feat: initialize Kurdistan SDK - independent fork of Polkadot SDK

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

@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+mod util;
+
+use crate::Pallet as EthereumBeaconClient;
+use frame_benchmarking::v2::*;
+use frame_system::RawOrigin;
+use hex_literal::hex;
+use snowbridge_beacon_primitives::{
+	fast_aggregate_verify,
+	merkle_proof::{generalized_index_length, subtree_index},
+	prepare_aggregate_pubkey, prepare_aggregate_signature, verify_merkle_branch, Fork,
+};
+use snowbridge_pallet_ethereum_client_fixtures::*;
+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(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();
+
+		let fork_versions = ForkVersions {
+			genesis: Fork { version: hex!("00000000"), epoch: 0 },
+			altair: Fork { version: hex!("01000000"), epoch: 0 },
+			bellatrix: Fork { version: hex!("02000000"), epoch: 0 },
+			capella: Fork { version: hex!("03000000"), epoch: 0 },
+			deneb: Fork { version: hex!("04000000"), epoch: 0 },
+			electra: Fork { version: hex!("05000000"), epoch: 80000000000 },
+			fulu: Fork { version: hex!("06000000"), epoch: 80000000001 },
+		};
+		let finalized_root_gindex = EthereumBeaconClient::<T>::finalized_root_gindex_at_slot(
+			update.attested_header.slot,
+			fork_versions,
+		);
+		#[block]
+		{
+			verify_merkle_branch(
+				block_root,
+				&update.finality_branch,
+				subtree_index(finalized_root_gindex),
+				generalized_index_length(finalized_root_gindex),
+				update.attested_header.state_root,
+			);
+		}
+
+		Ok(())
+	}
+
+	impl_benchmark_test_suite!(EthereumBeaconClient, crate::mock::new_tester(), crate::mock::Test);
+}

bridges/snowbridge/pallets/ethereum-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 snowbridge_beacon_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/pallets/ethereum-client/src/config/altair.rs

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+
+/// Generalized Indices
+/// related to Merkle proofs
+/// get_generalized_index(BeaconState, 'block_roots')
+pub const BLOCK_ROOTS_INDEX: usize = 37;
+/// get_generalized_index(BeaconState, 'finalized_checkpoint', 'root')
+pub const FINALIZED_ROOT_INDEX: usize = 105;
+/// get_generalized_index(BeaconState, 'current_sync_committee')
+pub const CURRENT_SYNC_COMMITTEE_INDEX: usize = 54;
+/// get_generalized_index(BeaconState, 'next_sync_committee')
+pub const NEXT_SYNC_COMMITTEE_INDEX: usize = 55;
+///  get_generalized_index(BeaconBlockBody, 'execution_payload')
+pub const EXECUTION_HEADER_INDEX: usize = 25;

bridges/snowbridge/pallets/ethereum-client/src/config/electra.rs

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+
+/// Generalized Indices
+/// related to Merkle proofs
+/// get_generalized_index(BeaconState, 'block_roots')
+pub const BLOCK_ROOTS_INDEX: usize = 69;
+/// get_generalized_index(BeaconState, 'finalized_checkpoint', 'root')
+pub const FINALIZED_ROOT_INDEX: usize = 169;
+/// get_generalized_index(BeaconState, 'current_sync_committee')
+pub const CURRENT_SYNC_COMMITTEE_INDEX: usize = 86;
+/// get_generalized_index(BeaconState, 'next_sync_committee')
+pub const NEXT_SYNC_COMMITTEE_INDEX: usize = 87;

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

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use static_assertions::const_assert;
+
+pub mod altair;
+pub mod electra;
+
+/// Sizes related to SSZ encoding
+pub const MAX_EXTRA_DATA_BYTES: usize = 32;
+pub const MAX_LOGS_BLOOM_SIZE: usize = 256;
+pub const MAX_FEE_RECIPIENT_SIZE: usize = 20;
+
+/// Sanity value to constrain the max size of a merkle branch proof.
+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];
+/// Validators public keys are 48 bytes.
+pub const PUBKEY_SIZE: usize = 48;
+/// Signatures produced by validators are 96 bytes.
+pub const SIGNATURE_SIZE: usize = 96;
+
+// Sanity check for the sync committee bits (see SYNC_COMMITTEE_BITS_SIZE).
+const_assert!(SYNC_COMMITTEE_BITS_SIZE == SYNC_COMMITTEE_SIZE / 8);
+
+/// Defined in <https://github.com/ethereum/consensus-specs/tree/f1dff5f6768608d890fc0b347e548297fc3e1f1c/presets/mainnet>
+/// There are 32 slots in an epoch. An epoch is 6.4 minutes long.
+pub const SLOTS_PER_EPOCH: usize = 32;
+/// 256 epochs in a sync committee period. Frequency of sync committee (subset of Ethereum
+/// validators) change is every ~27 hours.
+pub const EPOCHS_PER_SYNC_COMMITTEE_PERIOD: usize = 256;
+/// A sync committee contains 512 randomly selected validators.
+pub const SYNC_COMMITTEE_SIZE: usize = 512;
+/// An array of sync committee block votes, one bit representing the vote of one validator.
+pub const SYNC_COMMITTEE_BITS_SIZE: usize = SYNC_COMMITTEE_SIZE / 8;
+/// The size of the block root array in the beacon state, used for ancestry proofs.
+pub const SLOTS_PER_HISTORICAL_ROOT: usize = 8192;
+/// The index of the block_roots field in the beacon state tree.
+pub const BLOCK_ROOT_AT_INDEX_DEPTH: usize = 13;

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

@@ -0,0 +1,32 @@
+// 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] {
+	snowbridge_beacon_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/pallets/ethereum-client/src/impls.rs

