/snowbridge/spec.json
+// --execution=wasm
+// --pallet
+// ethereum_beacon_client
+// --extrinsic
+// *
+// --steps
+// 10
+// --repeat
+// 10
+// --output
+// pallets/ethereum-beacon-client/src/weights.rs
+// --template
+// templates/module-weight-template.hbs
+
+#![cfg_attr(rustfmt, rustfmt_skip)]
+#![allow(unused_parens)]
+#![allow(unused_imports)]
+
+use frame_support::{traits::Get, weights::{Weight, constants::RocksDbWeight}};
+use sp_std::marker::PhantomData;
+
+/// Weight functions needed for ethereum_beacon_client.
+pub trait WeightInfo {
+	fn force_checkpoint() -> Weight;
+	fn submit() -> Weight;
+	fn submit_with_sync_committee() -> Weight;
+	fn submit_execution_header() -> Weight;
+}
+
+// For backwards compatibility and tests
+impl WeightInfo for () {
+	fn force_checkpoint() -> Weight {
+		Weight::from_parts(97_263_571_000_u64, 0)
+			.saturating_add(Weight::from_parts(0, 3501))
+			.saturating_add(RocksDbWeight::get().reads(2))
+			.saturating_add(RocksDbWeight::get().writes(9))
+	}
+	fn submit() -> Weight {
+		Weight::from_parts(26_051_019_000_u64, 0)
+			.saturating_add(Weight::from_parts(0, 93857))
+			.saturating_add(RocksDbWeight::get().reads(8))
+			.saturating_add(RocksDbWeight::get().writes(4))
+	}
+	fn submit_with_sync_committee() -> Weight {
+		Weight::from_parts(122_461_312_000_u64, 0)
+			.saturating_add(Weight::from_parts(0, 93857))
+			.saturating_add(RocksDbWeight::get().reads(6))
+			.saturating_add(RocksDbWeight::get().writes(1))
+	}
+	fn submit_execution_header() -> Weight {
+		Weight::from_parts(113_158_000_u64, 0)
+			.saturating_add(Weight::from_parts(0, 3537))
+			.saturating_add(RocksDbWeight::get().reads(5))
+			.saturating_add(RocksDbWeight::get().writes(4))
+	}
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/execution-header-update.minimal.json

@@ -0,0 +1,43 @@
+{
+  "header": {
+    "slot": 3622,
+    "proposer_index": 7,
+    "parent_root": "0x254c9215f6cce83e21b9776afb482181639602d3cb58cf99452a6a4a4f603930",
+    "state_root": "0xea98df6d30817d63f3e54ea118e2b1ba8675753c72dec1661c503d4eb43f9bdd",
+    "body_root": "0x765a0616a31d38e0ca2d10f6e8b234dd3d07e16aa929bcbc4de775c93f1972fd"
+  },
+  "ancestry_proof": {
+    "header_branch": [
+      "0x7690506882ac8c5f01d00f3ade06439259a3a0261ef5d61ec44920678b4104e6",
+      "0xf01aa0fdd7c9ef7b1affb7854fe8cbcc5c70643ee5b83e032faa702a0675a8cb",
+      "0x273a7b300b75ffa2c765af50680aa836299264f2107f38010278822313181801",
+      "0x30fe73a3bae6a31af32656ab759a4b67d27a213e01012b96cc4fedd0f2e77c75",
+      "0x7246cb3a35f13a1f0bbf907887985bb5382c45f2aa1699dbca48a0a82d5330af",
+      "0x5e7270e88a22dd4a905b2e76da2c8c358baeddd34de6c64a71bb1c80070ab717"
+    ],
+    "finalized_block_root": "0xa6fdc5df11c1759d11c9f0353a666715e5677e9ffd7d414e44cff0970553f1c9"
+  },
+  "execution_header": {
+    "parent_hash": "0x6c9657f1267ad6040ea017ff6d02b55c4ba25cb092b8326d321dd98d01d1ee64",
+    "fee_recipient": "0x0000000000000000000000000000000000000000",
+    "state_root": "0x01f975f7cdff9b0a8844304aa59062fe18af0fef4636539312dfe20d238600ba",
+    "receipts_root": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+    "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    "prev_randao": "0xcdfcab74bc26b3f4311afdc72d2d21d33a4b045187a01fa208a9d687a6d1d25c",
+    "block_number": 3622,
+    "gas_limit": 30000000,
+    "gas_used": 0,
+    "timestamp": 1685722543,
+    "extra_data": "0xd983010b02846765746888676f312e31392e358664617277696e",
+    "base_fee_per_gas": 7,
+    "block_hash": "0x38c80e0e26cb80730df627d32f50266bd0fe32fb12b7606300ad81aa2b4033db",
+    "transactions_root": "0x7ffe241ea60187fdb0187bfa22de35d1f9bed7ab061d9401fd47e34a54fbede1",
+    "withdrawals_root": "0x28ba1834a3a7b657460ce79fa3a1d909ab8828fd557659d4d0554a9bdbc0ec30"
+  },
+  "execution_branch": [
+    "0x005b8d55b34b4323bfd4773c28b09eb53bc87959e65411ccd23728c7e42d5ff2",
+    "0x336488033fe5f3ef4ccc12af07b9370b92e553e35ecb4a337a1b1c0e4afe1e0e",
+    "0xdb56114e00fdd4c1f85c892bf35ac9a89289aaecb1ebd0a96cde606a748b5d71",
+    "0x7061330dada1ba1c602ba98f647a441885460ed0db00483fea1282385dfab84b"
+  ]
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/finalized-header-update.minimal.json

@@ -0,0 +1,38 @@
+{
+  "attested_header": {
+    "slot": 3640,
+    "proposer_index": 5,
+    "parent_root": "0xf062fcec9c3379a08e6add37a834b1e39af395fc343973e44957ecebbf2ecddd",
+    "state_root": "0xb1581cb62fe376e305e02f26463153f5dfb804d8df97ef40fc315c1bc30731ba",
+    "body_root": "0x98461abcc6d130b7bcb9430292c8a269ea9f01082685347e2968d892f716067c"
+  },
+  "sync_aggregate": {
+    "sync_committee_bits": "0xffffffff",
+    "sync_committee_signature": "0x925c6e4b67890a7e28a7ca19853f88247e92014b9d233ac9058efd4f3827f0055db308debe17596e635b93727b5a851e1366ca801f30b03fdec722f45011504702a27646488b5ab5e3428fe7b4d4a50132f374612f66e45d68db27c568f96f08"
+  },
+  "signature_slot": 3641,
+  "next_sync_committee_update": null,
+  "finalized_header": {
+    "slot": 3624,
+    "proposer_index": 7,
+    "parent_root": "0x7690506882ac8c5f01d00f3ade06439259a3a0261ef5d61ec44920678b4104e6",
+    "state_root": "0x3726ebb8d9973977a71a8389caf5fc5830eeb8cd4fdfbbc7b0c4e6ca3e6a4090",
+    "body_root": "0x0f9a3f0fa5a4ffaf7c10504c86f23e7d554366ffd069fe958a160b253c3fd409"
+  },
+  "finality_branch": [
+    "0xc501000000000000000000000000000000000000000000000000000000000000",
+    "0x10c726fac935bf9657cc7476d3cfa7bedec5983dcfb59e8a7df6d0a619e108d7",
+    "0x83c3d5360d254f4a44be712c1f433e88e810b6d1e0e789e90bada9e36126b857",
+    "0x97245fa01a89a6d7b4542cd731fef699f58b2bbaabdd6f641334c9e9eeae3a20",
+    "0xc3d19c773f66ab94bc2106d5e75a3205398dd6e94b6f8a5716f347741eb9fc5a",
+    "0x9e5040e56d765c1add56779a716be7497be27cba37f866cd8d34418d55e48715"
+  ],
+  "block_roots_root": "0x29a54625749fa25f9e36df14a3baa335c58246bba2f8c7eb8b1ec2e4908e2fd0",
+  "block_roots_branch": [
+    "0x53616f9298818a8423c98adc47c92aaf82f0c5c911dc4ee5f88ba6d3022341c1",
+    "0x5d2f1c4bce6f63f26cbe3fbf480281c04a6b14bea74350a88ee945354ecbd79d",
+    "0x8333eefc7eaa4d10091e2014b3aae2bf6bd2d10c22c67100e189f8ab6caab261",
+    "0x3edfa69130bc193dec47c27a5903f03d5262b75899b69c0e95ac1816a664a3e7",
+    "0x5e046000f85aede8d4c28140b27778488d4ad21b1e16e345055d07ee53f2711b"
+  ]
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/initial-checkpoint.minimal.json

@@ -0,0 +1,62 @@
+{
+  "header": {
+    "slot": 3616,
+    "proposer_index": 7,
+    "parent_root": "0x6c5e8c7b32b7bfbb250fa8fd7bc348d7325fb2bfc869e4c506af6802fcad87f4",
+    "state_root": "0x3e467e3429a1ae36572fe3fe1c953381242e950254cf97c7527a8cea8aa6c9de",
+    "body_root": "0x7da749680d2b0b4f779047fcfe7d0c13d247f6d23478817fe9c6fbe07993adb2"
+  },
+  "current_sync_committee": {
+    "pubkeys": [
+      "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+      "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+      "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+      "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+      "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+      "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+      "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+      "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+      "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+      "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+      "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+      "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+      "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+      "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+      "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+      "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+      "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+      "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+      "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+      "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+      "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+      "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+      "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+      "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+      "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+      "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+      "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+      "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+      "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+      "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+      "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+      "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c"
+    ],
+    "aggregate_pubkey": "0x8fe11476a05750c52618deb79918e2e674f56dfbf12dbce55ae4386d108e8a1e83c6326f5957e2ef19137582ce270dc6"
+  },
+  "current_sync_committee_branch": [
+    "0x46af3f54acbea439b63aa5bb699c8f25ff584b23912366788f7c8e95011ce324",
+    "0x41dcb71ec3b3940399118d28e09fdc58a8e33b818b8c5cbb933c59929504ca08",
+    "0xfa53febb29348e3493a50c0e7c6d35796bf69c54dfc6f42f7600612789d0ed6d",
+    "0x5e7ea1693066b604fc60d4657b43e7a4aafd3f4f54d9a740d2abe765e92d8385",
+    "0x16c9bca64a82e80c23817bfec345d088e0adc3865e392965c1244f97979f816a"
+  ],
+  "validators_root": "0x270d43e74ce340de4bca2b1936beca0f4f5408d9e78aec4850920baf659d5b69",
+  "block_roots_root": "0x00f6bbdeac1e1a922a9bf0e78720c0bffe558d8195e8ede8cb72bbd295f242f2",
+  "block_roots_branch": [
+    "0x7a61086fb9e53ab4dd87243d6288c51793696168a73773277630da5b20bf6091",
+    "0x60733905cdc5dd65d05161bb3138eecc47d6d6057ab36b0d36cf5a3200484143",
+    "0x86d7de634ae45de5b3cbbc562dd976de7d06a3d96f83147413536e6b108c7a39",
+    "0x0ada571c9e0da6fce8dd13e6d9ce173768521ac32e0af456634556176789fa6e",
+    "0x2341538fd0aafbc1ff0f513545e5dcd4b8905dc9e00d6173480c18a4e8086ebc"
+  ]
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/next-finalized-header-update.minimal.json

@@ -0,0 +1,38 @@
+{
+  "attested_header": {
+    "slot": 3696,
+    "proposer_index": 1,
+    "parent_root": "0x04a63c5dfb726c31a32a72c1c426ff89e21363223d7096486b629f1d58abe5d8",
+    "state_root": "0xbe20e69420cbf9400224ec5edeb0843776a2ccf945e9a3ba9311ae812cad1e30",
+    "body_root": "0x1d2acd1748f1c58096d1edc8badd3a1d7e1dc3c33bcb9229e4c03f3a84efeadb"
+  },
+  "sync_aggregate": {
+    "sync_committee_bits": "0xffffffff",
+    "sync_committee_signature": "0xafa79bc0f3c731ab1eb6aeafc582a7dd1c100ea471df3af6ff485b58661b3ef8077264dea0b60df9aec2d3ca8ddab6770fc9d061462e5a6dc718146085425f863d00921c42413805cb5b4c5175f36f2087cfed740bb7d57e8d5b48352643cd5b"
+  },
+  "signature_slot": 3697,
+  "next_sync_committee_update": null,
+  "finalized_header": {
+    "slot": 3680,
+    "proposer_index": 7,
+    "parent_root": "0x4d8f4fc47ad3eb045bd20cae13af6df02f96a3f8d7c8a285190ba10cfe2b84cf",
+    "state_root": "0xd498766d77277fe16a6a4609ab3ac3a6e9887d162d8dfffdfc9cc4ae833e4127",
+    "body_root": "0x9ba73bc9a4907cac0b887550e2b01a63dcc70473753ffcc243d33394cc64b4c0"
+  },
+  "finality_branch": [
+    "0xcc01000000000000000000000000000000000000000000000000000000000000",
+    "0x10c726fac935bf9657cc7476d3cfa7bedec5983dcfb59e8a7df6d0a619e108d7",
+    "0x142061c4bc3673bf774cb8c7b6085057bd0ca85672b43afa2d9581b0b6a44e54",
+    "0x48b8cd8ca9d9563e30c1cca2a854cd7f75eb4cb013d10809b3138a72d94ea0c5",
+    "0x9b39523d05013ac7cbb9f43e5d6f9dc033b12aa1d6d6edd994ddc4f5efe7be9d",
+    "0x066c9aa26107bc8cb28bc73e518da6cc865ec1d67516b6ca24663b6b7ae3cb21"
+  ],
+  "block_roots_root": "0xb15aa2483811d8c5616cb93710f4fcb809d97443caac9de163f943a30f385db6",
+  "block_roots_branch": [
+    "0xf7a43ad317417daa4c2a1e93c54895895a824ef1e43320eb44eab16673da5a61",
+    "0xe4b8d640660f765c2ef4dc886025dc8e54c6e70b66192582f42837ed5e9d8d41",
+    "0x841f113dc81e76419b6cdec8b0cf2fc20f9381492ed3c79e9b49179b4d3eacbc",
+    "0xeb5fdc4d8b5282b653ecbc9caa93bcfe482f6d6a32cbb0d9eb011bef947579bb",
+    "0x1f328cc5640efb191ae6aa86223b1aa9d083b26ac3e1fa3c071327bb09dc5727"
+  ]
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/next-sync-committee-update.minimal.json

@@ -0,0 +1,83 @@
+{
+  "attested_header": {
+    "slot": 3664,
+    "proposer_index": 4,
+    "parent_root": "0x15ac23a0c16bfa81e8595621118040c3e6cbddd4b09bae6fb39ba5fefd0258e8",
+    "state_root": "0x6fb81aa3827e7d580bb05b4df2686c9a49508bde2f8342fd75be609a23dd8362",
+    "body_root": "0x9906a1ae8065d268f8acb7f1b3119408d2f7f8e6e0764370c16ea3d15134981f"
+  },
+  "sync_aggregate": {
+    "sync_committee_bits": "0xffffffff",
+    "sync_committee_signature": "0xa9b5584ec9290a4ac6c5616639d031f9ab1064d63b4889f1da52f6f4d66b645fca48bbe2fe8484adb0c05c647edd694d0340cf684b8ccf8e34c6d8cf447cfcfdcb856f5abdcfd85ada5a4a04d4c8f6f40c6e99308893c3941485a436d6c8e5f7"
+  },
+  "signature_slot": 3665,
+  "next_sync_committee_update": {
+    "next_sync_committee": {
+      "pubkeys": [
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373"
+      ],
+      "aggregate_pubkey": "0x8fe11476a05750c52618deb79918e2e674f56dfbf12dbce55ae4386d108e8a1e83c6326f5957e2ef19137582ce270dc6"
+    },
+    "next_sync_committee_branch": [
+      "0x46af3f54acbea439b63aa5bb699c8f25ff584b23912366788f7c8e95011ce324",
+      "0x5b118fe110ee4a1b0cf9823bc189fb38eb55a7b49adbdafcf466ec7cd4b7fd68",
+      "0xc2f12fb91a61abedb47f62a98258960edca21f31494cdf59b47a1c721e3e98f8",
+      "0x16fdfd5e6b591b3140a76efa4593a9c4d105b9e5c62d6f44edbd24790657be50",
+      "0xc8175ab66690cc94c0a24452754addd62a06948de5db9814e813437a130de452"
+    ]
+  },
+  "finalized_header": {
+    "slot": 3648,
+    "proposer_index": 1,
+    "parent_root": "0x991ee98a70e8f90bdd61d0f5554e53d37473e75e16af171f6d88f27d20223dae",
+    "state_root": "0x59b04d660ac772005a13a7dc1d5f99bb0d0292f3c422f04f7365198d70dd30de",
+    "body_root": "0x5151f035e146258e7327ad9cf1df13f8ddec7a7842c19993cf739358717b5565"
+  },
+  "finality_branch": [
+    "0xc801000000000000000000000000000000000000000000000000000000000000",
+    "0x10c726fac935bf9657cc7476d3cfa7bedec5983dcfb59e8a7df6d0a619e108d7",
+    "0x142061c4bc3673bf774cb8c7b6085057bd0ca85672b43afa2d9581b0b6a44e54",
+    "0xc2f12fb91a61abedb47f62a98258960edca21f31494cdf59b47a1c721e3e98f8",
+    "0x16fdfd5e6b591b3140a76efa4593a9c4d105b9e5c62d6f44edbd24790657be50",
+    "0xc8175ab66690cc94c0a24452754addd62a06948de5db9814e813437a130de452"
+  ],
+  "block_roots_root": "0xe6e2adaaad45363d7112945ef670e21c66bcb3276dc450962ade1e8950230380",
+  "block_roots_branch": [
+    "0x386ede102258966d4c23031c5a02de2af8180d475c4c1716b07fb5b9f142a817",
+    "0x35e6c89bc38d993a1957f8a9fb1fbeab7420688091ba2cd7ee7b19b7e187f7d6",
+    "0x99249309825cafef7e694c09c4fdf95eb4b1e8743d3b23f6959d9980ad2d69b0",
+    "0x5e028d1d905db6430f0ce4aafbc78f442047ec3a132b4e69557fdf804a4cfbf3",
+    "0xd34afeab37851937920243683a1c926c41c626aacb145718fce755782d4996dd"
+  ]
+}

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/tests/fixtures/sync-committee-update.minimal.json

@@ -0,0 +1,83 @@
+{
+  "attested_header": {
+    "slot": 3600,
+    "proposer_index": 7,
+    "parent_root": "0xdf60c2d58beccd89678b9267c689e9ba1cf1d58ce5114ad5c16e8341459cfd75",
+    "state_root": "0x023f14c7a38ef4d6ec19b522edfb427c6b70c6ffbd8610ca802dd1491c92c852",
+    "body_root": "0x0f78a1c45e42711efc5fb7b7f6238be1bee9273f7c44ff6892d815858bb77e25"
+  },
+  "sync_aggregate": {
+    "sync_committee_bits": "0xffffffff",
+    "sync_committee_signature": "0xa4dd8f0991de88ca6f81476f72f48cdb67b9414ad7bf6bba37f627c5ec84dd2c2ebc12cddd5d2e7c927276cee2d3d144158b4c067db3e9911fe52fe1875b14c93f90e4eb57bf5e8f0e6e6effe22f9ba076f30207e0ec683354961ae8e9779556"
+  },
+  "signature_slot": 3601,
+  "next_sync_committee_update": {
+    "next_sync_committee": {
+      "pubkeys": [
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c",
+        "0xab0bdda0f85f842f431beaccf1250bf1fd7ba51b4100fd64364b6401fda85bb0069b3e715b58819684e7fc0b10a72a34",
+        "0xa8d4c7c27795a725961317ef5953a7032ed6d83739db8b0e8a72353d1b8b4439427f7efa2c89caa03cc9f28f8cbab8ac",
+        "0xa3a32b0f8b4ddb83f1a0a853d81dd725dfe577d4f4c3db8ece52ce2b026eca84815c1a7e8e92a4de3d755733bf7e4a9b",
+        "0xb89bebc699769726a318c8e9971bd3171297c61aea4a6578a7a4f94b547dcba5bac16a89108b6b6a1fe3695d1a874a0b",
+        "0x88c141df77cd9d8d7a71a75c826c41a9c9f03c6ee1b180f3e7852f6a280099ded351b58d66e653af8e42816a4d8f532e",
+        "0x81283b7a20e1ca460ebd9bbd77005d557370cabb1f9a44f530c4c4c66230f675f8df8b4c2818851aa7d77a80ca5a4a5e",
+        "0x9977f1c8b731a8d5558146bfb86caea26434f3c5878b589bf280a42c9159e700e9df0e4086296c20b011d2e78c27d373",
+        "0xa99a76ed7796f7be22d5b7e85deeb7c5677e88e511e0b337618f8c4eb61349b4bf2d153f649f7b53359fe8b94a38e44c"
+      ],
+      "aggregate_pubkey": "0x8fe11476a05750c52618deb79918e2e674f56dfbf12dbce55ae4386d108e8a1e83c6326f5957e2ef19137582ce270dc6"
+    },
+    "next_sync_committee_branch": [
+      "0x1446606d0129c324a4ea374bd29a625175e0659512cd8650097e0a9c38ce6379",
+      "0xd92466c7e9a53b7b55f4fdb151746a3058931d7559b7e84e7b15384ddc903ca0",
+      "0x9fd10c3f68b75cfd3ebd2af0d4e2cbbfbe120e0b5423dde89ff0f743c7a4f937",
+      "0x1ed6aac0ab29a883de2bb2e3579ad4d6807ddcf3db8afcaf0ae25a076ac9a5f4",
+      "0xf17a840df410a15f0e4e48abf521c29ad0d296d3fb4e8b847ea37f2cc8236f1f"
+    ]
+  },
+  "finalized_header": {
+    "slot": 3584,
+    "proposer_index": 1,
+    "parent_root": "0x91c285af2ec25d485310391afe667108b787ec570cdbb0e3fd87b1e0e2c47bd7",
+    "state_root": "0xccc4baf90024e035f1252520d2f2ef1e50f840ff0ecc8e6e365721e083871a32",
+    "body_root": "0x91df5e0077434aad609aaa7e030005cee77cca83868ffc2724e5befe9a3f6a02"
+  },
+  "finality_branch": [
+    "0xc001000000000000000000000000000000000000000000000000000000000000",
+    "0x10c726fac935bf9657cc7476d3cfa7bedec5983dcfb59e8a7df6d0a619e108d7",
+    "0x83c3d5360d254f4a44be712c1f433e88e810b6d1e0e789e90bada9e36126b857",
+    "0x9fd10c3f68b75cfd3ebd2af0d4e2cbbfbe120e0b5423dde89ff0f743c7a4f937",
+    "0x1ed6aac0ab29a883de2bb2e3579ad4d6807ddcf3db8afcaf0ae25a076ac9a5f4",
+    "0xf17a840df410a15f0e4e48abf521c29ad0d296d3fb4e8b847ea37f2cc8236f1f"
+  ],
+  "block_roots_root": "0x9eab8a05c396a29c32f4f8ac9654fc0fb7cd97ec659236392ede48951a794505",
+  "block_roots_branch": [
+    "0x5c175efdbafacdfdab21c93a318b0e8e2291a5a86c40b1fc564f91ad33c106d4",
+    "0x5c1e0b76176ab033858b2835f90d5e25d708b563f77efd7d9938f0faa1c20878",
+    "0x7aea32464adee801e2a05c3af227f24231d3c088e3b7265a5fada9ac850549fe",
+    "0x9d9fca29e23c5d4ae433adf17e7fd9a0e4d1b09b68f5c45e7ca1b13ebe4a9e98",
+    "0x6b35238f188021c859d6b317457ebb6fe4cf362cab35c988010cb1343eabbfc5"
+  ]
+}

bridges/snowbridge/parachain/pallets/inbound-queue/Cargo.toml

@@ -0,0 +1,93 @@
+[package]
+name = "snowbridge-inbound-queue"
+description = "Snowbridge Inbound Queue"
+version = "0.1.1"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+serde = { version = "1.0.188", optional = true }
+codec = { version = "3.6.1", package = "parity-scale-codec", default-features = false, features = ["derive"] }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+hex-literal = { version = "0.4.1", optional = true }
+log = { version = "0.4.20", default-features = false }
+alloy-primitives = { version = "0.4.2", default-features = false, features = ["rlp"] }
+alloy-sol-types = { version = "0.4.2", default-features = false }
+alloy-rlp = { version = "0.3.3", default-features = false, features = ["derive"] }
+num-traits = { version = "0.2.16", default-features = false }
+
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking", default-features = false, optional = true }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+pallet-balances = { path = "../../../../../substrate/frame/balances", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+snowbridge-ethereum = { path = "../../primitives/ethereum", default-features = false }
+snowbridge-router-primitives = { path = "../../primitives/router", default-features = false }
+snowbridge-beacon-primitives = { path = "../../primitives/beacon", default-features = false, optional = true }
+
+[dev-dependencies]
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking" }
+sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
+snowbridge-beacon-primitives = { path = "../../primitives/beacon" }
+snowbridge-ethereum-beacon-client = { path = "../../pallets/ethereum-beacon-client" }
+hex-literal = { version = "0.4.1" }
+
+[features]
+default = ["std"]
+std = [
+	"alloy-primitives/std",
+	"alloy-rlp/std",
+	"alloy-sol-types/std",
+	"codec/std",
+	"frame-benchmarking/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"num-traits/std",
+	"pallet-balances/std",
+	"scale-info/std",
+	"serde",
+	"snowbridge-core/std",
+	"snowbridge-ethereum/std",
+	"snowbridge-router-primitives/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm-builder/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"frame-benchmarking",
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"hex-literal",
+	"pallet-balances/runtime-benchmarks",
+	"snowbridge-beacon-primitives",
+	"snowbridge-core/runtime-benchmarks",
+	"snowbridge-ethereum-beacon-client/runtime-benchmarks",
+	"snowbridge-router-primitives/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
+	"snowbridge-ethereum-beacon-client/try-runtime",
+	"sp-runtime/try-runtime",
+]

bridges/snowbridge/parachain/pallets/inbound-queue/src/benchmarking/fixtures.rs

@@ -0,0 +1,40 @@
+use hex_literal::hex;
+use snowbridge_beacon_primitives::CompactExecutionHeader;
+use snowbridge_core::inbound::{Log, Message, Proof};
+use sp_std::vec;
+
+pub struct InboundQueueTest {
+	pub execution_header: CompactExecutionHeader,
+	pub message: Message,
+}
+
+pub fn make_create_message() -> InboundQueueTest {
+	InboundQueueTest{
+        execution_header: CompactExecutionHeader{
+            parent_hash: hex!("b5608f0af7c3b6fe5c593772fc25436b8d6549eb236adb0855c6ad33e0004e04").into(),
+            block_number: 115,
+            state_root: hex!("47ed174789836c622499d9659a4ac32c3b91a7b15642d39b0a11b82ff23995c1").into(),
+            receipts_root: hex!("42c08b5303fcdf9e49c833fe5f1182cdbc8206bf8aec581125fc34aba11e1f1a").into(),
+        },
+        message: Message {
+            event_log: 	Log {
+                address: hex!("eda338e4dc46038493b885327842fd3e301cab39").into(),
+                topics: vec![
+                    hex!("7153f9357c8ea496bba60bf82e67143e27b64462b49041f8e689e1b05728f84f").into(),
+                    hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539").into(),
+                    hex!("5f7060e971b0dc81e63f0aa41831091847d97c1a4693ac450cc128c7214e65e0").into(),
+                ],
+                data: hex!("00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000002e00a736aa00000000000087d1f7fdfee7f651fabc8bfcb6e086c278b77a7d00e40b54020000000000000000000000000000000000000000000000000000000000").into(),
+            },
+            proof: Proof {
+                block_hash: hex!("add15f439c8a57fe375d0a679870b1359921d70cb0e3e44f0dd3e272849f4097").into(),
+                tx_index: 0,
+                data: (vec![
+                    hex!("42c08b5303fcdf9e49c833fe5f1182cdbc8206bf8aec581125fc34aba11e1f1a").to_vec(),
+                ], vec![
+                    hex!("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").to_vec(),
+                ]),
+            },
+        },
+    }
+}

bridges/snowbridge/parachain/pallets/inbound-queue/src/benchmarking/mod.rs

@@ -0,0 +1,55 @@
+mod fixtures;
+
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use crate::Pallet as InboundQueue;
+use frame_benchmarking::v2::*;
+use frame_support::assert_ok;
+use frame_system::RawOrigin;
+
+#[benchmarks]
+mod benchmarks {
+	use super::*;
+	use crate::benchmarking::fixtures::make_create_message;
+
+	#[benchmark]
+	fn submit() -> Result<(), BenchmarkError> {
+		let caller: T::AccountId = whitelisted_caller();
+
+		let create_message = make_create_message();
+
+		T::Helper::initialize_storage(
+			create_message.message.proof.block_hash,
+			create_message.execution_header,
+		);
+
+		let sovereign_account = sibling_sovereign_account::<T>(1000u32.into());
+
+		let minimum_balance = T::Token::minimum_balance();
+
+		// So that the receiving account exists
+		assert_ok!(T::Token::mint_into(&caller, minimum_balance));
+		// Fund the sovereign account (parachain sovereign account) so it can transfer a reward
+		// fee to the caller account
+		assert_ok!(T::Token::mint_into(
+			&sovereign_account,
+			3_000_000_000_000u128
+				.try_into()
+				.unwrap_or_else(|_| panic!("unable to cast sovereign account balance")),
+		));
+
+		#[block]
+		{
+			assert_ok!(InboundQueue::<T>::submit(
+				RawOrigin::Signed(caller.clone()).into(),
+				create_message.message,
+			));
+		}
+
+		Ok(())
+	}
+
+	impl_benchmark_test_suite!(InboundQueue, crate::mock::new_tester(), crate::mock::Test);
+}

bridges/snowbridge/parachain/pallets/inbound-queue/src/envelope.rs

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use snowbridge_core::{inbound::Log, ChannelId};
+
+use sp_core::{RuntimeDebug, H160, H256};
+use sp_std::{convert::TryFrom, prelude::*};
+
+use alloy_primitives::B256;
+use alloy_sol_types::{sol, SolEvent};
+
+sol! {
+	event OutboundMessageAccepted(bytes32 indexed channel_id, uint64 nonce, bytes32 indexed message_id, bytes payload);
+}
+
+/// An inbound message that has had its outer envelope decoded.
+#[derive(Clone, RuntimeDebug)]
+pub struct Envelope {
+	/// The address of the outbound queue on Ethereum that emitted this message as an event log
+	pub gateway: H160,
+	/// The message Channel
+	pub channel_id: ChannelId,
+	/// A nonce for enforcing replay protection and ordering.
+	pub nonce: u64,
+	/// An id for tracing the message on its route (has no role in bridge consensus)
+	pub message_id: H256,
+	/// The inner payload generated from the source application.
+	pub payload: Vec<u8>,
+}
+
+#[derive(Copy, Clone, RuntimeDebug)]
+pub struct EnvelopeDecodeError;
+
+impl TryFrom<&Log> for Envelope {
+	type Error = EnvelopeDecodeError;
+
+	fn try_from(log: &Log) -> Result<Self, Self::Error> {
+		let topics: Vec<B256> = log.topics.iter().map(|x| B256::from_slice(x.as_ref())).collect();
+
+		let event = OutboundMessageAccepted::decode_log(topics, &log.data, true)
+			.map_err(|_| EnvelopeDecodeError)?;
+
+		Ok(Self {
+			gateway: log.address,
+			channel_id: ChannelId::from(event.channel_id.as_ref()),
+			nonce: event.nonce,
+			message_id: H256::from(event.message_id.as_ref()),
+			payload: event.payload,
+		})
+	}
+}

bridges/snowbridge/parachain/pallets/inbound-queue/src/lib.rs

@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Inbound Queue
+//!
+//! # Overview
+//!
+//! Receives messages emitted by the Gateway contract on Ethereum, whereupon they are verified,
+//! translated to XCM, and finally sent to their final destination parachain.
+//!
+//! The message relayers are rewarded using native currency from the sovereign account of the
+//! destination parachain.
+//!
+//! # Extrinsics
+//!
+//! ## Governance
+//!
+//! * [`Call::set_operating_mode`]: Set the operating mode of the pallet. Can be used to disable
+//!   processing of inbound messages.
+//!
+//! ## Message Submission
+//!
+//! * [`Call::submit`]: Submit a message for verification and dispatch the final destination
+//!   parachain.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+mod envelope;
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+
+#[cfg(feature = "runtime-benchmarks")]
+use snowbridge_beacon_primitives::CompactExecutionHeader;
+
+pub mod weights;
+
+#[cfg(test)]
+mod mock;
+
+#[cfg(test)]
+mod test;
+
+use codec::{Decode, DecodeAll, Encode};
+use envelope::Envelope;
+use frame_support::{
+	traits::{
+		fungible::{Inspect, Mutate},
+		tokens::{Fortitude, Precision, Preservation},
+	},
+	weights::WeightToFee,
+	PalletError,
+};
+use frame_system::ensure_signed;
+use scale_info::TypeInfo;
+use sp_core::{H160, H256};
+use sp_std::{convert::TryFrom, vec};
+use xcm::prelude::{
+	send_xcm, Instruction::SetTopic, Junction::*, Junctions::*, MultiLocation,
+	SendError as XcmpSendError, SendXcm, Xcm, XcmHash,
+};
+
+use snowbridge_core::{
+	inbound::{Message, VerificationError, Verifier},
+	sibling_sovereign_account, BasicOperatingMode, Channel, ChannelId, ParaId, StaticLookup,
+};
+use snowbridge_router_primitives::{
+	inbound,
+	inbound::{ConvertMessage, ConvertMessageError},
+};
+use sp_runtime::traits::Saturating;
+
+pub use weights::WeightInfo;
+
+type BalanceOf<T> =
+	<<T as pallet::Config>::Token as Inspect<<T as frame_system::Config>::AccountId>>::Balance;
+
+pub use pallet::*;
+
+pub const LOG_TARGET: &str = "snowbridge-inbound-queue";
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+	use snowbridge_core::PricingParameters;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[cfg(feature = "runtime-benchmarks")]
+	pub trait BenchmarkHelper<T> {
+		fn initialize_storage(block_hash: H256, header: CompactExecutionHeader);
+	}
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		/// The verifier for inbound messages from Ethereum
+		type Verifier: Verifier;
+
+		/// Message relayers are rewarded with this asset
+		type Token: Mutate<Self::AccountId> + Inspect<Self::AccountId>;
+
+		/// XCM message sender
+		type XcmSender: SendXcm;
+
+		// Address of the Gateway contract
+		#[pallet::constant]
+		type GatewayAddress: Get<H160>;
+
+		/// Convert inbound message to XCM
+		type MessageConverter: ConvertMessage<
+			AccountId = Self::AccountId,
+			Balance = BalanceOf<Self>,
+		>;
+
+		/// Lookup a channel descriptor
+		type ChannelLookup: StaticLookup<Source = ChannelId, Target = Channel>;
+
+		/// Lookup pricing parameters
+		type PricingParameters: Get<PricingParameters<BalanceOf<Self>>>;
+
+		type WeightInfo: WeightInfo;
+
+		#[cfg(feature = "runtime-benchmarks")]
+		type Helper: BenchmarkHelper<Self>;
+
+		/// Convert a weight value into deductible balance type.
+		type WeightToFee: WeightToFee<Balance = BalanceOf<Self>>;
+
+		/// Convert a length value into deductible balance type
+		type LengthToFee: WeightToFee<Balance = BalanceOf<Self>>;
+
+		/// The upper limit here only used to estimate delivery cost
+		type MaxMessageSize: Get<u32>;
+	}
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T> {
+		/// A message was received from Ethereum
+		MessageReceived {
+			/// The message channel
+			channel_id: ChannelId,
+			/// The message nonce
+			nonce: u64,
+			/// ID of the XCM message which was forwarded to the final destination parachain
+			message_id: [u8; 32],
+		},
+		/// Set OperatingMode
+		OperatingModeChanged { mode: BasicOperatingMode },
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		/// Message came from an invalid outbound channel on the Ethereum side.
+		InvalidGateway,
+		/// Message has an invalid envelope.
+		InvalidEnvelope,
+		/// Message has an unexpected nonce.
+		InvalidNonce,
+		/// Message has an invalid payload.
+		InvalidPayload,
+		/// Message channel is invalid
+		InvalidChannel,
+		/// The max nonce for the type has been reached
+		MaxNonceReached,
+		/// Cannot convert location
+		InvalidAccountConversion,
+		/// Pallet is halted
+		Halted,
+		/// Message verification error,
+		Verification(VerificationError),
+		/// XCMP send failure
+		Send(SendError),
+		/// Message conversion error
+		ConvertMessage(ConvertMessageError),
+	}
+
+	#[derive(Clone, Encode, Decode, Eq, PartialEq, Debug, TypeInfo, PalletError)]
+	pub enum SendError {
+		NotApplicable,
+		NotRoutable,
+		Transport,
+		DestinationUnsupported,
+		ExceedsMaxMessageSize,
+		MissingArgument,
+		Fees,
+	}
+
+	impl<T: Config> From<XcmpSendError> for Error<T> {
+		fn from(e: XcmpSendError) -> Self {
+			match e {
+				XcmpSendError::NotApplicable => Error::<T>::Send(SendError::NotApplicable),
+				XcmpSendError::Unroutable => Error::<T>::Send(SendError::NotRoutable),
+				XcmpSendError::Transport(_) => Error::<T>::Send(SendError::Transport),
+				XcmpSendError::DestinationUnsupported =>
+					Error::<T>::Send(SendError::DestinationUnsupported),
+				XcmpSendError::ExceedsMaxMessageSize =>
+					Error::<T>::Send(SendError::ExceedsMaxMessageSize),
+				XcmpSendError::MissingArgument => Error::<T>::Send(SendError::MissingArgument),
+				XcmpSendError::Fees => Error::<T>::Send(SendError::Fees),
+			}
+		}
+	}
+
+	/// The current nonce for each channel
+	#[pallet::storage]
+	pub type Nonce<T: Config> = StorageMap<_, Twox64Concat, ChannelId, u64, ValueQuery>;
+
+	/// The current operating mode of the pallet.
+	#[pallet::storage]
+	#[pallet::getter(fn operating_mode)]
+	pub type OperatingMode<T: Config> = StorageValue<_, BasicOperatingMode, ValueQuery>;
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		/// Submit an inbound message originating from the Gateway contract on Ethereum
+		#[pallet::call_index(0)]
+		#[pallet::weight(T::WeightInfo::submit())]
+		pub fn submit(origin: OriginFor<T>, message: Message) -> DispatchResult {
+			let who = ensure_signed(origin)?;
+			ensure!(!Self::operating_mode().is_halted(), Error::<T>::Halted);
+
+			// submit message to verifier for verification
+			T::Verifier::verify(&message.event_log, &message.proof)
+				.map_err(|e| Error::<T>::Verification(e))?;
+
+			// Decode event log into an Envelope
+			let envelope =
+				Envelope::try_from(&message.event_log).map_err(|_| Error::<T>::InvalidEnvelope)?;
+
+			// Verify that the message was submitted from the known Gateway contract
+			ensure!(T::GatewayAddress::get() == envelope.gateway, Error::<T>::InvalidGateway);
+
+			// Retrieve the registered channel for this message
+			let channel =
+				T::ChannelLookup::lookup(envelope.channel_id).ok_or(Error::<T>::InvalidChannel)?;
+
+			// Verify message nonce
+			<Nonce<T>>::try_mutate(envelope.channel_id, |nonce| -> DispatchResult {
+				if *nonce == u64::MAX {
+					return Err(Error::<T>::MaxNonceReached.into())
+				}
+				if envelope.nonce != nonce.saturating_add(1) {
+					Err(Error::<T>::InvalidNonce.into())
+				} else {
+					*nonce = nonce.saturating_add(1);
+					Ok(())
+				}
+			})?;
+
+			// Reward relayer from the sovereign account of the destination parachain
+			// Expected to fail if sovereign account has no funds
+			let sovereign_account = sibling_sovereign_account::<T>(channel.para_id);
+			let delivery_cost = Self::calculate_delivery_cost(message.encode().len() as u32);
+			T::Token::transfer(&sovereign_account, &who, delivery_cost, Preservation::Preserve)?;
+
+			// Decode message into XCM
+			let (xcm, fee) =
+				match inbound::VersionedMessage::decode_all(&mut envelope.payload.as_ref()) {
+					Ok(message) => Self::do_convert(envelope.message_id, message)?,
+					Err(_) => return Err(Error::<T>::InvalidPayload.into()),
+				};
+
+			// We embed fees for xcm execution inside the xcm program using teleports
+			// so we must burn the amount of the fee embedded into the XCM script.
+			T::Token::burn_from(&sovereign_account, fee, Precision::Exact, Fortitude::Polite)?;
+
+			log::info!(
+				target: LOG_TARGET,
+				"💫 xcm {:?} sent with fee {:?}",
+				xcm,
+				fee
+			);
+
+			// Attempt to send XCM to a dest parachain
+			let message_id = Self::send_xcm(xcm, channel.para_id)?;
+
+			Self::deposit_event(Event::MessageReceived {
+				channel_id: envelope.channel_id,
+				nonce: envelope.nonce,
+				message_id,
+			});
+
+			Ok(())
+		}
+
+		/// Halt or resume all pallet operations. May only be called by root.
+		#[pallet::call_index(1)]
+		#[pallet::weight((T::DbWeight::get().reads_writes(1, 1), DispatchClass::Operational))]
+		pub fn set_operating_mode(
+			origin: OriginFor<T>,
+			mode: BasicOperatingMode,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			OperatingMode::<T>::set(mode);
+			Self::deposit_event(Event::OperatingModeChanged { mode });
+			Ok(())
+		}
+	}
+
+	impl<T: Config> Pallet<T> {
+		pub fn do_convert(
+			message_id: H256,
+			message: inbound::VersionedMessage,
+		) -> Result<(Xcm<()>, BalanceOf<T>), Error<T>> {
+			let (mut xcm, fee) =
+				T::MessageConverter::convert(message).map_err(|e| Error::<T>::ConvertMessage(e))?;
+			// Append the message id as an XCM topic
+			xcm.inner_mut().extend(vec![SetTopic(message_id.into())]);
+			Ok((xcm, fee))
+		}
+
+		pub fn send_xcm(xcm: Xcm<()>, dest: ParaId) -> Result<XcmHash, Error<T>> {
+			let dest = MultiLocation { parents: 1, interior: X1(Parachain(dest.into())) };
+			let (xcm_hash, _) = send_xcm::<T::XcmSender>(dest, xcm).map_err(Error::<T>::from)?;
+			Ok(xcm_hash)
+		}
+
+		pub fn calculate_delivery_cost(length: u32) -> BalanceOf<T> {
+			let weight_fee = T::WeightToFee::weight_to_fee(&T::WeightInfo::submit());
+			let len_fee = T::LengthToFee::weight_to_fee(&Weight::from_parts(length as u64, 0));
+			weight_fee
+				.saturating_add(len_fee)
+				.saturating_add(T::PricingParameters::get().rewards.local)
+		}
+	}
+
+	/// API for accessing the delivery cost of a message
+	impl<T: Config> Get<BalanceOf<T>> for Pallet<T> {
+		fn get() -> BalanceOf<T> {
+			// Cost here based on MaxMessagePayloadSize(the worst case)
+			Self::calculate_delivery_cost(T::MaxMessageSize::get())
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/inbound-queue/src/mock.rs