@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+use frame_support::ensure;
+use snowbridge_beacon_primitives::ExecutionProof;
+
+use snowbridge_beacon_primitives::{
+	merkle_proof::{generalized_index_length, subtree_index},
+	receipt::verify_receipt_proof,
+};
+use snowbridge_ethereum::Log as AlloyLog;
+use snowbridge_verification_primitives::{
+	VerificationError::{self, *},
+	Verifier, *,
+};
+
+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 is sent with the message. The beacon header containing the execution header
+	/// is also sent with the message, to check if the header is an ancestor of a finalized
+	/// header.
+	fn verify(event_log: &Log, proof: &Proof) -> Result<(), VerificationError> {
+		Self::verify_execution_proof(&proof.execution_proof)
+			.map_err(|e| InvalidExecutionProof(e.into()))?;
+
+		Self::verify_receipt_inclusion(
+			proof.execution_proof.execution_header.receipts_root(),
+			&proof.receipt_proof.1,
+			event_log,
+		)?;
+
+		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,
+		receipt_proof: &[Vec<u8>],
+		log: &Log,
+	) -> Result<(), VerificationError> {
+		let receipt = verify_receipt_proof(receipts_root, receipt_proof).ok_or(InvalidProof)?;
+		if !receipt.logs().iter().any(|l| Self::check_log_match(log, l)) {
+			tracing::error!(
+				target: "ethereum-client",
+				"💫 Event log not found in receipt for transaction",
+			);
+			return Err(LogNotFound);
+		}
+		Ok(())
+	}
+
+	fn check_log_match(log: &Log, receipt_log: &AlloyLog) -> bool {
+		let equal = receipt_log.data.data.0 == log.data &&
+			receipt_log.address.0 == log.address.0 &&
+			receipt_log.topics().len() == log.topics.len();
+		if !equal {
+			return false;
+		}
+		for (_, (topic1, topic2)) in receipt_log.topics().iter().zip(log.topics.iter()).enumerate()
+		{
+			if topic1.0 != topic2.0 {
+				return false;
+			}
+		}
+		true
+	}
+
+	/// Validates an execution header with ancestry_proof against a finalized checkpoint on
+	/// chain.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 verify_execution_proof(execution_proof: &ExecutionProof) -> 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!(
+			execution_proof.header.slot <= latest_finalized_state.slot,
+			Error::<T>::HeaderNotFinalized
+		);
+
+		let beacon_block_root: H256 = execution_proof
+			.header
+			.hash_tree_root()
+			.map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+
+		match &execution_proof.ancestry_proof {
+			Some(proof) => {
+				Self::verify_ancestry_proof(
+					beacon_block_root,
+					execution_proof.header.slot,
+					&proof.header_branch,
+					proof.finalized_block_root,
+				)?;
+			},
+			None => {
+				// If the ancestry proof is not provided, we expect this beacon header to be a
+				// finalized beacon header. We need to check that the header hash matches the
+				// finalized header root at the expected slot.
+				let state = <FinalizedBeaconState<T>>::get(beacon_block_root)
+					.ok_or(Error::<T>::ExpectedFinalizedHeaderNotStored)?;
+				if execution_proof.header.slot != state.slot {
+					return Err(Error::<T>::ExpectedFinalizedHeaderNotStored.into());
+				}
+			},
+		}
+
+		// 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 = execution_proof
+			.execution_header
+			.hash_tree_root()
+			.map_err(|_| Error::<T>::BlockBodyHashTreeRootFailed)?;
+
+		let execution_header_gindex = Self::execution_header_gindex();
+		ensure!(
+			verify_merkle_branch(
+				execution_header_root,
+				&execution_proof.execution_branch,
+				subtree_index(execution_header_gindex),
+				generalized_index_length(execution_header_gindex),
+				execution_proof.header.body_root
+			),
+			Error::<T>::InvalidExecutionHeaderProof
+		);
+		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(())
+	}
+}

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

@@ -0,0 +1,764 @@
+// 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 consensus updates.
+//!
+//! ## Consensus Updates
+//!
+//! * [`Call::submit`]: Submit a finalized beacon header with an optional sync committee update
+#![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(test)]
+mod tests;
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+
+use frame_support::{
+	dispatch::{DispatchResult, PostDispatchInfo},
+	pallet_prelude::OptionQuery,
+	traits::Get,
+	transactional,
+};
+use frame_system::ensure_signed;
+use snowbridge_beacon_primitives::{
+	fast_aggregate_verify,
+	merkle_proof::{generalized_index_length, subtree_index},
+	verify_merkle_branch, BeaconHeader, BlsError, CompactBeaconState, 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,
+};
+use types::{CheckpointUpdate, FinalizedBeaconStateBuffer, SyncCommitteePrepared, Update};
+
+pub use pallet::*;
+
+pub use config::SLOTS_PER_HISTORICAL_ROOT;
+
+pub const LOG_TARGET: &str = "ethereum-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 {
+			const MAX_REDUNDANCY: u32 = 20;
+			config::EPOCHS_PER_SYNC_COMMITTEE_PERIOD as u32 * MAX_REDUNDANCY
+		}
+	}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+		#[pallet::constant]
+		type ForkVersions: Get<ForkVersions>;
+		/// Minimum gap between finalized headers for an update to be free.
+		#[pallet::constant]
+		type FreeHeadersInterval: 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,
+		},
+		SyncCommitteeUpdated {
+			period: u64,
+		},
+		/// Set OperatingMode
+		OperatingModeChanged {
+			mode: BasicOperatingMode,
+		},
+	}
+
+	#[pallet::error]
+	pub enum Error<T> {
+		SkippedSyncCommitteePeriod,
+		SyncCommitteeUpdateRequired,
+		/// Attested header is older than latest finalized header.
+		IrrelevantUpdate,
+		NotBootstrapped,
+		SyncCommitteeParticipantsNotSupermajority,
+		InvalidHeaderMerkleProof,
+		InvalidSyncCommitteeMerkleProof,
+		InvalidExecutionHeaderProof,
+		InvalidAncestryMerkleProof,
+		InvalidBlockRootsRootMerkleProof,
+		/// The gap between the finalized headers is larger than the sync committee period,
+		/// rendering execution headers unprovable using ancestry proofs (blocks root size is
+		/// the same as the sync committee period slots).
+		InvalidFinalizedHeaderGap,
+		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 type InitialCheckpointRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Latest imported finalized block root
+	#[pallet::storage]
+	#[pallet::getter(fn latest_finalized_block_root)]
+	pub type LatestFinalizedBlockRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Beacon state by finalized block root
+	#[pallet::storage]
+	#[pallet::getter(fn finalized_beacon_state)]
+	pub type FinalizedBeaconState<T: Config> =
+		StorageMap<_, Identity, H256, CompactBeaconState, OptionQuery>;
+
+	/// Finalized Headers: Current position in ring buffer
+	#[pallet::storage]
+	pub type FinalizedBeaconStateIndex<T: Config> = StorageValue<_, u32, ValueQuery>;
+
+	/// Finalized Headers: Mapping of ring buffer index to a pruning candidate
+	#[pallet::storage]
+	pub type FinalizedBeaconStateMapping<T: Config> =
+		StorageMap<_, Identity, u32, H256, ValueQuery>;
+
+	#[pallet::storage]
+	#[pallet::getter(fn validators_root)]
+	pub type ValidatorsRoot<T: Config> = StorageValue<_, H256, ValueQuery>;
+
+	/// Sync committee for current period
+	#[pallet::storage]
+	pub type CurrentSyncCommittee<T: Config> = StorageValue<_, SyncCommitteePrepared, ValueQuery>;
+
+	/// Sync committee for next period
+	#[pallet::storage]
+	pub type NextSyncCommittee<T: Config> = StorageValue<_, SyncCommitteePrepared, ValueQuery>;
+
+	/// The last period where the next sync committee was updated for free.
+	#[pallet::storage]
+	pub type LatestSyncCommitteeUpdatePeriod<T: Config> = StorageValue<_, 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> {
+		#[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>) -> DispatchResultWithPostInfo {
+			ensure_signed(origin)?;
+			ensure!(!Self::operating_mode().is_halted(), Error::<T>::Halted);
+			Self::process_update(&update)
+		}
+
+		/// 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)?;
+
+			let fork_versions = T::ForkVersions::get();
+			let sync_committee_gindex = Self::current_sync_committee_gindex_at_slot(
+				update.header.slot,
+				fork_versions.clone(),
+			);
+			// Verifies the sync committee in the Beacon state.
+			ensure!(
+				verify_merkle_branch(
+					sync_committee_root,
+					&update.current_sync_committee_branch,
+					subtree_index(sync_committee_gindex),
+					generalized_index_length(sync_committee_gindex),
+					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.
+			let block_roots_gindex =
+				Self::block_roots_gindex_at_slot(update.header.slot, fork_versions);
+			ensure!(
+				verify_merkle_branch(
+					update.block_roots_root,
+					&update.block_roots_branch,
+					subtree_index(block_roots_gindex),
+					generalized_index_length(block_roots_gindex),
+					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);
+
+			Self::store_validators_root(update.validators_root);
+			Self::store_finalized_header(update.header, update.block_roots_root)?;
+
+			Ok(())
+		}
+
+		pub(crate) fn process_update(update: &Update) -> DispatchResultWithPostInfo {
+			Self::verify_update(update)?;
+			Self::apply_update(update)
+		}
+
+		/// 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_finalized_period = compute_period(update.finalized_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 the finalized header gap between the current finalized header and new imported
+			// header is not larger than the sync committee period, otherwise we cannot do
+			// ancestry proofs for execution headers in the gap.
+			ensure!(
+				latest_finalized_state
+					.slot
+					.saturating_add(config::SLOTS_PER_HISTORICAL_ROOT as u64) >=
+					update.finalized_header.slot,
+				Error::<T>::InvalidFinalizedHeaderGap
+			);
+
+			let fork_versions = T::ForkVersions::get();
+			let finalized_root_gindex = Self::finalized_root_gindex_at_slot(
+				update.attested_header.slot,
+				fork_versions.clone(),
+			);
+			// 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,
+					subtree_index(finalized_root_gindex),