@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use frame_support::{
+	parameter_types,
+	traits::{ConstU128, ConstU32, Everything},
+	weights::IdentityFee,
+};
+use hex_literal::hex;
+use snowbridge_beacon_primitives::{Fork, ForkVersions};
+use snowbridge_core::{
+	gwei,
+	inbound::{Log, Proof, VerificationError},
+	meth, Channel, ChannelId, PricingParameters, Rewards, StaticLookup,
+};
+use snowbridge_router_primitives::inbound::MessageToXcm;
+use sp_core::{H160, H256};
+use sp_runtime::{
+	traits::{BlakeTwo256, IdentifyAccount, IdentityLookup, Verify},
+	BuildStorage, FixedU128, MultiSignature,
+};
+use sp_std::convert::From;
+use xcm::v3::{prelude::*, MultiAssets, SendXcm};
+
+use crate::{self as inbound_queue};
+
+type Block = frame_system::mocking::MockBlock<Test>;
+
+frame_support::construct_runtime!(
+	pub enum Test
+	{
+		System: frame_system::{Pallet, Call, Storage, Event<T>},
+		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
+		EthereumBeaconClient: snowbridge_ethereum_beacon_client::{Pallet, Call, Storage, Event<T>},
+		InboundQueue: inbound_queue::{Pallet, Call, Storage, Event<T>},
+	}
+);
+
+pub type Signature = MultiSignature;
+pub type AccountId = <<Signature as Verify>::Signer as IdentifyAccount>::AccountId;
+
+parameter_types! {
+	pub const BlockHashCount: u64 = 250;
+}
+
+type Balance = u128;
+
+impl frame_system::Config for Test {
+	type BaseCallFilter = Everything;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type RuntimeOrigin = RuntimeOrigin;
+	type RuntimeCall = RuntimeCall;
+	type RuntimeTask = RuntimeTask;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type RuntimeEvent = RuntimeEvent;
+	type BlockHashCount = BlockHashCount;
+	type DbWeight = ();
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = pallet_balances::AccountData<u128>;
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+	type Nonce = u64;
+	type Block = Block;
+}
+
+impl pallet_balances::Config for Test {
+	type MaxLocks = ();
+	type MaxReserves = ();
+	type ReserveIdentifier = [u8; 8];
+	type Balance = Balance;
+	type RuntimeEvent = RuntimeEvent;
+	type DustRemoval = ();
+	type ExistentialDeposit = ConstU128<1>;
+	type AccountStore = System;
+	type WeightInfo = ();
+	type FreezeIdentifier = ();
+	type MaxFreezes = ();
+	type RuntimeHoldReason = ();
+	type RuntimeFreezeReason = ();
+	type MaxHolds = ();
+}
+
+parameter_types! {
+	pub const ExecutionHeadersPruneThreshold: u32 = 10;
+	pub const ChainForkVersions: ForkVersions = ForkVersions{
+		genesis: Fork {
+			version: [0, 0, 0, 1], // 0x00000001
+			epoch: 0,
+		},
+		altair: Fork {
+			version: [1, 0, 0, 1], // 0x01000001
+			epoch: 0,
+		},
+		bellatrix: Fork {
+			version: [2, 0, 0, 1], // 0x02000001
+			epoch: 0,
+		},
+		capella: Fork {
+			version: [3, 0, 0, 1], // 0x03000001
+			epoch: 0,
+		},
+	};
+}
+
+impl snowbridge_ethereum_beacon_client::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type ForkVersions = ChainForkVersions;
+	type MaxExecutionHeadersToKeep = ExecutionHeadersPruneThreshold;
+	type WeightInfo = ();
+}
+
+// Mock verifier
+pub struct MockVerifier;
+
+impl Verifier for MockVerifier {
+	fn verify(_: &Log, _: &Proof) -> Result<(), VerificationError> {
+		Ok(())
+	}
+}
+
+const GATEWAY_ADDRESS: [u8; 20] = hex!["eda338e4dc46038493b885327842fd3e301cab39"];
+
+parameter_types! {
+	pub const EthereumNetwork: xcm::v3::NetworkId = xcm::v3::NetworkId::Ethereum { chain_id: 11155111 };
+	pub const GatewayAddress: H160 = H160(GATEWAY_ADDRESS);
+	pub const CreateAssetCall: [u8;2] = [53, 0];
+	pub const CreateAssetExecutionFee: u128 = 2_000_000_000;
+	pub const CreateAssetDeposit: u128 = 100_000_000_000;
+	pub const SendTokenExecutionFee: u128 = 1_000_000_000;
+	pub const InitialFund: u128 = 1_000_000_000_000;
+	pub const InboundQueuePalletInstance: u8 = 80;
+}
+
+#[cfg(feature = "runtime-benchmarks")]
+impl<T: snowbridge_ethereum_beacon_client::Config> BenchmarkHelper<T> for Test {
+	// not implemented since the MockVerifier is used for tests
+	fn initialize_storage(_: H256, _: CompactExecutionHeader) {}
+}
+
+// Mock XCM sender that always succeeds
+pub struct MockXcmSender;
+
+impl SendXcm for MockXcmSender {
+	type Ticket = Xcm<()>;
+
+	fn validate(
+		dest: &mut Option<MultiLocation>,
+		xcm: &mut Option<xcm::v3::Xcm<()>>,
+	) -> SendResult<Self::Ticket> {
+		match dest {
+			Some(MultiLocation { interior, .. }) => {
+				if let X1(Parachain(1001)) = interior {
+					return Err(XcmpSendError::NotApplicable)
+				}
+				Ok((xcm.clone().unwrap(), MultiAssets::default()))
+			},
+			_ => Ok((xcm.clone().unwrap(), MultiAssets::default())),
+		}
+	}
+
+	fn deliver(xcm: Self::Ticket) -> core::result::Result<XcmHash, XcmpSendError> {
+		let hash = xcm.using_encoded(sp_io::hashing::blake2_256);
+		Ok(hash)
+	}
+}
+
+parameter_types! {
+	pub const OwnParaId: ParaId = ParaId::new(1013);
+	pub Parameters: PricingParameters<u128> = PricingParameters {
+		exchange_rate: FixedU128::from_rational(1, 400),
+		fee_per_gas: gwei(20),
+		rewards: Rewards { local: DOT, remote: meth(1) }
+	};
+}
+
+pub const DOT: u128 = 10_000_000_000;
+
+pub struct MockChannelLookup;
+impl StaticLookup for MockChannelLookup {
+	type Source = ChannelId;
+	type Target = Channel;
+
+	fn lookup(channel_id: Self::Source) -> Option<Self::Target> {
+		if channel_id !=
+			hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539").into()
+		{
+			return None
+		}
+		Some(Channel { agent_id: H256::zero(), para_id: ASSET_HUB_PARAID.into() })
+	}
+}
+
+impl inbound_queue::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type Verifier = MockVerifier;
+	type Token = Balances;
+	type XcmSender = MockXcmSender;
+	type WeightInfo = ();
+	type GatewayAddress = GatewayAddress;
+	type MessageConverter = MessageToXcm<
+		CreateAssetCall,
+		CreateAssetDeposit,
+		InboundQueuePalletInstance,
+		AccountId,
+		Balance,
+	>;
+	type PricingParameters = Parameters;
+	type ChannelLookup = MockChannelLookup;
+	#[cfg(feature = "runtime-benchmarks")]
+	type Helper = Test;
+	type WeightToFee = IdentityFee<u128>;
+	type LengthToFee = IdentityFee<u128>;
+	type MaxMessageSize = ConstU32<1024>;
+}
+
+pub fn last_events(n: usize) -> Vec<RuntimeEvent> {
+	frame_system::Pallet::<Test>::events()
+		.into_iter()
+		.rev()
+		.take(n)
+		.rev()
+		.map(|e| e.event)
+		.collect()
+}
+
+pub fn expect_events(e: Vec<RuntimeEvent>) {
+	assert_eq!(last_events(e.len()), e);
+}
+
+pub fn setup() {
+	System::set_block_number(1);
+	Balances::mint_into(
+		&sibling_sovereign_account::<Test>(ASSET_HUB_PARAID.into()),
+		InitialFund::get(),
+	)
+	.unwrap();
+	Balances::mint_into(
+		&sibling_sovereign_account::<Test>(TEMPLATE_PARAID.into()),
+		InitialFund::get(),
+	)
+	.unwrap();
+}
+
+pub fn new_tester() -> sp_io::TestExternalities {
+	let storage = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+	let mut ext: sp_io::TestExternalities = storage.into();
+	ext.execute_with(setup);
+	ext
+}
+
+// Generated from smoketests:
+//   cd smoketests
+//   ./make-bindings
+//   cargo test --test register_token -- --nocapture
+pub fn mock_event_log() -> Log {
+	Log {
+        // gateway address
+        address: hex!("eda338e4dc46038493b885327842fd3e301cab39").into(),
+        topics: vec![
+            hex!("7153f9357c8ea496bba60bf82e67143e27b64462b49041f8e689e1b05728f84f").into(),
+            // channel id
+            hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539").into(),
+            // message id
+            hex!("5f7060e971b0dc81e63f0aa41831091847d97c1a4693ac450cc128c7214e65e0").into(),
+        ],
+        // Nonce + Payload
+        data: hex!("00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000002e000f000000000000000087d1f7fdfee7f651fabc8bfcb6e086c278b77a7d00e40b54020000000000000000000000000000000000000000000000000000000000").into(),
+    }
+}
+
+pub fn mock_event_log_invalid_channel() -> Log {
+	Log {
+        address: hex!("eda338e4dc46038493b885327842fd3e301cab39").into(),
+        topics: vec![
+            hex!("7153f9357c8ea496bba60bf82e67143e27b64462b49041f8e689e1b05728f84f").into(),
+            // invalid channel id
+            hex!("0000000000000000000000000000000000000000000000000000000000000000").into(),
+            hex!("5f7060e971b0dc81e63f0aa41831091847d97c1a4693ac450cc128c7214e65e0").into(),
+        ],
+        data: hex!("00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000001e000f000000000000000087d1f7fdfee7f651fabc8bfcb6e086c278b77a7d0000").into(),
+    }
+}
+
+pub fn mock_event_log_invalid_gateway() -> Log {
+	Log {
+        // gateway address
+        address: H160::zero(),
+        topics: vec![
+            hex!("7153f9357c8ea496bba60bf82e67143e27b64462b49041f8e689e1b05728f84f").into(),
+            // channel id
+            hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539").into(),
+            // message id
+            hex!("5f7060e971b0dc81e63f0aa41831091847d97c1a4693ac450cc128c7214e65e0").into(),
+        ],
+        // Nonce + Payload
+        data: hex!("00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000001e000f000000000000000087d1f7fdfee7f651fabc8bfcb6e086c278b77a7d0000").into(),
+    }
+}
+
+pub const ASSET_HUB_PARAID: u32 = 1000u32;
+pub const TEMPLATE_PARAID: u32 = 1001u32;

bridges/snowbridge/parachain/pallets/inbound-queue/src/test.rs

@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use frame_support::{assert_noop, assert_ok};
+use hex_literal::hex;
+use snowbridge_core::{inbound::Proof, ChannelId};
+use sp_keyring::AccountKeyring as Keyring;
+use sp_runtime::{DispatchError, TokenError};
+use sp_std::convert::From;
+
+use crate::{Error, Event as InboundQueueEvent};
+
+use crate::mock::*;
+
+#[test]
+fn test_submit_happy_path() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let channel_sovereign = sibling_sovereign_account::<Test>(ASSET_HUB_PARAID.into());
+
+		let origin = RuntimeOrigin::signed(relayer.clone());
+
+		// Submit message
+		let message = Message {
+			event_log: mock_event_log(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+
+		let initial_fund = InitialFund::get();
+		assert_eq!(Balances::balance(&relayer), 0);
+		assert_eq!(Balances::balance(&channel_sovereign), initial_fund);
+
+		assert_ok!(InboundQueue::submit(origin.clone(), message.clone()));
+		expect_events(vec![InboundQueueEvent::MessageReceived {
+			channel_id: hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539")
+				.into(),
+			nonce: 1,
+			message_id: [
+				27, 217, 88, 127, 46, 143, 199, 70, 236, 66, 212, 244, 85, 221, 153, 104, 175, 37,
+				224, 20, 140, 95, 140, 7, 27, 74, 182, 199, 77, 12, 194, 236,
+			],
+		}
+		.into()]);
+
+		let delivery_cost = InboundQueue::calculate_delivery_cost(message.encode().len() as u32);
+		assert!(
+			Parameters::get().rewards.local < delivery_cost,
+			"delivery cost exceeds pure reward"
+		);
+
+		assert_eq!(Balances::balance(&relayer), delivery_cost, "relayer was rewarded");
+		assert!(
+			Balances::balance(&channel_sovereign) <= initial_fund - delivery_cost,
+			"sovereign account paid reward"
+		);
+	});
+}
+
+#[test]
+fn test_submit_xcm_invalid_channel() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let origin = RuntimeOrigin::signed(relayer);
+
+		// Deposit funds into sovereign account of parachain 1001
+		let sovereign_account = sibling_sovereign_account::<Test>(TEMPLATE_PARAID.into());
+		println!("account: {}", sovereign_account);
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		// Submit message
+		let message = Message {
+			event_log: mock_event_log_invalid_channel(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+		assert_noop!(
+			InboundQueue::submit(origin.clone(), message.clone()),
+			Error::<Test>::InvalidChannel,
+		);
+	});
+}
+
+#[test]
+fn test_submit_with_invalid_gateway() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let origin = RuntimeOrigin::signed(relayer);
+
+		// Deposit funds into sovereign account of Asset Hub (Statemint)
+		let sovereign_account = sibling_sovereign_account::<Test>(ASSET_HUB_PARAID.into());
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		// Submit message
+		let message = Message {
+			event_log: mock_event_log_invalid_gateway(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+		assert_noop!(
+			InboundQueue::submit(origin.clone(), message.clone()),
+			Error::<Test>::InvalidGateway
+		);
+	});
+}
+
+#[test]
+fn test_submit_with_invalid_nonce() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let origin = RuntimeOrigin::signed(relayer);
+
+		// Deposit funds into sovereign account of Asset Hub (Statemint)
+		let sovereign_account = sibling_sovereign_account::<Test>(ASSET_HUB_PARAID.into());
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		// Submit message
+		let message = Message {
+			event_log: mock_event_log(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+		assert_ok!(InboundQueue::submit(origin.clone(), message.clone()));
+
+		let nonce: u64 = <Nonce<Test>>::get(ChannelId::from(hex!(
+			"c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539"
+		)));
+		assert_eq!(nonce, 1);
+
+		// Submit the same again
+		assert_noop!(
+			InboundQueue::submit(origin.clone(), message.clone()),
+			Error::<Test>::InvalidNonce
+		);
+	});
+}
+
+#[test]
+fn test_submit_no_funds_to_reward_relayers() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let origin = RuntimeOrigin::signed(relayer);
+
+		// Reset balance of sovereign_account to zero so to trigger the FundsUnavailable error
+		let sovereign_account = sibling_sovereign_account::<Test>(ASSET_HUB_PARAID.into());
+		Balances::set_balance(&sovereign_account, 0);
+
+		// Submit message
+		let message = Message {
+			event_log: mock_event_log(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+		assert_noop!(
+			InboundQueue::submit(origin.clone(), message.clone()),
+			TokenError::FundsUnavailable
+		);
+	});
+}
+
+#[test]
+fn test_set_operating_mode() {
+	new_tester().execute_with(|| {
+		let relayer: AccountId = Keyring::Bob.into();
+		let origin = RuntimeOrigin::signed(relayer);
+		let message = Message {
+			event_log: mock_event_log(),
+			proof: Proof {
+				block_hash: Default::default(),
+				tx_index: Default::default(),
+				data: Default::default(),
+			},
+		};
+
+		assert_ok!(InboundQueue::set_operating_mode(
+			RuntimeOrigin::root(),
+			snowbridge_core::BasicOperatingMode::Halted
+		));
+
+		assert_noop!(InboundQueue::submit(origin, message), Error::<Test>::Halted);
+	});
+}
+
+#[test]
+fn test_set_operating_mode_root_only() {
+	new_tester().execute_with(|| {
+		assert_noop!(
+			InboundQueue::set_operating_mode(
+				RuntimeOrigin::signed(Keyring::Bob.into()),
+				snowbridge_core::BasicOperatingMode::Halted
+			),
+			DispatchError::BadOrigin
+		);
+	});
+}

bridges/snowbridge/parachain/pallets/inbound-queue/src/weights.rs

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Autogenerated weights for `snowbridge_inbound_queue`
+//!
+//! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
+//! DATE: 2023-07-14, STEPS: `50`, REPEAT: `20`, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! WORST CASE MAP SIZE: `1000000`
+//! HOSTNAME: `macbook pro 14 m2`, CPU: `m2-arm64`
+//! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("bridge-hub-rococo-dev"), DB CACHE: 1024
+
+#![cfg_attr(rustfmt, rustfmt_skip)]
+#![allow(unused_parens)]
+#![allow(unused_imports)]
+
+use frame_support::{traits::Get, weights::{Weight, constants::RocksDbWeight}};
+use sp_std::marker::PhantomData;
+
+/// Weight functions needed for ethereum_beacon_client.
+pub trait WeightInfo {
+    fn submit() -> Weight;
+}
+
+// For backwards compatibility and tests
+impl WeightInfo for () {
+    fn submit() -> Weight {
+        Weight::from_parts(70_000_000, 0)
+            .saturating_add(Weight::from_parts(0, 3601))
+            .saturating_add(RocksDbWeight::get().reads(2))
+            .saturating_add(RocksDbWeight::get().writes(2))
+    }
+}

bridges/snowbridge/parachain/pallets/outbound-queue/Cargo.toml

@@ -0,0 +1,78 @@
+[package]
+name = "snowbridge-outbound-queue"
+description = "Snowbridge Outbound Queue"
+version = "0.1.1"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+serde = { version = "1.0.188", features = ["alloc", "derive"], default-features = false }
+codec = { version = "3.6.1", package = "parity-scale-codec", default-features = false, features = ["derive"] }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+hex-literal = { version = "0.4.1", optional = true }
+
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking", default-features = false, optional = true }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-arithmetic = { path = "../../../../../substrate/primitives/arithmetic", default-features = false }
+
+bridge-hub-common = { path = "../../../../../cumulus/parachains/runtimes/bridge-hubs/common", default-features = false }
+
+snowbridge-core = { path = "../../primitives/core", features = ["serde"], default-features = false }
+snowbridge-outbound-queue-merkle-tree = { path = "merkle-tree", default-features = false }
+ethabi = { git = "https://github.com/snowfork/ethabi-decode.git", package = "ethabi-decode", branch = "master", default-features = false }
+
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+
+[dev-dependencies]
+pallet-message-queue = { path = "../../../../../substrate/frame/message-queue", default-features = false }
+sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
+hex-literal = { version = "0.4.1" }
+
+[features]
+default = ["std"]
+std = [
+	"bridge-hub-common/std",
+	"codec/std",
+	"ethabi/std",
+	"frame-benchmarking/std",
+	"frame-support/std",
+	"frame-system/std",
+	"pallet-message-queue/std",
+	"scale-info/std",
+	"serde/std",
+	"snowbridge-core/std",
+	"snowbridge-outbound-queue-merkle-tree/std",
+	"sp-arithmetic/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"bridge-hub-common/runtime-benchmarks",
+	"frame-benchmarking",
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"hex-literal",
+	"pallet-message-queue/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-message-queue/try-runtime",
+	"sp-runtime/try-runtime",
+]

bridges/snowbridge/parachain/pallets/outbound-queue/merkle-tree/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "snowbridge-outbound-queue-merkle-tree"
+description = "Snowbridge Outbound Queue Merkle Tree"
+version = "0.1.1"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { version = "3.1.5", package = "parity-scale-codec", default-features = false, features = ["derive"] }
+scale-info = { version = "2.7.0", default-features = false, features = ["derive"] }
+
+sp-core = { path = "../../../../../../substrate/primitives/core", default-features = false }
+sp-runtime = { path = "../../../../../../substrate/primitives/runtime", default-features = false }
+
+[dev-dependencies]
+hex-literal = { version = "0.4.1" }
+env_logger = "0.9"
+hex = "0.4"
+array-bytes = "4.1"
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"scale-info/std",
+	"sp-core/std",
+	"sp-runtime/std",
+]

bridges/snowbridge/parachain/pallets/outbound-queue/merkle-tree/src/lib.rs

@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+// SPDX-FileCopyrightText: 2021-2022 Parity Technologies (UK) Ltd.
+#![cfg_attr(not(feature = "std"), no_std)]
+#![warn(missing_docs)]
+
+//! This crate implements a simple binary Merkle Tree utilities required for inter-op with Ethereum
+//! bridge & Solidity contract.
+//!
+//! The implementation is optimised for usage within Substrate Runtime and supports no-std
+//! compilation targets.
+//!
+//! Merkle Tree is constructed from arbitrary-length leaves, that are initially hashed using the
+//! same `\[`Hasher`\]` as the inner nodes.
+//! Inner nodes are created by concatenating child hashes and hashing again. The implementation
+//! does not perform any sorting of the input data (leaves) nor when inner nodes are created.
+//!
+//! If the number of leaves is not even, last leaf (hash of) is promoted to the upper layer.
+
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+#[cfg(not(feature = "std"))]
+use alloc::vec;
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
+use codec::{Decode, Encode};
+use scale_info::TypeInfo;
+use sp_core::{RuntimeDebug, H256};
+use sp_runtime::traits::Hash;
+
+/// Construct a root hash of a Binary Merkle Tree created from given leaves.
+///
+/// See crate-level docs for details about Merkle Tree construction.
+///
+/// In case an empty list of leaves is passed the function returns a 0-filled hash.
+pub fn merkle_root<H, I>(leaves: I) -> H256
+where
+	H: Hash<Output = H256>,
+	I: Iterator<Item = H256>,
+{
+	merkelize::<H, _, _>(leaves, &mut ())
+}
+
+fn merkelize<H, V, I>(leaves: I, visitor: &mut V) -> H256
+where
+	H: Hash<Output = H256>,
+	V: Visitor,
+	I: Iterator<Item = H256>,
+{
+	let upper = Vec::with_capacity(leaves.size_hint().0);
+	let mut next = match merkelize_row::<H, _, _>(leaves, upper, visitor) {
+		Ok(root) => return root,
+		Err(next) if next.is_empty() => return H256::default(),
+		Err(next) => next,
+	};
+
+	let mut upper = Vec::with_capacity((next.len() + 1) / 2);
+	loop {
+		visitor.move_up();
+
+		match merkelize_row::<H, _, _>(next.drain(..), upper, visitor) {
+			Ok(root) => return root,
+			Err(t) => {
+				// swap collections to avoid allocations
+				upper = next;
+				next = t;
+			},
+		};
+	}
+}
+
+/// A generated merkle proof.
+///
+/// The structure contains all necessary data to later on verify the proof and the leaf itself.
+#[derive(Encode, Decode, RuntimeDebug, PartialEq, Eq, TypeInfo)]
+pub struct MerkleProof {
+	/// Root hash of generated merkle tree.
+	pub root: H256,
+	/// Proof items (does not contain the leaf hash, nor the root obviously).
+	///
+	/// This vec contains all inner node hashes necessary to reconstruct the root hash given the
+	/// leaf hash.
+	pub proof: Vec<H256>,
+	/// Number of leaves in the original tree.
+	///
+	/// This is needed to detect a case where we have an odd number of leaves that "get promoted"
+	/// to upper layers.
+	pub number_of_leaves: u64,
+	/// Index of the leaf the proof is for (0-based).
+	pub leaf_index: u64,
+	/// Leaf content (hashed).
+	pub leaf: H256,
+}
+
+/// A trait of object inspecting merkle root creation.
+///
+/// It can be passed to [`merkelize_row`] or [`merkelize`] functions and will be notified
+/// about tree traversal.
+trait Visitor {
+	/// We are moving one level up in the tree.
+	fn move_up(&mut self);
+
+	/// We are creating an inner node from given `left` and `right` nodes.
+	///
+	/// Note that in case of last odd node in the row `right` might be empty.
+	/// The method will also visit the `root` hash (level 0).
+	///
+	/// The `index` is an index of `left` item.
+	fn visit(&mut self, index: u64, left: &Option<H256>, right: &Option<H256>);
+}
+
+/// No-op implementation of the visitor.
+impl Visitor for () {
+	fn move_up(&mut self) {}
+	fn visit(&mut self, _index: u64, _left: &Option<H256>, _right: &Option<H256>) {}
+}
+
+/// Construct a Merkle Proof for leaves given by indices.
+///
+/// The function constructs a (partial) Merkle Tree first and stores all elements required
+/// to prove the requested item (leaf) given the root hash.
+///
+/// Both the Proof and the Root Hash are returned.
+///
+/// # Panic
+///
+/// The function will panic if given `leaf_index` is greater than the number of leaves.
+pub fn merkle_proof<H, I>(leaves: I, leaf_index: u64) -> MerkleProof
+where
+	H: Hash<Output = H256>,
+	I: Iterator<Item = H256>,
+{
+	let mut leaf = None;
+	let mut hashes = vec![];
+	let mut number_of_leaves = 0;
+	for (idx, l) in (0u64..).zip(leaves) {
+		// count the leaves
+		number_of_leaves = idx + 1;
+		hashes.push(l);
+		// find the leaf for the proof
+		if idx == leaf_index {
+			leaf = Some(l);
+		}
+	}
+
+	/// The struct collects a proof for single leaf.
+	struct ProofCollection {
+		proof: Vec<H256>,
+		position: u64,
+	}
+
+	impl ProofCollection {
+		fn new(position: u64) -> Self {
+			ProofCollection { proof: Default::default(), position }
+		}
+	}
+
+	impl Visitor for ProofCollection {
+		fn move_up(&mut self) {
+			self.position /= 2;
+		}
+
+		fn visit(&mut self, index: u64, left: &Option<H256>, right: &Option<H256>) {
+			// we are at left branch - right goes to the proof.
+			if self.position == index {
+				if let Some(right) = right {
+					self.proof.push(*right);
+				}
+			}
+			// we are at right branch - left goes to the proof.
+			if self.position == index + 1 {
+				if let Some(left) = left {
+					self.proof.push(*left);
+				}
+			}
+		}
+	}
+
+	let mut collect_proof = ProofCollection::new(leaf_index);
+
+	let root = merkelize::<H, _, _>(hashes.into_iter(), &mut collect_proof);
+	let leaf = leaf.expect("Requested `leaf_index` is greater than number of leaves.");
+
+	#[cfg(feature = "debug")]
+	log::debug!(
+		"[merkle_proof] Proof: {:?}",
+		collect_proof.proof.iter().map(hex::encode).collect::<Vec<_>>()
+	);
+
+	MerkleProof { root, proof: collect_proof.proof, number_of_leaves, leaf_index, leaf }
+}
+
+/// Leaf node for proof verification.
+///
+/// Can be either a value that needs to be hashed first,
+/// or the hash itself.
+#[derive(Debug, PartialEq, Eq)]
+pub enum Leaf<'a> {
+	/// Leaf content.
+	Value(&'a [u8]),
+	/// Hash of the leaf content.
+	Hash(H256),
+}
+
+impl<'a, T: AsRef<[u8]>> From<&'a T> for Leaf<'a> {
+	fn from(v: &'a T) -> Self {
+		Leaf::Value(v.as_ref())
+	}
+}
+
+impl<'a> From<H256> for Leaf<'a> {
+	fn from(v: H256) -> Self {
+		Leaf::Hash(v)
+	}
+}
+
+/// Verify Merkle Proof correctness versus given root hash.
+///
+/// The proof is NOT expected to contain leaf hash as the first
+/// element, but only all adjacent nodes required to eventually by process of
+/// concatenating and hashing end up with given root hash.
+///
+/// The proof must not contain the root hash.
+pub fn verify_proof<'a, H, P, L>(
+	root: &'a H256,
+	proof: P,
+	number_of_leaves: u64,
+	leaf_index: u64,
+	leaf: L,
+) -> bool
+where
+	H: Hash<Output = H256>,
+	P: IntoIterator<Item = H256>,
+	L: Into<Leaf<'a>>,
+{
+	if leaf_index >= number_of_leaves {
+		return false
+	}
+
+	let leaf_hash = match leaf.into() {
+		Leaf::Value(content) => <H as Hash>::hash(content),
+		Leaf::Hash(hash) => hash,
+	};
+
+	let hash_len = <H as sp_core::Hasher>::LENGTH;
+	let mut combined = [0_u8; 64];
+	let computed = proof.into_iter().fold(leaf_hash, |a, b| {
+		if a < b {
+			combined[..hash_len].copy_from_slice(a.as_ref());
+			combined[hash_len..].copy_from_slice(b.as_ref());
+		} else {
+			combined[..hash_len].copy_from_slice(b.as_ref());
+			combined[hash_len..].copy_from_slice(a.as_ref());
+		}
+		<H as Hash>::hash(&combined)
+	});
+
+	root == &computed
+}
+
+/// Processes a single row (layer) of a tree by taking pairs of elements,
+/// concatenating them, hashing and placing into resulting vector.
+///
+/// In case only one element is provided it is returned via `Ok` result, in any other case (also an
+/// empty iterator) an `Err` with the inner nodes of upper layer is returned.
+fn merkelize_row<H, V, I>(
+	mut iter: I,
+	mut next: Vec<H256>,
+	visitor: &mut V,
+) -> Result<H256, Vec<H256>>
+where
+	H: Hash<Output = H256>,
+	V: Visitor,
+	I: Iterator<Item = H256>,
+{
+	#[cfg(feature = "debug")]
+	log::debug!("[merkelize_row]");
+	next.clear();
+
+	let hash_len = <H as sp_core::Hasher>::LENGTH;
+	let mut index = 0;
+	let mut combined = vec![0_u8; hash_len * 2];
+	loop {
+		let a = iter.next();
+		let b = iter.next();
+		visitor.visit(index, &a, &b);
+
+		#[cfg(feature = "debug")]
+		log::debug!("  {:?}\n  {:?}", a.as_ref().map(hex::encode), b.as_ref().map(hex::encode));
+
+		index += 2;
+		match (a, b) {
+			(Some(a), Some(b)) => {
+				if a < b {
+					combined[..hash_len].copy_from_slice(a.as_ref());
+					combined[hash_len..].copy_from_slice(b.as_ref());
+				} else {
+					combined[..hash_len].copy_from_slice(b.as_ref());
+					combined[hash_len..].copy_from_slice(a.as_ref());
+				}
+
+				next.push(<H as Hash>::hash(&combined));
+			},
+			// Odd number of items. Promote the item to the upper layer.
+			(Some(a), None) if !next.is_empty() => {
+				next.push(a);
+			},
+			// Last item = root.
+			(Some(a), None) => return Ok(a),
+			// Finish up, no more items.
+			_ => {
+				#[cfg(feature = "debug")]
+				log::debug!(
+					"[merkelize_row] Next: {:?}",
+					next.iter().map(hex::encode).collect::<Vec<_>>()
+				);
+				return Err(next)
+			},
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use hex_literal::hex;
+	use sp_core::keccak_256;
+	use sp_runtime::traits::Keccak256;
+
+	fn make_leaves(count: u64) -> Vec<H256> {
+		(0..count).map(|i| keccak_256(&i.to_le_bytes()).into()).collect()
+	}
+
+	#[test]
+	fn should_generate_empty_root() {
+		// given
+		let _ = env_logger::try_init();
+		let data = vec![];
+
+		// when
+		let out = merkle_root::<Keccak256, _>(data.into_iter());
+
+		// then
+		assert_eq!(
+			hex::encode(out),
+			"0000000000000000000000000000000000000000000000000000000000000000"
+		);
+	}
+
+	#[test]
+	fn should_generate_single_root() {
+		// given
+		let _ = env_logger::try_init();
+		let data = make_leaves(1);
+
+		// when
+		let out = merkle_root::<Keccak256, _>(data.into_iter());
+
+		// then
+		assert_eq!(
+			hex::encode(out),
+			"011b4d03dd8c01f1049143cf9c4c817e4b167f1d1b83e5c6f0f10d89ba1e7bce"
+		);
+	}
+
+	#[test]
+	fn should_generate_root_pow_2() {
+		// given
+		let _ = env_logger::try_init();
+		let data = make_leaves(2);
+
+		// when
+		let out = merkle_root::<Keccak256, _>(data.into_iter());
+
+		// then
+		assert_eq!(
+			hex::encode(out),
+			"e497bd1c13b13a60af56fa0d2703517c232fde213ad20d2c3dd60735c6604512"
+		);
+	}
+
+	#[test]
+	fn should_generate_root_complex() {
+		let _ = env_logger::try_init();
+		let test = |root, data: Vec<H256>| {
+			assert_eq!(
+				array_bytes::bytes2hex("", merkle_root::<Keccak256, _>(data.into_iter()).as_ref()),
+				root
+			);
+		};
+
+		test("816cc37bd8d39f7b0851838ebc875faf2afe58a03e95aca3b1333b3693f39dd3", make_leaves(3));
+
+		test("7501ea976cb92f305cca65ab11254589ea28bb8b59d3161506350adaa237d22f", make_leaves(4));
+
+		test("d26ba4eb398747bdd39255b1fadb99b803ce39696021b3b0bff7301ac146ee4e", make_leaves(10));
+	}
+
+	#[test]
+	#[ignore]
+	fn should_generate_and_verify_proof() {
+		// given
+		let _ = env_logger::try_init();
+		let data: Vec<H256> = make_leaves(3);
+
+		// when
+		let proof0 = merkle_proof::<Keccak256, _>(data.clone().into_iter(), 0);
+		assert!(verify_proof::<Keccak256, _, _>(
+			&proof0.root,
+			proof0.proof.clone(),
+			data.len() as u64,
+			proof0.leaf_index,
+			&data[0],
+		));
+
+		let proof1 = merkle_proof::<Keccak256, _>(data.clone().into_iter(), 1);
+		assert!(verify_proof::<Keccak256, _, _>(
+			&proof1.root,
+			proof1.proof,
+			data.len() as u64,
+			proof1.leaf_index,
+			&proof1.leaf,
+		));
+
+		let proof2 = merkle_proof::<Keccak256, _>(data.clone().into_iter(), 2);
+		assert!(verify_proof::<Keccak256, _, _>(
+			&proof2.root,
+			proof2.proof,
+			data.len() as u64,
+			proof2.leaf_index,
+			&proof2.leaf
+		));
+
+		// then
+		assert_eq!(hex::encode(proof0.root), hex::encode(proof1.root));
+		assert_eq!(hex::encode(proof2.root), hex::encode(proof1.root));
+
+		assert!(!verify_proof::<Keccak256, _, _>(
+			&H256::from_slice(&hex!(
+				"fb3b3be94be9e983ba5e094c9c51a7d96a4fa2e5d8e891df00ca89ba05bb1239"
+			)),
+			proof0.proof,
+			data.len() as u64,
+			proof0.leaf_index,
+			&proof0.leaf
+		));
+
+		assert!(!verify_proof::<Keccak256, _, _>(
+			&proof0.root,
+			vec![],
+			data.len() as u64,
+			proof0.leaf_index,
+			&proof0.leaf
+		));
+	}
+
+	#[test]
+	#[should_panic]
+	fn should_panic_on_invalid_leaf_index() {
+		let _ = env_logger::try_init();
+		merkle_proof::<Keccak256, _>(make_leaves(1).into_iter(), 5);
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/runtime-api/Cargo.toml

@@ -0,0 +1,34 @@
+[package]
+name = "snowbridge-outbound-queue-runtime-api"
+description = "Snowbridge Outbound Queue Runtime API"
+version = "0.1.0"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { version = "3.1.5", package = "parity-scale-codec", features = ["derive"], default-features = false }
+sp-core = { path = "../../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../../substrate/primitives/std", default-features = false }
+sp-api = { path = "../../../../../../substrate/primitives/api", default-features = false }
+frame-support = { path = "../../../../../../substrate/frame/support", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../../polkadot/xcm", default-features = false }
+snowbridge-outbound-queue-merkle-tree = { path = "../merkle-tree", default-features = false }
+snowbridge-core = { path = "../../../primitives/core", default-features = false }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"frame-support/std",
+	"snowbridge-core/std",
+	"snowbridge-outbound-queue-merkle-tree/std",
+	"sp-api/std",
+	"sp-core/std",
+	"sp-std/std",
+	"xcm/std",
+]

bridges/snowbridge/parachain/pallets/outbound-queue/runtime-api/src/lib.rs

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use frame_support::traits::tokens::Balance as BalanceT;
+use snowbridge_core::outbound::Message;
+use snowbridge_outbound_queue_merkle_tree::MerkleProof;
+
+sp_api::decl_runtime_apis! {
+	pub trait OutboundQueueApi<Balance> where Balance: BalanceT
+	{
+		/// Generate a merkle proof for a committed message identified by `leaf_index`.
+		/// The merkle root is stored in the block header as a
+		/// `\[`sp_runtime::generic::DigestItem::Other`\]`
+		fn prove_message(leaf_index: u64) -> Option<MerkleProof>;
+
+		/// Calculate the delivery fee for `message`
+		fn calculate_fee(message: Message) -> Option<Balance>;
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/api.rs

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Helpers for implementing runtime api
+
+use crate::{Config, MessageLeaves};
+use frame_support::storage::StorageStreamIter;
+use snowbridge_core::outbound::{Message, SendMessage};
+use snowbridge_outbound_queue_merkle_tree::{merkle_proof, MerkleProof};
+
+pub fn prove_message<T>(leaf_index: u64) -> Option<MerkleProof>
+where
+	T: Config,
+{
+	if !MessageLeaves::<T>::exists() {
+		return None
+	}
+	let proof =
+		merkle_proof::<<T as Config>::Hashing, _>(MessageLeaves::<T>::stream_iter(), leaf_index);
+	Some(proof)
+}
+
+pub fn calculate_fee<T>(message: Message) -> Option<T::Balance>
+where
+	T: Config,
+{
+	match crate::Pallet::<T>::validate(&message) {
+		Ok((_, fees)) => Some(fees.total()),
+		_ => None,
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/benchmarking.rs

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use bridge_hub_common::AggregateMessageOrigin;
+use codec::Encode;
+use frame_benchmarking::v2::*;
+use snowbridge_core::{
+	outbound::{Command, Initializer},
+	ChannelId,
+};
+use sp_core::{H160, H256};
+
+#[allow(unused_imports)]
+use crate::Pallet as OutboundQueue;
+
+#[benchmarks(
+	where
+		<T as Config>::MaxMessagePayloadSize: Get<u32>,
+)]
+mod benchmarks {
+	use super::*;
+
+	/// Benchmark for processing a message.
+	#[benchmark]
+	fn do_process_message() -> Result<(), BenchmarkError> {
+		let enqueued_message = QueuedMessage {
+			id: H256::zero(),
+			channel_id: ChannelId::from([1; 32]),
+			command: Command::Upgrade {
+				impl_address: H160::zero(),
+				impl_code_hash: H256::zero(),
+				initializer: Some(Initializer {
+					params: [7u8; 256].into_iter().collect(),
+					maximum_required_gas: 200_000,
+				}),
+			},
+		};
+		let origin = AggregateMessageOrigin::Snowbridge([1; 32].into());
+		let encoded_enqueued_message = enqueued_message.encode();
+
+		#[block]
+		{
+			let _ = OutboundQueue::<T>::do_process_message(origin, &encoded_enqueued_message);
+		}
+
+		assert_eq!(MessageLeaves::<T>::decode_len().unwrap(), 1);
+
+		Ok(())
+	}
+
+	/// Benchmark for producing final messages commitment
+	#[benchmark]
+	fn commit() -> Result<(), BenchmarkError> {
+		// Assume worst case, where `MaxMessagesPerBlock` messages need to be committed.
+		for i in 0..T::MaxMessagesPerBlock::get() {
+			let leaf_data: [u8; 1] = [i as u8];
+			let leaf = <T as Config>::Hashing::hash(&leaf_data);
+			MessageLeaves::<T>::append(leaf);
+		}
+
+		#[block]
+		{
+			OutboundQueue::<T>::commit();
+		}
+
+		Ok(())
+	}
+
+	/// Benchmark for producing commitment for a single message
+	#[benchmark]
+	fn commit_single() -> Result<(), BenchmarkError> {
+		let leaf = <T as Config>::Hashing::hash(&[100; 1]);
+		MessageLeaves::<T>::append(leaf);
+
+		#[block]
+		{
+			OutboundQueue::<T>::commit();
+		}
+
+		Ok(())
+	}
+
+	impl_benchmark_test_suite!(OutboundQueue, crate::mock::new_tester(), crate::mock::Test,);
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/lib.rs