+					generalized_index_length(finalized_root_gindex),
+					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`.
+			let block_roots_gindex = Self::block_roots_gindex_at_slot(
+				update.finalized_header.slot,
+				fork_versions.clone(),
+			);
+			ensure!(
+				verify_merkle_branch(
+					update.block_roots_root,
+					&update.block_roots_branch,
+					subtree_index(block_roots_gindex),
+					generalized_index_length(block_roots_gindex),
+					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
+					);
+				}
+				let next_sync_committee_gindex = Self::next_sync_committee_gindex_at_slot(
+					update.attested_header.slot,
+					fork_versions,
+				);
+				ensure!(
+					verify_merkle_branch(
+						sync_committee_root,
+						&next_sync_committee_update.next_sync_committee_branch,
+						subtree_index(next_sync_committee_gindex),
+						generalized_index_length(next_sync_committee_gindex),
+						update.attested_header.state_root
+					),
+					Error::<T>::InvalidSyncCommitteeMerkleProof
+				);
+			} else {
+				ensure!(
+					update_finalized_period == store_period,
+					Error::<T>::SyncCommitteeUpdateRequired
+				);
+			}
+
+			// 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. Updates are free
+		/// if the certain conditions specified in `check_refundable` are met.
+		fn apply_update(update: &Update) -> DispatchResultWithPostInfo {
+			let latest_finalized_state =
+				FinalizedBeaconState::<T>::get(LatestFinalizedBlockRoot::<T>::get())
+					.ok_or(Error::<T>::NotBootstrapped)?;
+
+			let pays_fee = Self::check_refundable(update, latest_finalized_state.slot);
+			let actual_weight = match update.next_sync_committee_update {
+				None => T::WeightInfo::submit(),
+				Some(_) => T::WeightInfo::submit_with_sync_committee(),
+			};
+
+			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);
+				}
+				tracing::info!(
+					target: LOG_TARGET,
+					period=%update_finalized_period,
+					"💫 SyncCommitteeUpdated."
+				);
+				<LatestSyncCommitteeUpdatePeriod<T>>::set(update_finalized_period);
+				Self::deposit_event(Event::SyncCommitteeUpdated {
+					period: update_finalized_period,
+				});
+			};
+
+			if update.finalized_header.slot > latest_finalized_state.slot {
+				Self::store_finalized_header(update.finalized_header, update.block_roots_root)?;
+			}
+
+			Ok(PostDispatchInfo { actual_weight: Some(actual_weight), pays_fee })
+		}
+
+		/// 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.
+		pub fn store_finalized_header(
+			header: BeaconHeader,
+			block_roots_root: H256,
+		) -> DispatchResult {
+			let slot = header.slot;
+
+			let header_root: H256 =
+				header.hash_tree_root().map_err(|_| Error::<T>::HeaderHashTreeRootFailed)?;
+
+			<FinalizedBeaconStateBuffer<T>>::insert(
+				header_root,
+				CompactBeaconState { slot: header.slot, block_roots_root },
+			);
+			<LatestFinalizedBlockRoot<T>>::set(header_root);
+
+			tracing::info!(
+				target: LOG_TARGET,
+				root=%header_root,
+				%slot,
+				"💫 Updated latest finalized block."
+			);
+
+			Self::deposit_event(Event::BeaconHeaderImported { block_hash: header_root, slot });
+
+			Ok(())
+		}
+
+		/// 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.fulu.epoch {
+				return fork_versions.fulu.version;
+			}
+			if epoch >= fork_versions.electra.epoch {
+				return fork_versions.electra.version;
+			}
+			if epoch >= fork_versions.deneb.epoch {
+				return fork_versions.deneb.version;
+			}
+			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.clone());
+				}
+			}
+			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 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)
+		}
+
+		/// Updates are free if the update is successful and the interval between the latest
+		/// finalized header in storage and the newly imported header is large enough. All
+		/// successful sync committee updates are free.
+		pub(super) fn check_refundable(update: &Update, latest_slot: u64) -> Pays {
+			// If the sync committee was successfully updated, the update may be free.
+			let update_period = compute_period(update.finalized_header.slot);
+			let latest_free_update_period = LatestSyncCommitteeUpdatePeriod::<T>::get();
+			// If the next sync committee is not known and this update sets it, the update is free.
+			// If the sync committee update is in a period that we have not received an update for,
+			// the update is free.
+			let refundable =
+				!<NextSyncCommittee<T>>::exists() || update_period > latest_free_update_period;
+			if update.next_sync_committee_update.is_some() && refundable {
+				return Pays::No;
+			}
+
+			// If the latest finalized header is larger than the minimum slot interval, the header
+			// import transaction is free.
+			if update.finalized_header.slot >=
+				latest_slot.saturating_add(T::FreeHeadersInterval::get() as u64)
+			{
+				return Pays::No;
+			}
+
+			Pays::Yes
+		}
+
+		pub fn finalized_root_gindex_at_slot(slot: u64, fork_versions: ForkVersions) -> usize {
+			let epoch = compute_epoch(slot, config::SLOTS_PER_EPOCH as u64);
+
+			if epoch >= fork_versions.electra.epoch {
+				return config::electra::FINALIZED_ROOT_INDEX;
+			}
+
+			config::altair::FINALIZED_ROOT_INDEX
+		}
+
+		pub fn current_sync_committee_gindex_at_slot(
+			slot: u64,
+			fork_versions: ForkVersions,
+		) -> usize {
+			let epoch = compute_epoch(slot, config::SLOTS_PER_EPOCH as u64);
+
+			if epoch >= fork_versions.electra.epoch {
+				return config::electra::CURRENT_SYNC_COMMITTEE_INDEX;
+			}
+
+			config::altair::CURRENT_SYNC_COMMITTEE_INDEX
+		}
+
+		pub fn next_sync_committee_gindex_at_slot(slot: u64, fork_versions: ForkVersions) -> usize {
+			let epoch = compute_epoch(slot, config::SLOTS_PER_EPOCH as u64);
+
+			if epoch >= fork_versions.electra.epoch {
+				return config::electra::NEXT_SYNC_COMMITTEE_INDEX;
+			}
+
+			config::altair::NEXT_SYNC_COMMITTEE_INDEX
+		}
+
+		pub fn block_roots_gindex_at_slot(slot: u64, fork_versions: ForkVersions) -> usize {
+			let epoch = compute_epoch(slot, config::SLOTS_PER_EPOCH as u64);
+
+			if epoch >= fork_versions.electra.epoch {
+				return config::electra::BLOCK_ROOTS_INDEX;
+			}
+
+			config::altair::BLOCK_ROOTS_INDEX
+		}
+
+		pub fn execution_header_gindex() -> usize {
+			config::altair::EXECUTION_HEADER_INDEX
+		}
+	}
+}