@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Pallet for committing outbound messages for delivery to Ethereum
+//!
+//! # Overview
+//!
+//! Messages come either from sibling parachains via XCM, or BridgeHub itself
+//! via the `snowbridge-system` pallet:
+//!
+//! 1. `snowbridge_router_primitives::outbound::EthereumBlobExporter::deliver`
+//! 2. `snowbridge_system::Pallet::send`
+//!
+//! The message submission pipeline works like this:
+//! 1. The message is first validated via the implementation for
+//!    [`snowbridge_core::outbound::SendMessage::validate`]
+//! 2. The message is then enqueued for later processing via the implementation for
+//!    [`snowbridge_core::outbound::SendMessage::deliver`]
+//! 3. The underlying message queue is implemented by [`Config::MessageQueue`]
+//! 4. The message queue delivers messages back to this pallet via the implementation for
+//!    [`frame_support::traits::ProcessMessage::process_message`]
+//! 5. The message is processed in `Pallet::do_process_message`: a. Assigned a nonce b. ABI-encoded,
+//!    hashed, and stored in the `MessageLeaves` vector
+//! 6. At the end of the block, a merkle root is constructed from all the leaves in `MessageLeaves`.
+//! 7. This merkle root is inserted into the parachain header as a digest item
+//! 8. Offchain relayers are able to relay the message to Ethereum after: a. Generating a merkle
+//!    proof for the committed message using the `prove_message` runtime API b. Reading the actual
+//!    message content from the `Messages` vector in storage
+//!
+//! On the Ethereum side, the message root is ultimately the thing being
+//! verified by the Polkadot light client.
+//!
+//! # Message Priorities
+//!
+//! The processing of governance commands can never be halted. This effectively
+//! allows us to pause processing of normal user messages while still allowing
+//! governance commands to be sent to Ethereum.
+//!
+//! # Fees
+//!
+//! An upfront fee must be paid for delivering a message. This fee covers several
+//! components:
+//! 1. The weight of processing the message locally
+//! 2. The gas refund paid out to relayers for message submission
+//! 3. An additional reward paid out to relayers for message submission
+//!
+//! Messages are weighed to determine the maximum amount of gas they could
+//! consume on Ethereum. Using this upper bound, a final fee can be calculated.
+//!
+//! The fee calculation also requires the following parameters:
+//! * ETH/DOT exchange rate
+//! * Ether fee per unit of gas
+//!
+//! By design, it is expected that governance should manually update these
+//! parameters every few weeks using the `set_pricing_parameters` extrinsic in the
+//! system pallet.
+//!
+//! ## Fee Computation Function
+//!
+//! ```text
+//! LocalFee(Message) = WeightToFee(ProcessMessageWeight(Message))
+//! RemoteFee(Message) = MaxGasRequired(Message) * FeePerGas + Reward
+//! Fee(Message) = LocalFee(Message) + (RemoteFee(Message) / Ratio("ETH/DOT"))
+//! ```
+//!
+//! By design, the computed fee is always going to conservative, to cover worst-case
+//! costs of dispatch on Ethereum. In future iterations of the design, we will optimize
+//! this, or provide a mechanism to asynchronously refund a portion of collected fees.
+//!
+//! # Extrinsics
+//!
+//! * [`Call::set_operating_mode`]: Set the operating mode
+//!
+//! # Runtime API
+//!
+//! * `prove_message`: Generate a merkle proof for a committed message
+//! * `calculate_fee`: Calculate the delivery fee for a message
+#![cfg_attr(not(feature = "std"), no_std)]
+pub mod api;
+pub mod process_message_impl;
+pub mod send_message_impl;
+pub mod types;
+pub mod weights;
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+
+#[cfg(test)]
+mod mock;
+
+#[cfg(test)]
+mod test;
+
+use bridge_hub_common::{AggregateMessageOrigin, CustomDigestItem};
+use codec::Decode;
+use frame_support::{
+	storage::StorageStreamIter,
+	traits::{tokens::Balance, Contains, Defensive, EnqueueMessage, Get, ProcessMessageError},
+	weights::{Weight, WeightToFee},
+};
+use snowbridge_core::{
+	outbound::{Fee, GasMeter, QueuedMessage, VersionedQueuedMessage, ETHER_DECIMALS},
+	BasicOperatingMode, ChannelId,
+};
+use snowbridge_outbound_queue_merkle_tree::merkle_root;
+pub use snowbridge_outbound_queue_merkle_tree::MerkleProof;
+use sp_core::{H256, U256};
+use sp_runtime::{
+	traits::{CheckedDiv, Hash},
+	DigestItem,
+};
+use sp_std::prelude::*;
+pub use types::{CommittedMessage, FeeConfigRecord, ProcessMessageOriginOf};
+pub use weights::WeightInfo;
+
+pub use pallet::*;
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+	use snowbridge_core::PricingParameters;
+	use sp_arithmetic::FixedU128;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		type Hashing: Hash<Output = H256>;
+
+		type MessageQueue: EnqueueMessage<AggregateMessageOrigin>;
+
+		/// Measures the maximum gas used to execute a command on Ethereum
+		type GasMeter: GasMeter;
+
+		type Balance: Balance + From<u128>;
+
+		/// Number of decimal places in native currency
+		#[pallet::constant]
+		type Decimals: Get<u8>;
+
+		/// Max bytes in a message payload
+		#[pallet::constant]
+		type MaxMessagePayloadSize: Get<u32>;
+
+		/// Max number of messages processed per block
+		#[pallet::constant]
+		type MaxMessagesPerBlock: Get<u32>;
+
+		/// Check whether a channel exists
+		type Channels: Contains<ChannelId>;
+
+		type PricingParameters: Get<PricingParameters<Self::Balance>>;
+
+		/// Convert a weight value into a deductible fee based.
+		type WeightToFee: WeightToFee<Balance = Self::Balance>;
+
+		/// Weight information for extrinsics in this pallet
+		type WeightInfo: WeightInfo;
+	}
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		/// Message has been queued and will be processed in the future
+		MessageQueued {
+			/// ID of the message. Usually the XCM message hash or a SetTopic.
+			id: H256,
+		},
+		/// Message will be committed at the end of current block. From now on, to track the
+		/// progress the message, use the `nonce` of `id`.
+		MessageAccepted {
+			/// ID of the message
+			id: H256,
+			/// The nonce assigned to this message
+			nonce: u64,
+		},
+		/// Some messages have been committed
+		MessagesCommitted {
+			/// Merkle root of the committed messages
+			root: H256,
+			/// number of committed messages
+			count: u64,
+		},
+		/// Set OperatingMode
+		OperatingModeChanged {
+			mode: BasicOperatingMode,
+		},
+		FeeConfigChanged {
+			fee_config: FeeConfigRecord,
+		},
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		/// The message is too large
+		MessageTooLarge,
+		/// The pallet is halted
+		Halted,
+		// Invalid fee config
+		InvalidFeeConfig,
+		/// Invalid Channel
+		InvalidChannel,
+	}
+
+	/// Messages to be committed in the current block. This storage value is killed in
+	/// `on_initialize`, so should never go into block PoV.
+	///
+	/// Is never read in the runtime, only by offchain message relayers.
+	///
+	/// Inspired by the `frame_system::Pallet::Events` storage value
+	#[pallet::storage]
+	#[pallet::unbounded]
+	pub(super) type Messages<T: Config> = StorageValue<_, Vec<CommittedMessage>, ValueQuery>;
+
+	/// Hashes of the ABI-encoded messages in the [`Messages`] storage value. Used to generate a
+	/// merkle root during `on_finalize`. This storage value is killed in
+	/// `on_initialize`, so should never go into block PoV.
+	#[pallet::storage]
+	#[pallet::unbounded]
+	#[pallet::getter(fn message_leaves)]
+	pub(super) type MessageLeaves<T: Config> = StorageValue<_, Vec<H256>, ValueQuery>;
+
+	/// The current nonce for each message origin
+	#[pallet::storage]
+	pub type Nonce<T: Config> = StorageMap<_, Twox64Concat, ChannelId, u64, ValueQuery>;
+
+	/// The current operating mode of the pallet.
+	#[pallet::storage]
+	#[pallet::getter(fn operating_mode)]
+	pub type OperatingMode<T: Config> = StorageValue<_, BasicOperatingMode, ValueQuery>;
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T>
+	where
+		T::AccountId: AsRef<[u8]>,
+	{
+		fn on_initialize(_: BlockNumberFor<T>) -> Weight {
+			// Remove storage from previous block
+			Messages::<T>::kill();
+			MessageLeaves::<T>::kill();
+			// Reserve some weight for the `on_finalize` handler
+			T::WeightInfo::commit()
+		}
+
+		fn on_finalize(_: BlockNumberFor<T>) {
+			Self::commit();
+		}
+
+		fn integrity_test() {
+			let decimals = T::Decimals::get();
+			assert!(decimals == 10 || decimals == 12, "Decimals should be 10 or 12");
+		}
+	}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		/// Halt or resume all pallet operations. May only be called by root.
+		#[pallet::call_index(0)]
+		#[pallet::weight((T::DbWeight::get().reads_writes(1, 1), DispatchClass::Operational))]
+		pub fn set_operating_mode(
+			origin: OriginFor<T>,
+			mode: BasicOperatingMode,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			OperatingMode::<T>::put(mode);
+			Self::deposit_event(Event::OperatingModeChanged { mode });
+			Ok(())
+		}
+	}
+
+	impl<T: Config> Pallet<T> {
+		/// Generate a messages commitment and insert it into the header digest
+		pub(crate) fn commit() {
+			let count = MessageLeaves::<T>::decode_len().unwrap_or_default() as u64;
+			if count == 0 {
+				return
+			}
+
+			// Create merkle root of messages
+			let root = merkle_root::<<T as Config>::Hashing, _>(MessageLeaves::<T>::stream_iter());
+
+			let digest_item: DigestItem = CustomDigestItem::Snowbridge(root).into();
+
+			// Insert merkle root into the header digest
+			<frame_system::Pallet<T>>::deposit_log(digest_item);
+
+			Self::deposit_event(Event::MessagesCommitted { root, count });
+		}
+
+		/// Process a message delivered by the MessageQueue pallet
+		pub(crate) fn do_process_message(
+			_: ProcessMessageOriginOf<T>,
+			mut message: &[u8],
+		) -> Result<bool, ProcessMessageError> {
+			use ProcessMessageError::*;
+
+			// Yield if the maximum number of messages has been processed this block.
+			// This ensures that the weight of `on_finalize` has a known maximum bound.
+			ensure!(
+				MessageLeaves::<T>::decode_len().unwrap_or(0) <
+					T::MaxMessagesPerBlock::get() as usize,
+				Yield
+			);
+
+			// Decode bytes into versioned message
+			let versioned_queued_message: VersionedQueuedMessage =
+				VersionedQueuedMessage::decode(&mut message).map_err(|_| Corrupt)?;
+
+			// Convert versioned message into latest supported message version
+			let queued_message: QueuedMessage =
+				versioned_queued_message.try_into().map_err(|_| Unsupported)?;
+
+			// Obtain next nonce
+			let nonce = <Nonce<T>>::try_mutate(
+				queued_message.channel_id,
+				|nonce| -> Result<u64, ProcessMessageError> {
+					*nonce = nonce.checked_add(1).ok_or(Unsupported)?;
+					Ok(*nonce)
+				},
+			)?;
+
+			let pricing_params = T::PricingParameters::get();
+			let command = queued_message.command.index();
+			let params = queued_message.command.abi_encode();
+			let max_dispatch_gas =
+				T::GasMeter::maximum_dispatch_gas_used_at_most(&queued_message.command);
+			let reward = pricing_params.rewards.remote;
+
+			// Construct the final committed message
+			let message = CommittedMessage {
+				channel_id: queued_message.channel_id,
+				nonce,
+				command,
+				params,
+				max_dispatch_gas,
+				max_fee_per_gas: pricing_params
+					.fee_per_gas
+					.try_into()
+					.defensive_unwrap_or(u128::MAX),
+				reward: reward.try_into().defensive_unwrap_or(u128::MAX),
+				id: queued_message.id,
+			};
+
+			// ABI-encode and hash the prepared message
+			let message_abi_encoded = ethabi::encode(&[message.clone().into()]);
+			let message_abi_encoded_hash = <T as Config>::Hashing::hash(&message_abi_encoded);
+
+			Messages::<T>::append(Box::new(message));
+			MessageLeaves::<T>::append(message_abi_encoded_hash);
+
+			Self::deposit_event(Event::MessageAccepted { id: queued_message.id, nonce });
+
+			Ok(true)
+		}
+
+		/// Calculate total fee in native currency to cover all costs of delivering a message to the
+		/// remote destination. See module-level documentation for more details.
+		pub(crate) fn calculate_fee(
+			gas_used_at_most: u64,
+			params: PricingParameters<T::Balance>,
+		) -> Fee<T::Balance> {
+			// Remote fee in ether
+			let fee = Self::calculate_remote_fee(
+				gas_used_at_most,
+				params.fee_per_gas,
+				params.rewards.remote,
+			);
+
+			// downcast to u128
+			let fee: u128 = fee.try_into().defensive_unwrap_or(u128::MAX);
+
+			// convert to local currency
+			let fee = FixedU128::from_inner(fee)
+				.checked_div(&params.exchange_rate)
+				.expect("exchange rate is not zero; qed")
+				.into_inner();
+
+			// adjust fixed point to match local currency
+			let fee = Self::convert_from_ether_decimals(fee);
+
+			Fee::from((Self::calculate_local_fee(), fee))
+		}
+
+		/// Calculate fee in remote currency for dispatching a message on Ethereum
+		pub(crate) fn calculate_remote_fee(
+			gas_used_at_most: u64,
+			fee_per_gas: U256,
+			reward: U256,
+		) -> U256 {
+			fee_per_gas.saturating_mul(gas_used_at_most.into()).saturating_add(reward)
+		}
+
+		/// The local component of the message processing fees in native currency
+		pub(crate) fn calculate_local_fee() -> T::Balance {
+			T::WeightToFee::weight_to_fee(
+				&T::WeightInfo::do_process_message().saturating_add(T::WeightInfo::commit_single()),
+			)
+		}
+
+		// 1 DOT has 10 digits of precision
+		// 1 KSM has 12 digits of precision
+		// 1 ETH has 18 digits of precision
+		pub(crate) fn convert_from_ether_decimals(value: u128) -> T::Balance {
+			let decimals = ETHER_DECIMALS.saturating_sub(T::Decimals::get()) as u32;
+			let denom = 10u128.saturating_pow(decimals);
+			value.checked_div(denom).expect("divisor is non-zero; qed").into()
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/mock.rs

@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use frame_support::{
+	parameter_types,
+	traits::{Everything, Hooks},
+	weights::IdentityFee,
+};
+
+use snowbridge_core::{
+	gwei, meth,
+	outbound::*,
+	pricing::{PricingParameters, Rewards},
+	ParaId, PRIMARY_GOVERNANCE_CHANNEL,
+};
+use sp_core::{ConstU32, ConstU8, H160, H256};
+use sp_runtime::{
+	traits::{BlakeTwo256, IdentityLookup, Keccak256},
+	AccountId32, BuildStorage, FixedU128,
+};
+use sp_std::marker::PhantomData;
+
+type Block = frame_system::mocking::MockBlock<Test>;
+type AccountId = AccountId32;
+
+frame_support::construct_runtime!(
+	pub enum Test
+	{
+		System: frame_system::{Pallet, Call, Storage, Event<T>},
+		MessageQueue: pallet_message_queue::{Pallet, Call, Storage, Event<T>},
+		OutboundQueue: crate::{Pallet, Storage, Event<T>},
+	}
+);
+
+parameter_types! {
+	pub const BlockHashCount: u64 = 250;
+}
+
+impl frame_system::Config for Test {
+	type BaseCallFilter = Everything;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type RuntimeOrigin = RuntimeOrigin;
+	type RuntimeCall = RuntimeCall;
+	type RuntimeTask = RuntimeTask;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type RuntimeEvent = RuntimeEvent;
+	type BlockHashCount = BlockHashCount;
+	type DbWeight = ();
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+	type Nonce = u64;
+	type Block = Block;
+}
+
+parameter_types! {
+	pub const HeapSize: u32 = 32 * 1024;
+	pub const MaxStale: u32 = 32;
+	pub static ServiceWeight: Option<Weight> = Some(Weight::from_parts(100, 100));
+}
+
+impl pallet_message_queue::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type WeightInfo = ();
+	type MessageProcessor = OutboundQueue;
+	type Size = u32;
+	type QueueChangeHandler = ();
+	type HeapSize = HeapSize;
+	type MaxStale = MaxStale;
+	type ServiceWeight = ServiceWeight;
+	type QueuePausedQuery = ();
+}
+
+parameter_types! {
+	pub const OwnParaId: ParaId = ParaId::new(1013);
+	pub Parameters: PricingParameters<u128> = PricingParameters {
+		exchange_rate: FixedU128::from_rational(1, 400),
+		fee_per_gas: gwei(20),
+		rewards: Rewards { local: DOT, remote: meth(1) }
+	};
+}
+
+pub const DOT: u128 = 10_000_000_000;
+
+impl crate::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type Hashing = Keccak256;
+	type MessageQueue = MessageQueue;
+	type Decimals = ConstU8<12>;
+	type MaxMessagePayloadSize = ConstU32<1024>;
+	type MaxMessagesPerBlock = ConstU32<20>;
+	type GasMeter = ConstantGasMeter;
+	type Balance = u128;
+	type PricingParameters = Parameters;
+	type Channels = Everything;
+	type WeightToFee = IdentityFee<u128>;
+	type WeightInfo = ();
+}
+
+fn setup() {
+	System::set_block_number(1);
+}
+
+pub fn new_tester() -> sp_io::TestExternalities {
+	let storage = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+	let mut ext: sp_io::TestExternalities = storage.into();
+	ext.execute_with(setup);
+	ext
+}
+
+pub fn run_to_end_of_next_block() {
+	// finish current block
+	MessageQueue::on_finalize(System::block_number());
+	OutboundQueue::on_finalize(System::block_number());
+	System::on_finalize(System::block_number());
+	// start next block
+	System::set_block_number(System::block_number() + 1);
+	System::on_initialize(System::block_number());
+	OutboundQueue::on_initialize(System::block_number());
+	MessageQueue::on_initialize(System::block_number());
+	// finish next block
+	MessageQueue::on_finalize(System::block_number());
+	OutboundQueue::on_finalize(System::block_number());
+	System::on_finalize(System::block_number());
+}
+
+pub fn mock_governance_message<T>() -> Message
+where
+	T: Config,
+{
+	let _marker = PhantomData::<T>; // for clippy
+
+	Message {
+		id: None,
+		channel_id: PRIMARY_GOVERNANCE_CHANNEL,
+		command: Command::Upgrade {
+			impl_address: H160::zero(),
+			impl_code_hash: H256::zero(),
+			initializer: None,
+		},
+	}
+}
+
+// Message should fail validation as it is too large
+pub fn mock_invalid_governance_message<T>() -> Message
+where
+	T: Config,
+{
+	let _marker = PhantomData::<T>; // for clippy
+
+	Message {
+		id: None,
+		channel_id: PRIMARY_GOVERNANCE_CHANNEL,
+		command: Command::Upgrade {
+			impl_address: H160::zero(),
+			impl_code_hash: H256::zero(),
+			initializer: Some(Initializer {
+				params: (0..1000).map(|_| 1u8).collect::<Vec<u8>>(),
+				maximum_required_gas: 0,
+			}),
+		},
+	}
+}
+
+pub fn mock_message(sibling_para_id: u32) -> Message {
+	Message {
+		id: None,
+		channel_id: ParaId::from(sibling_para_id).into(),
+		command: Command::AgentExecute {
+			agent_id: Default::default(),
+			command: AgentExecuteCommand::TransferToken {
+				token: Default::default(),
+				recipient: Default::default(),
+				amount: 0,
+			},
+		},
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/process_message_impl.rs

@@ -0,0 +1,23 @@
+//! Implementation for [`frame_support::traits::ProcessMessage`]
+use super::*;
+use crate::weights::WeightInfo;
+use frame_support::{
+	traits::{ProcessMessage, ProcessMessageError},
+	weights::WeightMeter,
+};
+
+impl<T: Config> ProcessMessage for Pallet<T> {
+	type Origin = AggregateMessageOrigin;
+	fn process_message(
+		message: &[u8],
+		origin: Self::Origin,
+		meter: &mut WeightMeter,
+		_: &mut [u8; 32],
+	) -> Result<bool, ProcessMessageError> {
+		let weight = T::WeightInfo::do_process_message();
+		if meter.try_consume(weight).is_err() {
+			return Err(ProcessMessageError::Overweight(weight))
+		}
+		Self::do_process_message(origin, message)
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/send_message_impl.rs

@@ -0,0 +1,98 @@
+//! Implementation for [`snowbridge_core::outbound::SendMessage`]
+use super::*;
+use bridge_hub_common::AggregateMessageOrigin;
+use codec::Encode;
+use frame_support::{
+	ensure,
+	traits::{EnqueueMessage, Get},
+	CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound,
+};
+use frame_system::unique;
+use snowbridge_core::{
+	outbound::{
+		Fee, Message, QueuedMessage, SendError, SendMessage, SendMessageFeeProvider,
+		VersionedQueuedMessage,
+	},
+	ChannelId, PRIMARY_GOVERNANCE_CHANNEL,
+};
+use sp_core::H256;
+use sp_runtime::BoundedVec;
+
+/// The maximal length of an enqueued message, as determined by the MessageQueue pallet
+pub type MaxEnqueuedMessageSizeOf<T> =
+	<<T as Config>::MessageQueue as EnqueueMessage<AggregateMessageOrigin>>::MaxMessageLen;
+
+#[derive(Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound)]
+pub struct Ticket<T>
+where
+	T: Config,
+{
+	pub message_id: H256,
+	pub channel_id: ChannelId,
+	pub message: BoundedVec<u8, MaxEnqueuedMessageSizeOf<T>>,
+}
+
+impl<T> SendMessage for Pallet<T>
+where
+	T: Config,
+{
+	type Ticket = Ticket<T>;
+
+	fn validate(
+		message: &Message,
+	) -> Result<(Self::Ticket, Fee<<Self as SendMessageFeeProvider>::Balance>), SendError> {
+		// The inner payload should not be too large
+		let payload = message.command.abi_encode();
+		ensure!(
+			payload.len() < T::MaxMessagePayloadSize::get() as usize,
+			SendError::MessageTooLarge
+		);
+
+		// Ensure there is a registered channel we can transmit this message on
+		ensure!(T::Channels::contains(&message.channel_id), SendError::InvalidChannel);
+
+		// Generate a unique message id unless one is provided
+		let message_id: H256 = message
+			.id
+			.unwrap_or_else(|| unique((message.channel_id, &message.command)).into());
+
+		let gas_used_at_most = T::GasMeter::maximum_gas_used_at_most(&message.command);
+		let fee = Self::calculate_fee(gas_used_at_most, T::PricingParameters::get());
+
+		let queued_message: VersionedQueuedMessage = QueuedMessage {
+			id: message_id,
+			channel_id: message.channel_id,
+			command: message.command.clone(),
+		}
+		.into();
+		// The whole message should not be too large
+		let encoded = queued_message.encode().try_into().map_err(|_| SendError::MessageTooLarge)?;
+
+		let ticket = Ticket { message_id, channel_id: message.channel_id, message: encoded };
+
+		Ok((ticket, fee))
+	}
+
+	fn deliver(ticket: Self::Ticket) -> Result<H256, SendError> {
+		let origin = AggregateMessageOrigin::Snowbridge(ticket.channel_id);
+
+		if ticket.channel_id != PRIMARY_GOVERNANCE_CHANNEL {
+			ensure!(!Self::operating_mode().is_halted(), SendError::Halted);
+		}
+
+		let message = ticket.message.as_bounded_slice();
+
+		T::MessageQueue::enqueue_message(message, origin);
+		Self::deposit_event(Event::MessageQueued { id: ticket.message_id });
+		Ok(ticket.message_id)
+	}
+}
+
+impl<T: Config> SendMessageFeeProvider for Pallet<T> {
+	type Balance = T::Balance;
+
+	/// The local component of the message processing fees in native currency
+	fn local_fee() -> Self::Balance {
+		Self::calculate_local_fee()
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/test.rs

@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{mock::*, *};
+
+use frame_support::{
+	assert_err, assert_noop, assert_ok,
+	traits::{Hooks, ProcessMessage, ProcessMessageError},
+	weights::WeightMeter,
+};
+
+use codec::Encode;
+use snowbridge_core::{
+	outbound::{Command, SendError, SendMessage},
+	ParaId,
+};
+use sp_arithmetic::FixedU128;
+use sp_core::H256;
+use sp_runtime::FixedPointNumber;
+
+#[test]
+fn submit_messages_and_commit() {
+	new_tester().execute_with(|| {
+		for para_id in 1000..1004 {
+			let message = mock_message(para_id);
+			let (ticket, _) = OutboundQueue::validate(&message).unwrap();
+			assert_ok!(OutboundQueue::deliver(ticket));
+		}
+
+		ServiceWeight::set(Some(Weight::MAX));
+		run_to_end_of_next_block();
+
+		for para_id in 1000..1004 {
+			let origin: ParaId = (para_id as u32).into();
+			let channel_id: ChannelId = origin.into();
+			assert_eq!(Nonce::<Test>::get(channel_id), 1);
+		}
+
+		let digest = System::digest();
+		let digest_items = digest.logs();
+		assert!(digest_items.len() == 1 && digest_items[0].as_other().is_some());
+		assert_eq!(Messages::<Test>::decode_len(), Some(4));
+	});
+}
+
+#[test]
+fn submit_message_fail_too_large() {
+	new_tester().execute_with(|| {
+		let message = mock_invalid_governance_message::<Test>();
+		assert_err!(OutboundQueue::validate(&message), SendError::MessageTooLarge);
+	});
+}
+
+#[test]
+fn convert_from_ether_decimals() {
+	assert_eq!(
+		OutboundQueue::convert_from_ether_decimals(1_000_000_000_000_000_000),
+		1_000_000_000_000
+	);
+}
+
+#[test]
+fn commit_exits_early_if_no_processed_messages() {
+	new_tester().execute_with(|| {
+		// on_finalize should do nothing, nor should it panic
+		OutboundQueue::on_finalize(System::block_number());
+
+		let digest = System::digest();
+		let digest_items = digest.logs();
+		assert_eq!(digest_items.len(), 0);
+	});
+}
+
+#[test]
+fn process_message_yields_on_max_messages_per_block() {
+	new_tester().execute_with(|| {
+		for _ in 0..<Test as Config>::MaxMessagesPerBlock::get() {
+			MessageLeaves::<Test>::append(H256::zero())
+		}
+
+		let channel_id: ChannelId = ParaId::from(1000).into();
+		let origin = AggregateMessageOrigin::Snowbridge(channel_id);
+		let message = QueuedMessage {
+			id: Default::default(),
+			channel_id,
+			command: Command::Upgrade {
+				impl_address: Default::default(),
+				impl_code_hash: Default::default(),
+				initializer: None,
+			},
+		}
+		.encode();
+
+		let mut meter = WeightMeter::new();
+
+		assert_noop!(
+			OutboundQueue::process_message(message.as_slice(), origin, &mut meter, &mut [0u8; 32]),
+			ProcessMessageError::Yield
+		);
+	})
+}
+
+#[test]
+fn process_message_fails_on_max_nonce_reached() {
+	new_tester().execute_with(|| {
+		let sibling_id = 1000;
+		let channel_id: ChannelId = ParaId::from(sibling_id).into();
+		let origin = AggregateMessageOrigin::Snowbridge(channel_id);
+		let message: QueuedMessage = QueuedMessage {
+			id: H256::zero(),
+			channel_id,
+			command: mock_message(sibling_id).command,
+		};
+		let versioned_queued_message: VersionedQueuedMessage = message.try_into().unwrap();
+		let encoded = versioned_queued_message.encode();
+		let mut meter = WeightMeter::with_limit(Weight::MAX);
+
+		Nonce::<Test>::set(channel_id, u64::MAX);
+
+		assert_noop!(
+			OutboundQueue::process_message(encoded.as_slice(), origin, &mut meter, &mut [0u8; 32]),
+			ProcessMessageError::Unsupported
+		);
+	})
+}
+
+#[test]
+fn process_message_fails_on_overweight_message() {
+	new_tester().execute_with(|| {
+		let sibling_id = 1000;
+		let channel_id: ChannelId = ParaId::from(sibling_id).into();
+		let origin = AggregateMessageOrigin::Snowbridge(channel_id);
+		let message: QueuedMessage = QueuedMessage {
+			id: H256::zero(),
+			channel_id,
+			command: mock_message(sibling_id).command,
+		};
+		let versioned_queued_message: VersionedQueuedMessage = message.try_into().unwrap();
+		let encoded = versioned_queued_message.encode();
+		let mut meter = WeightMeter::with_limit(Weight::from_parts(1, 1));
+		assert_noop!(
+			OutboundQueue::process_message(encoded.as_slice(), origin, &mut meter, &mut [0u8; 32]),
+			ProcessMessageError::Overweight(<Test as Config>::WeightInfo::do_process_message())
+		);
+	})
+}
+
+// Governance messages should be able to bypass a halted operating mode
+// Other message sends should fail when halted
+#[test]
+fn submit_upgrade_message_success_when_queue_halted() {
+	new_tester().execute_with(|| {
+		// halt the outbound queue
+		OutboundQueue::set_operating_mode(RuntimeOrigin::root(), BasicOperatingMode::Halted)
+			.unwrap();
+
+		// submit a high priority message from bridge_hub should success
+		let message = mock_governance_message::<Test>();
+		let (ticket, _) = OutboundQueue::validate(&message).unwrap();
+		assert_ok!(OutboundQueue::deliver(ticket));
+
+		// submit a low priority message from asset_hub will fail as pallet is halted
+		let message = mock_message(1000);
+		let (ticket, _) = OutboundQueue::validate(&message).unwrap();
+		assert_noop!(OutboundQueue::deliver(ticket), SendError::Halted);
+	});
+}
+
+#[test]
+fn governance_message_does_not_get_the_chance_to_processed_in_same_block_when_congest_of_low_priority_sibling_messages(
+) {
+	use snowbridge_core::PRIMARY_GOVERNANCE_CHANNEL;
+	use AggregateMessageOrigin::*;
+
+	let sibling_id: u32 = 1000;
+	let sibling_channel_id: ChannelId = ParaId::from(sibling_id).into();
+
+	new_tester().execute_with(|| {
+		// submit a lot of low priority messages from asset_hub which will need multiple blocks to
+		// execute(20 messages for each block so 40 required at least 2 blocks)
+		let max_messages = 40;
+		for _ in 0..max_messages {
+			// submit low priority message
+			let message = mock_message(sibling_id);
+			let (ticket, _) = OutboundQueue::validate(&message).unwrap();
+			OutboundQueue::deliver(ticket).unwrap();
+		}
+
+		let footprint = MessageQueue::footprint(Snowbridge(sibling_channel_id));
+		assert_eq!(footprint.storage.count, (max_messages) as u64);
+
+		let message = mock_governance_message::<Test>();
+		let (ticket, _) = OutboundQueue::validate(&message).unwrap();
+		OutboundQueue::deliver(ticket).unwrap();
+
+		// move to next block
+		ServiceWeight::set(Some(Weight::MAX));
+		run_to_end_of_next_block();
+
+		// first process 20 messages from sibling channel
+		let footprint = MessageQueue::footprint(Snowbridge(sibling_channel_id));
+		assert_eq!(footprint.storage.count, 40 - 20);
+
+		// and governance message does not have the chance to execute in same block
+		let footprint = MessageQueue::footprint(Snowbridge(PRIMARY_GOVERNANCE_CHANNEL));
+		assert_eq!(footprint.storage.count, 1);
+
+		// move to next block
+		ServiceWeight::set(Some(Weight::MAX));
+		run_to_end_of_next_block();
+
+		// now governance message get executed in this block
+		let footprint = MessageQueue::footprint(Snowbridge(PRIMARY_GOVERNANCE_CHANNEL));
+		assert_eq!(footprint.storage.count, 0);
+
+		// and this time process 19 messages from sibling channel so we have 1 message left
+		let footprint = MessageQueue::footprint(Snowbridge(sibling_channel_id));
+		assert_eq!(footprint.storage.count, 1);
+
+		// move to the next block, the last 1 message from sibling channel get executed
+		ServiceWeight::set(Some(Weight::MAX));
+		run_to_end_of_next_block();
+		let footprint = MessageQueue::footprint(Snowbridge(sibling_channel_id));
+		assert_eq!(footprint.storage.count, 0);
+	});
+}
+
+#[test]
+fn convert_local_currency() {
+	new_tester().execute_with(|| {
+		let fee: u128 = 1_000_000;
+		let fee1 = FixedU128::from_inner(fee).into_inner();
+		let fee2 = FixedU128::from(fee)
+			.into_inner()
+			.checked_div(FixedU128::accuracy())
+			.expect("accuracy is not zero; qed");
+		assert_eq!(fee, fee1);
+		assert_eq!(fee, fee2);
+	});
+}
+
+#[test]
+fn encode_digest_item_with_correct_index() {
+	new_tester().execute_with(|| {
+		let digest_item: DigestItem = CustomDigestItem::Snowbridge(H256::default()).into();
+		let enum_prefix = match digest_item {
+			DigestItem::Other(data) => data[0],
+			_ => u8::MAX,
+		};
+		assert_eq!(enum_prefix, 0);
+	});
+}
+
+#[test]
+fn encode_digest_item() {
+	new_tester().execute_with(|| {
+		let digest_item: DigestItem = CustomDigestItem::Snowbridge([5u8; 32].into()).into();
+		let digest_item_raw = digest_item.encode();
+		assert_eq!(digest_item_raw[0], 0); // DigestItem::Other
+		assert_eq!(digest_item_raw[2], 0); // CustomDigestItem::Snowbridge
+		assert_eq!(
+			digest_item_raw,
+			[
+				0, 132, 0, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+				5, 5, 5, 5, 5, 5, 5, 5
+			]
+		);
+	});
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/types.rs

@@ -0,0 +1,99 @@
+use codec::{Decode, Encode, MaxEncodedLen};
+use ethabi::Token;
+use frame_support::traits::ProcessMessage;
+use scale_info::TypeInfo;
+use serde::{Deserialize, Serialize};
+use sp_arithmetic::FixedU128;
+use sp_core::H256;
+use sp_runtime::{traits::Zero, RuntimeDebug};
+use sp_std::prelude::*;
+
+use super::Pallet;
+
+use snowbridge_core::ChannelId;
+pub use snowbridge_outbound_queue_merkle_tree::MerkleProof;
+
+pub type ProcessMessageOriginOf<T> = <Pallet<T> as ProcessMessage>::Origin;
+
+pub const LOG_TARGET: &str = "snowbridge-outbound-queue";
+
+/// Message which has been assigned a nonce and will be committed at the end of a block
+#[derive(Encode, Decode, Clone, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct CommittedMessage {
+	/// Message channel
+	pub channel_id: ChannelId,
+	/// Unique nonce to prevent replaying messages
+	#[codec(compact)]
+	pub nonce: u64,
+	/// Command to execute in the Gateway contract
+	pub command: u8,
+	/// Params for the command
+	pub params: Vec<u8>,
+	/// Maximum gas allowed for message dispatch
+	#[codec(compact)]
+	pub max_dispatch_gas: u64,
+	/// Maximum fee per gas
+	#[codec(compact)]
+	pub max_fee_per_gas: u128,
+	/// Reward in ether for delivering this message, in addition to the gas refund
+	#[codec(compact)]
+	pub reward: u128,
+	/// Message ID (Used for tracing messages across route, has no role in consensus)
+	pub id: H256,
+}
+
+/// Convert message into an ABI-encoded form for delivery to the InboundQueue contract on Ethereum
+impl From<CommittedMessage> for Token {
+	fn from(x: CommittedMessage) -> Token {
+		Token::Tuple(vec![
+			Token::FixedBytes(Vec::from(x.channel_id.as_ref())),
+			Token::Uint(x.nonce.into()),
+			Token::Uint(x.command.into()),
+			Token::Bytes(x.params.to_vec()),
+			Token::Uint(x.max_dispatch_gas.into()),
+			Token::Uint(x.max_fee_per_gas.into()),
+			Token::Uint(x.reward.into()),
+			Token::FixedBytes(Vec::from(x.id.as_ref())),
+		])
+	}
+}
+
+/// Configuration for fee calculations
+#[derive(
+	Encode,
+	Decode,
+	Copy,
+	Clone,
+	PartialEq,
+	RuntimeDebug,
+	MaxEncodedLen,
+	TypeInfo,
+	Serialize,
+	Deserialize,
+)]
+pub struct FeeConfigRecord {
+	/// ETH/DOT exchange rate
+	pub exchange_rate: FixedU128,
+	/// Ether fee per unit of gas
+	pub fee_per_gas: u128,
+	/// Ether reward for delivering message
+	pub reward: u128,
+}
+
+#[derive(RuntimeDebug)]
+pub struct InvalidFeeConfig;
+
+impl FeeConfigRecord {
+	pub fn validate(&self) -> Result<(), InvalidFeeConfig> {
+		if self.exchange_rate == FixedU128::zero() {
+			return Err(InvalidFeeConfig)
+		}
+		if self.fee_per_gas == 0 {
+			return Err(InvalidFeeConfig)
+		}
+		if self.reward == 0 {
+			return Err(InvalidFeeConfig)
+		}
+		Ok(())
+	}
+}

bridges/snowbridge/parachain/pallets/outbound-queue/src/weights.rs

@@ -0,0 +1,81 @@
+
+//! Autogenerated weights for `snowbridge_outbound_queue`
+//!
+//! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
+//! DATE: 2023-10-19, STEPS: `2`, REPEAT: `1`, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! WORST CASE MAP SIZE: `1000000`
+//! HOSTNAME: `192.168.1.7`, CPU: `<UNKNOWN>`
+//! WASM-EXECUTION: `Compiled`, CHAIN: `Some("bridge-hub-rococo-dev")`, DB CACHE: `1024`
+
+// Executed Command:
+// target/release/polkadot-parachain
+// benchmark
+// pallet
+// --chain=bridge-hub-rococo-dev
+// --pallet=snowbridge_outbound_queue
+// --extrinsic=*
+// --execution=wasm
+// --wasm-execution=compiled
+// --template
+// ../parachain/templates/module-weight-template.hbs
+// --output
+// ../parachain/pallets/outbound-queue/src/weights.rs
+
+#![cfg_attr(rustfmt, rustfmt_skip)]
+#![allow(unused_parens)]
+#![allow(unused_imports)]
+#![allow(missing_docs)]
+
+use frame_support::{traits::Get, weights::{Weight, constants::RocksDbWeight}};
+use core::marker::PhantomData;
+
+/// Weight functions needed for `snowbridge_outbound_queue`.
+pub trait WeightInfo {
+	fn do_process_message() -> Weight;
+	fn commit() -> Weight;
+	fn commit_single() -> Weight;
+}
+
+// For backwards compatibility and tests.
+impl WeightInfo for () {
+	/// Storage: EthereumOutboundQueue MessageLeaves (r:1 w:1)
+	/// Proof Skipped: EthereumOutboundQueue MessageLeaves (max_values: Some(1), max_size: None, mode: Measured)
+	/// Storage: EthereumOutboundQueue PendingHighPriorityMessageCount (r:1 w:1)
+	/// Proof: EthereumOutboundQueue PendingHighPriorityMessageCount (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue Nonce (r:1 w:1)
+	/// Proof: EthereumOutboundQueue Nonce (max_values: None, max_size: Some(20), added: 2495, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue Messages (r:1 w:1)
+	/// Proof Skipped: EthereumOutboundQueue Messages (max_values: Some(1), max_size: None, mode: Measured)
+	fn do_process_message() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `42`
+		//  Estimated: `3485`
+		// Minimum execution time: 39_000_000 picoseconds.
+		Weight::from_parts(39_000_000, 3485)
+			.saturating_add(RocksDbWeight::get().reads(4_u64))
+			.saturating_add(RocksDbWeight::get().writes(4_u64))
+	}
+	/// Storage: EthereumOutboundQueue MessageLeaves (r:1 w:0)
+	/// Proof Skipped: EthereumOutboundQueue MessageLeaves (max_values: Some(1), max_size: None, mode: Measured)
+	/// Storage: System Digest (r:1 w:1)
+	/// Proof Skipped: System Digest (max_values: Some(1), max_size: None, mode: Measured)
+	fn commit() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `1094`
+		//  Estimated: `2579`
+		// Minimum execution time: 28_000_000 picoseconds.
+		Weight::from_parts(28_000_000, 2579)
+			.saturating_add(RocksDbWeight::get().reads(2_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+
+	fn commit_single() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `1094`
+		//  Estimated: `2579`
+		// Minimum execution time: 9_000_000 picoseconds.
+		Weight::from_parts(9_000_000, 1586)
+			.saturating_add(RocksDbWeight::get().reads(2_u64))
+			.saturating_add(RocksDbWeight::get().writes(1_u64))
+	}
+}

bridges/snowbridge/parachain/pallets/system/Cargo.toml

@@ -0,0 +1,83 @@
+[package]
+name = "snowbridge-system"
+description = "Snowbridge System"
+version = "0.1.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = [
+	"derive",
+] }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking", default-features = false, optional = true }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+log = { version = "0.4.20", default-features = false }
+
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+xcm-executor = { package = "staging-xcm-executor", path = "../../../../../polkadot/xcm/xcm-executor", default-features = false }
+
+ethabi = { git = "https://github.com/Snowfork/ethabi-decode.git", package = "ethabi-decode", branch = "master", default-features = false }
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+
+[dev-dependencies]
+hex = "0.4.1"
+hex-literal = { version = "0.4.1" }
+pallet-balances = { path = "../../../../../substrate/frame/balances" }
+sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
+polkadot-primitives = { path = "../../../../../polkadot/primitives" }
+pallet-message-queue = { path = "../../../../../substrate/frame/message-queue" }
+snowbridge-outbound-queue = { path = "../outbound-queue" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"ethabi/std",
+	"frame-benchmarking?/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"scale-info/std",
+	"snowbridge-core/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
+	"pallet-message-queue/runtime-benchmarks",
+	"polkadot-primitives/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"snowbridge-outbound-queue/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+	"xcm-executor/runtime-benchmarks",
+]
+try-runtime = [
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
+	"pallet-message-queue/try-runtime",
+	"snowbridge-outbound-queue/try-runtime",
+	"sp-runtime/try-runtime",
+]

bridges/snowbridge/parachain/pallets/system/README.md

@@ -0,0 +1 @@
+License: MIT-0

bridges/snowbridge/parachain/pallets/system/runtime-api/Cargo.toml

@@ -0,0 +1,32 @@
+[package]
+name = "snowbridge-system-runtime-api"
+description = "Snowbridge System Runtime API"
+version = "0.1.0"
+edition = "2021"
+authors = ["Snowfork <contact@snowfork.com>"]
+repository = "https://github.com/Snowfork/snowbridge"
+license = "Apache-2.0"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = [
+	"derive",
+] }
+sp-core = { path = "../../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../../substrate/primitives/std", default-features = false }
+sp-api = { path = "../../../../../../substrate/primitives/api", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../../polkadot/xcm", default-features = false }
+snowbridge-core = { path = "../../../primitives/core", default-features = false }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"snowbridge-core/std",
+	"sp-api/std",
+	"sp-core/std",
+	"sp-std/std",
+	"xcm/std",
+]

bridges/snowbridge/parachain/pallets/system/runtime-api/src/lib.rs

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use snowbridge_core::AgentId;
+use xcm::VersionedMultiLocation;
+
+sp_api::decl_runtime_apis! {
+	pub trait ControlApi
+	{
+		fn agent_id(location: VersionedMultiLocation) -> Option<AgentId>;
+	}
+}

bridges/snowbridge/parachain/pallets/system/src/api.rs

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Helpers for implementing runtime api
+
+use snowbridge_core::AgentId;
+use xcm::{prelude::*, VersionedMultiLocation};
+
+use crate::{agent_id_of, Config};
+
+pub fn agent_id<Runtime>(location: VersionedMultiLocation) -> Option<AgentId>
+where
+	Runtime: Config,
+{
+	let location: MultiLocation = location.try_into().ok()?;
+	agent_id_of::<Runtime>(&location).ok()
+}

bridges/snowbridge/parachain/pallets/system/src/benchmarking.rs

@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Benchmarking setup for pallet-template
+use super::*;
+
+#[allow(unused)]
+use crate::Pallet as SnowbridgeControl;
+use frame_benchmarking::v2::*;
+use frame_system::RawOrigin;
+use snowbridge_core::{eth, outbound::OperatingMode};
+use sp_runtime::SaturatedConversion;
+use xcm::prelude::*;
+
+#[allow(clippy::result_large_err)]
+fn fund_sovereign_account<T: Config>(para_id: ParaId) -> Result<(), BenchmarkError> {
+	let amount: BalanceOf<T> = (10_000_000_000_000_u64).saturated_into::<u128>().saturated_into();
+	let sovereign_account = sibling_sovereign_account::<T>(para_id);
+	T::Token::mint_into(&sovereign_account, amount)?;
+	Ok(())
+}
+
+#[benchmarks]
+mod benchmarks {
+	use super::*;
+
+	#[benchmark]
+	fn upgrade() -> Result<(), BenchmarkError> {
+		let impl_address = H160::repeat_byte(1);
+		let impl_code_hash = H256::repeat_byte(1);
+
+		// Assume 256 bytes passed to initializer
+		let params: Vec<u8> = (0..256).map(|_| 1u8).collect();
+
+		#[extrinsic_call]
+		_(
+			RawOrigin::Root,
+			impl_address,
+			impl_code_hash,
+			Some(Initializer { params, maximum_required_gas: 100000 }),
+		);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn set_operating_mode() -> Result<(), BenchmarkError> {
+		#[extrinsic_call]
+		_(RawOrigin::Root, OperatingMode::RejectingOutboundMessages);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn set_pricing_parameters() -> Result<(), BenchmarkError> {
+		let params = T::DefaultPricingParameters::get();
+
+		#[extrinsic_call]
+		_(RawOrigin::Root, params);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn create_agent() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+
+		#[extrinsic_call]
+		_(origin as T::RuntimeOrigin);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn create_channel() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+
+		SnowbridgeControl::<T>::create_agent(origin.clone())?;
+
+		#[extrinsic_call]
+		_(origin as T::RuntimeOrigin, OperatingMode::Normal);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn update_channel() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+		SnowbridgeControl::<T>::create_agent(origin.clone())?;
+		SnowbridgeControl::<T>::create_channel(origin.clone(), OperatingMode::Normal)?;
+
+		#[extrinsic_call]
+		_(origin as T::RuntimeOrigin, OperatingMode::RejectingOutboundMessages);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn force_update_channel() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		let channel_id: ChannelId = ParaId::from(origin_para_id).into();
+
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+		SnowbridgeControl::<T>::create_agent(origin.clone())?;
+		SnowbridgeControl::<T>::create_channel(origin.clone(), OperatingMode::Normal)?;
+
+		#[extrinsic_call]
+		_(RawOrigin::Root, channel_id, OperatingMode::RejectingOutboundMessages);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn transfer_native_from_agent() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+		SnowbridgeControl::<T>::create_agent(origin.clone())?;
+		SnowbridgeControl::<T>::create_channel(origin.clone(), OperatingMode::Normal)?;
+
+		#[extrinsic_call]
+		_(origin as T::RuntimeOrigin, H160::default(), 1);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn force_transfer_native_from_agent() -> Result<(), BenchmarkError> {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let origin = T::Helper::make_xcm_origin(origin_location);
+		fund_sovereign_account::<T>(origin_para_id.into())?;
+		SnowbridgeControl::<T>::create_agent(origin.clone())?;
+
+		let versioned_location: VersionedMultiLocation = origin_location.into();
+
+		#[extrinsic_call]
+		_(RawOrigin::Root, Box::new(versioned_location), H160::default(), 1);
+
+		Ok(())
+	}
+
+	#[benchmark]
+	fn set_token_transfer_fees() -> Result<(), BenchmarkError> {
+		#[extrinsic_call]
+		_(RawOrigin::Root, 1, 1, eth(1));
+
+		Ok(())
+	}
+
+	impl_benchmark_test_suite!(
+		SnowbridgeControl,
+		crate::mock::new_test_ext(true),
+		crate::mock::Test
+	);
+}