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

@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use crate as ethereum_beacon_client;
+use crate::config;
+use frame_support::{derive_impl, dispatch::DispatchResult, parameter_types};
+use pallet_timestamp;
+use snowbridge_beacon_primitives::{Fork, ForkVersions};
+use snowbridge_verification_primitives::{Log, Proof};
+use sp_std::default::Default;
+use std::{fs::File, path::PathBuf};
+
+type Block = frame_system::mocking::MockBlock<Test>;
+use frame_support::traits::ConstU32;
+use hex_literal::hex;
+use sp_runtime::BuildStorage;
+
+fn load_fixture<T>(basename: String) -> 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_proof_fixture() -> snowbridge_beacon_primitives::ExecutionProof {
+	load_fixture("execution-proof.json".to_string()).unwrap()
+}
+
+pub fn load_checkpoint_update_fixture(
+) -> snowbridge_beacon_primitives::CheckpointUpdate<{ config::SYNC_COMMITTEE_SIZE }> {
+	load_fixture("initial-checkpoint.json".to_string()).unwrap()
+}
+
+pub fn load_sync_committee_update_fixture() -> snowbridge_beacon_primitives::Update<
+	{ config::SYNC_COMMITTEE_SIZE },
+	{ config::SYNC_COMMITTEE_BITS_SIZE },
+> {
+	load_fixture("sync-committee-update.json".to_string()).unwrap()
+}
+
+pub fn load_finalized_header_update_fixture() -> snowbridge_beacon_primitives::Update<
+	{ config::SYNC_COMMITTEE_SIZE },
+	{ config::SYNC_COMMITTEE_BITS_SIZE },
+> {
+	load_fixture("finalized-header-update.json".to_string()).unwrap()
+}
+
+pub fn load_next_sync_committee_update_fixture() -> snowbridge_beacon_primitives::Update<
+	{ config::SYNC_COMMITTEE_SIZE },
+	{ config::SYNC_COMMITTEE_BITS_SIZE },
+> {
+	load_fixture("next-sync-committee-update.json".to_string()).unwrap()
+}
+
+pub fn load_next_finalized_header_update_fixture() -> snowbridge_beacon_primitives::Update<
+	{ config::SYNC_COMMITTEE_SIZE },
+	{ config::SYNC_COMMITTEE_BITS_SIZE },
+> {
+	load_fixture("next-finalized-header-update.json".to_string()).unwrap()
+}
+
+pub fn load_sync_committee_update_period_0() -> Box<
+	snowbridge_beacon_primitives::Update<
+		{ config::SYNC_COMMITTEE_SIZE },
+		{ config::SYNC_COMMITTEE_BITS_SIZE },
+	>,
+> {
+	Box::new(load_fixture("sync-committee-update-period-0.json".to_string()).unwrap())
+}
+
+pub fn load_sync_committee_update_period_0_older_fixture() -> Box<
+	snowbridge_beacon_primitives::Update<
+		{ config::SYNC_COMMITTEE_SIZE },
+		{ config::SYNC_COMMITTEE_BITS_SIZE },
+	>,
+> {
+	Box::new(load_fixture("sync-committee-update-period-0-older.json".to_string()).unwrap())
+}
+
+pub fn load_sync_committee_update_period_0_newer_fixture() -> Box<
+	snowbridge_beacon_primitives::Update<
+		{ config::SYNC_COMMITTEE_SIZE },
+		{ config::SYNC_COMMITTEE_BITS_SIZE },
+	>,
+> {
+	Box::new(load_fixture("sync-committee-update-period-0-newer.json".to_string()).unwrap())
+}
+
+pub fn get_message_verification_payload() -> (Log, Proof) {
+	let inbound_fixture = snowbridge_pallet_ethereum_client_fixtures::make_inbound_fixture();
+	(inbound_fixture.event.event_log, inbound_fixture.event.proof)
+}
+
+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>},
+	}
+);
+
+#[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
+impl frame_system::Config for Test {
+	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: hex!("00000000"),
+			epoch: 0,
+		},
+		altair: Fork {
+			version: hex!("01000000"),
+			epoch: 0,
+		},
+		bellatrix: Fork {
+			version: hex!("02000000"),
+			epoch: 0,
+		},
+		capella: Fork {
+			version: hex!("03000000"),
+			epoch: 0,
+		},
+		deneb: Fork {
+			version: hex!("04000000"),
+			epoch: 0,
+		},
+		electra: Fork {
+			version: hex!("05000000"),
+			epoch: 0,
+		},
+		fulu: Fork {
+			version: hex!("06000000"),
+			epoch: 100000000,
+		}
+	};
+}
+
+pub const FREE_SLOTS_INTERVAL: u32 = config::SLOTS_PER_EPOCH as u32;
+
+impl ethereum_beacon_client::Config for Test {
+	type RuntimeEvent = RuntimeEvent;
+	type ForkVersions = ChainForkVersions;
+	type FreeHeadersInterval = ConstU32<FREE_SLOTS_INTERVAL>;
+	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 ext = sp_io::TestExternalities::new(t);
+	ext
+}
+
+pub fn initialize_storage() -> DispatchResult {
+	let inbound_fixture = snowbridge_pallet_ethereum_client_fixtures::make_inbound_fixture();
+	EthereumBeaconClient::store_finalized_header(
+		inbound_fixture.finalized_header,
+		inbound_fixture.block_roots_root,
+	)
+}