bridges/snowbridge/parachain/pallets/system/src/lib.rs

@@ -0,0 +1,681 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Governance API for controlling the Ethereum side of the bridge
+//!
+//! # Extrinsics
+//!
+//! ## Agents
+//!
+//! Agents are smart contracts on Ethereum that act as proxies for consensus systems on Polkadot
+//! networks.
+//!
+//! * [`Call::create_agent`]: Create agent for a sibling parachain
+//! * [`Call::transfer_native_from_agent`]: Withdraw ether from an agent
+//!
+//! The `create_agent` extrinsic should be called via an XCM `Transact` instruction from the sibling
+//! parachain.
+//!
+//! ## Channels
+//!
+//! Each sibling parachain has its own dedicated messaging channel for sending and receiving
+//! messages. As a prerequisite to creating a channel, the sibling should have already created
+//! an agent using the `create_agent` extrinsic.
+//!
+//! * [`Call::create_channel`]: Create channel for a sibling
+//! * [`Call::update_channel`]: Update a channel for a sibling
+//!
+//! ## Governance
+//!
+//! Only Polkadot governance itself can call these extrinsics. Delivery fees are waived.
+//!
+//! * [`Call::upgrade`]`: Upgrade the gateway contract
+//! * [`Call::set_operating_mode`]: Update the operating mode of the gateway contract
+//! * [`Call::force_update_channel`]: Allow root to update a channel for a sibling
+//! * [`Call::force_transfer_native_from_agent`]: Allow root to withdraw ether from an agent
+//!
+//! Typically, Polkadot governance will use the `force_transfer_native_from_agent` and
+//! `force_update_channel` and extrinsics to manage agents and channels for system parachains.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub use pallet::*;
+
+#[cfg(test)]
+mod mock;
+
+#[cfg(test)]
+mod tests;
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+pub mod migration;
+
+pub mod api;
+pub mod weights;
+pub use weights::*;
+
+use frame_support::{
+	pallet_prelude::*,
+	traits::{
+		fungible::{Inspect, Mutate},
+		tokens::Preservation,
+		Contains, EnsureOrigin,
+	},
+};
+use frame_system::pallet_prelude::*;
+use snowbridge_core::{
+	meth,
+	outbound::{Command, Initializer, Message, OperatingMode, SendError, SendMessage},
+	sibling_sovereign_account, AgentId, Channel, ChannelId, ParaId,
+	PricingParameters as PricingParametersRecord, PRIMARY_GOVERNANCE_CHANNEL,
+	SECONDARY_GOVERNANCE_CHANNEL,
+};
+use sp_core::{RuntimeDebug, H160, H256};
+use sp_io::hashing::blake2_256;
+use sp_runtime::{traits::BadOrigin, DispatchError, SaturatedConversion};
+use sp_std::prelude::*;
+use xcm::prelude::*;
+use xcm_executor::traits::ConvertLocation;
+
+#[cfg(feature = "runtime-benchmarks")]
+use frame_support::traits::OriginTrait;
+
+pub use pallet::*;
+
+pub type BalanceOf<T> =
+	<<T as pallet::Config>::Token as Inspect<<T as frame_system::Config>::AccountId>>::Balance;
+pub type AccountIdOf<T> = <T as frame_system::Config>::AccountId;
+pub type PricingParametersOf<T> = PricingParametersRecord<BalanceOf<T>>;
+
+/// Ensure origin location is a sibling
+fn ensure_sibling<T>(location: &MultiLocation) -> Result<(ParaId, H256), DispatchError>
+where
+	T: Config,
+{
+	match location {
+		MultiLocation { parents: 1, interior: X1(Parachain(para_id)) } => {
+			let agent_id = agent_id_of::<T>(location)?;
+			Ok(((*para_id).into(), agent_id))
+		},
+		_ => Err(BadOrigin.into()),
+	}
+}
+
+/// Hash the location to produce an agent id
+fn agent_id_of<T: Config>(location: &MultiLocation) -> Result<H256, DispatchError> {
+	T::AgentIdOf::convert_location(location).ok_or(Error::<T>::LocationConversionFailed.into())
+}
+
+#[cfg(feature = "runtime-benchmarks")]
+pub trait BenchmarkHelper<O>
+where
+	O: OriginTrait,
+{
+	fn make_xcm_origin(location: MultiLocation) -> O;
+}
+
+/// Whether a fee should be withdrawn to an account for sending an outbound message
+#[derive(Clone, PartialEq, RuntimeDebug)]
+pub enum PaysFee<T>
+where
+	T: Config,
+{
+	/// Fully charge includes (local + remote fee)
+	Yes(AccountIdOf<T>),
+	/// Partially charge includes local fee only
+	Partial(AccountIdOf<T>),
+	/// No charge
+	No,
+}
+
+#[frame_support::pallet]
+pub mod pallet {
+	use snowbridge_core::StaticLookup;
+	use sp_core::U256;
+
+	use super::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+
+		/// Send messages to Ethereum
+		type OutboundQueue: SendMessage<Balance = BalanceOf<Self>>;
+
+		/// Origin check for XCM locations that can create agents
+		type SiblingOrigin: EnsureOrigin<Self::RuntimeOrigin, Success = MultiLocation>;
+
+		/// Converts MultiLocation to AgentId
+		type AgentIdOf: ConvertLocation<AgentId>;
+
+		/// Token reserved for control operations
+		type Token: Mutate<Self::AccountId>;
+
+		/// TreasuryAccount to collect fees
+		#[pallet::constant]
+		type TreasuryAccount: Get<Self::AccountId>;
+
+		/// Number of decimal places of local currency
+		type DefaultPricingParameters: Get<PricingParametersOf<Self>>;
+
+		/// Cost of delivering a message from Ethereum
+		type InboundDeliveryCost: Get<BalanceOf<Self>>;
+
+		type WeightInfo: WeightInfo;
+
+		#[cfg(feature = "runtime-benchmarks")]
+		type Helper: BenchmarkHelper<Self::RuntimeOrigin>;
+	}
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		/// An Upgrade message was sent to the Gateway
+		Upgrade {
+			impl_address: H160,
+			impl_code_hash: H256,
+			initializer_params_hash: Option<H256>,
+		},
+		/// An CreateAgent message was sent to the Gateway
+		CreateAgent {
+			location: Box<MultiLocation>,
+			agent_id: AgentId,
+		},
+		/// An CreateChannel message was sent to the Gateway
+		CreateChannel {
+			channel_id: ChannelId,
+			agent_id: AgentId,
+		},
+		/// An UpdateChannel message was sent to the Gateway
+		UpdateChannel {
+			channel_id: ChannelId,
+			mode: OperatingMode,
+		},
+		/// An SetOperatingMode message was sent to the Gateway
+		SetOperatingMode {
+			mode: OperatingMode,
+		},
+		/// An TransferNativeFromAgent message was sent to the Gateway
+		TransferNativeFromAgent {
+			agent_id: AgentId,
+			recipient: H160,
+			amount: u128,
+		},
+		/// A SetTokenTransferFees message was sent to the Gateway
+		SetTokenTransferFees {
+			create_asset_xcm: u128,
+			transfer_asset_xcm: u128,
+			register_token: U256,
+		},
+		PricingParametersChanged {
+			params: PricingParametersOf<T>,
+		},
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		LocationConversionFailed,
+		AgentAlreadyCreated,
+		NoAgent,
+		ChannelAlreadyCreated,
+		NoChannel,
+		UnsupportedLocationVersion,
+		InvalidLocation,
+		Send(SendError),
+		InvalidTokenTransferFees,
+		InvalidPricingParameters,
+	}
+
+	/// The set of registered agents
+	#[pallet::storage]
+	#[pallet::getter(fn agents)]
+	pub type Agents<T: Config> = StorageMap<_, Twox64Concat, AgentId, (), OptionQuery>;
+
+	/// The set of registered channels
+	#[pallet::storage]
+	#[pallet::getter(fn channels)]
+	pub type Channels<T: Config> = StorageMap<_, Twox64Concat, ChannelId, Channel, OptionQuery>;
+
+	#[pallet::storage]
+	#[pallet::getter(fn parameters)]
+	pub type PricingParameters<T: Config> =
+		StorageValue<_, PricingParametersOf<T>, ValueQuery, T::DefaultPricingParameters>;
+
+	#[pallet::genesis_config]
+	#[derive(frame_support::DefaultNoBound)]
+	pub struct GenesisConfig<T: Config> {
+		// Own parachain id
+		pub para_id: ParaId,
+		// AssetHub's parachain id
+		pub asset_hub_para_id: ParaId,
+		#[serde(skip)]
+		pub _config: PhantomData<T>,
+	}
+
+	#[pallet::genesis_build]
+	impl<T: Config> BuildGenesisConfig for GenesisConfig<T> {
+		fn build(&self) {
+			Pallet::<T>::initialize(self.para_id, self.asset_hub_para_id).expect("infallible; qed");
+		}
+	}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		/// Sends command to the Gateway contract to upgrade itself with a new implementation
+		/// contract
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be `Root`.
+		/// - `impl_address`: The address of the implementation contract.
+		/// - `impl_code_hash`: The codehash of the implementation contract.
+		/// - `initializer`: Optionally call an initializer on the implementation contract.
+		#[pallet::call_index(0)]
+		#[pallet::weight((T::WeightInfo::upgrade(), DispatchClass::Operational))]
+		pub fn upgrade(
+			origin: OriginFor<T>,
+			impl_address: H160,
+			impl_code_hash: H256,
+			initializer: Option<Initializer>,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			let initializer_params_hash: Option<H256> =
+				initializer.as_ref().map(|i| H256::from(blake2_256(i.params.as_ref())));
+			let command = Command::Upgrade { impl_address, impl_code_hash, initializer };
+			Self::send(PRIMARY_GOVERNANCE_CHANNEL, command, PaysFee::<T>::No)?;
+
+			Self::deposit_event(Event::<T>::Upgrade {
+				impl_address,
+				impl_code_hash,
+				initializer_params_hash,
+			});
+			Ok(())
+		}
+
+		/// Sends a message to the Gateway contract to change its operating mode
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be `MultiLocation`
+		#[pallet::call_index(1)]
+		#[pallet::weight((T::WeightInfo::set_operating_mode(), DispatchClass::Operational))]
+		pub fn set_operating_mode(origin: OriginFor<T>, mode: OperatingMode) -> DispatchResult {
+			ensure_root(origin)?;
+
+			let command = Command::SetOperatingMode { mode };
+			Self::send(PRIMARY_GOVERNANCE_CHANNEL, command, PaysFee::<T>::No)?;
+
+			Self::deposit_event(Event::<T>::SetOperatingMode { mode });
+			Ok(())
+		}
+
+		/// Set pricing parameters on both sides of the bridge
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be root
+		#[pallet::call_index(2)]
+		#[pallet::weight((T::WeightInfo::set_pricing_parameters(), DispatchClass::Operational))]
+		pub fn set_pricing_parameters(
+			origin: OriginFor<T>,
+			params: PricingParametersOf<T>,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			params.validate().map_err(|_| Error::<T>::InvalidPricingParameters)?;
+			PricingParameters::<T>::put(params.clone());
+
+			let command = Command::SetPricingParameters {
+				exchange_rate: params.exchange_rate.into(),
+				delivery_cost: T::InboundDeliveryCost::get().saturated_into::<u128>(),
+			};
+			Self::send(PRIMARY_GOVERNANCE_CHANNEL, command, PaysFee::<T>::No)?;
+
+			Self::deposit_event(Event::PricingParametersChanged { params });
+			Ok(())
+		}
+
+		/// Sends a command to the Gateway contract to instantiate a new agent contract representing
+		/// `origin`.
+		///
+		/// Fee required: Yes
+		///
+		/// - `origin`: Must be `MultiLocation` of a sibling parachain
+		#[pallet::call_index(3)]
+		#[pallet::weight(T::WeightInfo::create_agent())]
+		pub fn create_agent(origin: OriginFor<T>) -> DispatchResult {
+			let origin_location: MultiLocation = T::SiblingOrigin::ensure_origin(origin)?;
+
+			// Ensure that origin location is some consensus system on a sibling parachain
+			let (para_id, agent_id) = ensure_sibling::<T>(&origin_location)?;
+
+			// Record the agent id or fail if it has already been created
+			ensure!(!Agents::<T>::contains_key(agent_id), Error::<T>::AgentAlreadyCreated);
+			Agents::<T>::insert(agent_id, ());
+
+			let command = Command::CreateAgent { agent_id };
+			let pays_fee = PaysFee::<T>::Yes(sibling_sovereign_account::<T>(para_id));
+			Self::send(SECONDARY_GOVERNANCE_CHANNEL, command, pays_fee)?;
+
+			Self::deposit_event(Event::<T>::CreateAgent {
+				location: Box::new(origin_location),
+				agent_id,
+			});
+			Ok(())
+		}
+
+		/// Sends a message to the Gateway contract to create a new channel representing `origin`
+		///
+		/// Fee required: Yes
+		///
+		/// This extrinsic is permissionless, so a fee is charged to prevent spamming and pay
+		/// for execution costs on the remote side.
+		///
+		/// The message is sent over the bridge on BridgeHub's own channel to the Gateway.
+		///
+		/// - `origin`: Must be `MultiLocation`
+		/// - `mode`: Initial operating mode of the channel
+		#[pallet::call_index(4)]
+		#[pallet::weight(T::WeightInfo::create_channel())]
+		pub fn create_channel(origin: OriginFor<T>, mode: OperatingMode) -> DispatchResult {
+			let origin_location: MultiLocation = T::SiblingOrigin::ensure_origin(origin)?;
+
+			// Ensure that origin location is a sibling parachain
+			let (para_id, agent_id) = ensure_sibling::<T>(&origin_location)?;
+
+			let channel_id: ChannelId = para_id.into();
+
+			ensure!(Agents::<T>::contains_key(agent_id), Error::<T>::NoAgent);
+			ensure!(!Channels::<T>::contains_key(channel_id), Error::<T>::ChannelAlreadyCreated);
+
+			let channel = Channel { agent_id, para_id };
+			Channels::<T>::insert(channel_id, channel);
+
+			let command = Command::CreateChannel { channel_id, agent_id, mode };
+			let pays_fee = PaysFee::<T>::Yes(sibling_sovereign_account::<T>(para_id));
+			Self::send(SECONDARY_GOVERNANCE_CHANNEL, command, pays_fee)?;
+
+			Self::deposit_event(Event::<T>::CreateChannel { channel_id, agent_id });
+			Ok(())
+		}
+
+		/// Sends a message to the Gateway contract to update a channel configuration
+		///
+		/// The origin must already have a channel initialized, as this message is sent over it.
+		///
+		/// A partial fee will be charged for local processing only.
+		///
+		/// - `origin`: Must be `MultiLocation`
+		/// - `mode`: Initial operating mode of the channel
+		#[pallet::call_index(5)]
+		#[pallet::weight(T::WeightInfo::update_channel())]
+		pub fn update_channel(origin: OriginFor<T>, mode: OperatingMode) -> DispatchResult {
+			let origin_location: MultiLocation = T::SiblingOrigin::ensure_origin(origin)?;
+
+			// Ensure that origin location is a sibling parachain
+			let (para_id, _) = ensure_sibling::<T>(&origin_location)?;
+
+			let channel_id: ChannelId = para_id.into();
+
+			ensure!(Channels::<T>::contains_key(channel_id), Error::<T>::NoChannel);
+
+			let command = Command::UpdateChannel { channel_id, mode };
+			let pays_fee = PaysFee::<T>::Partial(sibling_sovereign_account::<T>(para_id));
+
+			// Parachains send the update message on their own channel
+			Self::send(channel_id, command, pays_fee)?;
+
+			Self::deposit_event(Event::<T>::UpdateChannel { channel_id, mode });
+			Ok(())
+		}
+
+		/// Sends a message to the Gateway contract to update an arbitrary channel
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be root
+		/// - `channel_id`: ID of channel
+		/// - `mode`: Initial operating mode of the channel
+		/// - `outbound_fee`: Fee charged to users for sending outbound messages to Polkadot
+		#[pallet::call_index(6)]
+		#[pallet::weight(T::WeightInfo::force_update_channel())]
+		pub fn force_update_channel(
+			origin: OriginFor<T>,
+			channel_id: ChannelId,
+			mode: OperatingMode,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			ensure!(Channels::<T>::contains_key(channel_id), Error::<T>::NoChannel);
+
+			let command = Command::UpdateChannel { channel_id, mode };
+			Self::send(PRIMARY_GOVERNANCE_CHANNEL, command, PaysFee::<T>::No)?;
+
+			Self::deposit_event(Event::<T>::UpdateChannel { channel_id, mode });
+			Ok(())
+		}
+
+		/// Sends a message to the Gateway contract to transfer ether from an agent to `recipient`.
+		///
+		/// A partial fee will be charged for local processing only.
+		///
+		/// - `origin`: Must be `MultiLocation`
+		#[pallet::call_index(7)]
+		#[pallet::weight(T::WeightInfo::transfer_native_from_agent())]
+		pub fn transfer_native_from_agent(
+			origin: OriginFor<T>,
+			recipient: H160,
+			amount: u128,
+		) -> DispatchResult {
+			let origin_location: MultiLocation = T::SiblingOrigin::ensure_origin(origin)?;
+
+			// Ensure that origin location is some consensus system on a sibling parachain
+			let (para_id, agent_id) = ensure_sibling::<T>(&origin_location)?;
+
+			// Since the origin is also the owner of the channel, they only need to pay
+			// the local processing fee.
+			let pays_fee = PaysFee::<T>::Partial(sibling_sovereign_account::<T>(para_id));
+
+			Self::do_transfer_native_from_agent(
+				agent_id,
+				para_id.into(),
+				recipient,
+				amount,
+				pays_fee,
+			)
+		}
+
+		/// Sends a message to the Gateway contract to transfer ether from an agent to `recipient`.
+		///
+		/// Privileged. Can only be called by root.
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be root
+		/// - `location`: Location used to resolve the agent
+		/// - `recipient`: Recipient of funds
+		/// - `amount`: Amount to transfer
+		#[pallet::call_index(8)]
+		#[pallet::weight(T::WeightInfo::force_transfer_native_from_agent())]
+		pub fn force_transfer_native_from_agent(
+			origin: OriginFor<T>,
+			location: Box<VersionedMultiLocation>,
+			recipient: H160,
+			amount: u128,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			// Ensure that location is some consensus system on a sibling parachain
+			let location: MultiLocation =
+				(*location).try_into().map_err(|_| Error::<T>::UnsupportedLocationVersion)?;
+			let (_, agent_id) =
+				ensure_sibling::<T>(&location).map_err(|_| Error::<T>::InvalidLocation)?;
+
+			let pays_fee = PaysFee::<T>::No;
+
+			Self::do_transfer_native_from_agent(
+				agent_id,
+				PRIMARY_GOVERNANCE_CHANNEL,
+				recipient,
+				amount,
+				pays_fee,
+			)
+		}
+
+		/// Sends a message to the Gateway contract to update fee related parameters for
+		/// token transfers.
+		///
+		/// Privileged. Can only be called by root.
+		///
+		/// Fee required: No
+		///
+		/// - `origin`: Must be root
+		/// - `create_asset_xcm`: The XCM execution cost for creating a new asset class on AssetHub,
+		///   in DOT
+		/// - `transfer_asset_xcm`: The XCM execution cost for performing a reserve transfer on
+		///   AssetHub, in DOT
+		/// - `register_token`: The Ether fee for registering a new token, to discourage spamming
+		#[pallet::call_index(9)]
+		#[pallet::weight((T::WeightInfo::set_token_transfer_fees(), DispatchClass::Operational))]
+		pub fn set_token_transfer_fees(
+			origin: OriginFor<T>,
+			create_asset_xcm: u128,
+			transfer_asset_xcm: u128,
+			register_token: U256,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			// Basic validation of new costs. Particularly for token registration, we want to ensure
+			// its relatively expensive to discourage spamming. Like at least 100 USD.
+			ensure!(
+				create_asset_xcm > 0 && transfer_asset_xcm > 0 && register_token > meth(100),
+				Error::<T>::InvalidTokenTransferFees
+			);
+
+			let command = Command::SetTokenTransferFees {
+				create_asset_xcm,
+				transfer_asset_xcm,
+				register_token,
+			};
+			Self::send(PRIMARY_GOVERNANCE_CHANNEL, command, PaysFee::<T>::No)?;
+
+			Self::deposit_event(Event::<T>::SetTokenTransferFees {
+				create_asset_xcm,
+				transfer_asset_xcm,
+				register_token,
+			});
+			Ok(())
+		}
+	}
+
+	impl<T: Config> Pallet<T> {
+		/// Send `command` to the Gateway on the Channel identified by `channel_id`
+		fn send(channel_id: ChannelId, command: Command, pays_fee: PaysFee<T>) -> DispatchResult {
+			let message = Message { id: None, channel_id, command };
+			let (ticket, fee) =
+				T::OutboundQueue::validate(&message).map_err(|err| Error::<T>::Send(err))?;
+
+			let payment = match pays_fee {
+				PaysFee::Yes(account) => Some((account, fee.total())),
+				PaysFee::Partial(account) => Some((account, fee.local)),
+				PaysFee::No => None,
+			};
+
+			if let Some((payer, fee)) = payment {
+				T::Token::transfer(
+					&payer,
+					&T::TreasuryAccount::get(),
+					fee,
+					Preservation::Preserve,
+				)?;
+			}
+
+			T::OutboundQueue::deliver(ticket).map_err(|err| Error::<T>::Send(err))?;
+			Ok(())
+		}
+
+		/// Issue a `Command::TransferNativeFromAgent` command. The command will be sent on the
+		/// channel `channel_id`
+		pub fn do_transfer_native_from_agent(
+			agent_id: H256,
+			channel_id: ChannelId,
+			recipient: H160,
+			amount: u128,
+			pays_fee: PaysFee<T>,
+		) -> DispatchResult {
+			ensure!(Agents::<T>::contains_key(agent_id), Error::<T>::NoAgent);
+
+			let command = Command::TransferNativeFromAgent { agent_id, recipient, amount };
+			Self::send(channel_id, command, pays_fee)?;
+
+			Self::deposit_event(Event::<T>::TransferNativeFromAgent {
+				agent_id,
+				recipient,
+				amount,
+			});
+			Ok(())
+		}
+
+		/// Initializes agents and channels.
+		pub fn initialize(para_id: ParaId, asset_hub_para_id: ParaId) -> Result<(), DispatchError> {
+			// Asset Hub
+			let asset_hub_location: MultiLocation =
+				ParentThen(X1(Parachain(asset_hub_para_id.into()))).into();
+			let asset_hub_agent_id = agent_id_of::<T>(&asset_hub_location)?;
+			let asset_hub_channel_id: ChannelId = asset_hub_para_id.into();
+			Agents::<T>::insert(asset_hub_agent_id, ());
+			Channels::<T>::insert(
+				asset_hub_channel_id,
+				Channel { agent_id: asset_hub_agent_id, para_id: asset_hub_para_id },
+			);
+
+			// Governance channels
+			let bridge_hub_agent_id = agent_id_of::<T>(&MultiLocation::here())?;
+			// Agent for BridgeHub
+			Agents::<T>::insert(bridge_hub_agent_id, ());
+
+			// Primary governance channel
+			Channels::<T>::insert(
+				PRIMARY_GOVERNANCE_CHANNEL,
+				Channel { agent_id: bridge_hub_agent_id, para_id },
+			);
+
+			// Secondary governance channel
+			Channels::<T>::insert(
+				SECONDARY_GOVERNANCE_CHANNEL,
+				Channel { agent_id: bridge_hub_agent_id, para_id },
+			);
+
+			Ok(())
+		}
+
+		/// Checks if the pallet has been initialized.
+		pub(crate) fn is_initialized() -> bool {
+			let primary_exists = Channels::<T>::contains_key(PRIMARY_GOVERNANCE_CHANNEL);
+			let secondary_exists = Channels::<T>::contains_key(SECONDARY_GOVERNANCE_CHANNEL);
+			primary_exists && secondary_exists
+		}
+	}
+
+	impl<T: Config> StaticLookup for Pallet<T> {
+		type Source = ChannelId;
+		type Target = Channel;
+		fn lookup(channel_id: Self::Source) -> Option<Self::Target> {
+			Channels::<T>::get(channel_id)
+		}
+	}
+
+	impl<T: Config> Contains<ChannelId> for Pallet<T> {
+		fn contains(channel_id: &ChannelId) -> bool {
+			Channels::<T>::get(channel_id).is_some()
+		}
+	}
+
+	impl<T: Config> Get<PricingParametersOf<T>> for Pallet<T> {
+		fn get() -> PricingParametersOf<T> {
+			PricingParameters::<T>::get()
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/system/src/migration.rs

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Governance API for controlling the Ethereum side of the bridge
+use super::*;
+use frame_support::traits::OnRuntimeUpgrade;
+use log;
+
+#[cfg(feature = "try-runtime")]
+use sp_runtime::TryRuntimeError;
+
+pub mod v0 {
+	use frame_support::{pallet_prelude::*, weights::Weight};
+
+	use super::*;
+
+	const LOG_TARGET: &str = "ethereum_system::migration";
+
+	pub struct InitializeOnUpgrade<T, BridgeHubParaId, AssetHubParaId>(
+		sp_std::marker::PhantomData<(T, BridgeHubParaId, AssetHubParaId)>,
+	);
+	impl<T, BridgeHubParaId, AssetHubParaId> OnRuntimeUpgrade
+		for InitializeOnUpgrade<T, BridgeHubParaId, AssetHubParaId>
+	where
+		T: Config,
+		BridgeHubParaId: Get<u32>,
+		AssetHubParaId: Get<u32>,
+	{
+		fn on_runtime_upgrade() -> Weight {
+			if !Pallet::<T>::is_initialized() {
+				Pallet::<T>::initialize(
+					BridgeHubParaId::get().into(),
+					AssetHubParaId::get().into(),
+				)
+				.expect("infallible; qed");
+				log::info!(
+					target: LOG_TARGET,
+					"Ethereum system initialized."
+				);
+				T::DbWeight::get().reads_writes(2, 5)
+			} else {
+				log::info!(
+					target: LOG_TARGET,
+					"Ethereum system already initialized. Skipping."
+				);
+				T::DbWeight::get().reads(2)
+			}
+		}
+
+		#[cfg(feature = "try-runtime")]
+		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
+			if !Pallet::<T>::is_initialized() {
+				log::info!(
+					target: LOG_TARGET,
+					"Agents and channels not initialized. Initialization will run."
+				);
+			} else {
+				log::info!(
+					target: LOG_TARGET,
+					"Agents and channels are initialized. Initialization will not run."
+				);
+			}
+			Ok(vec![])
+		}
+
+		#[cfg(feature = "try-runtime")]
+		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
+			frame_support::ensure!(
+				Pallet::<T>::is_initialized(),
+				"Agents and channels were not initialized."
+			);
+			Ok(())
+		}
+	}
+}

bridges/snowbridge/parachain/pallets/system/src/mock.rs

@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate as snowbridge_system;
+use frame_support::{
+	parameter_types,
+	traits::{tokens::fungible::Mutate, ConstU128, ConstU16, ConstU64, ConstU8},
+	weights::IdentityFee,
+	PalletId,
+};
+use sp_core::H256;
+use xcm_executor::traits::ConvertLocation;
+
+use snowbridge_core::{
+	gwei, meth, outbound::ConstantGasMeter, sibling_sovereign_account, AgentId, AllowSiblingsOnly,
+	ParaId, PricingParameters, Rewards,
+};
+use sp_runtime::{
+	traits::{AccountIdConversion, BlakeTwo256, IdentityLookup, Keccak256},
+	AccountId32, BuildStorage, FixedU128,
+};
+use xcm::prelude::*;
+
+#[cfg(feature = "runtime-benchmarks")]
+use crate::BenchmarkHelper;
+
+type Block = frame_system::mocking::MockBlock<Test>;
+type Balance = u128;
+
+pub type AccountId = AccountId32;
+
+// A stripped-down version of pallet-xcm that only inserts an XCM origin into the runtime
+#[allow(dead_code)]
+#[frame_support::pallet]
+mod pallet_xcm_origin {
+	use frame_support::{
+		pallet_prelude::*,
+		traits::{Contains, OriginTrait},
+	};
+	use xcm::latest::prelude::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		type RuntimeOrigin: From<Origin> + From<<Self as frame_system::Config>::RuntimeOrigin>;
+	}
+
+	// Insert this custom Origin into the aggregate RuntimeOrigin
+	#[pallet::origin]
+	#[derive(PartialEq, Eq, Clone, Encode, Decode, RuntimeDebug, TypeInfo, MaxEncodedLen)]
+	pub struct Origin(pub MultiLocation);
+
+	impl From<MultiLocation> for Origin {
+		fn from(location: MultiLocation) -> Origin {
+			Origin(location)
+		}
+	}
+
+	/// `EnsureOrigin` implementation succeeding with a `MultiLocation` value to recognize and
+	/// filter the contained location
+	pub struct EnsureXcm<F>(PhantomData<F>);
+	impl<O: OriginTrait + From<Origin>, F: Contains<MultiLocation>> EnsureOrigin<O> for EnsureXcm<F>
+	where
+		O::PalletsOrigin: From<Origin> + TryInto<Origin, Error = O::PalletsOrigin>,
+	{
+		type Success = MultiLocation;
+
+		fn try_origin(outer: O) -> Result<Self::Success, O> {
+			outer.try_with_caller(|caller| {
+				caller.try_into().and_then(|o| match o {
+					Origin(location) if F::contains(&location) => Ok(location),
+					o => Err(o.into()),
+				})
+			})
+		}
+
+		#[cfg(feature = "runtime-benchmarks")]
+		fn try_successful_origin() -> Result<O, ()> {
+			Ok(O::from(Origin(MultiLocation { parents: 1, interior: X1(Parachain(2000)) })))
+		}
+	}
+}
+
+// Configure a mock runtime to test the pallet.
+frame_support::construct_runtime!(
+	pub enum Test
+	{
+		System: frame_system,
+		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
+		XcmOrigin: pallet_xcm_origin::{Pallet, Origin},
+		OutboundQueue: snowbridge_outbound_queue::{Pallet, Call, Storage, Event<T>},
+		EthereumSystem: snowbridge_system,
+		MessageQueue: pallet_message_queue::{Pallet, Call, Storage, Event<T>}
+	}
+);
+
+impl frame_system::Config for Test {
+	type BaseCallFilter = frame_support::traits::Everything;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type RuntimeOrigin = RuntimeOrigin;
+	type RuntimeCall = RuntimeCall;
+	type RuntimeTask = RuntimeTask;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type RuntimeEvent = RuntimeEvent;
+	type BlockHashCount = ConstU64<250>;
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = pallet_balances::AccountData<u128>;
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ConstU16<42>;
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+	type Nonce = u64;
+	type Block = Block;
+}
+
+impl pallet_balances::Config for Test {
+	type MaxLocks = ();
+	type MaxReserves = ();
+	type ReserveIdentifier = [u8; 8];
+	type Balance = Balance;
+	type RuntimeEvent = RuntimeEvent;
+	type DustRemoval = ();
+	type ExistentialDeposit = ConstU128<1>;
+	type AccountStore = System;
+	type WeightInfo = ();
+	type FreezeIdentifier = ();
+	type MaxFreezes = ();
+	type RuntimeHoldReason = ();
+	type RuntimeFreezeReason = ();
+	type MaxHolds = ();
+}
+
+impl pallet_xcm_origin::Config for Test {
+	type RuntimeOrigin = RuntimeOrigin;
+}
+
+parameter_types! {
+	pub const HeapSize: u32 = 32 * 1024;
+	pub const MaxStale: u32 = 32;
+	pub static ServiceWeight: Option<Weight> = Some(Weight::from_parts(100, 100));
+}
+
+impl pallet_message_queue::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type WeightInfo = ();
+	type MessageProcessor = OutboundQueue;
+	type Size = u32;
+	type QueueChangeHandler = ();
+	type HeapSize = HeapSize;
+	type MaxStale = MaxStale;
+	type ServiceWeight = ServiceWeight;
+	type QueuePausedQuery = ();
+}
+
+parameter_types! {
+	pub const MaxMessagePayloadSize: u32 = 1024;
+	pub const MaxMessagesPerBlock: u32 = 20;
+	pub const OwnParaId: ParaId = ParaId::new(1013);
+}
+
+impl snowbridge_outbound_queue::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type Hashing = Keccak256;
+	type MessageQueue = MessageQueue;
+	type Decimals = ConstU8<10>;
+	type MaxMessagePayloadSize = MaxMessagePayloadSize;
+	type MaxMessagesPerBlock = MaxMessagesPerBlock;
+	type GasMeter = ConstantGasMeter;
+	type Balance = u128;
+	type PricingParameters = EthereumSystem;
+	type Channels = EthereumSystem;
+	type WeightToFee = IdentityFee<u128>;
+	type WeightInfo = ();
+}
+
+parameter_types! {
+	pub const SS58Prefix: u8 = 42;
+	pub const AnyNetwork: Option<NetworkId> = None;
+	pub const RelayNetwork: Option<NetworkId> = Some(NetworkId::Kusama);
+	pub const RelayLocation: MultiLocation = MultiLocation::parent();
+	pub UniversalLocation: InteriorMultiLocation =
+		X2(GlobalConsensus(RelayNetwork::get().unwrap()), Parachain(1013));
+}
+
+pub const DOT: u128 = 10_000_000_000;
+
+parameter_types! {
+	pub TreasuryAccount: AccountId = PalletId(*b"py/trsry").into_account_truncating();
+	pub Fee: u64 = 1000;
+	pub const RococoNetwork: NetworkId = NetworkId::Rococo;
+	pub const InitialFunding: u128 = 1_000_000_000_000;
+	pub AssetHubParaId: ParaId = ParaId::new(1000);
+	pub TestParaId: u32 = 2000;
+	pub Parameters: PricingParameters<u128> = PricingParameters {
+		exchange_rate: FixedU128::from_rational(1, 400),
+		fee_per_gas: gwei(20),
+		rewards: Rewards { local: DOT, remote: meth(1) }
+	};
+	pub const InboundDeliveryCost: u128 = 1_000_000_000;
+
+}
+
+#[cfg(feature = "runtime-benchmarks")]
+impl BenchmarkHelper<RuntimeOrigin> for () {
+	fn make_xcm_origin(location: MultiLocation) -> RuntimeOrigin {
+		RuntimeOrigin::from(pallet_xcm_origin::Origin(location))
+	}
+}
+
+impl crate::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type OutboundQueue = OutboundQueue;
+	type SiblingOrigin = pallet_xcm_origin::EnsureXcm<AllowSiblingsOnly>;
+	type AgentIdOf = snowbridge_core::AgentIdOf;
+	type TreasuryAccount = TreasuryAccount;
+	type Token = Balances;
+	type DefaultPricingParameters = Parameters;
+	type WeightInfo = ();
+	type InboundDeliveryCost = InboundDeliveryCost;
+	#[cfg(feature = "runtime-benchmarks")]
+	type Helper = ();
+}
+
+// Build genesis storage according to the mock runtime.
+pub fn new_test_ext(genesis_build: bool) -> sp_io::TestExternalities {
+	let mut storage = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+
+	if genesis_build {
+		crate::GenesisConfig::<Test> {
+			para_id: OwnParaId::get(),
+			asset_hub_para_id: AssetHubParaId::get(),
+			_config: Default::default(),
+		}
+		.assimilate_storage(&mut storage)
+		.unwrap();
+	}
+
+	let mut ext: sp_io::TestExternalities = storage.into();
+	let initial_amount = InitialFunding::get();
+	let test_para_id = TestParaId::get();
+	let sovereign_account = sibling_sovereign_account::<Test>(test_para_id.into());
+	let treasury_account = TreasuryAccount::get();
+	ext.execute_with(|| {
+		System::set_block_number(1);
+		Balances::mint_into(&AccountId32::from([0; 32]), initial_amount).unwrap();
+		Balances::mint_into(&sovereign_account, initial_amount).unwrap();
+		Balances::mint_into(&treasury_account, initial_amount).unwrap();
+	});
+	ext
+}
+
+// Test helpers
+
+pub fn make_xcm_origin(location: MultiLocation) -> RuntimeOrigin {
+	pallet_xcm_origin::Origin(location).into()
+}
+
+pub fn make_agent_id(location: MultiLocation) -> AgentId {
+	<Test as snowbridge_system::Config>::AgentIdOf::convert_location(&location)
+		.expect("convert location")
+}

bridges/snowbridge/parachain/pallets/system/src/tests.rs

@@ -0,0 +1,664 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{mock::*, *};
+use frame_support::{assert_noop, assert_ok};
+use hex_literal::hex;
+use snowbridge_core::{eth, sibling_sovereign_account_raw};
+use sp_core::H256;
+use sp_runtime::{AccountId32, DispatchError::BadOrigin, TokenError};
+
+#[test]
+fn create_agent() {
+	new_test_ext(true).execute_with(|| {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let agent_id = make_agent_id(origin_location);
+		let sovereign_account = sibling_sovereign_account::<Test>(origin_para_id.into());
+
+		// fund sovereign account of origin
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		assert!(!Agents::<Test>::contains_key(agent_id));
+
+		let origin = make_xcm_origin(origin_location);
+		assert_ok!(EthereumSystem::create_agent(origin));
+
+		assert!(Agents::<Test>::contains_key(agent_id));
+	});
+}
+
+#[test]
+fn test_agent_for_here() {
+	new_test_ext(true).execute_with(|| {
+		let origin_location = MultiLocation::here();
+		let agent_id = make_agent_id(origin_location);
+		assert_eq!(
+			agent_id,
+			hex!("03170a2e7597b7b7e3d84c05391d139a62b157e78786d8c082f29dcf4c111314").into(),
+		)
+	});
+}
+
+#[test]
+fn create_agent_fails_on_funds_unavailable() {
+	new_test_ext(true).execute_with(|| {
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(2000)) };
+		let origin = make_xcm_origin(origin_location);
+		// Reset balance of sovereign_account to zero so to trigger the FundsUnavailable error
+		let sovereign_account = sibling_sovereign_account::<Test>(2000.into());
+		Balances::set_balance(&sovereign_account, 0);
+		assert_noop!(EthereumSystem::create_agent(origin), TokenError::FundsUnavailable);
+	});
+}
+
+#[test]
+fn create_agent_bad_origin() {
+	new_test_ext(true).execute_with(|| {
+		// relay chain location not allowed
+		assert_noop!(
+			EthereumSystem::create_agent(make_xcm_origin(MultiLocation {
+				parents: 1,
+				interior: Here,
+			})),
+			BadOrigin,
+		);
+
+		// local account location not allowed
+		assert_noop!(
+			EthereumSystem::create_agent(make_xcm_origin(MultiLocation {
+				parents: 0,
+				interior: X1(Junction::AccountId32 { network: None, id: [67u8; 32] }),
+			})),
+			BadOrigin,
+		);
+
+		// Signed origin not allowed
+		assert_noop!(
+			EthereumSystem::create_agent(RuntimeOrigin::signed([14; 32].into())),
+			BadOrigin
+		);
+
+		// None origin not allowed
+		assert_noop!(EthereumSystem::create_agent(RuntimeOrigin::none()), BadOrigin);
+	});
+}
+
+#[test]
+fn upgrade_as_root() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let address: H160 = Default::default();
+		let code_hash: H256 = Default::default();
+
+		assert_ok!(EthereumSystem::upgrade(origin, address, code_hash, None));
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(crate::Event::Upgrade {
+			impl_address: address,
+			impl_code_hash: code_hash,
+			initializer_params_hash: None,
+		}));
+	});
+}
+
+#[test]
+fn upgrade_as_signed_fails() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::signed(AccountId32::new([0; 32]));
+		let address: H160 = Default::default();
+		let code_hash: H256 = Default::default();
+
+		assert_noop!(EthereumSystem::upgrade(origin, address, code_hash, None), BadOrigin);
+	});
+}
+
+#[test]
+fn upgrade_with_params() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let address: H160 = Default::default();
+		let code_hash: H256 = Default::default();
+		let initializer: Option<Initializer> =
+			Some(Initializer { params: [0; 256].into(), maximum_required_gas: 10000 });
+		assert_ok!(EthereumSystem::upgrade(origin, address, code_hash, initializer));
+	});
+}
+
+#[test]
+fn set_operating_mode() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let mode = OperatingMode::RejectingOutboundMessages;
+
+		assert_ok!(EthereumSystem::set_operating_mode(origin, mode));
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(crate::Event::SetOperatingMode {
+			mode,
+		}));
+	});
+}
+
+#[test]
+fn set_operating_mode_as_signed_fails() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::signed([14; 32].into());
+		let mode = OperatingMode::RejectingOutboundMessages;
+
+		assert_noop!(EthereumSystem::set_operating_mode(origin, mode), BadOrigin);
+	});
+}
+
+#[test]
+fn set_pricing_parameters() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let mut params = Parameters::get();
+		params.rewards.local = 7;
+
+		assert_ok!(EthereumSystem::set_pricing_parameters(origin, params));
+
+		assert_eq!(PricingParameters::<Test>::get().rewards.local, 7);
+	});
+}
+
+#[test]
+fn set_pricing_parameters_as_signed_fails() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::signed([14; 32].into());
+		let params = Parameters::get();
+
+		assert_noop!(EthereumSystem::set_pricing_parameters(origin, params), BadOrigin);
+	});
+}
+
+#[test]
+fn set_pricing_parameters_invalid() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let mut params = Parameters::get();
+		params.rewards.local = 0;
+
+		assert_noop!(
+			EthereumSystem::set_pricing_parameters(origin.clone(), params),
+			Error::<Test>::InvalidPricingParameters
+		);
+
+		let mut params = Parameters::get();
+		params.exchange_rate = 0u128.into();
+		assert_noop!(
+			EthereumSystem::set_pricing_parameters(origin.clone(), params),
+			Error::<Test>::InvalidPricingParameters
+		);
+		params = Parameters::get();
+		params.fee_per_gas = sp_core::U256::zero();
+		assert_noop!(
+			EthereumSystem::set_pricing_parameters(origin.clone(), params),
+			Error::<Test>::InvalidPricingParameters
+		);
+		params = Parameters::get();
+		params.rewards.local = 0;
+		assert_noop!(
+			EthereumSystem::set_pricing_parameters(origin.clone(), params),
+			Error::<Test>::InvalidPricingParameters
+		);
+		params = Parameters::get();
+		params.rewards.remote = sp_core::U256::zero();
+		assert_noop!(
+			EthereumSystem::set_pricing_parameters(origin, params),
+			Error::<Test>::InvalidPricingParameters
+		);
+	});
+}
+
+#[test]
+fn set_token_transfer_fees() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+
+		assert_ok!(EthereumSystem::set_token_transfer_fees(origin, 1, 1, eth(1)));
+	});
+}
+
+#[test]
+fn set_token_transfer_fees_root_only() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::signed([14; 32].into());
+
+		assert_noop!(EthereumSystem::set_token_transfer_fees(origin, 1, 1, 1.into()), BadOrigin);
+	});
+}
+
+#[test]
+fn set_token_transfer_fees_invalid() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+
+		assert_noop!(
+			EthereumSystem::set_token_transfer_fees(origin, 0, 0, 0.into()),
+			Error::<Test>::InvalidTokenTransferFees
+		);
+	});
+}
+
+#[test]
+fn create_channel() {
+	new_test_ext(true).execute_with(|| {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let sovereign_account = sibling_sovereign_account::<Test>(origin_para_id.into());
+		let origin = make_xcm_origin(origin_location);
+
+		// fund sovereign account of origin
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin, OperatingMode::Normal));
+	});
+}
+
+#[test]
+fn create_channel_fail_already_exists() {
+	new_test_ext(true).execute_with(|| {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let sovereign_account = sibling_sovereign_account::<Test>(origin_para_id.into());
+		let origin = make_xcm_origin(origin_location);
+
+		// fund sovereign account of origin
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin.clone(), OperatingMode::Normal));
+
+		assert_noop!(
+			EthereumSystem::create_channel(origin, OperatingMode::Normal),
+			Error::<Test>::ChannelAlreadyCreated
+		);
+	});
+}
+
+#[test]
+fn create_channel_bad_origin() {
+	new_test_ext(true).execute_with(|| {
+		// relay chain location not allowed
+		assert_noop!(
+			EthereumSystem::create_channel(
+				make_xcm_origin(MultiLocation { parents: 1, interior: Here }),
+				OperatingMode::Normal,
+			),
+			BadOrigin,
+		);
+
+		// child of sibling location not allowed
+		assert_noop!(
+			EthereumSystem::create_channel(
+				make_xcm_origin(MultiLocation {
+					parents: 1,
+					interior: X2(
+						Parachain(2000),
+						Junction::AccountId32 { network: None, id: [67u8; 32] }
+					),
+				}),
+				OperatingMode::Normal,
+			),
+			BadOrigin,
+		);
+
+		// local account location not allowed
+		assert_noop!(
+			EthereumSystem::create_channel(
+				make_xcm_origin(MultiLocation {
+					parents: 0,
+					interior: X1(Junction::AccountId32 { network: None, id: [67u8; 32] }),
+				}),
+				OperatingMode::Normal,
+			),
+			BadOrigin,
+		);
+
+		// Signed origin not allowed
+		assert_noop!(
+			EthereumSystem::create_channel(
+				RuntimeOrigin::signed([14; 32].into()),
+				OperatingMode::Normal,
+			),
+			BadOrigin
+		);
+
+		// None origin not allowed
+		assert_noop!(EthereumSystem::create_agent(RuntimeOrigin::none()), BadOrigin);
+	});
+}
+
+#[test]
+fn update_channel() {
+	new_test_ext(true).execute_with(|| {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let sovereign_account = sibling_sovereign_account::<Test>(origin_para_id.into());
+		let origin = make_xcm_origin(origin_location);
+
+		// First create the channel
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin.clone(), OperatingMode::Normal));
+
+		// Now try to update it
+		assert_ok!(EthereumSystem::update_channel(origin, OperatingMode::Normal));
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(crate::Event::UpdateChannel {
+			channel_id: ParaId::from(2000).into(),
+			mode: OperatingMode::Normal,
+		}));
+	});
+}
+
+#[test]
+fn update_channel_bad_origin() {
+	new_test_ext(true).execute_with(|| {
+		let mode = OperatingMode::Normal;
+
+		// relay chain location not allowed
+		assert_noop!(
+			EthereumSystem::update_channel(
+				make_xcm_origin(MultiLocation { parents: 1, interior: Here }),
+				mode,
+			),
+			BadOrigin,
+		);
+
+		// child of sibling location not allowed
+		assert_noop!(
+			EthereumSystem::update_channel(
+				make_xcm_origin(MultiLocation {
+					parents: 1,
+					interior: X2(
+						Parachain(2000),
+						Junction::AccountId32 { network: None, id: [67u8; 32] }
+					),
+				}),
+				mode,
+			),
+			BadOrigin,
+		);
+
+		// local account location not allowed
+		assert_noop!(
+			EthereumSystem::update_channel(
+				make_xcm_origin(MultiLocation {
+					parents: 0,
+					interior: X1(Junction::AccountId32 { network: None, id: [67u8; 32] }),
+				}),
+				mode,
+			),
+			BadOrigin,
+		);
+
+		// Signed origin not allowed
+		assert_noop!(
+			EthereumSystem::update_channel(RuntimeOrigin::signed([14; 32].into()), mode),
+			BadOrigin
+		);
+
+		// None origin not allowed
+		assert_noop!(EthereumSystem::update_channel(RuntimeOrigin::none(), mode), BadOrigin);
+	});
+}
+
+#[test]
+fn update_channel_fails_not_exist() {
+	new_test_ext(true).execute_with(|| {
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(2000)) };
+		let origin = make_xcm_origin(origin_location);
+
+		// Now try to update it
+		assert_noop!(
+			EthereumSystem::update_channel(origin, OperatingMode::Normal),
+			Error::<Test>::NoChannel
+		);
+	});
+}
+
+#[test]
+fn force_update_channel() {
+	new_test_ext(true).execute_with(|| {
+		let origin_para_id = 2000;
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(origin_para_id)) };
+		let sovereign_account = sibling_sovereign_account::<Test>(origin_para_id.into());
+		let origin = make_xcm_origin(origin_location);
+
+		let channel_id: ChannelId = ParaId::from(origin_para_id).into();
+
+		// First create the channel
+		let _ = Balances::mint_into(&sovereign_account, 10000);
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin.clone(), OperatingMode::Normal));
+
+		// Now try to force update it
+		let force_origin = RuntimeOrigin::root();
+		assert_ok!(EthereumSystem::force_update_channel(
+			force_origin,
+			channel_id,
+			OperatingMode::Normal,
+		));
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(crate::Event::UpdateChannel {
+			channel_id: ParaId::from(2000).into(),
+			mode: OperatingMode::Normal,
+		}));
+	});
+}
+
+#[test]
+fn force_update_channel_bad_origin() {
+	new_test_ext(true).execute_with(|| {
+		let mode = OperatingMode::Normal;
+
+		// signed origin not allowed
+		assert_noop!(
+			EthereumSystem::force_update_channel(
+				RuntimeOrigin::signed([14; 32].into()),
+				ParaId::from(1000).into(),
+				mode,
+			),
+			BadOrigin,
+		);
+	});
+}
+
+#[test]
+fn transfer_native_from_agent() {
+	new_test_ext(true).execute_with(|| {
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(2000)) };
+		let origin = make_xcm_origin(origin_location);
+		let recipient: H160 = [27u8; 20].into();
+		let amount = 103435;
+
+		// First create the agent and channel
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin, OperatingMode::Normal));
+
+		let origin = make_xcm_origin(origin_location);
+		assert_ok!(EthereumSystem::transfer_native_from_agent(origin, recipient, amount),);
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(
+			crate::Event::TransferNativeFromAgent {
+				agent_id: make_agent_id(origin_location),
+				recipient,
+				amount,
+			},
+		));
+	});
+}
+
+#[test]
+fn force_transfer_native_from_agent() {
+	new_test_ext(true).execute_with(|| {
+		let origin = RuntimeOrigin::root();
+		let location = MultiLocation { parents: 1, interior: X1(Parachain(2000)) };
+		let versioned_location: Box<VersionedMultiLocation> = Box::new(location.into());
+		let recipient: H160 = [27u8; 20].into();
+		let amount = 103435;
+
+		// First create the agent
+		Agents::<Test>::insert(make_agent_id(location), ());
+
+		assert_ok!(EthereumSystem::force_transfer_native_from_agent(
+			origin,
+			versioned_location,
+			recipient,
+			amount
+		),);
+
+		System::assert_last_event(RuntimeEvent::EthereumSystem(
+			crate::Event::TransferNativeFromAgent {
+				agent_id: make_agent_id(location),
+				recipient,
+				amount,
+			},
+		));
+	});
+}
+
+#[test]
+fn force_transfer_native_from_agent_bad_origin() {
+	new_test_ext(true).execute_with(|| {
+		let recipient: H160 = [27u8; 20].into();
+		let amount = 103435;
+
+		// signed origin not allowed
+		assert_noop!(
+			EthereumSystem::force_transfer_native_from_agent(
+				RuntimeOrigin::signed([14; 32].into()),
+				Box::new(
+					MultiLocation {
+						parents: 1,
+						interior: X2(
+							Parachain(2000),
+							Junction::AccountId32 { network: None, id: [67u8; 32] }
+						),
+					}
+					.into()
+				),
+				recipient,
+				amount,
+			),
+			BadOrigin,
+		);
+	});
+}
+
+// NOTE: The following tests are not actually tests and are more about obtaining location
+// conversions for devops purposes. They need to be removed here and incorporated into a command
+// line utility.
+
+#[ignore]
+#[test]
+fn check_sibling_sovereign_account() {
+	new_test_ext(true).execute_with(|| {
+		let para_id = 1001;
+		let sovereign_account = sibling_sovereign_account::<Test>(para_id.into());
+		let sovereign_account_raw = sibling_sovereign_account_raw(para_id.into());
+		println!(
+			"Sovereign account for parachain {}: {:#?}",
+			para_id,
+			hex::encode(sovereign_account.clone())
+		);
+		assert_eq!(sovereign_account, sovereign_account_raw.into());
+	});
+}
+
+#[test]
+fn charge_fee_for_create_agent() {
+	new_test_ext(true).execute_with(|| {
+		let para_id: u32 = TestParaId::get();
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(para_id)) };
+		let origin = make_xcm_origin(origin_location);
+		let sovereign_account = sibling_sovereign_account::<Test>(para_id.into());
+		let (_, agent_id) = ensure_sibling::<Test>(&origin_location).unwrap();
+
+		let initial_sovereign_balance = Balances::balance(&sovereign_account);
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		let fee_charged = initial_sovereign_balance - Balances::balance(&sovereign_account);
+
+		assert_ok!(EthereumSystem::create_channel(origin, OperatingMode::Normal));
+
+		// assert sovereign_balance decreased by (fee.base_fee + fee.delivery_fee)
+		let message = Message {
+			id: None,
+			channel_id: ParaId::from(para_id).into(),
+			command: Command::CreateAgent { agent_id },
+		};
+		let (_, fee) = OutboundQueue::validate(&message).unwrap();
+		assert_eq!(fee.local + fee.remote, fee_charged);
+
+		// and treasury_balance increased
+		let treasury_balance = Balances::balance(&TreasuryAccount::get());
+		assert!(treasury_balance > InitialFunding::get());
+
+		let final_sovereign_balance = Balances::balance(&sovereign_account);
+		// (sovereign_balance + treasury_balance) keeps the same
+		assert_eq!(final_sovereign_balance + treasury_balance, { InitialFunding::get() * 2 });
+	});
+}
+
+#[test]
+fn charge_fee_for_transfer_native_from_agent() {
+	new_test_ext(true).execute_with(|| {
+		let para_id: u32 = TestParaId::get();
+		let origin_location = MultiLocation { parents: 1, interior: X1(Parachain(para_id)) };
+		let recipient: H160 = [27u8; 20].into();
+		let amount = 103435;
+		let origin = make_xcm_origin(origin_location);
+		let (_, agent_id) = ensure_sibling::<Test>(&origin_location).unwrap();
+
+		let sovereign_account = sibling_sovereign_account::<Test>(para_id.into());
+
+		// create_agent & create_channel first
+		assert_ok!(EthereumSystem::create_agent(origin.clone()));
+		assert_ok!(EthereumSystem::create_channel(origin.clone(), OperatingMode::Normal));
+
+		// assert sovereign_balance decreased by only the base_fee
+		let sovereign_balance_before = Balances::balance(&sovereign_account);
+		assert_ok!(EthereumSystem::transfer_native_from_agent(origin.clone(), recipient, amount));
+		let message = Message {
+			id: None,
+			channel_id: ParaId::from(para_id).into(),
+			command: Command::TransferNativeFromAgent { agent_id, recipient, amount },
+		};
+		let (_, fee) = OutboundQueue::validate(&message).unwrap();
+		let sovereign_balance_after = Balances::balance(&sovereign_account);
+		assert_eq!(sovereign_balance_after + fee.local, sovereign_balance_before);
+	});
+}
+
+#[test]
+fn charge_fee_for_upgrade() {
+	new_test_ext(true).execute_with(|| {
+		let para_id: u32 = TestParaId::get();
+		let origin = RuntimeOrigin::root();
+		let address: H160 = Default::default();
+		let code_hash: H256 = Default::default();
+		let initializer: Option<Initializer> =
+			Some(Initializer { params: [0; 256].into(), maximum_required_gas: 10000 });
+		assert_ok!(EthereumSystem::upgrade(origin, address, code_hash, initializer.clone()));
+
+		// assert sovereign_balance does not change as we do not charge for sudo operations
+		let sovereign_account = sibling_sovereign_account::<Test>(para_id.into());
+		let sovereign_balance = Balances::balance(&sovereign_account);
+		assert_eq!(sovereign_balance, InitialFunding::get());
+	});
+}
+
+#[test]
+fn genesis_build_initializes_correctly() {
+	new_test_ext(true).execute_with(|| {
+		assert!(EthereumSystem::is_initialized(), "Ethereum uninitialized.");
+	});
+}
+
+#[test]
+fn no_genesis_build_is_uninitialized() {
+	new_test_ext(false).execute_with(|| {
+		assert!(!EthereumSystem::is_initialized(), "Ethereum initialized.");
+	});
+}

bridges/snowbridge/parachain/pallets/system/src/weights.rs

@@ -0,0 +1,249 @@
+
+//! Autogenerated weights for `snowbridge_system`
+//!
+//! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
+//! DATE: 2023-10-09, STEPS: `2`, REPEAT: `1`, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! WORST CASE MAP SIZE: `1000000`
+//! HOSTNAME: `crake.local`, CPU: `<UNKNOWN>`
+//! WASM-EXECUTION: `Compiled`, CHAIN: `Some("bridge-hub-rococo-dev")`, DB CACHE: `1024`
+
+// Executed Command:
+// target/release/polkadot-parachain
+// benchmark
+// pallet
+// --chain
+// bridge-hub-rococo-dev
+// --pallet=snowbridge_system
+// --extrinsic=*
+// --execution=wasm
+// --wasm-execution=compiled
+// --template
+// ../parachain/templates/module-weight-template.hbs
+// --output
+// ../parachain/pallets/control/src/weights.rs
+
+#![cfg_attr(rustfmt, rustfmt_skip)]
+#![allow(unused_parens)]
+#![allow(unused_imports)]
+#![allow(missing_docs)]
+
+use frame_support::{traits::Get, weights::{Weight, constants::RocksDbWeight}};
+use core::marker::PhantomData;
+
+/// Weight functions needed for `snowbridge_system`.
+pub trait WeightInfo {
+	fn upgrade() -> Weight;
+	fn create_agent() -> Weight;
+	fn create_channel() -> Weight;
+	fn update_channel() -> Weight;
+	fn force_update_channel() -> Weight;
+	fn set_operating_mode() -> Weight;
+	fn transfer_native_from_agent() -> Weight;
+	fn force_transfer_native_from_agent() -> Weight;
+	fn set_token_transfer_fees() -> Weight;
+	fn set_pricing_parameters() -> Weight;
+}
+
+// For backwards compatibility and tests.
+impl WeightInfo for () {
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:1)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn upgrade() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `80`
+		//  Estimated: `3517`
+		// Minimum execution time: 44_000_000 picoseconds.
+		Weight::from_parts(44_000_000, 3517)
+			.saturating_add(RocksDbWeight::get().reads(4_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+	/// Storage: EthereumSystem Agents (r:1 w:1)
+	/// Proof: EthereumSystem Agents (max_values: None, max_size: Some(40), added: 2515, mode: MaxEncodedLen)
+	/// Storage: System Account (r:2 w:2)
+	/// Proof: System Account (max_values: None, max_size: Some(128), added: 2603, mode: MaxEncodedLen)
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:1)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn create_agent() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `187`
+		//  Estimated: `6196`
+		// Minimum execution time: 85_000_000 picoseconds.
+		Weight::from_parts(85_000_000, 6196)
+			.saturating_add(RocksDbWeight::get().reads(7_u64))
+			.saturating_add(RocksDbWeight::get().writes(6_u64))
+	}
+	/// Storage: System Account (r:2 w:2)
+	/// Proof: System Account (max_values: None, max_size: Some(128), added: 2603, mode: MaxEncodedLen)
+	/// Storage: EthereumSystem Agents (r:1 w:0)
+	/// Proof: EthereumSystem Agents (max_values: None, max_size: Some(40), added: 2515, mode: MaxEncodedLen)
+	/// Storage: EthereumSystem Channels (r:1 w:1)
+	/// Proof: EthereumSystem Channels (max_values: None, max_size: Some(12), added: 2487, mode: MaxEncodedLen)
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:1 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn create_channel() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `602`
+		//  Estimated: `69050`
+		// Minimum execution time: 83_000_000 picoseconds.
+		Weight::from_parts(83_000_000, 69050)
+			.saturating_add(RocksDbWeight::get().reads(8_u64))
+			.saturating_add(RocksDbWeight::get().writes(5_u64))
+	}
+	/// Storage: EthereumSystem Channels (r:1 w:0)
+	/// Proof: EthereumSystem Channels (max_values: None, max_size: Some(12), added: 2487, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:2 w:2)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:0)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn update_channel() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `256`
+		//  Estimated: `6044`
+		// Minimum execution time: 40_000_000 picoseconds.
+		Weight::from_parts(40_000_000, 6044)
+			.saturating_add(RocksDbWeight::get().reads(5_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+	/// Storage: EthereumSystem Channels (r:1 w:0)
+	/// Proof: EthereumSystem Channels (max_values: None, max_size: Some(12), added: 2487, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:2 w:2)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:0)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn force_update_channel() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `256`
+		//  Estimated: `6044`
+		// Minimum execution time: 41_000_000 picoseconds.
+		Weight::from_parts(41_000_000, 6044)
+			.saturating_add(RocksDbWeight::get().reads(5_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:1)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn set_operating_mode() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `80`
+		//  Estimated: `3517`
+		// Minimum execution time: 31_000_000 picoseconds.
+		Weight::from_parts(31_000_000, 3517)
+			.saturating_add(RocksDbWeight::get().reads(4_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+	/// Storage: EthereumSystem Agents (r:1 w:0)
+	/// Proof: EthereumSystem Agents (max_values: None, max_size: Some(40), added: 2515, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:2 w:2)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:0)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn transfer_native_from_agent() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `252`
+		//  Estimated: `6044`
+		// Minimum execution time: 45_000_000 picoseconds.
+		Weight::from_parts(45_000_000, 6044)
+			.saturating_add(RocksDbWeight::get().reads(5_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+	/// Storage: EthereumSystem Agents (r:1 w:0)
+	/// Proof: EthereumSystem Agents (max_values: None, max_size: Some(40), added: 2515, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:2 w:2)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:0)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn force_transfer_native_from_agent() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `252`
+		//  Estimated: `6044`
+		// Minimum execution time: 42_000_000 picoseconds.
+		Weight::from_parts(42_000_000, 6044)
+			.saturating_add(RocksDbWeight::get().reads(5_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:1)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn set_token_transfer_fees() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `80`
+		//  Estimated: `3517`
+		// Minimum execution time: 31_000_000 picoseconds.
+		Weight::from_parts(42_000_000, 3517)
+			.saturating_add(RocksDbWeight::get().reads(4_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+
+	/// Storage: ParachainInfo ParachainId (r:1 w:0)
+	/// Proof: ParachainInfo ParachainId (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
+	/// Storage: EthereumOutboundQueue PalletOperatingMode (r:1 w:0)
+	/// Proof: EthereumOutboundQueue PalletOperatingMode (max_values: Some(1), max_size: Some(1), added: 496, mode: MaxEncodedLen)
+	/// Storage: MessageQueue BookStateFor (r:1 w:1)
+	/// Proof: MessageQueue BookStateFor (max_values: None, max_size: Some(52), added: 2527, mode: MaxEncodedLen)
+	/// Storage: MessageQueue ServiceHead (r:1 w:1)
+	/// Proof: MessageQueue ServiceHead (max_values: Some(1), max_size: Some(5), added: 500, mode: MaxEncodedLen)
+	/// Storage: MessageQueue Pages (r:0 w:1)
+	/// Proof: MessageQueue Pages (max_values: None, max_size: Some(65585), added: 68060, mode: MaxEncodedLen)
+	fn set_pricing_parameters() -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `80`
+		//  Estimated: `3517`
+		// Minimum execution time: 31_000_000 picoseconds.
+		Weight::from_parts(42_000_000, 3517)
+			.saturating_add(RocksDbWeight::get().reads(4_u64))
+			.saturating_add(RocksDbWeight::get().writes(3_u64))
+	}
+}

bridges/snowbridge/parachain/primitives/beacon/Cargo.toml

@@ -0,0 +1,52 @@
+[package]
+name = "snowbridge-beacon-primitives"
+description = "Snowbridge Beacon Primitives"
+version = "0.0.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+serde = { version = "1.0.188", optional = true, features = ["derive"] }
+hex = { version = "0.4", default-features = false }
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+rlp = { version = "0.5", default-features = false }
+
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+
+ssz_rs = { version = "0.9.0", default-features = false }
+ssz_rs_derive = { version = "0.9.0", default-features = false }
+byte-slice-cast = { version = "1.2.1", default-features = false }
+
+snowbridge-ethereum = { path = "../../primitives/ethereum", default-features = false }
+static_assertions = { version = "1.1.0" }
+milagro_bls = { git = "https://github.com/snowfork/milagro_bls", default-features = false, rev = "a6d66e4eb89015e352fb1c9f7b661ecdbb5b2176" }
+
+[dev-dependencies]
+hex-literal = { version = "0.4.1" }
+
+[features]
+default = ["std"]
+std = [
+	"byte-slice-cast/std",
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"hex/std",
+	"milagro_bls/std",
+	"rlp/std",
+	"scale-info/std",
+	"serde",
+	"snowbridge-ethereum/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"ssz_rs/std",
+]

bridges/snowbridge/parachain/primitives/beacon/src/bits.rs

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use sp_std::{convert::TryInto, prelude::*};
+use ssz_rs::{Bitvector, Deserialize};
+
+pub fn decompress_sync_committee_bits<
+	const SYNC_COMMITTEE_SIZE: usize,
+	const SYNC_COMMITTEE_BITS_SIZE: usize,
+>(
+	input: [u8; SYNC_COMMITTEE_BITS_SIZE],
+) -> [u8; SYNC_COMMITTEE_SIZE] {
+	Bitvector::<{ SYNC_COMMITTEE_SIZE }>::deserialize(&input)
+		.expect("checked statically; qed")
+		.iter()
+		.map(|bit| u8::from(bit == true))
+		.collect::<Vec<u8>>()
+		.try_into()
+		.expect("checked statically; qed")
+}

bridges/snowbridge/parachain/primitives/beacon/src/bls.rs

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{PublicKey, Signature};
+use codec::{Decode, Encode};
+use frame_support::{ensure, PalletError};
+pub use milagro_bls::{
+	AggregatePublicKey, AggregateSignature, PublicKey as PublicKeyPrepared,
+	Signature as SignaturePrepared,
+};
+use scale_info::TypeInfo;
+use sp_core::H256;
+use sp_runtime::RuntimeDebug;
+use sp_std::prelude::*;
+
+#[derive(Copy, Clone, Encode, Decode, Eq, PartialEq, TypeInfo, RuntimeDebug, PalletError)]
+pub enum BlsError {
+	InvalidSignature,
+	InvalidPublicKey,
+	InvalidAggregatePublicKeys,
+	SignatureVerificationFailed,
+}
+
+/// fast_aggregate_verify optimized with aggregate key subtracting absent ones.
+pub fn fast_aggregate_verify(
+	aggregate_pubkey: &PublicKeyPrepared,
+	absent_pubkeys: &Vec<PublicKeyPrepared>,
+	message: H256,
+	signature: &Signature,
+) -> Result<(), BlsError> {
+	let agg_sig = prepare_aggregate_signature(signature)?;
+	let agg_key = prepare_aggregate_pubkey_from_absent(aggregate_pubkey, absent_pubkeys)?;
+	fast_aggregate_verify_pre_aggregated(agg_sig, agg_key, message)
+}
+
+/// Decompress one public key into a point in G1.
+pub fn prepare_milagro_pubkey(pubkey: &PublicKey) -> Result<PublicKeyPrepared, BlsError> {
+	PublicKeyPrepared::from_bytes_unchecked(&pubkey.0).map_err(|_| BlsError::InvalidPublicKey)
+}
+
+/// Prepare for G1 public keys.
+pub fn prepare_g1_pubkeys(pubkeys: &[PublicKey]) -> Result<Vec<PublicKeyPrepared>, BlsError> {
+	pubkeys
+		.iter()
+		// Deserialize one public key from compressed bytes
+		.map(prepare_milagro_pubkey)
+		.collect::<Result<Vec<PublicKeyPrepared>, BlsError>>()
+}
+
+/// Prepare for G1 AggregatePublicKey.
+pub fn prepare_aggregate_pubkey(
+	pubkeys: &[PublicKeyPrepared],
+) -> Result<AggregatePublicKey, BlsError> {
+	AggregatePublicKey::into_aggregate(pubkeys).map_err(|_| BlsError::InvalidPublicKey)
+}
+
+/// Prepare for G1 AggregatePublicKey.
+pub fn prepare_aggregate_pubkey_from_absent(
+	aggregate_key: &PublicKeyPrepared,
+	absent_pubkeys: &Vec<PublicKeyPrepared>,
+) -> Result<AggregatePublicKey, BlsError> {
+	let mut aggregate_pubkey = AggregatePublicKey::from_public_key(aggregate_key);
+	if !absent_pubkeys.is_empty() {
+		let absent_aggregate_key = prepare_aggregate_pubkey(absent_pubkeys)?;
+		aggregate_pubkey.point.sub(&absent_aggregate_key.point);
+	}
+	Ok(AggregatePublicKey { point: aggregate_pubkey.point })
+}
+
+/// Prepare for G2 AggregateSignature, normally more expensive than G1 operation.
+pub fn prepare_aggregate_signature(signature: &Signature) -> Result<AggregateSignature, BlsError> {
+	Ok(AggregateSignature::from_signature(
+		&SignaturePrepared::from_bytes(&signature.0).map_err(|_| BlsError::InvalidSignature)?,
+	))
+}
+
+/// fast_aggregate_verify_pre_aggregated which is the most expensive call in beacon light client.
+pub fn fast_aggregate_verify_pre_aggregated(
+	agg_sig: AggregateSignature,
+	aggregate_key: AggregatePublicKey,
+	message: H256,
+) -> Result<(), BlsError> {
+	ensure!(
+		agg_sig.fast_aggregate_verify_pre_aggregated(&message[..], &aggregate_key),
+		BlsError::SignatureVerificationFailed
+	);
+	Ok(())
+}

bridges/snowbridge/parachain/primitives/beacon/src/config.rs

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+pub const MAX_PROOF_SIZE: u32 = 20;
+
+pub const FEE_RECIPIENT_SIZE: usize = 20;
+pub const EXTRA_DATA_SIZE: usize = 32;
+pub const LOGS_BLOOM_SIZE: usize = 256;
+
+pub const PUBKEY_SIZE: usize = 48;
+pub const SIGNATURE_SIZE: usize = 96;

bridges/snowbridge/parachain/primitives/beacon/src/lib.rs

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod bits;
+pub mod bls;
+pub mod config;
+pub mod merkle_proof;
+pub mod receipt;
+pub mod ssz;
+pub mod types;
+pub mod updates;
+
+#[cfg(feature = "std")]
+mod serde_utils;
+
+pub use types::{
+	BeaconHeader, CompactBeaconState, CompactExecutionHeader, ExecutionHeaderState,
+	ExecutionPayloadHeader, FinalizedHeaderState, Fork, ForkData, ForkVersion, ForkVersions, Mode,
+	PublicKey, Signature, SigningData, SyncAggregate, SyncCommittee, SyncCommitteePrepared,
+};
+pub use updates::{CheckpointUpdate, ExecutionHeaderUpdate, NextSyncCommitteeUpdate, Update};
+
+pub use bits::decompress_sync_committee_bits;
+pub use bls::{
+	fast_aggregate_verify, prepare_aggregate_pubkey, prepare_aggregate_pubkey_from_absent,
+	prepare_aggregate_signature, prepare_g1_pubkeys, AggregatePublicKey, AggregateSignature,
+	BlsError, PublicKeyPrepared, SignaturePrepared,
+};
+pub use merkle_proof::verify_merkle_branch;
+pub use receipt::verify_receipt_proof;

bridges/snowbridge/parachain/primitives/beacon/src/merkle_proof.rs

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use sp_core::H256;
+use sp_io::hashing::sha2_256;
+
+/// Specified by <https://github.com/ethereum/consensus-specs/blob/fe9c1a8cbf0c2da8a4f349efdcd77dd7ac8445c4/specs/phase0/beacon-chain.md?plain=1#L742>
+/// with improvements from <https://github.com/ethereum/consensus-specs/blob/dev/ssz/merkle-proofs.md>
+pub fn verify_merkle_branch(
+	leaf: H256,
+	branch: &[H256],
+	index: usize,
+	depth: usize,
+	root: H256,
+) -> bool {
+	// verify the proof length
+	if branch.len() != depth {
+		return false
+	}
+	// verify the computed merkle root
+	root == compute_merkle_root(leaf, branch, index)
+}
+
+fn compute_merkle_root(leaf: H256, proof: &[H256], index: usize) -> H256 {
+	let mut value: [u8; 32] = leaf.into();
+	for (i, node) in proof.iter().enumerate() {
+		let mut data = [0u8; 64];
+		if generalized_index_bit(index, i) {
+			// right node
+			data[0..32].copy_from_slice(node.as_bytes());
+			data[32..64].copy_from_slice(&value);
+			value = sha2_256(&data);
+		} else {
+			// left node
+			data[0..32].copy_from_slice(&value);
+			data[32..64].copy_from_slice(node.as_bytes());
+			value = sha2_256(&data);
+		}
+	}
+	value.into()
+}
+
+/// Spec: <https://github.com/ethereum/consensus-specs/blob/fe9c1a8cbf0c2da8a4f349efdcd77dd7ac8445c4/ssz/merkle-proofs.md#get_generalized_index_bit>
+fn generalized_index_bit(index: usize, position: usize) -> bool {
+	index & (1 << position) > 0
+}
+
+/// Spec: <https://github.com/ethereum/consensus-specs/blob/fe9c1a8cbf0c2da8a4f349efdcd77dd7ac8445c4/specs/altair/light-client/sync-protocol.md#get_subtree_index>
+pub const fn subtree_index(generalized_index: usize) -> usize {
+	generalized_index % (1 << generalized_index_length(generalized_index))
+}
+
+/// Spec: <https://github.com/ethereum/consensus-specs/blob/fe9c1a8cbf0c2da8a4f349efdcd77dd7ac8445c4/ssz/merkle-proofs.md#get_generalized_index_length>
+pub const fn generalized_index_length(generalized_index: usize) -> usize {
+	match generalized_index.checked_ilog2() {
+		Some(v) => v as usize,
+		None => panic!("checked statically; qed"),
+	}
+}

bridges/snowbridge/parachain/primitives/beacon/src/receipt.rs

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use sp_core::H256;
+use sp_io::hashing::keccak_256;
+use sp_std::prelude::*;
+
+use snowbridge_ethereum::{mpt, Receipt};
+
+pub fn verify_receipt_proof(
+	receipts_root: H256,
+	proof: &[Vec<u8>],
+) -> Option<Result<Receipt, rlp::DecoderError>> {
+	match apply_merkle_proof(proof) {
+		Some((root, data)) if root == receipts_root => Some(rlp::decode(&data)),
+		Some((_, _)) => None,
+		None => None,
+	}
+}
+
+fn apply_merkle_proof(proof: &[Vec<u8>]) -> Option<(H256, Vec<u8>)> {
+	let mut iter = proof.iter().rev();
+	let first_bytes = match iter.next() {
+		Some(b) => b,
+		None => return None,
+	};
+	let item_to_prove: mpt::ShortNode = rlp::decode(first_bytes).ok()?;
+
+	let final_hash: Option<[u8; 32]> = iter.try_fold(keccak_256(first_bytes), |acc, x| {
+		let node: Box<dyn mpt::Node> = x.as_slice().try_into().ok()?;
+		if (*node).contains_hash(acc.into()) {
+			return Some(keccak_256(x))
+		}
+		None
+	});
+
+	final_hash.map(|hash| (hash.into(), item_to_prove.value))
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use hex_literal::hex;
+
+	#[test]
+	fn test_verify_receipt_proof() {
+		let root: H256 =
+			hex!("fd5e397a84884641f53c496804f24b5276cbb8c5c9cfc2342246be8e3ce5ad02").into();
+
+		// Valid proof
+		let proof_receipt5 = vec!(
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+		);
+		assert!(verify_receipt_proof(root, &proof_receipt5).is_some());
+
+		// Various invalid proofs
+		let proof_empty: Vec<Vec<u8>> = vec![];
+		let proof_missing_full_node = vec![proof_receipt5[0].clone(), proof_receipt5[2].clone()];
+		let proof_missing_short_node1 = vec![proof_receipt5[0].clone(), proof_receipt5[1].clone()];
+		let proof_missing_short_node2 = vec![proof_receipt5[0].clone()];
+		let proof_invalid_encoding = vec![proof_receipt5[2][2..].to_vec()];
+		let proof_no_full_node = vec![proof_receipt5[2].clone(), proof_receipt5[2].clone()];
+		assert!(verify_receipt_proof(root, &proof_empty).is_none());
+		assert!(verify_receipt_proof(root, &proof_missing_full_node).is_none());
+
+		assert_eq!(
+			verify_receipt_proof(root, &proof_missing_short_node1),
+			Some(Err(rlp::DecoderError::Custom("Unsupported receipt type")))
+		);
+
+		assert_eq!(
+			verify_receipt_proof(root, &proof_missing_short_node2),
+			Some(Err(rlp::DecoderError::Custom("Unsupported receipt type")))
+		);
+
+		assert!(verify_receipt_proof(root, &proof_invalid_encoding).is_none());
+		assert!(verify_receipt_proof(root, &proof_no_full_node).is_none());
+	}
+
+	#[test]
+	fn test_verify_receipt_proof_with_intermediate_short_node() {
+		let root: H256 =
+			hex!("d128e3a57142d2bf15bc0cbcac7ad54f40750d571b5c3097e425882c10c9ba66").into();
+
+		let proof_receipt263 = vec![
+			hex!("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").to_vec(),
+			hex!("f871a0246de222036ee6a03329b0105da0a6b3f916fc95a9ed5a403a581a0c4d74242ca0ac108a49a88b57a05ac34a108b39f1e45f6f167f2b9fbc8d52fb58e2e5a6af1ea0fcfe07ac2ccd3c28b6eab68d1bce112f6f6dbd9023e4ec3c05b96615aa803d798080808080808080808080808080").to_vec(),
+			hex!("e4820001a04fff54398cad4d05ea6abfd8b0f3b4fe14c04d7ff5f5211c5b927d9cf72ac1d8").to_vec(),
+			hex!("f851a096d010643ca2d47412ca66898286b5f2412963b9ec051b33e570d575914c9c5ca028cd24c652989542fe89479ec6388eac4592432242af5ba97563b3ac7c71c019808080808080808080808080808080").to_vec(),
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+		];
+		assert!(verify_receipt_proof(root, &proof_receipt263).is_some());
+	}
+}

bridges/snowbridge/parachain/primitives/beacon/src/serde_utils.rs

@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use sp_core::U256;
+
+use core::fmt::Formatter;
+use serde::{Deserialize, Deserializer};
+
+// helper to deserialize arbitrary arrays like [T; N]
+pub mod arrays {
+	use std::{convert::TryInto, marker::PhantomData};
+
+	use serde::{
+		de::{SeqAccess, Visitor},
+		ser::SerializeTuple,
+		Deserialize, Deserializer, Serialize, Serializer,
+	};
+
+	pub fn serialize<S: Serializer, T: Serialize, const N: usize>(
+		data: &[T; N],
+		ser: S,
+	) -> Result<S::Ok, S::Error> {
+		let mut s = ser.serialize_tuple(N)?;
+		for item in data {
+			s.serialize_element(item)?;
+		}
+		s.end()
+	}
+
+	struct ArrayVisitor<T, const N: usize>(PhantomData<T>);
+
+	impl<'de, T, const N: usize> Visitor<'de> for ArrayVisitor<T, N>
+	where
+		T: Deserialize<'de>,
+	{
+		type Value = [T; N];
+
+		fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+			formatter.write_str(&format!("an array of length {}", N))
+		}
+
+		#[inline]
+		fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+		where
+			A: SeqAccess<'de>,
+		{
+			// can be optimized using MaybeUninit
+			let mut data = Vec::with_capacity(N);
+			for _ in 0..N {
+				match (seq.next_element())? {
+					Some(val) => data.push(val),
+					None => return Err(serde::de::Error::invalid_length(N, &self)),
+				}
+			}
+			match data.try_into() {
+				Ok(arr) => Ok(arr),
+				Err(_) => unreachable!(),
+			}
+		}
+	}
+
+	pub fn deserialize<'de, D, T, const N: usize>(deserializer: D) -> Result<[T; N], D::Error>
+	where
+		D: Deserializer<'de>,
+		T: Deserialize<'de>,
+	{
+		deserializer.deserialize_tuple(N, ArrayVisitor::<T, N>(PhantomData))
+	}
+}
+
+pub(crate) fn from_hex_to_bytes<'de, D>(deserializer: D) -> Result<Vec<u8>, D::Error>
+where
+	D: Deserializer<'de>,
+{
+	let s = String::deserialize(deserializer)?;
+
+	let str_without_0x = match s.strip_prefix("0x") {
+		Some(val) => val,
+		None => &s,
+	};
+
+	let hex_bytes = match hex::decode(str_without_0x) {
+		Ok(bytes) => bytes,
+		Err(e) => return Err(serde::de::Error::custom(e.to_string())),
+	};
+
+	Ok(hex_bytes)
+}
+
+pub(crate) fn from_int_to_u256<'de, D>(deserializer: D) -> Result<U256, D::Error>
+where
+	D: Deserializer<'de>,
+{
+	let number = u128::deserialize(deserializer)?;
+
+	Ok(U256::from(number))
+}
+
+pub struct HexVisitor<const LENGTH: usize>();
+
+impl<'de, const LENGTH: usize> serde::de::Visitor<'de> for HexVisitor<LENGTH> {
+	type Value = [u8; LENGTH];
+
+	fn expecting(&self, formatter: &mut Formatter) -> sp_std::fmt::Result {
+		formatter.write_str("a hex string with an '0x' prefix")
+	}
+
+	fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+	where
+		E: serde::de::Error,
+	{
+		let stripped = match v.strip_prefix("0x") {
+			Some(stripped) => stripped,
+			None => v,
+		};
+
+		let decoded = match hex::decode(stripped) {
+			Ok(decoded) => decoded,
+			Err(e) => return Err(serde::de::Error::custom(e.to_string())),
+		};
+		if decoded.len() != LENGTH {
+			return Err(serde::de::Error::custom("publickey expected to be 48 characters"))
+		}
+
+		let data: Self::Value = decoded
+			.try_into()
+			.map_err(|_e| serde::de::Error::custom("hex data has unexpected length"))?;
+
+		Ok(data)
+	}
+}

bridges/snowbridge/parachain/primitives/beacon/src/ssz.rs

@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{
+	config::{EXTRA_DATA_SIZE, FEE_RECIPIENT_SIZE, LOGS_BLOOM_SIZE, PUBKEY_SIZE, SIGNATURE_SIZE},
+	types::{
+		BeaconHeader, ExecutionPayloadHeader, ForkData, SigningData, SyncAggregate, SyncCommittee,
+	},
+};
+use byte_slice_cast::AsByteSlice;
+use sp_core::H256;
+use sp_std::{vec, vec::Vec};
+use ssz_rs::{
+	prelude::{List, Vector},
+	Bitvector, Deserialize, DeserializeError, SimpleSerialize, SimpleSerializeError, Sized, U256,
+};
+use ssz_rs_derive::SimpleSerialize as SimpleSerializeDerive;
+
+#[derive(Default, SimpleSerializeDerive, Clone, Debug)]
+pub struct SSZBeaconBlockHeader {
+	pub slot: u64,
+	pub proposer_index: u64,
+	pub parent_root: [u8; 32],
+	pub state_root: [u8; 32],
+	pub body_root: [u8; 32],
+}
+
+impl From<BeaconHeader> for SSZBeaconBlockHeader {
+	fn from(beacon_header: BeaconHeader) -> Self {
+		SSZBeaconBlockHeader {
+			slot: beacon_header.slot,
+			proposer_index: beacon_header.proposer_index,
+			parent_root: beacon_header.parent_root.to_fixed_bytes(),
+			state_root: beacon_header.state_root.to_fixed_bytes(),
+			body_root: beacon_header.body_root.to_fixed_bytes(),
+		}
+	}
+}
+
+#[derive(Default, SimpleSerializeDerive, Clone)]
+pub struct SSZSyncCommittee<const COMMITTEE_SIZE: usize> {
+	pub pubkeys: Vector<Vector<u8, PUBKEY_SIZE>, COMMITTEE_SIZE>,
+	pub aggregate_pubkey: Vector<u8, PUBKEY_SIZE>,
+}
+
+impl<const COMMITTEE_SIZE: usize> From<SyncCommittee<COMMITTEE_SIZE>>
+	for SSZSyncCommittee<COMMITTEE_SIZE>
+{
+	fn from(sync_committee: SyncCommittee<COMMITTEE_SIZE>) -> Self {
+		let mut pubkeys_vec = Vec::new();
+
+		for pubkey in sync_committee.pubkeys.iter() {
+			// The only thing that can go wrong in the conversion from vec to Vector (ssz type) is
+			// that the Vector size is 0, or that the given data to create the Vector from does not
+			// match the expected size N. Because these sizes are statically checked (i.e.
+			// PublicKey's size is 48, and const PUBKEY_SIZE is 48, it is impossible for "try_from"
+			// to return an error condition.
+			let conv_pubkey = Vector::<u8, PUBKEY_SIZE>::try_from(pubkey.0.to_vec())
+				.expect("checked statically; qed");
+
+			pubkeys_vec.push(conv_pubkey);
+		}
+
+		let pubkeys = Vector::<Vector<u8, PUBKEY_SIZE>, { COMMITTEE_SIZE }>::try_from(pubkeys_vec)
+			.expect("checked statically; qed");
+
+		let aggregate_pubkey =
+			Vector::<u8, PUBKEY_SIZE>::try_from(sync_committee.aggregate_pubkey.0.to_vec())
+				.expect("checked statically; qed");
+
+		SSZSyncCommittee { pubkeys, aggregate_pubkey }
+	}
+}
+
+#[derive(Default, Debug, SimpleSerializeDerive, Clone)]
+pub struct SSZSyncAggregate<const COMMITTEE_SIZE: usize> {
+	pub sync_committee_bits: Bitvector<COMMITTEE_SIZE>,
+	pub sync_committee_signature: Vector<u8, SIGNATURE_SIZE>,
+}
+
+impl<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize>
+	From<SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>> for SSZSyncAggregate<COMMITTEE_SIZE>
+{
+	fn from(sync_aggregate: SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>) -> Self {
+		SSZSyncAggregate {
+			sync_committee_bits: Bitvector::<COMMITTEE_SIZE>::deserialize(
+				&sync_aggregate.sync_committee_bits,
+			)
+			.expect("checked statically; qed"),
+			sync_committee_signature: Vector::<u8, SIGNATURE_SIZE>::try_from(
+				sync_aggregate.sync_committee_signature.0.to_vec(),
+			)
+			.expect("checked statically; qed"),
+		}
+	}
+}
+
+#[derive(Default, SimpleSerializeDerive, Clone)]
+pub struct SSZForkData {
+	pub current_version: [u8; 4],
+	pub genesis_validators_root: [u8; 32],
+}
+
+impl From<ForkData> for SSZForkData {
+	fn from(fork_data: ForkData) -> Self {
+		SSZForkData {
+			current_version: fork_data.current_version,
+			genesis_validators_root: fork_data.genesis_validators_root,
+		}
+	}
+}
+
+#[derive(Default, SimpleSerializeDerive, Clone)]
+pub struct SSZSigningData {
+	pub object_root: [u8; 32],
+	pub domain: [u8; 32],
+}
+
+impl From<SigningData> for SSZSigningData {
+	fn from(signing_data: SigningData) -> Self {
+		SSZSigningData {
+			object_root: signing_data.object_root.into(),
+			domain: signing_data.domain.into(),
+		}
+	}
+}
+
+#[derive(Default, SimpleSerializeDerive, Clone, Debug)]
+pub struct SSZExecutionPayloadHeader {
+	pub parent_hash: [u8; 32],
+	pub fee_recipient: Vector<u8, FEE_RECIPIENT_SIZE>,
+	pub state_root: [u8; 32],
+	pub receipts_root: [u8; 32],
+	pub logs_bloom: Vector<u8, LOGS_BLOOM_SIZE>,
+	pub prev_randao: [u8; 32],
+	pub block_number: u64,
+	pub gas_limit: u64,
+	pub gas_used: u64,
+	pub timestamp: u64,
+	pub extra_data: List<u8, EXTRA_DATA_SIZE>,
+	pub base_fee_per_gas: U256,
+	pub block_hash: [u8; 32],
+	pub transactions_root: [u8; 32],
+	pub withdrawals_root: [u8; 32],
+}
+
+impl TryFrom<ExecutionPayloadHeader> for SSZExecutionPayloadHeader {
+	type Error = SimpleSerializeError;
+
+	fn try_from(payload: ExecutionPayloadHeader) -> Result<Self, Self::Error> {
+		Ok(SSZExecutionPayloadHeader {
+			parent_hash: payload.parent_hash.to_fixed_bytes(),
+			fee_recipient: Vector::<u8, FEE_RECIPIENT_SIZE>::try_from(
+				payload.fee_recipient.to_fixed_bytes().to_vec(),
+			)
+			.expect("checked statically; qed"),
+			state_root: payload.state_root.to_fixed_bytes(),
+			receipts_root: payload.receipts_root.to_fixed_bytes(),
+			// Logs bloom bytes size is not constrained, so here we do need to check the try_from
+			// error
+			logs_bloom: Vector::<u8, LOGS_BLOOM_SIZE>::try_from(payload.logs_bloom)
+				.map_err(|(_, err)| err)?,
+			prev_randao: payload.prev_randao.to_fixed_bytes(),
+			block_number: payload.block_number,
+			gas_limit: payload.gas_limit,
+			gas_used: payload.gas_used,
+			timestamp: payload.timestamp,
+			// Extra data bytes size is not constrained, so here we do need to check the try_from
+			// error
+			extra_data: List::<u8, EXTRA_DATA_SIZE>::try_from(payload.extra_data)
+				.map_err(|(_, err)| err)?,
+			base_fee_per_gas: U256::from_bytes_le(
+				payload
+					.base_fee_per_gas
+					.as_byte_slice()
+					.try_into()
+					.expect("checked in prep; qed"),
+			),
+			block_hash: payload.block_hash.to_fixed_bytes(),
+			transactions_root: payload.transactions_root.to_fixed_bytes(),
+			withdrawals_root: payload.withdrawals_root.to_fixed_bytes(),
+		})
+	}
+}
+
+pub fn hash_tree_root<T: SimpleSerialize>(mut object: T) -> Result<H256, SimpleSerializeError> {
+	match object.hash_tree_root() {
+		Ok(node) => {
+			let fixed_bytes: [u8; 32] =
+				node.as_ref().try_into().expect("Node is a newtype over [u8; 32]; qed");
+			Ok(fixed_bytes.into())
+		},
+		Err(err) => Err(err.into()),
+	}
+}