bridges/snowbridge/pallets/ethereum-client/src/tests.rs

@@ -0,0 +1,976 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+pub use crate::mock::*;
+use crate::{
+	config::{EPOCHS_PER_SYNC_COMMITTEE_PERIOD, SLOTS_PER_EPOCH, SLOTS_PER_HISTORICAL_ROOT},
+	functions::compute_period,
+	mock::{
+		get_message_verification_payload, load_checkpoint_update_fixture,
+		load_finalized_header_update_fixture, load_next_finalized_header_update_fixture,
+		load_next_sync_committee_update_fixture, load_sync_committee_update_fixture,
+	},
+	sync_committee_sum, verify_merkle_branch, BeaconHeader, CompactBeaconState, Error,
+	FinalizedBeaconState, LatestFinalizedBlockRoot, LatestSyncCommitteeUpdatePeriod,
+	NextSyncCommittee, SyncCommitteePrepared,
+};
+use frame_support::{assert_err, assert_noop, assert_ok, pallet_prelude::Pays};
+use hex_literal::hex;
+use snowbridge_beacon_primitives::{
+	merkle_proof::{generalized_index_length, subtree_index},
+	types::deneb,
+	Fork, ForkVersions, NextSyncCommitteeUpdate, VersionedExecutionPayloadHeader,
+};
+use snowbridge_verification_primitives::{VerificationError, Verifier};
+use sp_core::H256;
+use sp_runtime::DispatchError;
+
+/// Arbitrary hash used for tests and invalid hashes.
+const TEST_HASH: [u8; 32] =
+	hex!["5f6f02af29218292d21a69b64a794a7c0873b3e0f54611972863706e8cbdf371"];
+
+/* UNIT TESTS */
+
+#[test]
+pub fn sum_sync_committee_participation() {
+	new_tester().execute_with(|| {
+		assert_eq!(sync_committee_sum(&[0, 1, 0, 1, 1, 0, 1, 0, 1]), 5);
+	});
+}
+
+#[test]
+pub fn compute_domain() {
+	new_tester().execute_with(|| {
+		let domain = EthereumBeaconClient::compute_domain(
+			hex!("07000000").into(),
+			hex!("00000001"),
+			hex!("5dec7ae03261fde20d5b024dfabce8bac3276c9a4908e23d50ba8c9b50b0adff").into(),
+		);
+
+		assert_ok!(&domain);
+		assert_eq!(
+			domain.unwrap(),
+			hex!("0700000046324489ceb6ada6d118eacdbe94f49b1fcb49d5481a685979670c7c").into()
+		);
+	});
+}
+
+#[test]
+pub fn compute_signing_root_bls() {
+	new_tester().execute_with(|| {
+		let signing_root = EthereumBeaconClient::compute_signing_root(
+			&BeaconHeader {
+				slot: 3529537,
+				proposer_index: 192549,
+				parent_root: hex!(
+					"1f8dc05ea427f78e84e2e2666e13c3befb7106fd1d40ef8a3f67cf615f3f2a4c"
+				)
+				.into(),
+				state_root: hex!(
+					"0dfb492a83da711996d2d76b64604f9bca9dc08b6c13cf63b3be91742afe724b"
+				)
+				.into(),
+				body_root: hex!("66fba38f7c8c2526f7ddfe09c1a54dd12ff93bdd4d0df6a0950e88e802228bfa")
+					.into(),
+			},
+			hex!("07000000afcaaba0efab1ca832a15152469bb09bb84641c405171dfa2d3fb45f").into(),
+		);
+
+		assert_ok!(&signing_root);
+		assert_eq!(
+			signing_root.unwrap(),
+			hex!("3ff6e9807da70b2f65cdd58ea1b25ed441a1d589025d2c4091182026d7af08fb").into()
+		);
+	});
+}
+
+#[test]
+pub fn compute_signing_root() {
+	new_tester().execute_with(|| {
+		let signing_root = EthereumBeaconClient::compute_signing_root(
+			&BeaconHeader {
+				slot: 222472,
+				proposer_index: 10726,
+				parent_root: hex!(
+					"5d481a9721f0ecce9610eab51d400d223683d599b7fcebca7e4c4d10cdef6ebb"
+				)
+				.into(),
+				state_root: hex!(
+					"14eb4575895f996a84528b789ff2e4d5148242e2983f03068353b2c37015507a"
+				)
+				.into(),
+				body_root: hex!("7bb669c75b12e0781d6fa85d7fc2f32d64eafba89f39678815b084c156e46cac")
+					.into(),
+			},
+			hex!("07000000e7acb21061790987fa1c1e745cccfb358370b33e8af2b2c18938e6c2").into(),
+		);
+
+		assert_ok!(&signing_root);
+		assert_eq!(
+			signing_root.unwrap(),
+			hex!("da12b6a6d3516bc891e8a49f82fc1925cec40b9327e06457f695035303f55cd8").into()
+		);
+	});
+}
+
+#[test]
+pub fn compute_domain_bls() {
+	new_tester().execute_with(|| {
+		let domain = EthereumBeaconClient::compute_domain(
+			hex!("07000000").into(),
+			hex!("01000000"),
+			hex!("4b363db94e286120d76eb905340fdd4e54bfe9f06bf33ff6cf5ad27f511bfe95").into(),
+		);
+
+		assert_ok!(&domain);
+		assert_eq!(
+			domain.unwrap(),
+			hex!("07000000afcaaba0efab1ca832a15152469bb09bb84641c405171dfa2d3fb45f").into()
+		);
+	});
+}
+
+#[test]
+pub fn may_refund_call_fee() {
+	let finalized_update = Box::new(load_next_finalized_header_update_fixture());
+	let sync_committee_update = Box::new(load_sync_committee_update_fixture());
+	new_tester().execute_with(|| {
+		let free_headers_interval: u64 = crate::mock::FREE_SLOTS_INTERVAL as u64;
+		// Not free, smaller than the allowed free header interval
+		assert_eq!(
+			EthereumBeaconClient::check_refundable(
+				&finalized_update.clone(),
+				finalized_update.finalized_header.slot + free_headers_interval
+			),
+			Pays::Yes
+		);
+		// Is free, larger than the minimum interval
+		assert_eq!(
+			EthereumBeaconClient::check_refundable(
+				&finalized_update,
+				finalized_update.finalized_header.slot - (free_headers_interval + 2)
+			),
+			Pays::No
+		);
+		// Is free, valid sync committee update
+		assert_eq!(
+			EthereumBeaconClient::check_refundable(
+				&sync_committee_update,
+				finalized_update.finalized_header.slot
+			),
+			Pays::No
+		);
+	});
+}
+
+#[test]
+pub fn verify_merkle_branch_for_finalized_root() {
+	new_tester().execute_with(|| {
+		assert!(verify_merkle_branch(
+			hex!("0000000000000000000000000000000000000000000000000000000000000000").into(),
+			&[
+				hex!("0000000000000000000000000000000000000000000000000000000000000000").into(),
+				hex!("5f6f02af29218292d21a69b64a794a7c0873b3e0f54611972863706e8cbdf371").into(),
+				hex!("e7125ff9ab5a840c44bedb4731f440a405b44e15f2d1a89e27341b432fabe13d").into(),
+				hex!("002c1fe5bc0bd62db6f299a582f2a80a6d5748ccc82e7ed843eaf0ae0739f74a").into(),
+				hex!("d2dc4ba9fd4edff6716984136831e70a6b2e74fca27b8097a820cbbaa5a6e3c3").into(),
+				hex!("91f77a19d8afa4a08e81164bb2e570ecd10477b3b65c305566a6d2be88510584").into(),
+			],
+			subtree_index(crate::config::altair::FINALIZED_ROOT_INDEX),
+			generalized_index_length(crate::config::altair::FINALIZED_ROOT_INDEX),
+			hex!("e46559327592741956f6beaa0f52e49625eb85dce037a0bd2eff333c743b287f").into()
+		));
+	});
+}
+
+#[test]
+pub fn verify_merkle_branch_fails_if_depth_and_branch_dont_match() {
+	new_tester().execute_with(|| {
+		assert!(!verify_merkle_branch(
+			hex!("0000000000000000000000000000000000000000000000000000000000000000").into(),
+			&[
+				hex!("0000000000000000000000000000000000000000000000000000000000000000").into(),
+				hex!("5f6f02af29218292d21a69b64a794a7c0873b3e0f54611972863706e8cbdf371").into(),
+				hex!("e7125ff9ab5a840c44bedb4731f440a405b44e15f2d1a89e27341b432fabe13d").into(),
+			],
+			subtree_index(crate::config::altair::FINALIZED_ROOT_INDEX),
+			generalized_index_length(crate::config::altair::FINALIZED_ROOT_INDEX),
+			hex!("e46559327592741956f6beaa0f52e49625eb85dce037a0bd2eff333c743b287f").into()
+		));
+	});
+}
+
+#[test]
+pub fn sync_committee_participation_is_supermajority() {
+	let bits =
+		hex!("bffffffff7f1ffdfcfeffeffbfdffffbfffffdffffefefffdffff7f7ffff77fffdf7bff77ffdf7fffafffffff77fefffeff7effffffff5f7fedfffdfb6ddff7b"
+	);
+	let participation =
+		snowbridge_beacon_primitives::decompress_sync_committee_bits::<512, 64>(bits);
+	assert_ok!(EthereumBeaconClient::sync_committee_participation_is_supermajority(&participation));
+}
+
+#[test]
+pub fn sync_committee_participation_is_supermajority_errors_when_not_supermajority() {
+	new_tester().execute_with(|| {
+		let participation = hex!("0000000000000000000000000000000000000001010100010100000000000000000000000101010101000100010101010101010101010101010101010100010101000000000001010101010100010101000000000000000000000000000101000101010101010001010101010100010101010101010101010101000101010101010100010101010100000000010101010100000000000000000001010101010101010101010101010101010100010101010101010001010101010101010101010101010101000101010101010101010101010100010101010101010101010101010101010101010101010101010101010101010001010100010101010101010101000101010101010101010001010101010101010101000101010100010101010101010101010100010000000000000000000100000000000001010100000001000100010101010100000000000000000000000000000000000000010101010101010100010101010101010101010100010101010001010101010101010101010101010100000000000000000101010101000000000001000000000000000000010000000000000000000101010101010100010001010101010101000101010101010101010101010101010101000101010101010101010101010101010001010101010101010001010001000000000000000000000000000001000000000000");
+
+		assert_err!(
+			EthereumBeaconClient::sync_committee_participation_is_supermajority(&participation),