bridges/snowbridge/parachain/primitives/beacon/src/types.rs

@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::{Decode, Encode, MaxEncodedLen};
+use frame_support::{CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound};
+use scale_info::TypeInfo;
+use sp_core::{H160, H256, U256};
+use sp_runtime::RuntimeDebug;
+use sp_std::{boxed::Box, prelude::*};
+
+use crate::config::{PUBKEY_SIZE, SIGNATURE_SIZE};
+
+#[cfg(feature = "std")]
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+#[cfg(feature = "std")]
+use crate::serde_utils::HexVisitor;
+
+use crate::ssz::{
+	hash_tree_root, SSZBeaconBlockHeader, SSZExecutionPayloadHeader, SSZForkData, SSZSigningData,
+	SSZSyncAggregate, SSZSyncCommittee,
+};
+use ssz_rs::SimpleSerializeError;
+
+pub use crate::bits::decompress_sync_committee_bits;
+
+use crate::bls::{prepare_g1_pubkeys, prepare_milagro_pubkey, BlsError};
+use milagro_bls::PublicKey as PublicKeyPrepared;
+
+pub type ValidatorIndex = u64;
+pub type ForkVersion = [u8; 4];
+
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct ForkVersions {
+	pub genesis: Fork,
+	pub altair: Fork,
+	pub bellatrix: Fork,
+	pub capella: Fork,
+}
+
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct Fork {
+	pub version: [u8; 4],
+	pub epoch: u64,
+}
+
+#[derive(Copy, Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct PublicKey(pub [u8; PUBKEY_SIZE]);
+
+impl Default for PublicKey {
+	fn default() -> Self {
+		PublicKey([0u8; PUBKEY_SIZE])
+	}
+}
+
+impl From<[u8; PUBKEY_SIZE]> for PublicKey {
+	fn from(v: [u8; PUBKEY_SIZE]) -> Self {
+		Self(v)
+	}
+}
+
+impl MaxEncodedLen for PublicKey {
+	fn max_encoded_len() -> usize {
+		PUBKEY_SIZE
+	}
+}
+
+#[cfg(feature = "std")]
+impl<'de> Deserialize<'de> for PublicKey {
+	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+	where
+		D: Deserializer<'de>,
+	{
+		deserializer.deserialize_str(HexVisitor::<PUBKEY_SIZE>()).map(|v| v.into())
+	}
+}
+
+#[cfg(feature = "std")]
+impl Serialize for PublicKey {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: Serializer,
+	{
+		serializer.serialize_bytes(&self.0)
+	}
+}
+
+#[derive(Copy, Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct Signature(pub [u8; SIGNATURE_SIZE]);
+
+impl Default for Signature {
+	fn default() -> Self {
+		Signature([0u8; SIGNATURE_SIZE])
+	}
+}
+
+impl From<[u8; SIGNATURE_SIZE]> for Signature {
+	fn from(v: [u8; SIGNATURE_SIZE]) -> Self {
+		Self(v)
+	}
+}
+
+#[cfg(feature = "std")]
+impl<'de> Deserialize<'de> for Signature {
+	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+	where
+		D: Deserializer<'de>,
+	{
+		deserializer.deserialize_str(HexVisitor::<SIGNATURE_SIZE>()).map(|v| v.into())
+	}
+}
+
+#[derive(Copy, Clone, Default, Encode, Decode, TypeInfo, MaxEncodedLen)]
+pub struct ExecutionHeaderState {
+	pub beacon_block_root: H256,
+	pub beacon_slot: u64,
+	pub block_hash: H256,
+	pub block_number: u64,
+}
+
+#[derive(Copy, Clone, Default, Encode, Decode, TypeInfo, MaxEncodedLen)]
+pub struct FinalizedHeaderState {
+	pub beacon_block_root: H256,
+	pub beacon_slot: u64,
+}
+
+#[derive(Clone, Default, Encode, Decode, PartialEq, RuntimeDebug)]
+pub struct ForkData {
+	// 1 or 0 bit, indicates whether a sync committee participated in a vote
+	pub current_version: [u8; 4],
+	pub genesis_validators_root: [u8; 32],
+}
+
+impl ForkData {
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZForkData>(self.clone().into())
+	}
+}
+
+#[derive(Clone, Default, Encode, Decode, PartialEq, RuntimeDebug)]
+pub struct SigningData {
+	pub object_root: H256,
+	pub domain: H256,
+}
+
+impl SigningData {
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZSigningData>(self.clone().into())
+	}
+}
+
+/// Sync committee as it is stored in the runtime storage.
+#[derive(
+	Encode, Decode, PartialEqNoBound, CloneNoBound, RuntimeDebugNoBound, TypeInfo, MaxEncodedLen,
+)]
+#[cfg_attr(
+	feature = "std",
+	derive(Serialize, Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+#[codec(mel_bound())]
+pub struct SyncCommittee<const COMMITTEE_SIZE: usize> {
+	#[cfg_attr(feature = "std", serde(with = "crate::serde_utils::arrays"))]
+	pub pubkeys: [PublicKey; COMMITTEE_SIZE],
+	pub aggregate_pubkey: PublicKey,
+}
+
+impl<const COMMITTEE_SIZE: usize> Default for SyncCommittee<COMMITTEE_SIZE> {
+	fn default() -> Self {
+		SyncCommittee {
+			pubkeys: [Default::default(); COMMITTEE_SIZE],
+			aggregate_pubkey: Default::default(),
+		}
+	}
+}
+
+impl<const COMMITTEE_SIZE: usize> SyncCommittee<COMMITTEE_SIZE> {
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZSyncCommittee<COMMITTEE_SIZE>>(self.clone().into())
+	}
+}
+
+/// Prepared G1 public key of sync committee as it is stored in the runtime storage.
+#[derive(Clone, PartialEq, Eq, Encode, Decode, TypeInfo, MaxEncodedLen)]
+pub struct SyncCommitteePrepared<const COMMITTEE_SIZE: usize> {
+	pub root: H256,
+	pub pubkeys: Box<[PublicKeyPrepared; COMMITTEE_SIZE]>,
+	pub aggregate_pubkey: PublicKeyPrepared,
+}
+
+impl<const COMMITTEE_SIZE: usize> Default for SyncCommitteePrepared<COMMITTEE_SIZE> {
+	fn default() -> Self {
+		SyncCommitteePrepared {
+			root: H256::default(),
+			pubkeys: Box::new([PublicKeyPrepared::default(); COMMITTEE_SIZE]),
+			aggregate_pubkey: PublicKeyPrepared::default(),
+		}
+	}
+}
+
+impl<const COMMITTEE_SIZE: usize> TryFrom<&SyncCommittee<COMMITTEE_SIZE>>
+	for SyncCommitteePrepared<COMMITTEE_SIZE>
+{
+	type Error = BlsError;
+
+	fn try_from(sync_committee: &SyncCommittee<COMMITTEE_SIZE>) -> Result<Self, Self::Error> {
+		let g1_pubkeys = prepare_g1_pubkeys(&sync_committee.pubkeys)?;
+		let sync_committee_root = sync_committee.hash_tree_root().expect("checked statically; qed");
+
+		Ok(SyncCommitteePrepared::<COMMITTEE_SIZE> {
+			pubkeys: g1_pubkeys.try_into().expect("checked statically; qed"),
+			aggregate_pubkey: prepare_milagro_pubkey(&sync_committee.aggregate_pubkey)?,
+			root: sync_committee_root,
+		})
+	}
+}
+
+/// Beacon block header as it is stored in the runtime storage. The block root is the
+/// Merkleization of a BeaconHeader.
+#[derive(
+	Copy, Clone, Default, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo, MaxEncodedLen,
+)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+pub struct BeaconHeader {
+	// The slot for which this block is created. Must be greater than the slot of the block defined
+	// by parent root.
+	pub slot: u64,
+	// The index of the validator that proposed the block.
+	pub proposer_index: ValidatorIndex,
+	// The block root of the parent block, forming a block chain.
+	pub parent_root: H256,
+	// The hash root of the post state of running the state transition through this block.
+	pub state_root: H256,
+	// The hash root of the beacon block body
+	pub body_root: H256,
+}
+
+impl BeaconHeader {
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZBeaconBlockHeader>((*self).into())
+	}
+}
+
+#[derive(Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo)]
+#[cfg_attr(
+	feature = "std",
+	derive(Deserialize),
+	serde(
+		try_from = "IntermediateSyncAggregate",
+		deny_unknown_fields,
+		bound(serialize = ""),
+		bound(deserialize = "")
+	)
+)]
+#[codec(mel_bound())]
+pub struct SyncAggregate<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize> {
+	pub sync_committee_bits: [u8; COMMITTEE_BITS_SIZE],
+	pub sync_committee_signature: Signature,
+}
+
+impl<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize> Default
+	for SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>
+{
+	fn default() -> Self {
+		SyncAggregate {
+			sync_committee_bits: [0; COMMITTEE_BITS_SIZE],
+			sync_committee_signature: Default::default(),
+		}
+	}
+}
+
+impl<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize>
+	SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>
+{
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZSyncAggregate<COMMITTEE_SIZE>>(self.clone().into())
+	}
+}
+
+/// Serde deserialization helper for SyncAggregate
+#[cfg(feature = "std")]
+#[derive(Deserialize)]
+struct IntermediateSyncAggregate {
+	#[cfg_attr(feature = "std", serde(deserialize_with = "crate::serde_utils::from_hex_to_bytes"))]
+	pub sync_committee_bits: Vec<u8>,
+	pub sync_committee_signature: Signature,
+}
+
+#[cfg(feature = "std")]
+impl<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize>
+	TryFrom<IntermediateSyncAggregate> for SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>
+{
+	type Error = String;
+
+	fn try_from(other: IntermediateSyncAggregate) -> Result<Self, Self::Error> {
+		Ok(Self {
+			sync_committee_bits: other
+				.sync_committee_bits
+				.try_into()
+				.map_err(|_| "unexpected length".to_owned())?,
+			sync_committee_signature: other.sync_committee_signature,
+		})
+	}
+}
+
+/// ExecutionPayloadHeader
+/// <https://github.com/ethereum/annotated-spec/blob/master/capella/beacon-chain.md#executionpayloadheader>
+#[derive(
+	Default, Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo,
+)]
+#[cfg_attr(
+	feature = "std",
+	derive(Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+#[codec(mel_bound())]
+pub struct ExecutionPayloadHeader {
+	pub parent_hash: H256,
+	pub fee_recipient: H160,
+	pub state_root: H256,
+	pub receipts_root: H256,
+	#[cfg_attr(feature = "std", serde(deserialize_with = "crate::serde_utils::from_hex_to_bytes"))]
+	pub logs_bloom: Vec<u8>,
+	pub prev_randao: H256,
+	pub block_number: u64,
+	pub gas_limit: u64,
+	pub gas_used: u64,
+	pub timestamp: u64,
+	#[cfg_attr(feature = "std", serde(deserialize_with = "crate::serde_utils::from_hex_to_bytes"))]
+	pub extra_data: Vec<u8>,
+	#[cfg_attr(feature = "std", serde(deserialize_with = "crate::serde_utils::from_int_to_u256"))]
+	pub base_fee_per_gas: U256,
+	pub block_hash: H256,
+	pub transactions_root: H256,
+	pub withdrawals_root: H256,
+}
+
+impl ExecutionPayloadHeader {
+	pub fn hash_tree_root(&self) -> Result<H256, SimpleSerializeError> {
+		hash_tree_root::<SSZExecutionPayloadHeader>(self.clone().try_into()?)
+	}
+}
+
+#[derive(
+	Default,
+	Encode,
+	Decode,
+	CloneNoBound,
+	PartialEqNoBound,
+	RuntimeDebugNoBound,
+	TypeInfo,
+	MaxEncodedLen,
+)]
+pub struct CompactExecutionHeader {
+	pub parent_hash: H256,
+	#[codec(compact)]
+	pub block_number: u64,
+	pub state_root: H256,
+	pub receipts_root: H256,
+}
+
+impl From<ExecutionPayloadHeader> for CompactExecutionHeader {
+	fn from(execution_payload: ExecutionPayloadHeader) -> Self {
+		Self {
+			parent_hash: execution_payload.parent_hash,
+			block_number: execution_payload.block_number,
+			state_root: execution_payload.state_root,
+			receipts_root: execution_payload.receipts_root,
+		}
+	}
+}
+
+#[derive(
+	Default,
+	Encode,
+	Decode,
+	Copy,
+	Clone,
+	PartialEqNoBound,
+	RuntimeDebugNoBound,
+	TypeInfo,
+	MaxEncodedLen,
+)]
+pub struct CompactBeaconState {
+	#[codec(compact)]
+	pub slot: u64,
+	pub block_roots_root: H256,
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use hex_literal::hex;
+
+	#[test]
+	pub fn test_hash_beacon_header1() {
+		let hash_root = BeaconHeader {
+			slot: 3,
+			proposer_index: 2,
+			parent_root: hex!("796ea53efb534eab7777809cc5ee2d84e7f25024b9d0c4d7e5bcaab657e4bdbd")
+				.into(),
+			state_root: hex!("ba3ff080912be5c9c158b2e962c1b39a91bc0615762ba6fa2ecacafa94e9ae0a")
+				.into(),
+			body_root: hex!("a18d7fcefbb74a177c959160e0ee89c23546482154e6831237710414465dcae5")
+				.into(),
+		}
+		.hash_tree_root();
+
+		assert!(hash_root.is_ok());
+		assert_eq!(
+			hash_root.unwrap(),
+			hex!("7d42595818709e805dd2fa710a2d2c1f62576ef1ab7273941ac9130fb94b91f7").into()
+		);
+	}
+
+	#[test]
+	pub fn test_hash_beacon_header2() {
+		let hash_root = BeaconHeader {
+			slot: 3476424,
+			proposer_index: 314905,
+			parent_root: hex!("c069d7b49cffd2b815b0fb8007eb9ca91202ea548df6f3db60000f29b2489f28")
+				.into(),
+			state_root: hex!("444d293e4533501ee508ad608783a7d677c3c566f001313e8a02ce08adf590a3")
+				.into(),
+			body_root: hex!("6508a0241047f21ba88f05d05b15534156ab6a6f8e029a9a5423da429834e04a")
+				.into(),
+		}
+		.hash_tree_root();
+
+		assert!(hash_root.is_ok());
+		assert_eq!(
+			hash_root.unwrap(),
+			hex!("0aa41166ff01e58e111ac8c42309a738ab453cf8d7285ed8477b1c484acb123e").into()
+		);
+	}
+
+	#[test]
+	pub fn test_hash_fork_data() {
+		let hash_root = ForkData {
+			current_version: hex!("83f38a34"),
+			genesis_validators_root: hex!(
+				"22370bbbb358800f5711a10ea9845284272d8493bed0348cab87b8ab1e127930"
+			),
+		}
+		.hash_tree_root();
+
+		assert!(hash_root.is_ok());
+		assert_eq!(
+			hash_root.unwrap(),
+			hex!("57c12c4246bc7152b174b51920506bf943eff9c7ffa50b9533708e9cc1f680fc").into()
+		);
+	}
+
+	#[test]
+	pub fn test_hash_signing_data() {
+		let hash_root = SigningData {
+			object_root: hex!("63654cbe64fc07853f1198c165dd3d49c54fc53bc417989bbcc66da15f850c54")
+				.into(),
+			domain: hex!("037da907d1c3a03c0091b2254e1480d9b1783476e228ab29adaaa8f133e08f7a").into(),
+		}
+		.hash_tree_root();
+
+		assert!(hash_root.is_ok());
+		assert_eq!(
+			hash_root.unwrap(),
+			hex!("b9eb2caf2d691b183c2d57f322afe505c078cd08101324f61c3641714789a54e").into()
+		);
+	}
+
+	#[test]
+	pub fn test_hash_sync_aggregate() {
+		let hash_root = SyncAggregate::<512, 64>{
+				sync_committee_bits: hex!("cefffffefffffff767fffbedffffeffffeeffdffffdebffffff7f7dbdf7fffdffffbffcfffdff79dfffbbfefff2ffffff7ddeff7ffffc98ff7fbfffffffffff7"),
+				sync_committee_signature: hex!("8af1a8577bba419fe054ee49b16ed28e081dda6d3ba41651634685e890992a0b675e20f8d9f2ec137fe9eb50e838aa6117f9f5410e2e1024c4b4f0e098e55144843ce90b7acde52fe7b94f2a1037342c951dc59f501c92acf7ed944cb6d2b5f7").into(),
+		}.hash_tree_root();
+
+		assert!(hash_root.is_ok());
+		assert_eq!(
+			hash_root.unwrap(),
+			hex!("e6dcad4f60ce9ff8a587b110facbaf94721f06cd810b6d8bf6cffa641272808d").into()
+		);
+	}
+
+	#[test]
+	pub fn test_hash_execution_payload() {
+		let hash_root =
+            ExecutionPayloadHeader{
+                parent_hash: hex!("eadee5ab098dde64e9fd02ae5858064bad67064070679625b09f8d82dec183f7").into(),
+                fee_recipient: hex!("f97e180c050e5ab072211ad2c213eb5aee4df134").into(),
+                state_root: hex!("564fa064c2a324c2b5978d7fdfc5d4224d4f421a45388af1ed405a399c845dff").into(),
+                receipts_root: hex!("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421").into(),
+                logs_bloom: hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").to_vec(),
+                prev_randao: hex!("6bf538bdfbdf1c96ff528726a40658a91d0bda0f1351448c4c4f3604db2a0ccf").into(),
+                block_number: 477434,
+                gas_limit: 8154925,
+                gas_used: 0,
+                timestamp: 1652816940,
+                extra_data: vec![],
+                base_fee_per_gas: U256::from(7_i16),
+                block_hash: hex!("cd8df91b4503adb8f2f1c7a4f60e07a1f1a2cbdfa2a95bceba581f3ff65c1968").into(),
+                transactions_root: hex!("7ffe241ea60187fdb0187bfa22de35d1f9bed7ab061d9401fd47e34a54fbede1").into(),
+				withdrawals_root: hex!("28ba1834a3a7b657460ce79fa3a1d909ab8828fd557659d4d0554a9bdbc0ec30").into(),
+			}.hash_tree_root();
+		assert!(hash_root.is_ok());
+	}
+}
+
+/// Operating modes for beacon client
+#[derive(Encode, Decode, Copy, Clone, PartialEq, RuntimeDebug, TypeInfo)]
+pub enum Mode {
+	Active,
+	Blocked,
+}

bridges/snowbridge/parachain/primitives/beacon/src/updates.rs

@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::{Decode, Encode};
+use frame_support::{CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound};
+use scale_info::TypeInfo;
+use sp_core::H256;
+use sp_std::prelude::*;
+
+use crate::types::{BeaconHeader, ExecutionPayloadHeader, SyncAggregate, SyncCommittee};
+
+#[derive(Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo)]
+#[cfg_attr(
+	feature = "std",
+	derive(serde::Serialize, serde::Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+pub struct CheckpointUpdate<const COMMITTEE_SIZE: usize> {
+	pub header: BeaconHeader,
+	pub current_sync_committee: SyncCommittee<COMMITTEE_SIZE>,
+	pub current_sync_committee_branch: Vec<H256>,
+	pub validators_root: H256,
+	pub block_roots_root: H256,
+	pub block_roots_branch: Vec<H256>,
+}
+
+impl<const COMMITTEE_SIZE: usize> Default for CheckpointUpdate<COMMITTEE_SIZE> {
+	fn default() -> Self {
+		CheckpointUpdate {
+			header: Default::default(),
+			current_sync_committee: Default::default(),
+			current_sync_committee_branch: Default::default(),
+			validators_root: Default::default(),
+			block_roots_root: Default::default(),
+			block_roots_branch: Default::default(),
+		}
+	}
+}
+
+#[derive(
+	Default, Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo,
+)]
+#[cfg_attr(
+	feature = "std",
+	derive(serde::Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+pub struct Update<const COMMITTEE_SIZE: usize, const COMMITTEE_BITS_SIZE: usize> {
+	/// A recent header attesting to the finalized header, using its `state_root`.
+	pub attested_header: BeaconHeader,
+	/// The signing data that the sync committee produced for this attested header, including
+	/// who participated in the vote and the resulting signature.
+	pub sync_aggregate: SyncAggregate<COMMITTEE_SIZE, COMMITTEE_BITS_SIZE>,
+	/// The slot at which the sync aggregate can be found, typically attested_header.slot + 1, if
+	/// the next slot block was not missed.
+	pub signature_slot: u64,
+	/// The next sync committee for the next sync committee period, if present.
+	pub next_sync_committee_update: Option<NextSyncCommitteeUpdate<COMMITTEE_SIZE>>,
+	/// The latest finalized header.
+	pub finalized_header: BeaconHeader,
+	/// The merkle proof testifying to the finalized header, using the `attested_header.state_root`
+	/// as tree root.
+	pub finality_branch: Vec<H256>,
+	/// The finalized_header's `block_roots` root in the beacon state, used for ancestry proofs.
+	pub block_roots_root: H256,
+	/// The merkle path to prove the `block_roots_root` value.
+	pub block_roots_branch: Vec<H256>,
+}
+
+#[derive(
+	Default, Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo,
+)]
+#[cfg_attr(
+	feature = "std",
+	derive(serde::Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+pub struct NextSyncCommitteeUpdate<const COMMITTEE_SIZE: usize> {
+	pub next_sync_committee: SyncCommittee<COMMITTEE_SIZE>,
+	pub next_sync_committee_branch: Vec<H256>,
+}
+
+#[derive(Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo)]
+#[cfg_attr(
+	feature = "std",
+	derive(serde::Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+pub struct ExecutionHeaderUpdate {
+	/// Header for the beacon block containing the execution payload
+	pub header: BeaconHeader,
+	/// Proof that `header` is an ancestor of a finalized header
+	pub ancestry_proof: Option<AncestryProof>,
+	/// Execution header to be imported
+	pub execution_header: ExecutionPayloadHeader,
+	/// Merkle proof that execution payload is contained within `header`
+	pub execution_branch: Vec<H256>,
+}
+
+#[derive(Encode, Decode, CloneNoBound, PartialEqNoBound, RuntimeDebugNoBound, TypeInfo)]
+#[cfg_attr(
+	feature = "std",
+	derive(serde::Deserialize),
+	serde(deny_unknown_fields, bound(serialize = ""), bound(deserialize = ""))
+)]
+pub struct AncestryProof {
+	/// Merkle proof that `header` is an ancestor of `finalized_header`
+	pub header_branch: Vec<H256>,
+	/// Root of a finalized block that has already been imported into the light client
+	pub finalized_block_root: H256,
+}

bridges/snowbridge/parachain/primitives/core/Cargo.toml

@@ -0,0 +1,60 @@
+[package]
+name = "snowbridge-core"
+description = "Snowbridge Core"
+version = "0.1.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+serde = { version = "1.0.188", optional = true, features = ["alloc", "derive"], default-features = false }
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+hex-literal = { version = "0.4.1" }
+
+polkadot-parachain-primitives = { path = "../../../../../polkadot/parachain", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-arithmetic = { path = "../../../../../substrate/primitives/arithmetic", default-features = false }
+
+snowbridge-beacon-primitives = { path = "../../primitives/beacon", default-features = false }
+
+ethabi = { git = "https://github.com/Snowfork/ethabi-decode.git", package = "ethabi-decode", branch = "master", default-features = false }
+
+[dev-dependencies]
+hex = { version = "0.4.3" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"ethabi/std",
+	"frame-support/std",
+	"frame-system/std",
+	"polkadot-parachain-primitives/std",
+	"scale-info/std",
+	"serde/std",
+	"snowbridge-beacon-primitives/std",
+	"sp-arithmetic/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm-builder/std",
+	"xcm/std",
+]
+serde = ["dep:serde", "scale-info/serde"]
+runtime-benchmarks = [
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"polkadot-parachain-primitives/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+]

bridges/snowbridge/parachain/primitives/core/src/inbound.rs

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Types for representing inbound messages
+
+use codec::{Decode, Encode};
+use frame_support::PalletError;
+use scale_info::TypeInfo;
+use sp_core::{H160, H256};
+use sp_runtime::RuntimeDebug;
+use sp_std::vec::Vec;
+
+/// A trait for verifying inbound messages from Ethereum.
+pub trait Verifier {
+	fn verify(event: &Log, proof: &Proof) -> Result<(), VerificationError>;
+}
+
+#[derive(Clone, Encode, Decode, RuntimeDebug, PalletError, TypeInfo)]
+#[cfg_attr(feature = "std", derive(PartialEq))]
+pub enum VerificationError {
+	/// Execution header is missing
+	HeaderNotFound,
+	/// Event log was not found in the verified transaction receipt
+	LogNotFound,
+	/// Event log has an invalid format
+	InvalidLog,
+	/// Unable to verify the transaction receipt with the provided proof
+	InvalidProof,
+}
+
+pub type MessageNonce = u64;
+
+/// A bridge message from the Gateway contract on Ethereum
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct Message {
+	/// Event log emitted by Gateway contract
+	pub event_log: Log,
+	/// Inclusion proof for a transaction receipt containing the event log
+	pub proof: Proof,
+}
+
+const MAX_TOPICS: usize = 4;
+
+#[derive(Clone, RuntimeDebug)]
+pub enum LogValidationError {
+	TooManyTopics,
+}
+
+/// Event log
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct Log {
+	pub address: H160,
+	pub topics: Vec<H256>,
+	pub data: Vec<u8>,
+}
+
+impl Log {
+	pub fn validate(&self) -> Result<(), LogValidationError> {
+		if self.topics.len() > MAX_TOPICS {
+			return Err(LogValidationError::TooManyTopics)
+		}
+		Ok(())
+	}
+}
+
+/// Inclusion proof for a transaction receipt
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct Proof {
+	// The block hash of the block in which the receipt was included.
+	pub block_hash: H256,
+	// The index of the transaction (and receipt) within the block.
+	pub tx_index: u32,
+	// Proof keys and values (receipts tree)
+	pub data: (Vec<Vec<u8>>, Vec<Vec<u8>>),
+}

bridges/snowbridge/parachain/primitives/core/src/lib.rs

@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! # Core
+//!
+//! Common traits and types
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(test)]
+mod tests;
+
+pub mod inbound;
+pub mod operating_mode;
+pub mod outbound;
+pub mod pricing;
+pub mod ringbuffer;
+
+pub use polkadot_parachain_primitives::primitives::{
+	Id as ParaId, IsSystem, Sibling as SiblingParaId,
+};
+pub use ringbuffer::{RingBufferMap, RingBufferMapImpl};
+pub use sp_core::U256;
+
+use codec::{Decode, Encode, MaxEncodedLen};
+use frame_support::traits::Contains;
+use hex_literal::hex;
+use scale_info::TypeInfo;
+use sp_core::H256;
+use sp_io::hashing::keccak_256;
+use sp_runtime::{traits::AccountIdConversion, RuntimeDebug};
+use sp_std::prelude::*;
+use xcm::prelude::{
+	Junction::Parachain,
+	Junctions::{Here, X1},
+	MultiLocation,
+};
+use xcm_builder::{DescribeAllTerminal, DescribeFamily, DescribeLocation, HashedDescription};
+
+/// The ID of an agent contract
+pub type AgentId = H256;
+pub use operating_mode::BasicOperatingMode;
+
+pub use pricing::{PricingParameters, Rewards};
+
+pub fn sibling_sovereign_account<T>(para_id: ParaId) -> T::AccountId
+where
+	T: frame_system::Config,
+{
+	SiblingParaId::from(para_id).into_account_truncating()
+}
+
+pub fn sibling_sovereign_account_raw(para_id: ParaId) -> [u8; 32] {
+	SiblingParaId::from(para_id).into_account_truncating()
+}
+
+pub struct AllowSiblingsOnly;
+impl Contains<MultiLocation> for AllowSiblingsOnly {
+	fn contains(location: &MultiLocation) -> bool {
+		matches!(location, MultiLocation { parents: 1, interior: X1(Parachain(_)) })
+	}
+}
+
+pub fn gwei(x: u128) -> U256 {
+	U256::from(1_000_000_000u128).saturating_mul(x.into())
+}
+
+pub fn meth(x: u128) -> U256 {
+	U256::from(1_000_000_000_000_000u128).saturating_mul(x.into())
+}
+
+pub fn eth(x: u128) -> U256 {
+	U256::from(1_000_000_000_000_000_000u128).saturating_mul(x.into())
+}
+
+pub const ROC: u128 = 1_000_000_000_000;
+
+/// Identifier for a message channel
+#[derive(
+	Clone, Copy, Encode, Decode, PartialEq, Eq, Default, RuntimeDebug, MaxEncodedLen, TypeInfo,
+)]
+pub struct ChannelId([u8; 32]);
+
+/// Deterministically derive a ChannelId for a sibling parachain
+/// Generator: keccak256("para" + big_endian_bytes(para_id))
+///
+/// The equivalent generator on the Solidity side is in
+/// contracts/src/Types.sol:into().
+fn derive_channel_id_for_sibling(para_id: ParaId) -> ChannelId {
+	let para_id: u32 = para_id.into();
+	let para_id_bytes: [u8; 4] = para_id.to_be_bytes();
+	let prefix: [u8; 4] = *b"para";
+	let preimage: Vec<u8> = prefix.into_iter().chain(para_id_bytes).collect();
+	keccak_256(&preimage).into()
+}
+
+impl ChannelId {
+	pub const fn new(id: [u8; 32]) -> Self {
+		ChannelId(id)
+	}
+}
+
+impl From<ParaId> for ChannelId {
+	fn from(value: ParaId) -> Self {
+		derive_channel_id_for_sibling(value)
+	}
+}
+
+impl From<[u8; 32]> for ChannelId {
+	fn from(value: [u8; 32]) -> Self {
+		ChannelId(value)
+	}
+}
+
+impl From<ChannelId> for [u8; 32] {
+	fn from(value: ChannelId) -> Self {
+		value.0
+	}
+}
+
+impl<'a> From<&'a [u8; 32]> for ChannelId {
+	fn from(value: &'a [u8; 32]) -> Self {
+		ChannelId(*value)
+	}
+}
+
+impl From<H256> for ChannelId {
+	fn from(value: H256) -> Self {
+		ChannelId(value.into())
+	}
+}
+
+impl AsRef<[u8]> for ChannelId {
+	fn as_ref(&self) -> &[u8] {
+		&self.0
+	}
+}
+
+#[derive(Clone, Encode, Decode, RuntimeDebug, MaxEncodedLen, TypeInfo)]
+pub struct Channel {
+	/// ID of the agent contract deployed on Ethereum
+	pub agent_id: AgentId,
+	/// ID of the parachain who will receive or send messages using this channel
+	pub para_id: ParaId,
+}
+
+pub trait StaticLookup {
+	/// Type to lookup from.
+	type Source;
+	/// Type to lookup into.
+	type Target;
+	/// Attempt a lookup.
+	fn lookup(s: Self::Source) -> Option<Self::Target>;
+}
+
+/// Channel for high-priority governance commands
+pub const PRIMARY_GOVERNANCE_CHANNEL: ChannelId =
+	ChannelId::new(hex!("0000000000000000000000000000000000000000000000000000000000000001"));
+
+/// Channel for lower-priority governance commands
+pub const SECONDARY_GOVERNANCE_CHANNEL: ChannelId =
+	ChannelId::new(hex!("0000000000000000000000000000000000000000000000000000000000000002"));
+
+pub struct DescribeHere;
+impl DescribeLocation for DescribeHere {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, l.interior) {
+			(0, Here) => Some(Vec::<u8>::new().encode()),
+			_ => None,
+		}
+	}
+}
+
+/// Creates an AgentId from a MultiLocation. An AgentId is a unique mapping to a Agent contract on
+/// Ethereum which acts as the sovereign account for the MultiLocation.
+pub type AgentIdOf = HashedDescription<H256, (DescribeHere, DescribeFamily<DescribeAllTerminal>)>;

bridges/snowbridge/parachain/primitives/core/src/operating_mode.rs

@@ -0,0 +1,25 @@
+use codec::{Decode, Encode, MaxEncodedLen};
+use scale_info::TypeInfo;
+use sp_runtime::RuntimeDebug;
+
+/// Basic operating modes for a bridges module (Normal/Halted).
+#[derive(Encode, Decode, Clone, Copy, PartialEq, Eq, RuntimeDebug, TypeInfo, MaxEncodedLen)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum BasicOperatingMode {
+	/// Normal mode, when all operations are allowed.
+	Normal,
+	/// The pallet is halted. All non-governance operations are disabled.
+	Halted,
+}
+
+impl Default for BasicOperatingMode {
+	fn default() -> Self {
+		Self::Normal
+	}
+}
+
+impl BasicOperatingMode {
+	pub fn is_halted(&self) -> bool {
+		*self == BasicOperatingMode::Halted
+	}
+}

bridges/snowbridge/parachain/primitives/core/src/outbound.rs

@@ -0,0 +1,413 @@
+use codec::{Decode, Encode};
+use frame_support::PalletError;
+use scale_info::TypeInfo;
+use sp_arithmetic::traits::{BaseArithmetic, Unsigned};
+use sp_core::{RuntimeDebug, H256};
+pub use v1::{AgentExecuteCommand, Command, Initializer, Message, OperatingMode, QueuedMessage};
+
+/// Enqueued outbound messages need to be versioned to prevent data corruption
+/// or loss after forkless runtime upgrades
+#[derive(Encode, Decode, TypeInfo, Clone, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(PartialEq))]
+pub enum VersionedQueuedMessage {
+	V1(QueuedMessage),
+}
+
+impl TryFrom<VersionedQueuedMessage> for QueuedMessage {
+	type Error = ();
+	fn try_from(x: VersionedQueuedMessage) -> Result<Self, Self::Error> {
+		use VersionedQueuedMessage::*;
+		match x {
+			V1(x) => Ok(x),
+		}
+	}
+}
+
+impl<T: Into<QueuedMessage>> From<T> for VersionedQueuedMessage {
+	fn from(x: T) -> Self {
+		VersionedQueuedMessage::V1(x.into())
+	}
+}
+
+mod v1 {
+	use crate::{pricing::UD60x18, ChannelId};
+	use codec::{Decode, Encode};
+	use ethabi::Token;
+	use scale_info::TypeInfo;
+	use sp_core::{RuntimeDebug, H160, H256, U256};
+	use sp_std::{borrow::ToOwned, vec, vec::Vec};
+
+	/// A message which can be accepted by implementations of `/[`SendMessage`\]`
+	#[derive(Encode, Decode, TypeInfo, Clone, RuntimeDebug)]
+	#[cfg_attr(feature = "std", derive(PartialEq))]
+	pub struct Message {
+		/// ID for this message. One will be automatically generated if not provided.
+		///
+		/// When this message is created from an XCM message, the ID should be extracted
+		/// from the `SetTopic` instruction.
+		///
+		/// The ID plays no role in bridge consensus, and is purely meant for message tracing.
+		pub id: Option<H256>,
+		/// The message channel ID
+		pub channel_id: ChannelId,
+		/// The stable ID for a receiving gateway contract
+		pub command: Command,
+	}
+
+	/// The operating mode of Channels and Gateway contract on Ethereum.
+	#[derive(Copy, Clone, Encode, Decode, PartialEq, Eq, RuntimeDebug, TypeInfo)]
+	pub enum OperatingMode {
+		/// Normal operations. Allow sending and receiving messages.
+		Normal,
+		/// Reject outbound messages. This allows receiving governance messages but does now allow
+		/// enqueuing of new messages from the Ethereum side. This can be used to close off an
+		/// deprecated channel or pause the bridge for upgrade operations.
+		RejectingOutboundMessages,
+	}
+
+	/// A command which is executable by the Gateway contract on Ethereum
+	#[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
+	#[cfg_attr(feature = "std", derive(PartialEq))]
+	pub enum Command {
+		/// Execute a sub-command within an agent for a consensus system in Polkadot
+		AgentExecute {
+			/// The ID of the agent
+			agent_id: H256,
+			/// The sub-command to be executed
+			command: AgentExecuteCommand,
+		},
+		/// Upgrade the Gateway contract
+		Upgrade {
+			/// Address of the new implementation contract
+			impl_address: H160,
+			/// Codehash of the implementation contract
+			impl_code_hash: H256,
+			/// Optionally invoke an initializer in the implementation contract
+			initializer: Option<Initializer>,
+		},
+		/// Create an agent representing a consensus system on Polkadot
+		CreateAgent {
+			/// The ID of the agent, derived from the `MultiLocation` of the consensus system on
+			/// Polkadot
+			agent_id: H256,
+		},
+		/// Create bidirectional messaging channel to a parachain
+		CreateChannel {
+			/// The ID of the channel
+			channel_id: ChannelId,
+			/// The agent ID of the parachain
+			agent_id: H256,
+			/// Initial operating mode
+			mode: OperatingMode,
+		},
+		/// Update the configuration of a channel
+		UpdateChannel {
+			/// The ID of the channel
+			channel_id: ChannelId,
+			/// The new operating mode
+			mode: OperatingMode,
+		},
+		/// Set the global operating mode of the Gateway contract
+		SetOperatingMode {
+			/// The new operating mode
+			mode: OperatingMode,
+		},
+		/// Transfer ether from an agent contract to a recipient account
+		TransferNativeFromAgent {
+			/// The agent ID
+			agent_id: H256,
+			/// The recipient of the ether
+			recipient: H160,
+			/// The amount to transfer
+			amount: u128,
+		},
+		/// Set token fees of the Gateway contract
+		SetTokenTransferFees {
+			/// The fee(DOT) for the cost of creating asset on AssetHub
+			create_asset_xcm: u128,
+			/// The fee(DOT) for the cost of sending asset on AssetHub
+			transfer_asset_xcm: u128,
+			/// The fee(Ether) for register token to discourage spamming
+			register_token: U256,
+		},
+		/// Set pricing parameters
+		SetPricingParameters {
+			// ETH/DOT exchange rate
+			exchange_rate: UD60x18,
+			// Cost of delivering a message from Ethereum to BridgeHub, in ROC/KSM/DOT
+			delivery_cost: u128,
+		},
+	}
+
+	impl Command {
+		/// Compute the enum variant index
+		pub fn index(&self) -> u8 {
+			match self {
+				Command::AgentExecute { .. } => 0,
+				Command::Upgrade { .. } => 1,
+				Command::CreateAgent { .. } => 2,
+				Command::CreateChannel { .. } => 3,
+				Command::UpdateChannel { .. } => 4,
+				Command::SetOperatingMode { .. } => 5,
+				Command::TransferNativeFromAgent { .. } => 6,
+				Command::SetTokenTransferFees { .. } => 7,
+				Command::SetPricingParameters { .. } => 8,
+			}
+		}
+
+		/// ABI-encode the Command.
+		pub fn abi_encode(&self) -> Vec<u8> {
+			match self {
+				Command::AgentExecute { agent_id, command } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::FixedBytes(agent_id.as_bytes().to_owned()),
+						Token::Bytes(command.abi_encode()),
+					])]),
+				Command::Upgrade { impl_address, impl_code_hash, initializer, .. } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::Address(*impl_address),
+						Token::FixedBytes(impl_code_hash.as_bytes().to_owned()),
+						initializer
+							.clone()
+							.map_or(Token::Bytes(vec![]), |i| Token::Bytes(i.params)),
+					])]),
+				Command::CreateAgent { agent_id } =>
+					ethabi::encode(&[Token::Tuple(vec![Token::FixedBytes(
+						agent_id.as_bytes().to_owned(),
+					)])]),
+				Command::CreateChannel { channel_id, agent_id, mode } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::FixedBytes(channel_id.as_ref().to_owned()),
+						Token::FixedBytes(agent_id.as_bytes().to_owned()),
+						Token::Uint(U256::from((*mode) as u64)),
+					])]),
+				Command::UpdateChannel { channel_id, mode } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::FixedBytes(channel_id.as_ref().to_owned()),
+						Token::Uint(U256::from((*mode) as u64)),
+					])]),
+				Command::SetOperatingMode { mode } =>
+					ethabi::encode(&[Token::Tuple(vec![Token::Uint(U256::from((*mode) as u64))])]),
+				Command::TransferNativeFromAgent { agent_id, recipient, amount } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::FixedBytes(agent_id.as_bytes().to_owned()),
+						Token::Address(*recipient),
+						Token::Uint(U256::from(*amount)),
+					])]),
+				Command::SetTokenTransferFees {
+					create_asset_xcm,
+					transfer_asset_xcm,
+					register_token,
+				} => ethabi::encode(&[Token::Tuple(vec![
+					Token::Uint(U256::from(*create_asset_xcm)),
+					Token::Uint(U256::from(*transfer_asset_xcm)),
+					Token::Uint(*register_token),
+				])]),
+				Command::SetPricingParameters { exchange_rate, delivery_cost } =>
+					ethabi::encode(&[Token::Tuple(vec![
+						Token::Uint(exchange_rate.clone().into_inner()),
+						Token::Uint(U256::from(*delivery_cost)),
+					])]),
+			}
+		}
+	}
+
+	/// Representation of a call to the initializer of an implementation contract.
+	/// The initializer has the following ABI signature: `initialize(bytes)`.
+	#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+	pub struct Initializer {
+		/// ABI-encoded params of type `bytes` to pass to the initializer
+		pub params: Vec<u8>,
+		/// The initializer is allowed to consume this much gas at most.
+		pub maximum_required_gas: u64,
+	}
+
+	/// A Sub-command executable within an agent
+	#[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
+	#[cfg_attr(feature = "std", derive(PartialEq))]
+	pub enum AgentExecuteCommand {
+		/// Transfer ERC20 tokens
+		TransferToken {
+			/// Address of the ERC20 token
+			token: H160,
+			/// The recipient of the tokens
+			recipient: H160,
+			/// The amount of tokens to transfer
+			amount: u128,
+		},
+	}
+
+	impl AgentExecuteCommand {
+		fn index(&self) -> u8 {
+			match self {
+				AgentExecuteCommand::TransferToken { .. } => 0,
+			}
+		}
+
+		/// ABI-encode the sub-command
+		pub fn abi_encode(&self) -> Vec<u8> {
+			match self {
+				AgentExecuteCommand::TransferToken { token, recipient, amount } =>
+					ethabi::encode(&[
+						Token::Uint(self.index().into()),
+						Token::Bytes(ethabi::encode(&[
+							Token::Address(*token),
+							Token::Address(*recipient),
+							Token::Uint(U256::from(*amount)),
+						])),
+					]),
+			}
+		}
+	}
+
+	/// Message which is awaiting processing in the MessageQueue pallet
+	#[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
+	#[cfg_attr(feature = "std", derive(PartialEq))]
+	pub struct QueuedMessage {
+		/// Message ID
+		pub id: H256,
+		/// Channel ID
+		pub channel_id: ChannelId,
+		/// Command to execute in the Gateway contract
+		pub command: Command,
+	}
+}
+
+#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
+/// Fee for delivering message
+pub struct Fee<Balance>
+where
+	Balance: BaseArithmetic + Unsigned + Copy,
+{
+	/// Fee to cover cost of processing the message locally
+	pub local: Balance,
+	/// Fee to cover cost processing the message remotely
+	pub remote: Balance,
+}
+
+impl<Balance> Fee<Balance>
+where
+	Balance: BaseArithmetic + Unsigned + Copy,
+{
+	pub fn total(&self) -> Balance {
+		self.local.saturating_add(self.remote)
+	}
+}
+
+impl<Balance> From<(Balance, Balance)> for Fee<Balance>
+where
+	Balance: BaseArithmetic + Unsigned + Copy,
+{
+	fn from((local, remote): (Balance, Balance)) -> Self {
+		Self { local, remote }
+	}
+}
+
+/// A trait for sending messages to Ethereum
+pub trait SendMessage: SendMessageFeeProvider {
+	type Ticket: Clone + Encode + Decode;
+
+	/// Validate an outbound message and return a tuple:
+	/// 1. Ticket for submitting the message
+	/// 2. Delivery fee
+	fn validate(
+		message: &Message,
+	) -> Result<(Self::Ticket, Fee<<Self as SendMessageFeeProvider>::Balance>), SendError>;
+
+	/// Submit the message ticket for eventual delivery to Ethereum
+	fn deliver(ticket: Self::Ticket) -> Result<H256, SendError>;
+}
+
+pub trait Ticket: Encode + Decode + Clone {
+	fn message_id(&self) -> H256;
+}
+
+/// A trait for getting the local costs associated with sending a message.
+pub trait SendMessageFeeProvider {
+	type Balance: BaseArithmetic + Unsigned + Copy;
+
+	/// The local component of the message processing fees in native currency
+	fn local_fee() -> Self::Balance;
+}
+
+/// Reasons why sending to Ethereum could not be initiated
+#[derive(Copy, Clone, Encode, Decode, PartialEq, Eq, RuntimeDebug, PalletError, TypeInfo)]
+pub enum SendError {
+	/// Message is too large to be safely executed on Ethereum
+	MessageTooLarge,
+	/// The bridge has been halted for maintenance
+	Halted,
+	/// Invalid Channel
+	InvalidChannel,
+}
+
+pub trait GasMeter {
+	/// All the gas used for submitting a message to Ethereum, minus the cost of dispatching
+	/// the command within the message
+	const MAXIMUM_BASE_GAS: u64;
+
+	fn maximum_gas_used_at_most(command: &Command) -> u64 {
+		Self::MAXIMUM_BASE_GAS + Self::maximum_dispatch_gas_used_at_most(command)
+	}
+
+	/// Measures the maximum amount of gas a command payload will require to dispatch, AFTER
+	/// validation & verification.
+	fn maximum_dispatch_gas_used_at_most(command: &Command) -> u64;
+}
+
+/// A meter that assigns a constant amount of gas for the execution of a command
+///
+/// The gas figures are extracted from this report:
+/// > forge test --match-path test/Gateway.t.sol --gas-report
+///
+/// A healthy buffer is added on top of these figures to account for:
+/// * The EIP-150 63/64 rule
+/// * Future EVM upgrades that may increase gas cost
+pub struct ConstantGasMeter;
+
+impl GasMeter for ConstantGasMeter {
+	// The base transaction cost, which includes:
+	// 21_000 transaction cost, roughly worst case 64_000 for calldata, and 100_000
+	// for message verification
+	const MAXIMUM_BASE_GAS: u64 = 185_000;
+
+	fn maximum_dispatch_gas_used_at_most(command: &Command) -> u64 {
+		match command {
+			Command::CreateAgent { .. } => 275_000,
+			Command::CreateChannel { .. } => 100_000,
+			Command::UpdateChannel { .. } => 50_000,
+			Command::TransferNativeFromAgent { .. } => 60_000,
+			Command::SetOperatingMode { .. } => 40_000,
+			Command::AgentExecute { command, .. } => match command {
+				// Execute IERC20.transferFrom
+				//
+				// Worst-case assumptions are important:
+				// * No gas refund for clearing storage slot of source account in ERC20 contract
+				// * Assume dest account in ERC20 contract does not yet have a storage slot
+				// * ERC20.transferFrom possibly does other business logic besides updating balances
+				AgentExecuteCommand::TransferToken { .. } => 100_000,
+			},
+			Command::Upgrade { initializer, .. } => {
+				let initializer_max_gas = match *initializer {
+					Some(Initializer { maximum_required_gas, .. }) => maximum_required_gas,
+					None => 0,
+				};
+				// total maximum gas must also include the gas used for updating the proxy before
+				// the the initializer is called.
+				50_000 + initializer_max_gas
+			},
+			Command::SetTokenTransferFees { .. } => 60_000,
+			Command::SetPricingParameters { .. } => 60_000,
+		}
+	}
+}
+
+impl GasMeter for () {
+	const MAXIMUM_BASE_GAS: u64 = 1;
+
+	fn maximum_dispatch_gas_used_at_most(_: &Command) -> u64 {
+		1
+	}
+}
+
+pub const ETHER_DECIMALS: u8 = 18;