+			Error::<Test>::SyncCommitteeParticipantsNotSupermajority
+		);
+	});
+}
+
+#[test]
+fn compute_fork_version() {
+	let mock_fork_versions = ForkVersions {
+		genesis: Fork { version: [0, 0, 0, 0], epoch: 0 },
+		altair: Fork { version: [0, 0, 0, 1], epoch: 10 },
+		bellatrix: Fork { version: [0, 0, 0, 2], epoch: 20 },
+		capella: Fork { version: [0, 0, 0, 3], epoch: 30 },
+		deneb: Fork { version: [0, 0, 0, 4], epoch: 40 },
+		electra: Fork { version: [0, 0, 0, 5], epoch: 50 },
+		fulu: Fork { version: [0, 0, 0, 6], epoch: 60 },
+	};
+	new_tester().execute_with(|| {
+		assert_eq!(EthereumBeaconClient::select_fork_version(&mock_fork_versions, 0), [0, 0, 0, 0]);
+		assert_eq!(EthereumBeaconClient::select_fork_version(&mock_fork_versions, 1), [0, 0, 0, 0]);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 10),
+			[0, 0, 0, 1]
+		);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 21),
+			[0, 0, 0, 2]
+		);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 20),
+			[0, 0, 0, 2]
+		);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 32),
+			[0, 0, 0, 3]
+		);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 40),
+			[0, 0, 0, 4]
+		);
+		assert_eq!(
+			EthereumBeaconClient::select_fork_version(&mock_fork_versions, 50),
+			[0, 0, 0, 5]
+		);
+	});
+}
+
+#[test]
+fn find_absent_keys() {
+	let participation: [u8; 32] =
+		hex!("0001010101010100010101010101010101010101010101010101010101010101").into();
+	let update = load_sync_committee_update_fixture();
+	let sync_committee_prepared: SyncCommitteePrepared =
+		(&update.next_sync_committee_update.unwrap().next_sync_committee)
+			.try_into()
+			.unwrap();
+
+	new_tester().execute_with(|| {
+		let pubkeys = EthereumBeaconClient::find_pubkeys(
+			&participation,
+			(*sync_committee_prepared.pubkeys).as_ref(),
+			false,
+		);
+		assert_eq!(pubkeys.len(), 2);
+		assert_eq!(pubkeys[0], sync_committee_prepared.pubkeys[0]);
+		assert_eq!(pubkeys[1], sync_committee_prepared.pubkeys[7]);
+	});
+}
+
+#[test]
+fn find_present_keys() {
+	let participation: [u8; 32] =
+		hex!("0001000000000000010000000000000000000000000000000000010000000100").into();
+	let update = load_sync_committee_update_fixture();
+	let sync_committee_prepared: SyncCommitteePrepared =
+		(&update.next_sync_committee_update.unwrap().next_sync_committee)
+			.try_into()
+			.unwrap();
+
+	new_tester().execute_with(|| {
+		let pubkeys = EthereumBeaconClient::find_pubkeys(
+			&participation,
+			(*sync_committee_prepared.pubkeys).as_ref(),
+			true,
+		);
+		assert_eq!(pubkeys.len(), 4);
+		assert_eq!(pubkeys[0], sync_committee_prepared.pubkeys[1]);
+		assert_eq!(pubkeys[1], sync_committee_prepared.pubkeys[8]);
+		assert_eq!(pubkeys[2], sync_committee_prepared.pubkeys[26]);
+		assert_eq!(pubkeys[3], sync_committee_prepared.pubkeys[30]);
+	});
+}
+
+/* SYNC PROCESS TESTS */
+
+#[test]
+fn process_initial_checkpoint() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::force_checkpoint(
+			RuntimeOrigin::root(),
+			checkpoint.clone()
+		));
+		let block_root: H256 = checkpoint.header.hash_tree_root().unwrap();
+		assert!(<FinalizedBeaconState<Test>>::contains_key(block_root));
+	});
+}
+
+#[test]
+fn process_initial_checkpoint_with_invalid_sync_committee_proof() {
+	let mut checkpoint = Box::new(load_checkpoint_update_fixture());
+	checkpoint.current_sync_committee_branch[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_err!(
+			EthereumBeaconClient::force_checkpoint(RuntimeOrigin::root(), checkpoint),
+			Error::<Test>::InvalidSyncCommitteeMerkleProof
+		);
+	});
+}
+
+#[test]
+fn process_initial_checkpoint_with_invalid_blocks_root_proof() {
+	let mut checkpoint = Box::new(load_checkpoint_update_fixture());
+	checkpoint.block_roots_branch[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_err!(
+			EthereumBeaconClient::force_checkpoint(RuntimeOrigin::root(), checkpoint),
+			Error::<Test>::InvalidBlockRootsRootMerkleProof
+		);
+	});
+}
+
+#[test]
+fn submit_update_in_current_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_finalized_header_update_fixture());
+	let initial_period = compute_period(checkpoint.header.slot);
+	let update_period = compute_period(update.finalized_header.slot);
+	assert_eq!(initial_period, update_period);
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		let block_root: H256 = update.finalized_header.hash_tree_root().unwrap();
+		assert!(<FinalizedBeaconState<Test>>::contains_key(block_root));
+	});
+}
+
+#[test]
+fn submit_update_with_sync_committee_in_current_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_sync_committee_update_fixture());
+	let init_period = compute_period(checkpoint.header.slot);
+	let update_period = compute_period(update.finalized_header.slot);
+	assert_eq!(init_period, update_period);
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert!(!<NextSyncCommittee<Test>>::exists());
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		assert!(<NextSyncCommittee<Test>>::exists());
+	});
+}
+
+#[test]
+fn reject_submit_update_in_next_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let sync_committee_update = Box::new(load_sync_committee_update_fixture());
+	let update = Box::new(load_next_finalized_header_update_fixture());
+	let sync_committee_period = compute_period(sync_committee_update.finalized_header.slot);
+	let next_sync_committee_period = compute_period(update.finalized_header.slot);
+	assert_eq!(sync_committee_period + 1, next_sync_committee_period);
+	let next_sync_committee_update = Box::new(load_next_sync_committee_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), sync_committee_update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+
+		// check an update in the next period is rejected
+		let second_result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone());
+		assert_err!(second_result, Error::<Test>::SyncCommitteeUpdateRequired);
+		assert_eq!(second_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+
+		// submit update with next sync committee
+		let third_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), next_sync_committee_update);
+		assert_ok!(third_result);
+		assert_eq!(third_result.unwrap().pays_fee, Pays::No);
+		// check same header in the next period can now be submitted successfully
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone()));
+		let block_root: H256 = update.finalized_header.clone().hash_tree_root().unwrap();
+		assert!(<FinalizedBeaconState<Test>>::contains_key(block_root));
+	});
+}
+
+#[test]
+fn submit_update_with_invalid_header_proof() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let mut update = Box::new(load_sync_committee_update_fixture());
+	let init_period = compute_period(checkpoint.header.slot);
+	let update_period = compute_period(update.finalized_header.slot);
+	assert_eq!(init_period, update_period);
+	update.finality_branch[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert!(!<NextSyncCommittee<Test>>::exists());
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::InvalidHeaderMerkleProof);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_invalid_block_roots_proof() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let mut update = Box::new(load_sync_committee_update_fixture());
+	let init_period = compute_period(checkpoint.header.slot);
+	let update_period = compute_period(update.finalized_header.slot);
+	assert_eq!(init_period, update_period);
+	update.block_roots_branch[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert!(!<NextSyncCommittee<Test>>::exists());
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::InvalidBlockRootsRootMerkleProof);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_invalid_next_sync_committee_proof() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let mut update = Box::new(load_sync_committee_update_fixture());
+	let init_period = compute_period(checkpoint.header.slot);
+	let update_period = compute_period(update.finalized_header.slot);
+	assert_eq!(init_period, update_period);
+	if let Some(ref mut next_sync_committee_update) = update.next_sync_committee_update {
+		next_sync_committee_update.next_sync_committee_branch[0] = TEST_HASH.into();
+	}
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert!(!<NextSyncCommittee<Test>>::exists());
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::InvalidSyncCommitteeMerkleProof);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_skipped_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let sync_committee_update = Box::new(load_sync_committee_update_fixture());