bridges/snowbridge/parachain/primitives/core/src/pricing.rs

@@ -0,0 +1,67 @@
+use codec::{Decode, Encode, MaxEncodedLen};
+use scale_info::TypeInfo;
+use sp_arithmetic::traits::{BaseArithmetic, Unsigned, Zero};
+use sp_core::U256;
+use sp_runtime::{FixedU128, RuntimeDebug};
+use sp_std::prelude::*;
+
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, MaxEncodedLen, TypeInfo)]
+pub struct PricingParameters<Balance> {
+	/// ETH/DOT exchange rate
+	pub exchange_rate: FixedU128,
+	/// Relayer rewards
+	pub rewards: Rewards<Balance>,
+	/// Ether (wei) fee per gas unit
+	pub fee_per_gas: U256,
+}
+
+#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, MaxEncodedLen, TypeInfo)]
+pub struct Rewards<Balance> {
+	/// Local reward in DOT
+	pub local: Balance,
+	/// Remote reward in ETH (wei)
+	pub remote: U256,
+}
+
+#[derive(RuntimeDebug)]
+pub struct InvalidPricingParameters;
+
+impl<Balance> PricingParameters<Balance>
+where
+	Balance: BaseArithmetic + Unsigned + Copy,
+{
+	pub fn validate(&self) -> Result<(), InvalidPricingParameters> {
+		if self.exchange_rate == FixedU128::zero() {
+			return Err(InvalidPricingParameters)
+		}
+		if self.fee_per_gas == U256::zero() {
+			return Err(InvalidPricingParameters)
+		}
+		if self.rewards.local.is_zero() {
+			return Err(InvalidPricingParameters)
+		}
+		if self.rewards.remote.is_zero() {
+			return Err(InvalidPricingParameters)
+		}
+		Ok(())
+	}
+}
+
+/// Holder for fixed point number implemented in <https://github.com/PaulRBerg/prb-math>
+#[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
+#[cfg_attr(feature = "std", derive(PartialEq))]
+pub struct UD60x18(U256);
+
+impl From<FixedU128> for UD60x18 {
+	fn from(value: FixedU128) -> Self {
+		// Both FixedU128 and UD60x18 have 18 decimal places
+		let inner: u128 = value.into_inner();
+		UD60x18(inner.into())
+	}
+}
+
+impl UD60x18 {
+	pub fn into_inner(self) -> U256 {
+		self.0
+	}
+}

bridges/snowbridge/parachain/primitives/core/src/ringbuffer.rs

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::FullCodec;
+use core::{cmp::Ord, marker::PhantomData, ops::Add};
+use frame_support::storage::{types::QueryKindTrait, StorageMap, StorageValue};
+use sp_core::{Get, GetDefault};
+use sp_runtime::traits::{One, Zero};
+
+/// Trait object presenting the ringbuffer interface.
+pub trait RingBufferMap<Key, Value, QueryKind>
+where
+	Key: FullCodec,
+	Value: FullCodec,
+	QueryKind: QueryKindTrait<Value, GetDefault>,
+{
+	/// Insert a map entry.
+	fn insert(k: Key, v: Value);
+
+	/// Check if map contains a key
+	fn contains_key(k: Key) -> bool;
+
+	/// Get the value of the key
+	fn get(k: Key) -> QueryKind::Query;
+}
+
+pub struct RingBufferMapImpl<Index, B, CurrentIndex, Intermediate, M, QueryKind>(
+	PhantomData<(Index, B, CurrentIndex, Intermediate, M, QueryKind)>,
+);
+
+/// Ringbuffer implementation based on `RingBufferTransient`
+impl<Key, Value, Index, B, CurrentIndex, Intermediate, M, QueryKind>
+	RingBufferMap<Key, Value, QueryKind>
+	for RingBufferMapImpl<Index, B, CurrentIndex, Intermediate, M, QueryKind>
+where
+	Key: FullCodec + Clone,
+	Value: FullCodec,
+	Index: Ord + One + Zero + Add<Output = Index> + Copy + FullCodec + Eq,
+	B: Get<Index>,
+	CurrentIndex: StorageValue<Index, Query = Index>,
+	Intermediate: StorageMap<Index, Key, Query = Key>,
+	M: StorageMap<Key, Value, Query = QueryKind::Query>,
+	QueryKind: QueryKindTrait<Value, GetDefault>,
+{
+	/// Insert a map entry.
+	fn insert(k: Key, v: Value) {
+		let bound = B::get();
+		let mut current_index = CurrentIndex::get();
+
+		// Adding one here as bound denotes number of items but our index starts with zero.
+		if (current_index + Index::one()) >= bound {
+			current_index = Index::zero();
+		} else {
+			current_index = current_index + Index::one();
+		}
+
+		// Deleting earlier entry if it exists
+		if Intermediate::contains_key(current_index) {
+			let older_key = Intermediate::get(current_index);
+			M::remove(older_key);
+		}
+
+		Intermediate::insert(current_index, k.clone());
+		CurrentIndex::set(current_index);
+		M::insert(k, v);
+	}
+
+	/// Check if map contains a key
+	fn contains_key(k: Key) -> bool {
+		M::contains_key(k)
+	}
+
+	/// Get the value associated with key
+	fn get(k: Key) -> M::Query {
+		M::get(k)
+	}
+}

bridges/snowbridge/parachain/primitives/core/src/tests.rs

@@ -0,0 +1,13 @@
+use crate::{ChannelId, ParaId};
+use hex_literal::hex;
+
+const EXPECT_CHANNEL_ID: [u8; 32] =
+	hex!("c173fac324158e77fb5840738a1a541f633cbec8884c6a601c567d2b376a0539");
+
+// The Solidity equivalent code is tested in Gateway.t.sol:testDeriveChannelID
+#[test]
+fn generate_channel_id() {
+	let para_id: ParaId = 1000.into();
+	let channel_id: ChannelId = para_id.into();
+	assert_eq!(channel_id, EXPECT_CHANNEL_ID.into());
+}

bridges/snowbridge/parachain/primitives/core/tests/mod.rs

@@ -0,0 +1,14 @@
+#[cfg(test)]
+mod tests {
+	use frame_support::traits::Contains;
+	use snowbridge_core::AllowSiblingsOnly;
+	use xcm::prelude::{Junction::Parachain, Junctions::X1, MultiLocation};
+
+	#[test]
+	fn allow_siblings_predicate_only_allows_siblings() {
+		let sibling = MultiLocation::new(1, X1(Parachain(1000)));
+		let child = MultiLocation::new(0, X1(Parachain(1000)));
+		assert!(AllowSiblingsOnly::contains(&sibling), "Sibling returns true.");
+		assert!(!AllowSiblingsOnly::contains(&child), "Child returns false.");
+	}
+}

bridges/snowbridge/parachain/primitives/ethereum/.cargo/config.toml

@@ -0,0 +1,2 @@
+[target.wasm32-unknown-unknown]
+runner = 'wasm-bindgen-test-runner'

bridges/snowbridge/parachain/primitives/ethereum/Cargo.toml

@@ -0,0 +1,51 @@
+[package]
+name = "snowbridge-ethereum"
+description = "Snowbridge Ethereum"
+version = "0.1.0"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+serde = { version = "1.0.188", optional = true, features = ["derive"] }
+serde-big-array = { version = "0.3.2", optional = true, features = ["const-generics"] }
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = ["derive"] }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+ethbloom = { version = "0.13.0", default-features = false }
+ethereum-types = { version = "0.14.1", default-features = false, features = ["codec", "rlp", "serialize"] }
+hex = { package = "rustc-hex", version = "2.1.0", default-features = false }
+hex-literal = { version = "0.4.1", default-features = false }
+parity-bytes = { version = "0.1.2", default-features = false }
+rlp = { version = "0.5.2", default-features = false }
+
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+
+ethabi = { git = "https://github.com/snowfork/ethabi-decode.git", package = "ethabi-decode", branch = "master", default-features = false }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3.19"
+rand = "0.8.5"
+serde_json = "1.0.96"
+
+[features]
+default = ["std"]
+expensive_tests = []
+std = [
+	"codec/std",
+	"ethabi/std",
+	"ethbloom/std",
+	"ethereum-types/std",
+	"hex/std",
+	"parity-bytes/std",
+	"rlp/std",
+	"scale-info/std",
+	"serde",
+	"serde-big-array",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+]

bridges/snowbridge/parachain/primitives/ethereum/src/header.rs

@@ -0,0 +1,414 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::{Decode, Encode};
+use ethbloom::Bloom as EthBloom;
+use hex_literal::hex;
+use parity_bytes::Bytes;
+use rlp::RlpStream;
+use scale_info::TypeInfo;
+use sp_io::hashing::keccak_256;
+use sp_runtime::RuntimeDebug;
+use sp_std::{convert::TryInto, prelude::*};
+
+#[cfg(feature = "std")]
+use serde::{Deserialize, Serialize};
+
+#[cfg(feature = "std")]
+use serde_big_array::BigArray;
+
+use ethereum_types::{Address, H256, H64, U256};
+
+use crate::{mpt, receipt};
+
+/// Complete block header id.
+#[derive(Clone, Copy, Default, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+pub struct HeaderId {
+	/// Header number.
+	pub number: u64,
+	/// Header hash.
+	pub hash: H256,
+}
+
+const EMPTY_OMMERS_HASH: [u8; 32] =
+	hex!("1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347");
+
+/// An Ethereum block header.
+#[derive(Clone, Default, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+pub struct Header {
+	/// Parent block hash.
+	pub parent_hash: H256,
+	/// Block timestamp.
+	pub timestamp: u64,
+	/// Block number.
+	pub number: u64,
+	/// Block author.
+	pub author: Address,
+
+	/// Transactions root.
+	pub transactions_root: H256,
+	/// Block ommers hash.
+	pub ommers_hash: H256,
+	/// Block extra data.
+	pub extra_data: Bytes,
+
+	/// State root.
+	pub state_root: H256,
+	/// Block receipts root.
+	pub receipts_root: H256,
+	/// Block bloom.
+	pub logs_bloom: Bloom,
+	/// Gas used for contracts execution.
+	pub gas_used: U256,
+	/// Block gas limit.
+	pub gas_limit: U256,
+
+	/// Block difficulty.
+	pub difficulty: U256,
+	/// Vector of post-RLP-encoded fields.
+	pub seal: Vec<Bytes>,
+
+	// Base fee per gas (EIP-1559), only in headers from the London hardfork onwards.
+	pub base_fee: Option<U256>,
+}
+
+impl Header {
+	/// Compute hash of this header (keccak of the RLP with seal).
+	pub fn compute_hash(&self) -> H256 {
+		keccak_256(&self.rlp(true)).into()
+	}
+
+	/// Compute hash of the truncated header i.e. excluding seal.
+	pub fn compute_partial_hash(&self) -> H256 {
+		keccak_256(&self.rlp(false)).into()
+	}
+
+	pub fn check_receipt_proof(
+		&self,
+		proof: &[Vec<u8>],
+	) -> Option<Result<receipt::Receipt, rlp::DecoderError>> {
+		match self.apply_merkle_proof(proof) {
+			Some((root, data)) if root == self.receipts_root => Some(rlp::decode(&data)),
+			Some((_, _)) => None,
+			None => None,
+		}
+	}
+
+	pub fn apply_merkle_proof(&self, proof: &[Vec<u8>]) -> Option<(H256, Vec<u8>)> {
+		let mut iter = proof.iter().rev();
+		let first_bytes = match iter.next() {
+			Some(b) => b,
+			None => return None,
+		};
+		let item_to_prove: mpt::ShortNode = rlp::decode(first_bytes).ok()?;
+
+		let final_hash: Option<[u8; 32]> = iter.try_fold(keccak_256(first_bytes), |acc, x| {
+			let node: Box<dyn mpt::Node> = x.as_slice().try_into().ok()?;
+			if (*node).contains_hash(acc.into()) {
+				return Some(keccak_256(x))
+			}
+			None
+		});
+
+		final_hash.map(|hash| (hash.into(), item_to_prove.value))
+	}
+
+	pub fn mix_hash(&self) -> Option<H256> {
+		let bytes: Bytes = self.decoded_seal_field(0, 32)?;
+		let size = bytes.len();
+		let mut mix_hash = [0u8; 32];
+		for i in 0..size {
+			mix_hash[31 - i] = bytes[size - 1 - i];
+		}
+		Some(mix_hash.into())
+	}
+
+	pub fn nonce(&self) -> Option<H64> {
+		let bytes: Bytes = self.decoded_seal_field(1, 8)?;
+		let size = bytes.len();
+		let mut nonce = [0u8; 8];
+		for i in 0..size {
+			nonce[7 - i] = bytes[size - 1 - i];
+		}
+		Some(nonce.into())
+	}
+
+	pub fn has_ommers(&self) -> bool {
+		self.ommers_hash != EMPTY_OMMERS_HASH.into()
+	}
+
+	fn decoded_seal_field(&self, index: usize, max_len: usize) -> Option<Bytes> {
+		let bytes: Bytes = rlp::decode(self.seal.get(index)?).ok()?;
+		if bytes.len() > max_len {
+			return None
+		}
+		Some(bytes)
+	}
+
+	/// Returns header RLP with or without seals.
+	/// For EIP-1559 baseFee addition refer to:
+	/// <https://github.com/openethereum/openethereum/blob/193b25a22d5ff07759c6431129e95235510516f9/crates/ethcore/types/src/header.rs#L341>
+	fn rlp(&self, with_seal: bool) -> Bytes {
+		let mut s = RlpStream::new();
+
+		let stream_length_without_seal = if self.base_fee.is_some() { 14 } else { 13 };
+
+		if with_seal {
+			s.begin_list(stream_length_without_seal + self.seal.len());
+		} else {
+			s.begin_list(stream_length_without_seal);
+		}
+
+		s.append(&self.parent_hash);
+		s.append(&self.ommers_hash);
+		s.append(&self.author);
+		s.append(&self.state_root);
+		s.append(&self.transactions_root);
+		s.append(&self.receipts_root);
+		s.append(&EthBloom::from(self.logs_bloom.0));
+		s.append(&self.difficulty);
+		s.append(&self.number);
+		s.append(&self.gas_limit);
+		s.append(&self.gas_used);
+		s.append(&self.timestamp);
+		s.append(&self.extra_data);
+
+		if with_seal {
+			for b in &self.seal {
+				s.append_raw(b, 1);
+			}
+		}
+
+		if let Some(base_fee) = self.base_fee {
+			s.append(&base_fee);
+		}
+
+		s.out().to_vec()
+	}
+}
+
+/// Logs bloom.
+#[derive(Clone, Debug, Encode, Decode, TypeInfo)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+pub struct Bloom(#[cfg_attr(feature = "std", serde(with = "BigArray"))] [u8; 256]);
+
+impl<'a> From<&'a [u8; 256]> for Bloom {
+	fn from(buffer: &'a [u8; 256]) -> Bloom {
+		Bloom(*buffer)
+	}
+}
+
+impl PartialEq<Bloom> for Bloom {
+	fn eq(&self, other: &Bloom) -> bool {
+		self.0.iter().zip(other.0.iter()).all(|(l, r)| l == r)
+	}
+}
+
+impl Default for Bloom {
+	fn default() -> Self {
+		Bloom([0; 256])
+	}
+}
+
+impl rlp::Decodable for Bloom {
+	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		let v: Vec<u8> = rlp.as_val()?;
+		match v.len() {
+			256 => {
+				let mut bytes = [0u8; 256];
+				bytes.copy_from_slice(&v);
+				Ok(Self(bytes))
+			},
+			_ => Err(rlp::DecoderError::Custom("Expected 256 bytes")),
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+
+	use super::*;
+
+	#[test]
+	fn bloom_decode_rlp() {
+		let raw_bloom = hex!(
+			"
+			b901000420000000000000000000008002000000000001000000000001000000000000000000
+			0000000000000000000000000002000000080000000000000000200000000000000000000000
+			0000080000002200000000004000100000000000000000000000000000000000000000000000
+			0000000000000004000000001000010000000000080000000000400000000000000000000000
+			0000080000004000000000020000000000020000000000000000000000000000000000000000
+			0000040000000000020000000001000000000000000000000000000010000000020000200000
+			10200000000000010000000000000000000000000000000000000010000000
+		"
+		);
+		let expected_bytes = &raw_bloom[3..];
+		let bloom: Bloom = rlp::decode(&raw_bloom).unwrap();
+		assert_eq!(bloom.0, expected_bytes);
+	}
+
+	#[test]
+	fn header_compute_hash_poa() {
+		// PoA header
+		let header = Header {
+			parent_hash: Default::default(),
+			timestamp: 0,
+			number: 0,
+			author: Default::default(),
+			transactions_root: hex!(
+				"56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421"
+			)
+			.into(),
+			ommers_hash: hex!("1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347")
+				.into(),
+			extra_data: vec![],
+			state_root: hex!("eccf6b74c2bcbe115c71116a23fe963c54406010c244d9650526028ad3e32cce")
+				.into(),
+			receipts_root: hex!("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
+				.into(),
+			logs_bloom: Default::default(),
+			gas_used: Default::default(),
+			gas_limit: 0x222222.into(),
+			difficulty: 0x20000.into(),
+			seal: vec![vec![0x80], {
+				let mut vec = vec![0xb8, 0x41];
+				vec.resize(67, 0);
+				vec
+			}],
+			base_fee: None,
+		};
+		assert_eq!(
+			header.compute_hash().as_bytes(),
+			hex!("9ff57c7fa155853586382022f0982b71c51fa313a0942f8c456300896643e890"),
+		);
+	}
+
+	#[test]
+	fn header_compute_hash_pow() {
+		// <https://etherscan.io/block/11090290>
+		let nonce = hex!("6935bbe7b63c4f8e").to_vec();
+		let mix_hash =
+			hex!("be3adfb0087be62b28b716e2cdf3c79329df5caa04c9eee035d35b5d52102815").to_vec();
+		let header = Header {
+			parent_hash: hex!("bede0bddd6f32c895fc505ffe0c39d9bde58e9a5272f31a3dee448b796edcbe3")
+				.into(),
+			timestamp: 1603160977,
+			number: 11090290,
+			author: hex!("ea674fdde714fd979de3edf0f56aa9716b898ec8").into(),
+			transactions_root: hex!(
+				"56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421"
+			)
+			.into(),
+			ommers_hash: hex!("1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347")
+				.into(),
+			extra_data: hex!("65746865726d696e652d61736961312d33").to_vec(),
+			state_root: hex!("7dcb8aca872b712bad81df34a89d4efedc293566ffc3eeeb5cbcafcc703e42c9")
+				.into(),
+			receipts_root: hex!("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
+				.into(),
+			logs_bloom: Default::default(),
+			gas_used: 0.into(),
+			gas_limit: 0xbe8c19.into(),
+			difficulty: 0xbc140caa61087i64.into(),
+			seal: vec![rlp::encode(&mix_hash).to_vec(), rlp::encode(&nonce).to_vec()],
+			base_fee: None,
+		};
+		assert_eq!(
+			header.compute_hash().as_bytes(),
+			hex!("0f9bdc91c2e0140acb873330742bda8c8181fa3add91fe7ae046251679cedef7"),
+		);
+	}
+
+	#[test]
+	fn header_pow_seal_fields_extracted_correctly() {
+		let nonce: H64 = hex!("6935bbe7b63c4f8e").into();
+		let mix_hash: H256 =
+			hex!("be3adfb0087be62b28b716e2cdf3c79329df5caa04c9eee035d35b5d52102815").into();
+		let header = Header {
+			seal: vec![
+				rlp::encode(&mix_hash.0.to_vec()).to_vec(),
+				rlp::encode(&nonce.0.to_vec()).to_vec(),
+			],
+			..Default::default()
+		};
+
+		assert_eq!(header.nonce().unwrap(), nonce);
+		assert_eq!(header.mix_hash().unwrap(), mix_hash);
+	}
+
+	#[test]
+	fn header_pow_seal_fields_return_none_for_invalid_values() {
+		let nonce = hex!("696935bbe7b63c4f8e").to_vec();
+		let mix_hash =
+			hex!("bebe3adfb0087be62b28b716e2cdf3c79329df5caa04c9eee035d35b5d52102815").to_vec();
+		let mut header = Header {
+			seal: vec![rlp::encode(&mix_hash).to_vec(), rlp::encode(&nonce).to_vec()],
+			..Default::default()
+		};
+		assert_eq!(header.nonce(), None);
+		assert_eq!(header.mix_hash(), None);
+
+		header.seal = Vec::new();
+		assert_eq!(header.nonce(), None);
+		assert_eq!(header.mix_hash(), None);
+	}
+
+	#[test]
+	fn header_check_receipt_proof() {
+		let header = Header {
+			receipts_root: hex!("fd5e397a84884641f53c496804f24b5276cbb8c5c9cfc2342246be8e3ce5ad02")
+				.into(),
+			..Default::default()
+		};
+
+		// Valid proof
+		let proof_receipt5 = vec!(
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+		);
+		assert!(header.check_receipt_proof(&proof_receipt5).is_some());
+
+		// Various invalid proofs
+		let proof_empty: Vec<Vec<u8>> = vec![];
+		let proof_missing_full_node = vec![proof_receipt5[0].clone(), proof_receipt5[2].clone()];
+		let proof_missing_short_node1 = vec![proof_receipt5[0].clone(), proof_receipt5[1].clone()];
+		let proof_missing_short_node2 = vec![proof_receipt5[0].clone()];
+		let proof_invalid_encoding = vec![proof_receipt5[2][2..].to_vec()];
+		let proof_no_full_node = vec![proof_receipt5[2].clone(), proof_receipt5[2].clone()];
+		assert!(header.check_receipt_proof(&proof_empty).is_none());
+		assert!(header.check_receipt_proof(&proof_missing_full_node).is_none());
+
+		assert_eq!(
+			header.check_receipt_proof(&proof_missing_short_node1),
+			Some(Err(rlp::DecoderError::Custom("Unsupported receipt type")))
+		);
+
+		assert_eq!(
+			header.check_receipt_proof(&proof_missing_short_node2),
+			Some(Err(rlp::DecoderError::Custom("Unsupported receipt type")))
+		);
+
+		assert!(header.check_receipt_proof(&proof_invalid_encoding).is_none());
+		assert!(header.check_receipt_proof(&proof_no_full_node).is_none());
+	}
+
+	#[test]
+	fn header_check_receipt_proof_with_intermediate_short_node() {
+		let header = Header {
+			receipts_root: hex!("d128e3a57142d2bf15bc0cbcac7ad54f40750d571b5c3097e425882c10c9ba66")
+				.into(),
+			..Default::default()
+		};
+
+		let proof_receipt263 = vec![
+			hex!("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").to_vec(),
+			hex!("f871a0246de222036ee6a03329b0105da0a6b3f916fc95a9ed5a403a581a0c4d74242ca0ac108a49a88b57a05ac34a108b39f1e45f6f167f2b9fbc8d52fb58e2e5a6af1ea0fcfe07ac2ccd3c28b6eab68d1bce112f6f6dbd9023e4ec3c05b96615aa803d798080808080808080808080808080").to_vec(),
+			hex!("e4820001a04fff54398cad4d05ea6abfd8b0f3b4fe14c04d7ff5f5211c5b927d9cf72ac1d8").to_vec(),
+			hex!("f851a096d010643ca2d47412ca66898286b5f2412963b9ec051b33e570d575914c9c5ca028cd24c652989542fe89479ec6388eac4592432242af5ba97563b3ac7c71c019808080808080808080808080808080").to_vec(),
+			hex!("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").to_vec(),
+			hex!("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").to_vec(),
+		];
+		assert!(header.check_receipt_proof(&proof_receipt263).is_some());
+	}
+}

bridges/snowbridge/parachain/primitives/ethereum/src/lib.rs

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod header;
+pub mod log;
+pub mod mpt;
+pub mod receipt;
+
+pub use ethereum_types::{Address, H160, H256, H64, U256};
+
+pub use header::{Bloom, Header, HeaderId};
+pub use log::Log;
+pub use receipt::Receipt;
+
+#[derive(Debug)]
+pub enum DecodeError {
+	// Unexpected RLP data
+	InvalidRLP(rlp::DecoderError),
+	// Data does not match expected ABI
+	InvalidABI(ethabi::Error),
+	// Invalid message payload
+	InvalidPayload,
+}
+
+impl From<rlp::DecoderError> for DecodeError {
+	fn from(err: rlp::DecoderError) -> Self {
+		DecodeError::InvalidRLP(err)
+	}
+}
+
+impl From<ethabi::Error> for DecodeError {
+	fn from(err: ethabi::Error) -> Self {
+		DecodeError::InvalidABI(err)
+	}
+}

bridges/snowbridge/parachain/primitives/ethereum/src/log.rs

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::{Decode, Encode};
+use ethereum_types::{H160, H256};
+use sp_std::prelude::*;
+
+#[derive(Clone, Debug, Encode, Decode, PartialEq, Eq)]
+pub struct Log {
+	pub address: H160,
+	pub topics: Vec<H256>,
+	pub data: Vec<u8>,
+}
+
+impl rlp::Decodable for Log {
+	/// We need to implement rlp::Decodable manually as the derive macro RlpDecodable
+	/// didn't seem to generate the correct code for parsing our logs.
+	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		let mut iter = rlp.iter();
+
+		let address: H160 = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected log address")),
+		};
+
+		let topics: Vec<H256> = match iter.next() {
+			Some(data) => data.as_list()?,
+			None => return Err(rlp::DecoderError::Custom("Expected log topics")),
+		};
+
+		let data: Vec<u8> = match iter.next() {
+			Some(data) => data.data()?.to_vec(),
+			None => return Err(rlp::DecoderError::Custom("Expected log data")),
+		};
+
+		Ok(Self { address, topics, data })
+	}
+}
+
+#[cfg(test)]
+mod tests {
+
+	use super::Log;
+	use hex_literal::hex;
+
+	const RAW_LOG: [u8; 605] = hex!(
+		"
+		f9025a941cfd66659d44cfe2e627c5742ba7477a3284cffae1a0266413be5700ce8dd5ac6b9a7dfb
+		abe99b3e45cae9a68ac2757858710b401a38b9022000000000000000000000000000000000000000
+		00000000000000000000000060000000000000000000000000000000000000000000000000000000
+		00000000c00000000000000000000000000000000000000000000000000000000000000100000000
+		00000000000000000000000000000000000000000000000000000000283163466436363635394434
+		34636665324536323763353734324261373437376133323834634666410000000000000000000000
+		00000000000000000000000000000000000000000000000000000000000000000000000000000000
+		000000000773656e6445544800000000000000000000000000000000000000000000000000000000
+		00000000000000000000000000000000000000000000000000000001000000000000000000000000
+		00cffeaaf7681c89285d65cfbe808b80e50269657300000000000000000000000000000000000000
+		000000000000000000000000a0000000000000000000000000000000000000000000000000000000
+		0000000000000000000000000000000000000000000000000000000000000000000000000a000000
+		00000000000000000000000000000000000000000000000000000000020000000000000000000000
+		00000000000000000000000000000000000000002f3146524d4d3850456957585961783772705336
+		5834585a5831614141785357783143724b5479725659685632346667000000000000000000000000
+		0000000000
+	"
+	);
+
+	#[test]
+	fn decode_log() {
+		let log: Log = rlp::decode(&RAW_LOG).unwrap();
+		assert_eq!(log.address.as_bytes(), hex!["1cfd66659d44cfe2e627c5742ba7477a3284cffa"]);
+		assert_eq!(
+			log.topics[0].as_bytes(),
+			hex!["266413be5700ce8dd5ac6b9a7dfbabe99b3e45cae9a68ac2757858710b401a38"]
+		);
+	}
+}

bridges/snowbridge/parachain/primitives/ethereum/src/mpt.rs

@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Helper types to work with Ethereum's Merkle Patricia Trie nodes
+
+use ethereum_types::H256;
+use sp_std::{convert::TryFrom, prelude::*};
+
+pub trait Node {
+	fn contains_hash(&self, hash: H256) -> bool;
+}
+
+impl TryFrom<&[u8]> for Box<dyn Node> {
+	type Error = rlp::DecoderError;
+
+	fn try_from(bytes: &[u8]) -> Result<Box<dyn Node>, Self::Error> {
+		let rlp = rlp::Rlp::new(bytes);
+		match rlp.item_count()? {
+			2 => {
+				let node: ShortNode = rlp.as_val()?;
+				Ok(Box::new(node))
+			},
+			17 => {
+				let node: FullNode = rlp.as_val()?;
+				Ok(Box::new(node))
+			},
+			_ => Err(rlp::DecoderError::Custom("Invalid number of list elements")),
+		}
+	}
+}
+
+/// Intermediate trie node with children (refers to node with same name in Geth).
+/// This struct only handles the proof representation, i.e. a child is either empty
+/// or a 32-byte hash of its subtree.
+pub struct FullNode {
+	pub children: Vec<Option<H256>>,
+}
+
+impl rlp::Decodable for FullNode {
+	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		let children: Vec<Option<H256>> = rlp
+			.iter()
+			.map(|item| {
+				let v: Vec<u8> = item.as_val()?;
+				match v.len() {
+					0 => Ok(None),
+					32 => {
+						let mut bytes = [0u8; 32];
+						bytes.copy_from_slice(&v);
+						Ok(Some(bytes.into()))
+					},
+					_ => Err(rlp::DecoderError::Custom("Expected 32-byte hash or empty child")),
+				}
+			})
+			.collect::<Result<_, rlp::DecoderError>>()?;
+
+		Ok(Self { children })
+	}
+}
+
+impl Node for FullNode {
+	fn contains_hash(&self, hash: H256) -> bool {
+		self.children.iter().any(|h| Some(hash) == *h)
+	}
+}
+
+/// Trie node where `value` is either the RLP-encoded item we're
+/// proving or an intermediate hash (refers to node with same name in Geth)
+/// Proof verification should return `value`. `key` is an implementation
+/// detail of the trie.
+pub struct ShortNode {
+	pub key: Vec<u8>,
+	pub value: Vec<u8>,
+}
+
+impl rlp::Decodable for ShortNode {
+	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		let mut iter = rlp.iter();
+
+		let key: Vec<u8> = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected key bytes")),
+		};
+
+		let value: Vec<u8> = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected value bytes")),
+		};
+
+		Ok(Self { key, value })
+	}
+}
+
+impl Node for ShortNode {
+	fn contains_hash(&self, hash: H256) -> bool {
+		self.value == hash.0
+	}
+}
+
+#[cfg(test)]
+mod tests {
+
+	use super::*;
+	use hex_literal::hex;
+
+	const RAW_PROOF: [&[u8]; 3] = [
+        &hex!("f90131a0b5ba404eb5a6a88e56579f4d37ef9813b5ad7f86f0823ff3b407ac5a6bb465eca0398ead2655e78e03c127ce22c5830e90f18b1601ec055f938336c084feb915a9a026d322c26e46c50942c1aabde50e36df5cde572aed650ce73ea3182c6e90a02ca00600a356135f4db1db0d9842264cdff2652676f881669e91e316c0b6dd783011a0837f1deb4075336da320388c1edfffc56c448a43f4a5ba031300d32a7b509fc5a01c3ac82fd65b4aba7f9afaf604d9c82ec7e2deb573a091ae235751bc5c0c288da05d454159d9071b0f68b6e0503d290f23ac7602c1db0c569dee4605d8f5298f09a00bbed10350ec954448df795f6fd46e3faefc800ede061b3840eedc6e2b07a74da0acb02d26a3650f2064c14a435fdf1f668d8655daf455ebdf671713a7c089b3898080808080808080"),
+        &hex!("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"),
+        &hex!("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"),
+    ];
+
+	#[test]
+	fn decode_full_node() {
+		let node1: FullNode = rlp::decode(RAW_PROOF[0]).unwrap();
+		let node2: FullNode = rlp::decode(RAW_PROOF[1]).unwrap();
+		assert_eq!(node1.children.len(), 17);
+		assert_eq!(node2.children.len(), 17);
+		assert_eq!(node1.children.iter().filter(|c| c.is_none()).count(), 8);
+		assert_eq!(node2.children.iter().filter(|c| c.is_none()).count(), 2);
+
+		let result: Result<FullNode, rlp::DecoderError> = rlp::decode(RAW_PROOF[2]);
+		assert!(result.is_err());
+	}
+
+	#[test]
+	fn decode_short_node() {
+		// key + item value
+		let node: ShortNode = rlp::decode(RAW_PROOF[2]).unwrap();
+		assert_eq!(node.key, vec![32]);
+		assert!(!node.value.is_empty());
+
+		// key + item hash
+		let node: ShortNode = rlp::decode(&hex!(
+			"e4820001a04fff54398cad4d05ea6abfd8b0f3b4fe14c04d7ff5f5211c5b927d9cf72ac1d8"
+		))
+		.unwrap();
+		assert_eq!(node.key, vec![0, 1]);
+		assert_eq!(
+			node.value,
+			hex!("4fff54398cad4d05ea6abfd8b0f3b4fe14c04d7ff5f5211c5b927d9cf72ac1d8").to_vec()
+		);
+	}
+}

bridges/snowbridge/parachain/primitives/ethereum/src/receipt.rs

@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate::{Bloom, Log};
+use codec::{Decode, Encode};
+use sp_runtime::RuntimeDebug;
+use sp_std::prelude::*;
+
+#[derive(Clone, Default, Encode, Decode, PartialEq, RuntimeDebug)]
+pub struct Receipt {
+	pub post_state_or_status: Vec<u8>,
+	pub cumulative_gas_used: u64,
+	pub bloom: Bloom,
+	pub logs: Vec<Log>,
+}
+
+impl Receipt {
+	pub fn contains_log(&self, log: &Log) -> bool {
+		self.logs.iter().any(|l| l == log)
+	}
+
+	fn decode_list(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		let mut iter = rlp.iter();
+
+		let post_state_or_status: Vec<u8> = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected receipt post state or status")),
+		};
+
+		let cumulative_gas_used: u64 = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected receipt cumulative gas used")),
+		};
+
+		let bloom: Bloom = match iter.next() {
+			Some(data) => data.as_val()?,
+			None => return Err(rlp::DecoderError::Custom("Expected receipt bloom")),
+		};
+
+		let logs: Vec<Log> = match iter.next() {
+			Some(data) => data.as_list()?,
+			None => return Err(rlp::DecoderError::Custom("Expected receipt logs")),
+		};
+
+		Ok(Self { post_state_or_status, cumulative_gas_used, bloom, logs })
+	}
+}
+
+impl rlp::Decodable for Receipt {
+	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
+		if rlp.is_data() {
+			// Typed receipt
+			let data = rlp.as_raw();
+			match data[0] {
+				// 1 = EIP-2930, 2 = EIP-1559
+				1 | 2 => {
+					let receipt_rlp = &rlp::Rlp::new(&data[1..]);
+					if !receipt_rlp.is_list() {
+						return Err(rlp::DecoderError::RlpExpectedToBeList)
+					}
+					Self::decode_list(&rlp::Rlp::new(&data[1..]))
+				},
+				_ => Err(rlp::DecoderError::Custom("Unsupported receipt type")),
+			}
+		} else if rlp.is_list() {
+			// Legacy receipt
+			Self::decode_list(rlp)
+		} else {
+			Err(rlp::DecoderError::RlpExpectedToBeList)
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+
+	use super::Receipt;
+	use hex_literal::hex;
+
+	const RAW_RECEIPT: [u8; 1242] = hex!(
+		"
+		f904d701830652f0b901000420000000000000000000008002000000000001000000000001000000
+		00000000000000000000000000000000000000020000000800000000000000002000000000000000
+		00000000000008000000220000000000400010000000000000000000000000000000000000000000
+		00000000000000000004000000001000010000000000080000000000400000000000000000000000
+		00000800000040000000000200000000000200000000000000000000000000000000000000000000
+		04000000000002000000000100000000000000000000000000001000000002000020000010200000
+		000000010000000000000000000000000000000000000010000000f903ccf89b9421130f34829b4c
+		343142047a28ce96ec07814b15f863a0ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a116
+		28f55a4df523b3efa00000000000000000000000007d843005c7433c16b27ff939cb37471541561e
+		bda0000000000000000000000000e9c1281aae66801fa35ec404d5f2aea393ff6988a00000000000
+		0000000000000000000000000000000000000000000005d09b7380f89b9421130f34829b4c343142
+		047a28ce96ec07814b15f863a08c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200a
+		c8c7c3b925a00000000000000000000000007d843005c7433c16b27ff939cb37471541561ebda000
+		00000000000000000000007a250d5630b4cf539739df2c5dacb4c659f2488da0ffffffffffffffff
+		ffffffffffffffffffffffffffffffffffffffcc840c6920f89b94c02aaa39b223fe8d0a0e5c4f27
+		ead9083c756cc2f863a0ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523
+		b3efa0000000000000000000000000e9c1281aae66801fa35ec404d5f2aea393ff6988a000000000
+		00000000000000007a250d5630b4cf539739df2c5dacb4c659f2488da00000000000000000000000
+		0000000000000000000000000003e973b5a5d1078ef87994e9c1281aae66801fa35ec404d5f2aea3
+		93ff6988e1a01c411e9a96e071241c2f21f7726b17ae89e3cab4c78be50e062b03a9fffbbad1b840
+		000000000000000000000000000000000000000000000000000001f1420ad1d40000000000000000
+		000000000000000000000000000000014ad400879d159a38f8fc94e9c1281aae66801fa35ec404d5
+		f2aea393ff6988f863a0d78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159
+		d822a00000000000000000000000007a250d5630b4cf539739df2c5dacb4c659f2488da000000000
+		00000000000000007a250d5630b4cf539739df2c5dacb4c659f2488db88000000000000000000000
+		000000000000000000000000000000000005d415f332000000000000000000000000000000000000
+		00000000000000000000000000000000000000000000000000000000000000000000000000000000
+		00000000000000000000000000000000000000000000000000000000000003e973b5a5d1078ef87a
+		94c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2f842a07fcf532c15f0a6db0bd6d0e038bea71d
+		30d808c7d98cb3bf7268a95bf5081b65a00000000000000000000000007a250d5630b4cf539739df
+		2c5dacb4c659f2488da000000000000000000000000000000000000000000000000003e973b5a5d1
+		078e
+	"
+	);
+
+	#[test]
+	fn decode_legacy_receipt() {
+		let receipt: Receipt = rlp::decode(&RAW_RECEIPT).unwrap();
+		assert_eq!(receipt.post_state_or_status, vec!(1));
+		assert_eq!(receipt.cumulative_gas_used, 414448);
+		assert_eq!(
+			receipt.bloom,
+			(&hex!(
+				"
+				042000000000000000000000800200000000000100000000000100000000000000000000
+				000000000000000000000000020000000800000000000000002000000000000000000000
+				000000080000002200000000004000100000000000000000000000000000000000000000
+				000000000000000000000400000000100001000000000008000000000040000000000000
+				000000000000000800000040000000000200000000000200000000000000000000000000
+				000000000000000000040000000000020000000001000000000000000000000000000010
+				000000020000200000102000000000000100000000000000000000000000000000000000
+				10000000
+			"
+			))
+				.into(),
+		);
+		assert_eq!(receipt.logs.len(), 6);
+	}
+}

bridges/snowbridge/parachain/primitives/router/Cargo.toml

@@ -0,0 +1,61 @@
+[package]
+name = "snowbridge-router-primitives"
+description = "Snowbridge Router Primitives"
+version = "0.1.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+serde = { version = "1.0.188", optional = true, features = ["derive"] }
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
+scale-info = { version = "2.9.0", default-features = false, features = ["derive"] }
+log = { version = "0.4.20", default-features = false }
+
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+xcm-executor = { package = "staging-xcm-executor", path = "../../../../../polkadot/xcm/xcm-executor", default-features = false }
+
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+
+ethabi = { git = "https://github.com/Snowfork/ethabi-decode.git", package = "ethabi-decode", branch = "master", default-features = false }
+
+hex-literal = { version = "0.4.1" }
+
+[dev-dependencies]
+hex = { package = "rustc-hex", version = "2.1.0" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"ethabi/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"scale-info/std",
+	"serde",
+	"snowbridge-core/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+	"xcm-executor/runtime-benchmarks",
+]

bridges/snowbridge/parachain/primitives/router/src/inbound/mod.rs

@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Converts messages from Ethereum to XCM messages
+
+#[cfg(test)]
+mod tests;
+
+use codec::{Decode, Encode};
+use core::marker::PhantomData;
+use frame_support::{traits::tokens::Balance as BalanceT, weights::Weight, PalletError};
+use scale_info::TypeInfo;
+use sp_core::{Get, RuntimeDebug, H160};
+use sp_io::hashing::blake2_256;
+use sp_runtime::MultiAddress;
+use sp_std::prelude::*;
+use xcm::prelude::{Junction::AccountKey20, *};
+use xcm_executor::traits::ConvertLocation;
+
+const MINIMUM_DEPOSIT: u128 = 1;
+
+/// Messages from Ethereum are versioned. This is because in future,
+/// we may want to evolve the protocol so that the ethereum side sends XCM messages directly.
+/// Instead having BridgeHub transcode the messages into XCM.
+#[derive(Clone, Encode, Decode, RuntimeDebug)]
+pub enum VersionedMessage {
+	V1(MessageV1),
+}
+
+/// For V1, the ethereum side sends messages which are transcoded into XCM. These messages are
+/// self-contained, in that they can be transcoded using only information in the message.
+#[derive(Clone, Encode, Decode, RuntimeDebug)]
+pub struct MessageV1 {
+	/// EIP-155 chain id of the origin Ethereum network
+	pub chain_id: u64,
+	/// The command originating from the Gateway contract
+	pub command: Command,
+}
+
+#[derive(Clone, Encode, Decode, RuntimeDebug)]
+pub enum Command {
+	/// Register a wrapped token on the AssetHub `ForeignAssets` pallet
+	RegisterToken {
+		/// The address of the ERC20 token to be bridged over to AssetHub
+		token: H160,
+		/// XCM execution fee on AssetHub
+		fee: u128,
+	},
+	/// Send a token to AssetHub or another parachain
+	SendToken {
+		/// The address of the ERC20 token to be bridged over to AssetHub
+		token: H160,
+		/// The destination for the transfer
+		destination: Destination,
+		/// Amount to transfer
+		amount: u128,
+		/// XCM execution fee on AssetHub
+		fee: u128,
+	},
+}
+
+/// Destination for bridged tokens
+#[derive(Clone, Encode, Decode, RuntimeDebug)]
+pub enum Destination {
+	/// The funds will be deposited into account `id` on AssetHub
+	AccountId32 { id: [u8; 32] },
+	/// The funds will deposited into the sovereign account of destination parachain `para_id` on
+	/// AssetHub, Account `id` on the destination parachain will receive the funds via a
+	/// reserve-backed transfer. See <https://github.com/paritytech/xcm-format#depositreserveasset>
+	ForeignAccountId32 {
+		para_id: u32,
+		id: [u8; 32],
+		/// XCM execution fee on final destination
+		fee: u128,
+	},
+	/// The funds will deposited into the sovereign account of destination parachain `para_id` on
+	/// AssetHub, Account `id` on the destination parachain will receive the funds via a
+	/// reserve-backed transfer. See <https://github.com/paritytech/xcm-format#depositreserveasset>
+	ForeignAccountId20 {
+		para_id: u32,
+		id: [u8; 20],
+		/// XCM execution fee on final destination
+		fee: u128,
+	},
+}
+
+pub struct MessageToXcm<
+	CreateAssetCall,
+	CreateAssetDeposit,
+	InboundQueuePalletInstance,
+	AccountId,
+	Balance,
+> where
+	CreateAssetCall: Get<CallIndex>,
+	CreateAssetDeposit: Get<u128>,
+	Balance: BalanceT,
+{
+	_phantom: PhantomData<(
+		CreateAssetCall,
+		CreateAssetDeposit,
+		InboundQueuePalletInstance,
+		AccountId,
+		Balance,
+	)>,
+}
+
+/// Reason why a message conversion failed.
+#[derive(Copy, Clone, TypeInfo, PalletError, Encode, Decode, RuntimeDebug)]
+pub enum ConvertMessageError {
+	/// The message version is not supported for conversion.
+	UnsupportedVersion,
+}
+
+/// convert the inbound message to xcm which will be forwarded to the destination chain
+pub trait ConvertMessage {
+	type Balance: BalanceT + From<u128>;
+	type AccountId;
+	/// Converts a versioned message into an XCM message and an optional topicID
+	fn convert(message: VersionedMessage) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError>;
+}
+
+pub type CallIndex = [u8; 2];
+
+impl<CreateAssetCall, CreateAssetDeposit, InboundQueuePalletInstance, AccountId, Balance>
+	ConvertMessage
+	for MessageToXcm<
+		CreateAssetCall,
+		CreateAssetDeposit,
+		InboundQueuePalletInstance,
+		AccountId,
+		Balance,
+	> where
+	CreateAssetCall: Get<CallIndex>,
+	CreateAssetDeposit: Get<u128>,
+	InboundQueuePalletInstance: Get<u8>,
+	Balance: BalanceT + From<u128>,
+	AccountId: Into<[u8; 32]>,
+{
+	type Balance = Balance;
+	type AccountId = AccountId;
+
+	fn convert(message: VersionedMessage) -> Result<(Xcm<()>, Self::Balance), ConvertMessageError> {
+		use Command::*;
+		use VersionedMessage::*;
+		match message {
+			V1(MessageV1 { chain_id, command: RegisterToken { token, fee } }) =>
+				Ok(Self::convert_register_token(chain_id, token, fee)),
+			V1(MessageV1 { chain_id, command: SendToken { token, destination, amount, fee } }) =>
+				Ok(Self::convert_send_token(chain_id, token, destination, amount, fee)),
+		}
+	}
+}
+
+impl<CreateAssetCall, CreateAssetDeposit, InboundQueuePalletInstance, AccountId, Balance>
+	MessageToXcm<CreateAssetCall, CreateAssetDeposit, InboundQueuePalletInstance, AccountId, Balance>
+where
+	CreateAssetCall: Get<CallIndex>,
+	CreateAssetDeposit: Get<u128>,
+	InboundQueuePalletInstance: Get<u8>,
+	Balance: BalanceT + From<u128>,
+	AccountId: Into<[u8; 32]>,
+{
+	fn convert_register_token(chain_id: u64, token: H160, fee: u128) -> (Xcm<()>, Balance) {
+		let network = Ethereum { chain_id };
+		let xcm_fee: MultiAsset = (MultiLocation::parent(), fee).into();
+		let deposit: MultiAsset = (MultiLocation::parent(), CreateAssetDeposit::get()).into();
+
+		let total_amount = fee + CreateAssetDeposit::get();
+		let total: MultiAsset = (MultiLocation::parent(), total_amount).into();
+
+		let bridge_location: MultiLocation = (Parent, Parent, GlobalConsensus(network)).into();
+
+		let owner = GlobalConsensusEthereumConvertsFor::<[u8; 32]>::from_chain_id(&chain_id);
+		let asset_id = Self::convert_token_address(network, token);
+		let create_call_index: [u8; 2] = CreateAssetCall::get();
+		let inbound_queue_pallet_index = InboundQueuePalletInstance::get();
+
+		let xcm: Xcm<()> = vec![
+			// Teleport required fees.
+			ReceiveTeleportedAsset(total.into()),
+			// Pay for execution.
+			BuyExecution { fees: xcm_fee, weight_limit: Unlimited },
+			// Fund the snowbridge sovereign with the required deposit for creation.
+			DepositAsset { assets: Definite(deposit.into()), beneficiary: bridge_location },
+			// Only our inbound-queue pallet is allowed to invoke `UniversalOrigin`
+			DescendOrigin(X1(PalletInstance(inbound_queue_pallet_index))),
+			// Change origin to the bridge.
+			UniversalOrigin(GlobalConsensus(network)),
+			// Call create_asset on foreign assets pallet.
+			Transact {
+				origin_kind: OriginKind::Xcm,
+				require_weight_at_most: Weight::from_parts(400_000_000, 8_000),
+				call: (
+					create_call_index,
+					asset_id,
+					MultiAddress::<[u8; 32], ()>::Id(owner),
+					MINIMUM_DEPOSIT,
+				)
+					.encode()
+					.into(),
+			},
+			RefundSurplus,
+			// Clear the origin so that remaining assets in holding
+			// are claimable by the physical origin (BridgeHub)
+			ClearOrigin,
+		]
+		.into();
+
+		(xcm, total_amount.into())
+	}
+
+	fn convert_send_token(
+		chain_id: u64,
+		token: H160,
+		destination: Destination,
+		amount: u128,
+		asset_hub_fee: u128,
+	) -> (Xcm<()>, Balance) {
+		let network = Ethereum { chain_id };
+		let asset_hub_fee_asset: MultiAsset = (MultiLocation::parent(), asset_hub_fee).into();
+		let asset: MultiAsset = (Self::convert_token_address(network, token), amount).into();
+
+		let (dest_para_id, beneficiary, dest_para_fee) = match destination {
+			// Final destination is a 32-byte account on AssetHub
+			Destination::AccountId32 { id } => (
+				None,
+				MultiLocation { parents: 0, interior: X1(AccountId32 { network: None, id }) },
+				0,
+			),
+			// Final destination is a 32-byte account on a sibling of AssetHub
+			Destination::ForeignAccountId32 { para_id, id, fee } => (
+				Some(para_id),
+				MultiLocation { parents: 0, interior: X1(AccountId32 { network: None, id }) },
+				// Total fee needs to cover execution on AssetHub and Sibling
+				fee,
+			),
+			// Final destination is a 20-byte account on a sibling of AssetHub
+			Destination::ForeignAccountId20 { para_id, id, fee } => (
+				Some(para_id),
+				MultiLocation { parents: 0, interior: X1(AccountKey20 { network: None, key: id }) },
+				// Total fee needs to cover execution on AssetHub and Sibling
+				fee,
+			),
+		};
+
+		let total_fees = asset_hub_fee.saturating_add(dest_para_fee);
+		let total_fee_asset: MultiAsset = (MultiLocation::parent(), total_fees).into();
+		let inbound_queue_pallet_index = InboundQueuePalletInstance::get();
+
+		let mut instructions = vec![
+			ReceiveTeleportedAsset(total_fee_asset.into()),
+			BuyExecution { fees: asset_hub_fee_asset, weight_limit: Unlimited },
+			DescendOrigin(X1(PalletInstance(inbound_queue_pallet_index))),
+			UniversalOrigin(GlobalConsensus(network)),
+			ReserveAssetDeposited(asset.clone().into()),
+			ClearOrigin,
+		];
+
+		match dest_para_id {
+			Some(dest_para_id) => {
+				let dest_para_fee_asset: MultiAsset =
+					(MultiLocation::parent(), dest_para_fee).into();
+
+				instructions.extend(vec![
+					// Perform a deposit reserve to send to destination chain.
+					DepositReserveAsset {
+						assets: Definite(vec![dest_para_fee_asset.clone(), asset.clone()].into()),
+						dest: MultiLocation { parents: 1, interior: X1(Parachain(dest_para_id)) },
+						xcm: vec![
+							// Buy execution on target.
+							BuyExecution { fees: dest_para_fee_asset, weight_limit: Unlimited },
+							// Deposit asset to beneficiary.
+							DepositAsset { assets: Definite(asset.into()), beneficiary },
+						]
+						.into(),
+					},
+				]);
+			},
+			None => {
+				instructions.extend(vec![
+					// Deposit asset to beneficiary.
+					DepositAsset { assets: Definite(asset.into()), beneficiary },
+				]);
+			},
+		}
+
+		(instructions.into(), total_fees.into())
+	}
+
+	// Convert ERC20 token address to a Multilocation that can be understood by Assets Hub.
+	fn convert_token_address(network: NetworkId, token: H160) -> MultiLocation {
+		MultiLocation {
+			parents: 2,
+			interior: X2(
+				GlobalConsensus(network),
+				AccountKey20 { network: None, key: token.into() },
+			),
+		}
+	}
+}
+
+pub struct GlobalConsensusEthereumConvertsFor<AccountId>(PhantomData<AccountId>);
+impl<AccountId> ConvertLocation<AccountId> for GlobalConsensusEthereumConvertsFor<AccountId>
+where
+	AccountId: From<[u8; 32]> + Clone,
+{
+	fn convert_location(location: &MultiLocation) -> Option<AccountId> {
+		if let MultiLocation { interior: X1(GlobalConsensus(Ethereum { chain_id })), .. } = location
+		{
+			Some(Self::from_chain_id(chain_id).into())
+		} else {
+			None
+		}
+	}
+}
+
+impl<AccountId> GlobalConsensusEthereumConvertsFor<AccountId> {
+	pub fn from_chain_id(chain_id: &u64) -> [u8; 32] {
+		(b"ethereum-chain", chain_id).using_encoded(blake2_256)
+	}
+}

bridges/snowbridge/parachain/primitives/router/src/inbound/tests.rs

@@ -0,0 +1,41 @@
+use super::GlobalConsensusEthereumConvertsFor;
+use crate::inbound::CallIndex;
+use frame_support::parameter_types;
+use hex_literal::hex;
+use xcm::v3::prelude::*;
+use xcm_executor::traits::ConvertLocation;
+
+const NETWORK: NetworkId = Ethereum { chain_id: 11155111 };
+
+parameter_types! {
+	pub EthereumNetwork: NetworkId = NETWORK;
+
+	pub const CreateAssetCall: CallIndex = [1, 1];
+	pub const CreateAssetExecutionFee: u128 = 123;
+	pub const CreateAssetDeposit: u128 = 891;
+	pub const SendTokenExecutionFee: u128 = 592;
+}
+
+#[test]
+fn test_contract_location_with_network_converts_successfully() {
+	let expected_account: [u8; 32] =
+		hex!("ce796ae65569a670d0c1cc1ac12515a3ce21b5fbf729d63d7b289baad070139d");
+	let contract_location = MultiLocation { parents: 2, interior: X1(GlobalConsensus(NETWORK)) };
+
+	let account =
+		GlobalConsensusEthereumConvertsFor::<[u8; 32]>::convert_location(&contract_location)
+			.unwrap();
+
+	assert_eq!(account, expected_account);
+}
+
+#[test]
+fn test_contract_location_with_incorrect_location_fails_convert() {
+	let contract_location =
+		MultiLocation { parents: 2, interior: X2(GlobalConsensus(Polkadot), Parachain(1000)) };
+
+	assert_eq!(
+		GlobalConsensusEthereumConvertsFor::<[u8; 32]>::convert_location(&contract_location),
+		None,
+	);
+}

bridges/snowbridge/parachain/primitives/router/src/lib.rs

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+#![cfg_attr(not(feature = "std"), no_std)]
+
+pub mod inbound;
+pub mod outbound;

bridges/snowbridge/parachain/primitives/router/src/outbound/mod.rs

@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! Converts XCM messages into simpler commands that can be processed by the Gateway contract
+
+#[cfg(test)]
+mod tests;
+
+use core::slice::Iter;
+
+use codec::{Decode, Encode};
+
+use frame_support::{ensure, traits::Get};
+use snowbridge_core::{
+	outbound::{AgentExecuteCommand, Command, Message, SendMessage},
+	ChannelId, ParaId,
+};
+use sp_core::{H160, H256};
+use sp_std::{iter::Peekable, marker::PhantomData, prelude::*};
+use xcm::v3::prelude::*;
+use xcm_executor::traits::{ConvertLocation, ExportXcm};
+
+pub struct EthereumBlobExporter<
+	UniversalLocation,
+	EthereumNetwork,
+	OutboundQueue,
+	AgentHashedDescription,
+>(PhantomData<(UniversalLocation, EthereumNetwork, OutboundQueue, AgentHashedDescription)>);
+
+impl<UniversalLocation, EthereumNetwork, OutboundQueue, AgentHashedDescription> ExportXcm
+	for EthereumBlobExporter<UniversalLocation, EthereumNetwork, OutboundQueue, AgentHashedDescription>
+where
+	UniversalLocation: Get<InteriorMultiLocation>,
+	EthereumNetwork: Get<NetworkId>,
+	OutboundQueue: SendMessage<Balance = u128>,
+	AgentHashedDescription: ConvertLocation<H256>,
+{
+	type Ticket = (Vec<u8>, XcmHash);
+
+	fn validate(
+		network: NetworkId,
+		_channel: u32,
+		universal_source: &mut Option<InteriorMultiLocation>,
+		destination: &mut Option<InteriorMultiLocation>,
+		message: &mut Option<Xcm<()>>,
+	) -> SendResult<Self::Ticket> {
+		let expected_network = EthereumNetwork::get();
+		let universal_location = UniversalLocation::get();
+
+		if network != expected_network {
+			log::trace!(target: "xcm::ethereum_blob_exporter", "skipped due to unmatched bridge network {network:?}.");
+			return Err(SendError::NotApplicable)
+		}
+
+		let dest = destination.take().ok_or(SendError::MissingArgument)?;
+		if dest != Here {
+			log::trace!(target: "xcm::ethereum_blob_exporter", "skipped due to unmatched remote destination {dest:?}.");
+			return Err(SendError::NotApplicable)
+		}
+
+		let (local_net, local_sub) = universal_source
+			.take()
+			.ok_or_else(|| {
+				log::error!(target: "xcm::ethereum_blob_exporter", "universal source not provided.");
+				SendError::MissingArgument
+			})?
+			.split_global()
+			.map_err(|()| {
+				log::error!(target: "xcm::ethereum_blob_exporter", "could not get global consensus from universal source '{universal_source:?}'.");
+				SendError::Unroutable
+			})?;
+
+		if Ok(local_net) != universal_location.global_consensus() {
+			log::trace!(target: "xcm::ethereum_blob_exporter", "skipped due to unmatched relay network {local_net:?}.");
+			return Err(SendError::NotApplicable)
+		}
+
+		let para_id = match local_sub {
+			X1(Parachain(para_id)) => para_id,
+			_ => {
+				log::error!(target: "xcm::ethereum_blob_exporter", "could not get parachain id from universal source '{local_sub:?}'.");
+				return Err(SendError::MissingArgument)
+			},
+		};
+
+		let message = message.take().ok_or_else(|| {
+			log::error!(target: "xcm::ethereum_blob_exporter", "xcm message not provided.");
+			SendError::MissingArgument
+		})?;
+
+		let mut converter = XcmConverter::new(&message, &expected_network);
+		let (agent_execute_command, message_id) = converter.convert().map_err(|err|{
+			log::error!(target: "xcm::ethereum_blob_exporter", "unroutable due to pattern matching error '{err:?}'.");
+			SendError::Unroutable
+		})?;
+
+		let source_location: MultiLocation = MultiLocation { parents: 1, interior: local_sub };
+		let agent_id = match AgentHashedDescription::convert_location(&source_location) {
+			Some(id) => id,
+			None => {
+				log::error!(target: "xcm::ethereum_blob_exporter", "unroutable due to not being able to create agent id. '{source_location:?}'");
+				return Err(SendError::Unroutable)
+			},
+		};
+
+		let channel_id: ChannelId = ParaId::from(para_id).into();
+
+		let outbound_message = Message {
+			id: Some(message_id.into()),
+			channel_id,
+			command: Command::AgentExecute { agent_id, command: agent_execute_command },
+		};
+
+		// validate the message
+		let (ticket, fee) = OutboundQueue::validate(&outbound_message).map_err(|err| {
+			log::error!(target: "xcm::ethereum_blob_exporter", "OutboundQueue validation of message failed. {err:?}");
+			SendError::Unroutable
+		})?;
+
+		// convert fee to MultiAsset
+		let fee = MultiAsset::from((MultiLocation::parent(), fee.total())).into();
+
+		Ok(((ticket.encode(), message_id), fee))
+	}
+
+	fn deliver(blob: (Vec<u8>, XcmHash)) -> Result<XcmHash, SendError> {
+		let ticket: OutboundQueue::Ticket = OutboundQueue::Ticket::decode(&mut blob.0.as_ref())
+			.map_err(|_| {
+				log::trace!(target: "xcm::ethereum_blob_exporter", "undeliverable due to decoding error");
+				SendError::NotApplicable
+			})?;
+
+		let message_id = OutboundQueue::deliver(ticket).map_err(|_| {
+			log::error!(target: "xcm::ethereum_blob_exporter", "OutboundQueue submit of message failed");
+			SendError::Transport("other transport error")
+		})?;
+
+		log::info!(target: "xcm::ethereum_blob_exporter", "message delivered {message_id:#?}.");
+		Ok(message_id.into())
+	}
+}
+
+/// Errors that can be thrown to the pattern matching step.
+#[derive(PartialEq, Debug)]
+enum XcmConverterError {
+	UnexpectedEndOfXcm,
+	EndOfXcmMessageExpected,
+	WithdrawAssetExpected,
+	DepositAssetExpected,
+	NoReserveAssets,
+	FilterDoesNotConsumeAllAssets,
+	TooManyAssets,
+	ZeroAssetTransfer,
+	BeneficiaryResolutionFailed,
+	AssetResolutionFailed,
+	InvalidFeeAsset,
+	SetTopicExpected,
+}
+
+macro_rules! match_expression {
+	($expression:expr, $(|)? $( $pattern:pat_param )|+ $( if $guard: expr )?, $value:expr $(,)?) => {
+		match $expression {
+			$( $pattern )|+ $( if $guard )? => Some($value),
+			_ => None,
+		}
+	};
+}
+
+struct XcmConverter<'a, Call> {
+	iter: Peekable<Iter<'a, Instruction<Call>>>,
+	ethereum_network: &'a NetworkId,
+}
+impl<'a, Call> XcmConverter<'a, Call> {
+	fn new(message: &'a Xcm<Call>, ethereum_network: &'a NetworkId) -> Self {
+		Self { iter: message.inner().iter().peekable(), ethereum_network }
+	}
+
+	fn convert(&mut self) -> Result<(AgentExecuteCommand, [u8; 32]), XcmConverterError> {
+		// Get withdraw/deposit and make native tokens create message.
+		let result = self.native_tokens_unlock_message()?;
+
+		// All xcm instructions must be consumed before exit.
+		if self.next().is_ok() {
+			return Err(XcmConverterError::EndOfXcmMessageExpected)
+		}
+
+		Ok(result)
+	}
+
+	fn native_tokens_unlock_message(
+		&mut self,
+	) -> Result<(AgentExecuteCommand, [u8; 32]), XcmConverterError> {
+		use XcmConverterError::*;
+
+		// Get the reserve assets from WithdrawAsset.
+		let reserve_assets =
+			match_expression!(self.next()?, WithdrawAsset(reserve_assets), reserve_assets)
+				.ok_or(WithdrawAssetExpected)?;
+
+		// Check if clear origin exists and skip over it.
+		if match_expression!(self.peek(), Ok(ClearOrigin), ()).is_some() {
+			let _ = self.next();
+		}
+
+		// Get the fee asset item from BuyExecution or continue parsing.
+		let fee_asset = match_expression!(self.peek(), Ok(BuyExecution { fees, .. }), fees);
+		if fee_asset.is_some() {
+			let _ = self.next();
+		}
+
+		let (deposit_assets, beneficiary) = match_expression!(
+			self.next()?,
+			DepositAsset { assets, beneficiary },
+			(assets, beneficiary)
+		)
+		.ok_or(DepositAssetExpected)?;
+
+		// assert that the beneficiary is AccountKey20.
+		let recipient = match_expression!(
+			beneficiary,
+			MultiLocation { parents: 0, interior: X1(AccountKey20 { network, key }) }
+				if self.network_matches(network),
+			H160(*key)
+		)
+		.ok_or(BeneficiaryResolutionFailed)?;
+
+		// Make sure there are reserved assets.
+		if reserve_assets.len() == 0 {
+			return Err(NoReserveAssets)
+		}
+
+		// Check the the deposit asset filter matches what was reserved.
+		if reserve_assets.inner().iter().any(|asset| !deposit_assets.matches(asset)) {
+			return Err(FilterDoesNotConsumeAllAssets)
+		}
+
+		// We only support a single asset at a time.
+		ensure!(reserve_assets.len() == 1, TooManyAssets);
+		let reserve_asset = reserve_assets.get(0).ok_or(AssetResolutionFailed)?;
+
+		// If there was a fee specified verify it.
+		if let Some(fee_asset) = fee_asset {
+			// The fee asset must be the same as the reserve asset.
+			if fee_asset.id != reserve_asset.id || fee_asset.fun > reserve_asset.fun {
+				return Err(InvalidFeeAsset)
+			}
+		}
+
+		let (token, amount) = match_expression!(
+			reserve_asset,
+			MultiAsset {
+				id: Concrete(MultiLocation { parents: 0, interior: X1(AccountKey20 { network , key })}),
+				fun: Fungible(amount)
+			} if self.network_matches(network),
+			(H160(*key), *amount)
+		)
+		.ok_or(AssetResolutionFailed)?;
+
+		// transfer amount must be greater than 0.
+		ensure!(amount > 0, ZeroAssetTransfer);
+
+		// Check if there is a SetTopic and skip over it if found.
+		let topic_id = match_expression!(self.next()?, SetTopic(id), id).ok_or(SetTopicExpected)?;
+
+		Ok((AgentExecuteCommand::TransferToken { token, recipient, amount }, *topic_id))
+	}
+
+	fn next(&mut self) -> Result<&'a Instruction<Call>, XcmConverterError> {
+		self.iter.next().ok_or(XcmConverterError::UnexpectedEndOfXcm)
+	}
+
+	fn peek(&mut self) -> Result<&&'a Instruction<Call>, XcmConverterError> {
+		self.iter.peek().ok_or(XcmConverterError::UnexpectedEndOfXcm)
+	}
+
+	fn network_matches(&self, network: &Option<NetworkId>) -> bool {
+		if let Some(network) = network {
+			network == self.ethereum_network
+		} else {
+			true
+		}
+	}
+}

bridges/snowbridge/parachain/runtime/rococo-common/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "snowbridge-rococo-common"
+description = "Snowbridge Rococo Common"
+version = "0.0.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+log = { version = "0.4.20", default-features = false }
+
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+
+[dev-dependencies]
+
+[features]
+default = ["std"]
+std = [
+	"frame-support/std",
+	"log/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"frame-support/runtime-benchmarks",
+]

bridges/snowbridge/parachain/runtime/rococo-common/src/lib.rs

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! # Rococo Common
+//!
+//! Config used for the Rococo asset hub and bridge hub runtimes.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use frame_support::parameter_types;
+use xcm::opaque::lts::NetworkId;
+
+pub const INBOUND_QUEUE_MESSAGES_PALLET_INDEX: u8 = 80;
+
+parameter_types! {
+	// Network and location for the Ethereum chain.
+	pub EthereumNetwork: NetworkId = NetworkId::Ethereum { chain_id: 11155111 };
+}

bridges/snowbridge/parachain/runtime/runtime-common/Cargo.toml

@@ -0,0 +1,41 @@
+[package]
+name = "snowbridge-runtime-common"
+description = "Snowbridge Runtime Common"
+version = "0.1.1"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+log = { version = "0.4.20", default-features = false }
+
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+sp-arithmetic = { path = "../../../../../substrate/primitives/arithmetic", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+xcm-executor = { package = "staging-xcm-executor", path = "../../../../../polkadot/xcm/xcm-executor", default-features = false }
+
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+
+[dev-dependencies]
+
+[features]
+default = ["std"]
+std = [
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"snowbridge-core/std",
+	"sp-arithmetic/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+	"xcm/std",
+]
+runtime-benchmarks = [
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+	"xcm-executor/runtime-benchmarks",
+]

bridges/snowbridge/parachain/runtime/runtime-common/src/lib.rs

@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! # Runtime Common
+//!
+//! Common traits and types shared by runtimes.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use core::marker::PhantomData;
+use frame_support::traits::Get;
+use snowbridge_core::{outbound::SendMessageFeeProvider, sibling_sovereign_account_raw};
+use sp_arithmetic::traits::{BaseArithmetic, Unsigned};
+use xcm::prelude::*;
+use xcm_builder::{deposit_or_burn_fee, HandleFee};
+use xcm_executor::traits::{FeeReason, TransactAsset};
+
+/// A `HandleFee` implementation that takes fees from `ExportMessage` XCM instructions
+/// to Snowbridge and splits off the remote fee and deposits it to the origin
+/// parachain sovereign account. The local fee is then returned back to be handled by
+/// the next fee handler in the chain. Most likely the treasury account.
+pub struct XcmExportFeeToSibling<
+	Balance,
+	AccountId,
+	FeeAssetLocation,
+	EthereumNetwork,
+	AssetTransactor,
+	FeeProvider,
+>(
+	PhantomData<(
+		Balance,
+		AccountId,
+		FeeAssetLocation,
+		EthereumNetwork,
+		AssetTransactor,
+		FeeProvider,
+	)>,
+);
+
+impl<Balance, AccountId, FeeAssetLocation, EthereumNetwork, AssetTransactor, FeeProvider> HandleFee
+	for XcmExportFeeToSibling<
+		Balance,
+		AccountId,
+		FeeAssetLocation,
+		EthereumNetwork,
+		AssetTransactor,
+		FeeProvider,
+	> where
+	Balance: BaseArithmetic + Unsigned + Copy + From<u128> + Into<u128>,
+	AccountId: Clone + Into<[u8; 32]> + From<[u8; 32]>,
+	FeeAssetLocation: Get<MultiLocation>,
+	EthereumNetwork: Get<NetworkId>,
+	AssetTransactor: TransactAsset,
+	FeeProvider: SendMessageFeeProvider<Balance = Balance>,
+{
+	fn handle_fee(
+		fees: MultiAssets,
+		context: Option<&XcmContext>,
+		reason: FeeReason,
+	) -> MultiAssets {
+		let token_location = FeeAssetLocation::get();
+
+		// Check the reason to see if this export is for snowbridge.
+		if !matches!(
+			reason,
+			FeeReason::Export { network: bridged_network, destination }
+				if bridged_network == EthereumNetwork::get() && destination == Here
+		) {
+			return fees
+		}
+
+		// Get the parachain sovereign from the `context`.
+		let para_sovereign = if let Some(XcmContext {
+			origin: Some(MultiLocation { parents: 1, interior }),
+			..
+		}) = context
+		{
+			if let Some(Parachain(sibling_para_id)) = interior.first() {
+				let account: AccountId =
+					sibling_sovereign_account_raw((*sibling_para_id).into()).into();
+				account
+			} else {
+				return fees
+			}
+		} else {
+			return fees
+		};
+
+		// Get the total fee offered by export message.
+		let maybe_total_supplied_fee: Option<(usize, Balance)> = fees
+			.inner()
+			.iter()
+			.enumerate()
+			.filter_map(|(index, asset)| {
+				if let MultiAsset { id: Concrete(location), fun: Fungible(amount) } = asset {
+					if *location == token_location {
+						return Some((index, (*amount).into()))
+					}
+				}
+				None
+			})
+			.next();
+
+		if let Some((fee_index, total_fee)) = maybe_total_supplied_fee {
+			let remote_fee = total_fee.saturating_sub(FeeProvider::local_fee());
+			if remote_fee > (0u128).into() {
+				// Refund remote component of fee to physical origin
+				deposit_or_burn_fee::<AssetTransactor, _>(
+					MultiAsset { id: Concrete(token_location), fun: Fungible(remote_fee.into()) }
+						.into(),
+					context,
+					para_sovereign,
+				);
+				// Return remaining fee to the next fee handler in the chain.
+				let mut modified_fees = fees.inner().clone();
+				modified_fees.remove(fee_index);
+				modified_fees.push(MultiAsset {
+					id: Concrete(token_location),
+					fun: Fungible((total_fee - remote_fee).into()),
+				});
+				return modified_fees.into()
+			}
+		}
+
+		log::info!(
+			target: "xcm::fees",
+			"XcmExportFeeToSibling skipped: {fees:?}, context: {context:?}, reason: {reason:?}",
+		);
+		fees
+	}
+}

bridges/snowbridge/parachain/runtime/tests/Cargo.toml

@@ -0,0 +1,244 @@
+[package]
+name = "snowbridge-runtime-tests"
+description = "Snowbridge Runtime Tests"
+version = "0.1.0"
+authors = ["Snowfork <contact@snowfork.com>"]
+edition = "2021"
+license = "Apache-2.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
+hex-literal = { version = "0.4.1" }
+log = { version = "0.4.20", default-features = false }
+scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
+serde = { version = "1.0.188", optional = true, features = ["derive"] }
+smallvec = "1.11.0"
+
+# Substrate
+frame-benchmarking = { path = "../../../../../substrate/frame/benchmarking", default-features = false, optional = true }
+frame-executive = { path = "../../../../../substrate/frame/executive", default-features = false }
+frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
+frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
+frame-system-benchmarking = { path = "../../../../../substrate/frame/system/benchmarking", default-features = false, optional = true }
+frame-system-rpc-runtime-api = { path = "../../../../../substrate/frame/system/rpc/runtime-api", default-features = false }
+frame-try-runtime = { path = "../../../../../substrate/frame/try-runtime", default-features = false, optional = true }
+pallet-aura = { path = "../../../../../substrate/frame/aura", default-features = false }
+pallet-authorship = { path = "../../../../../substrate/frame/authorship", default-features = false }
+pallet-balances = { path = "../../../../../substrate/frame/balances", default-features = false }
+pallet-session = { path = "../../../../../substrate/frame/session", default-features = false }
+pallet-multisig = { path = "../../../../../substrate/frame/multisig", default-features = false }
+pallet-message-queue = { path = "../../../../../substrate/frame/message-queue", default-features = false }
+pallet-timestamp = { path = "../../../../../substrate/frame/timestamp", default-features = false }
+pallet-transaction-payment = { path = "../../../../../substrate/frame/transaction-payment", default-features = false }
+pallet-transaction-payment-rpc-runtime-api = { path = "../../../../../substrate/frame/transaction-payment/rpc/runtime-api", default-features = false }
+pallet-utility = { path = "../../../../../substrate/frame/utility", default-features = false }
+sp-api = { path = "../../../../../substrate/primitives/api", default-features = false }
+sp-block-builder = { path = "../../../../../substrate/primitives/block-builder", default-features = false }
+sp-consensus-aura = { path = "../../../../../substrate/primitives/consensus/aura", default-features = false }
+sp-core = { path = "../../../../../substrate/primitives/core", default-features = false }
+sp-genesis-builder = { path = "../../../../../substrate/primitives/genesis-builder", default-features = false }
+sp-inherents = { path = "../../../../../substrate/primitives/inherents", default-features = false }
+sp-io = { path = "../../../../../substrate/primitives/io", default-features = false }
+sp-offchain = { path = "../../../../../substrate/primitives/offchain", default-features = false }
+sp-runtime = { path = "../../../../../substrate/primitives/runtime", default-features = false }
+sp-session = { path = "../../../../../substrate/primitives/session", default-features = false }
+sp-std = { path = "../../../../../substrate/primitives/std", default-features = false }
+sp-storage = { path = "../../../../../substrate/primitives/storage", default-features = false }
+sp-transaction-pool = { path = "../../../../../substrate/primitives/transaction-pool", default-features = false }
+sp-version = { path = "../../../../../substrate/primitives/version", default-features = false }
+
+# Polkadot
+rococo-runtime-constants = { path = "../../../../../polkadot/runtime/rococo/constants", default-features = false }
+pallet-xcm = { path = "../../../../../polkadot/xcm/pallet-xcm", default-features = false }
+pallet-xcm-benchmarks = { path = "../../../../../polkadot/xcm/pallet-xcm-benchmarks", default-features = false, optional = true }
+polkadot-core-primitives = { path = "../../../../../polkadot/core-primitives", default-features = false }
+polkadot-parachain-primitives = { path = "../../../../../polkadot/parachain", default-features = false }
+polkadot-runtime-common = { path = "../../../../../polkadot/runtime/common", default-features = false }
+xcm = { package = "staging-xcm", path = "../../../../../polkadot/xcm", default-features = false }
+xcm-builder = { package = "staging-xcm-builder", path = "../../../../../polkadot/xcm/xcm-builder", default-features = false }
+xcm-executor = { package = "staging-xcm-executor", path = "../../../../../polkadot/xcm/xcm-executor", default-features = false }
+
+# Cumulus
+cumulus-pallet-aura-ext = { path = "../../../../../cumulus/pallets/aura-ext", default-features = false }
+cumulus-pallet-dmp-queue = { path = "../../../../../cumulus/pallets/dmp-queue", default-features = false }
+cumulus-pallet-parachain-system = { path = "../../../../../cumulus/pallets/parachain-system", default-features = false, features = ["parameterized-consensus-hook"] }
+cumulus-pallet-session-benchmarking = { path = "../../../../../cumulus/pallets/session-benchmarking", default-features = false }
+cumulus-pallet-xcm = { path = "../../../../../cumulus/pallets/xcm", default-features = false }
+cumulus-pallet-xcmp-queue = { path = "../../../../../cumulus/pallets/xcmp-queue", default-features = false, features = ["bridging"] }
+cumulus-primitives-core = { path = "../../../../../cumulus/primitives/core", default-features = false }
+cumulus-primitives-utility = { path = "../../../../../cumulus/primitives/utility", default-features = false }
+pallet-collator-selection = { path = "../../../../../cumulus/pallets/collator-selection", default-features = false }
+parachain-info = { package = "staging-parachain-info", path = "../../../../../cumulus/parachains/pallets/parachain-info", default-features = false }
+parachains-common = { path = "../../../../../cumulus/parachains/common", default-features = false }
+parachains-runtimes-test-utils = { path = "../../../../../cumulus/parachains/runtimes/test-utils", default-features = false }
+bridge-hub-rococo-runtime = { path = "../../../../../cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo", default-features = false }
+asset-hub-rococo-runtime = { path = "../../../../../cumulus/parachains/runtimes/assets/asset-hub-rococo", default-features = false }
+assets-common = { path = "../../../../../cumulus/parachains/runtimes/assets/common", default-features = false }
+
+# Ethereum Bridge (Snowbridge)
+snowbridge-core = { path = "../../primitives/core", default-features = false }
+snowbridge-beacon-primitives = { path = "../../primitives/beacon", default-features = false }
+snowbridge-router-primitives = { path = "../../primitives/router", default-features = false }
+snowbridge-ethereum-beacon-client = { path = "../../pallets/ethereum-beacon-client", default-features = false }
+snowbridge-inbound-queue = { path = "../../pallets/inbound-queue", default-features = false }
+snowbridge-outbound-queue = { path = "../../pallets/outbound-queue", default-features = false }
+snowbridge-outbound-queue-runtime-api = { path = "../../pallets/outbound-queue/runtime-api", default-features = false }
+snowbridge-system = { path = "../../pallets/system", default-features = false }
+snowbridge-system-runtime-api = { path = "../../pallets/system/runtime-api", default-features = false }
+
+[dev-dependencies]
+static_assertions = "1.1"
+bridge-hub-test-utils = { path = "../../../../../cumulus/parachains/runtimes/bridge-hubs/test-utils" }
+bridge-runtime-common = { path = "../../../../../bridges/bin/runtime-common", features = ["integrity-test"] }
+sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
+
+[features]
+default = ["std"]
+std = [
+	"asset-hub-rococo-runtime/std",
+	"assets-common/std",
+	"bridge-hub-rococo-runtime/std",
+	"codec/std",
+	"cumulus-pallet-aura-ext/std",
+	"cumulus-pallet-dmp-queue/std",
+	"cumulus-pallet-parachain-system/std",
+	"cumulus-pallet-session-benchmarking/std",
+	"cumulus-pallet-xcm/std",
+	"cumulus-pallet-xcmp-queue/std",
+	"cumulus-primitives-core/std",
+	"cumulus-primitives-utility/std",
+	"frame-benchmarking/std",
+	"frame-executive/std",
+	"frame-support/std",
+	"frame-system-benchmarking?/std",
+	"frame-system-rpc-runtime-api/std",
+	"frame-system/std",
+	"frame-try-runtime?/std",
+	"log/std",
+	"pallet-aura/std",
+	"pallet-authorship/std",
+	"pallet-balances/std",
+	"pallet-collator-selection/std",
+	"pallet-message-queue/std",
+	"pallet-multisig/std",
+	"pallet-session/std",
+	"pallet-timestamp/std",
+	"pallet-transaction-payment-rpc-runtime-api/std",
+	"pallet-transaction-payment/std",
+	"pallet-utility/std",
+	"pallet-xcm-benchmarks?/std",
+	"pallet-xcm/std",
+	"parachain-info/std",
+	"parachains-common/std",
+	"parachains-runtimes-test-utils/std",
+	"polkadot-core-primitives/std",
+	"polkadot-parachain-primitives/std",
+	"polkadot-runtime-common/std",
+	"rococo-runtime-constants/std",
+	"scale-info/std",
+	"serde",
+	"snowbridge-beacon-primitives/std",
+	"snowbridge-core/std",
+	"snowbridge-ethereum-beacon-client/std",
+	"snowbridge-inbound-queue/std",
+	"snowbridge-outbound-queue-runtime-api/std",
+	"snowbridge-outbound-queue/std",
+	"snowbridge-router-primitives/std",
+	"snowbridge-system-runtime-api/std",
+	"snowbridge-system/std",
+	"sp-api/std",
+	"sp-block-builder/std",
+	"sp-consensus-aura/std",
+	"sp-core/std",
+	"sp-genesis-builder/std",
+	"sp-inherents/std",
+	"sp-io/std",
+	"sp-offchain/std",
+	"sp-runtime/std",
+	"sp-session/std",
+	"sp-std/std",
+	"sp-storage/std",
+	"sp-transaction-pool/std",
+	"sp-version/std",
+	"xcm-builder/std",
+	"xcm-executor/std",
+	"xcm/std",
+]
+
+runtime-benchmarks = [
+	"asset-hub-rococo-runtime/runtime-benchmarks",
+	"assets-common/runtime-benchmarks",
+	"bridge-hub-rococo-runtime/runtime-benchmarks",
+	"bridge-runtime-common/runtime-benchmarks",
+	"cumulus-pallet-dmp-queue/runtime-benchmarks",
+	"cumulus-pallet-parachain-system/runtime-benchmarks",
+	"cumulus-pallet-session-benchmarking/runtime-benchmarks",
+	"cumulus-pallet-xcmp-queue/runtime-benchmarks",
+	"cumulus-primitives-core/runtime-benchmarks",
+	"cumulus-primitives-utility/runtime-benchmarks",
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-support/runtime-benchmarks",
+	"frame-system-benchmarking/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
+	"pallet-collator-selection/runtime-benchmarks",
+	"pallet-message-queue/runtime-benchmarks",
+	"pallet-multisig/runtime-benchmarks",
+	"pallet-timestamp/runtime-benchmarks",
+	"pallet-utility/runtime-benchmarks",
+	"pallet-xcm-benchmarks/runtime-benchmarks",
+	"pallet-xcm/runtime-benchmarks",
+	"parachains-common/runtime-benchmarks",
+	"polkadot-parachain-primitives/runtime-benchmarks",
+	"polkadot-runtime-common/runtime-benchmarks",
+	"snowbridge-core/runtime-benchmarks",
+	"snowbridge-ethereum-beacon-client/runtime-benchmarks",
+	"snowbridge-inbound-queue/runtime-benchmarks",
+	"snowbridge-outbound-queue/runtime-benchmarks",
+	"snowbridge-router-primitives/runtime-benchmarks",
+	"snowbridge-system/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+	"xcm-builder/runtime-benchmarks",
+	"xcm-executor/runtime-benchmarks",
+]
+
+try-runtime = [
+	"asset-hub-rococo-runtime/try-runtime",
+	"bridge-hub-rococo-runtime/try-runtime",
+	"cumulus-pallet-aura-ext/try-runtime",
+	"cumulus-pallet-dmp-queue/try-runtime",
+	"cumulus-pallet-parachain-system/try-runtime",
+	"cumulus-pallet-xcm/try-runtime",
+	"cumulus-pallet-xcmp-queue/try-runtime",
+	"frame-executive/try-runtime",
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"frame-try-runtime/try-runtime",
+	"pallet-aura/try-runtime",
+	"pallet-authorship/try-runtime",
+	"pallet-balances/try-runtime",
+	"pallet-collator-selection/try-runtime",
+	"pallet-message-queue/try-runtime",
+	"pallet-multisig/try-runtime",
+	"pallet-session/try-runtime",
+	"pallet-timestamp/try-runtime",
+	"pallet-transaction-payment/try-runtime",
+	"pallet-utility/try-runtime",
+	"pallet-xcm/try-runtime",
+	"parachain-info/try-runtime",
+	"polkadot-runtime-common/try-runtime",
+	"snowbridge-ethereum-beacon-client/try-runtime",
+	"snowbridge-inbound-queue/try-runtime",
+	"snowbridge-outbound-queue/try-runtime",
+	"snowbridge-system/try-runtime",
+	"sp-runtime/try-runtime",
+]
+beacon-spec-mainnet = [
+	"snowbridge-ethereum-beacon-client/beacon-spec-mainnet",
+]
+experimental = ["pallet-aura/experimental"]
+
+# A feature that should be enabled when the runtime should be built for on-chain
+# deployment. This will disable stuff that shouldn't be part of the on-chain wasm
+# to make it smaller like logging for example.
+on-chain-release-build = ["sp-api/disable-logging"]

bridges/snowbridge/parachain/runtime/tests/src/lib.rs

@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+
+#![cfg(test)]
+
+mod test_cases;
+
+use asset_hub_rococo_runtime::xcm_config::bridging::to_ethereum::DefaultBridgeHubEthereumBaseFee;
+use bridge_hub_rococo_runtime::{
+	xcm_config::XcmConfig, MessageQueueServiceWeight, Runtime, RuntimeEvent, SessionKeys,
+};
+use codec::Decode;
+use cumulus_primitives_core::XcmError::{FailedToTransactAsset, NotHoldingFees};
+use parachains_common::{AccountId, AuraId};
+use snowbridge_ethereum_beacon_client::WeightInfo;
+use sp_core::H160;
+use sp_keyring::AccountKeyring::Alice;
+
+pub fn collator_session_keys() -> bridge_hub_test_utils::CollatorSessionKeys<Runtime> {
+	bridge_hub_test_utils::CollatorSessionKeys::new(
+		AccountId::from(Alice),
+		AccountId::from(Alice),
+		SessionKeys { aura: AuraId::from(Alice.public()) },
+	)
+}
+
+#[test]
+pub fn transfer_token_to_ethereum_works() {
+	test_cases::send_transfer_token_message_success::<Runtime, XcmConfig>(
+		collator_session_keys(),
+		1013,
+		1000,
+		H160::random(),
+		H160::random(),
+		DefaultBridgeHubEthereumBaseFee::get(),
+		Box::new(|runtime_event_encoded: Vec<u8>| {
+			match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
+				Ok(RuntimeEvent::EthereumOutboundQueue(event)) => Some(event),
+				_ => None,
+			}
+		}),
+	)
+}
+
+#[test]
+pub fn unpaid_transfer_token_to_ethereum_fails_with_barrier() {
+	test_cases::send_unpaid_transfer_token_message::<Runtime, XcmConfig>(
+		collator_session_keys(),
+		1013,
+		1000,
+		H160::random(),
+		H160::random(),
+	)
+}
+
+#[test]
+pub fn transfer_token_to_ethereum_fee_not_enough() {
+	test_cases::send_transfer_token_message_failure::<Runtime, XcmConfig>(
+		collator_session_keys(),
+		1013,
+		1000,
+		DefaultBridgeHubEthereumBaseFee::get() + 1_000_000_000,
+		H160::random(),
+		H160::random(),
+		// fee not enough
+		1_000_000_000,
+		NotHoldingFees,
+	)
+}
+
+#[test]
+pub fn transfer_token_to_ethereum_insufficient_fund() {
+	test_cases::send_transfer_token_message_failure::<Runtime, XcmConfig>(
+		collator_session_keys(),
+		1013,
+		1000,
+		1_000_000_000,
+		H160::random(),
+		H160::random(),
+		DefaultBridgeHubEthereumBaseFee::get(),
+		FailedToTransactAsset("InsufficientBalance"),
+	)
+}
+
+#[test]
+fn max_message_queue_service_weight_is_more_than_beacon_extrinsic_weights() {
+	let max_message_queue_weight = MessageQueueServiceWeight::get();
+	let force_checkpoint =
+		<Runtime as snowbridge_ethereum_beacon_client::Config>::WeightInfo::force_checkpoint();
+	let submit_checkpoint =
+		<Runtime as snowbridge_ethereum_beacon_client::Config>::WeightInfo::submit();
+	max_message_queue_weight.all_gt(force_checkpoint);
+	max_message_queue_weight.all_gt(submit_checkpoint);
+}