+	let mut update = Box::new(load_next_finalized_header_update_fixture());
+	update.signature_slot += (EPOCHS_PER_SYNC_COMMITTEE_PERIOD * SLOTS_PER_EPOCH) as u64;
+	update.attested_header.slot = update.signature_slot - 1;
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), sync_committee_update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+
+		let second_result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(second_result, Error::<Test>::SkippedSyncCommitteePeriod);
+		assert_eq!(second_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_sync_committee_in_next_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_sync_committee_update_fixture());
+	let next_update = Box::new(load_next_sync_committee_update_fixture());
+	let update_period = compute_period(update.finalized_header.slot);
+	let next_update_period = compute_period(next_update.finalized_header.slot);
+	assert_eq!(update_period + 1, next_update_period);
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert!(!<NextSyncCommittee<Test>>::exists());
+
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		assert!(<NextSyncCommittee<Test>>::exists());
+
+		let second_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), next_update.clone());
+		assert_ok!(second_result);
+		assert_eq!(second_result.unwrap().pays_fee, Pays::No);
+		let last_finalized_state =
+			FinalizedBeaconState::<Test>::get(LatestFinalizedBlockRoot::<Test>::get()).unwrap();
+		let last_synced_period = compute_period(last_finalized_state.slot);
+		assert_eq!(last_synced_period, next_update_period);
+	});
+}
+
+#[test]
+fn submit_update_with_sync_committee_invalid_signature_slot() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let mut update = Box::new(load_sync_committee_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+
+		// makes an invalid update with signature_slot should be more than attested_slot
+		update.signature_slot = update.attested_header.slot;
+
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::InvalidUpdateSlot);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_skipped_sync_committee_period() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_update = Box::new(load_next_finalized_header_update_fixture());
+	let checkpoint_period = compute_period(checkpoint.header.slot);
+	let next_sync_committee_period = compute_period(finalized_update.finalized_header.slot);
+	assert_eq!(checkpoint_period + 1, next_sync_committee_period);
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_update);
+		assert_err!(result, Error::<Test>::SkippedSyncCommitteePeriod);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_irrelevant_update() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let mut update = Box::new(load_next_finalized_header_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+
+		// makes an invalid update where the attested_header slot value should be greater than the
+		// checkpoint slot value
+		update.finalized_header.slot = checkpoint.header.slot;
+		update.attested_header.slot = checkpoint.header.slot;
+		update.signature_slot = checkpoint.header.slot + 1;
+
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::IrrelevantUpdate);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_missing_bootstrap() {
+	let update = Box::new(load_next_finalized_header_update_fixture());
+
+	new_tester().execute_with(|| {
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_err!(result, Error::<Test>::NotBootstrapped);
+		assert_eq!(result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn submit_update_with_invalid_sync_committee_update() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_sync_committee_update_fixture());
+	let mut next_update = Box::new(load_next_sync_committee_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update);
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+
+		// makes update with invalid next_sync_committee
+		<FinalizedBeaconState<Test>>::mutate(<LatestFinalizedBlockRoot<Test>>::get(), |x| {
+			let prev = x.unwrap();
+			*x = Some(CompactBeaconState { slot: next_update.attested_header.slot, ..prev });
+		});
+		next_update.attested_header.slot += 1;
+		next_update.signature_slot = next_update.attested_header.slot + 1;
+		let next_sync_committee = NextSyncCommitteeUpdate::default();
+		next_update.next_sync_committee_update = Some(next_sync_committee);
+
+		let second_result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), next_update);
+		assert_err!(second_result, Error::<Test>::InvalidSyncCommitteeUpdate);
+		assert_eq!(second_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+/// Check that a gap of more than 8192 slots between finalized headers is not allowed.
+#[test]
+fn submit_finalized_header_update_with_too_large_gap() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_sync_committee_update_fixture());
+	let mut next_update = Box::new(load_next_sync_committee_update_fixture());
+
+	// Adds 8193 slots, so that the next update is still in the next sync committee, but the
+	// gap between the finalized headers is more than 8192 slots.
+	let slot_with_large_gap = checkpoint.header.slot + SLOTS_PER_HISTORICAL_ROOT as u64 + 1;
+
+	next_update.finalized_header.slot = slot_with_large_gap;
+	// Adding some slots to the attested header and signature slot since they need to be ahead
+	// of the finalized header.
+	next_update.attested_header.slot = slot_with_large_gap + 33;
+	next_update.signature_slot = slot_with_large_gap + 43;
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		assert!(<NextSyncCommittee<Test>>::exists());
+
+		let second_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), next_update.clone());
+		assert_err!(second_result, Error::<Test>::InvalidFinalizedHeaderGap);
+		assert_eq!(second_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+/// Check that a gap of 8192 slots between finalized headers is allowed.
+#[test]
+fn submit_finalized_header_update_with_gap_at_limit() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_sync_committee_update_fixture());
+	let mut next_update = Box::new(load_next_sync_committee_update_fixture());
+
+	next_update.finalized_header.slot = checkpoint.header.slot + SLOTS_PER_HISTORICAL_ROOT as u64;
+	// Adding some slots to the attested header and signature slot since they need to be ahead
+	// of the finalized header.
+	next_update.attested_header.slot =
+		checkpoint.header.slot + SLOTS_PER_HISTORICAL_ROOT as u64 + 33;
+	next_update.signature_slot = checkpoint.header.slot + SLOTS_PER_HISTORICAL_ROOT as u64 + 43;
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+
+		let result = EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		assert!(<NextSyncCommittee<Test>>::exists());
+
+		let second_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), next_update.clone());
+		assert_err!(
+			second_result,
+			// The test should pass the InvalidFinalizedHeaderGap check, and will fail at the
+			// next check, the merkle proof, because we changed the next_update slots.
+			Error::<Test>::InvalidHeaderMerkleProof
+		);
+		assert_eq!(second_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn duplicate_sync_committee_updates_are_not_free() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let sync_committee_update = Box::new(load_sync_committee_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		let result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), sync_committee_update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+
+		// Check that if the same update is submitted, the update is not free.
+		let second_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), sync_committee_update);
+		assert_ok!(second_result);
+		assert_eq!(second_result.unwrap().pays_fee, Pays::Yes);
+	});
+}
+
+#[test]
+fn sync_committee_update_for_sync_committee_already_imported_are_not_free() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let sync_committee_update = Box::new(load_sync_committee_update_fixture()); // slot 129
+	let second_sync_committee_update = load_sync_committee_update_period_0(); // slot 128
+	let third_sync_committee_update = load_sync_committee_update_period_0_newer_fixture(); // slot 224
+	let fourth_sync_committee_update = load_sync_committee_update_period_0_older_fixture(); // slot 96
+	let fith_sync_committee_update = Box::new(load_next_sync_committee_update_fixture()); // slot 8259
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_eq!(<LatestSyncCommitteeUpdatePeriod<Test>>::get(), 0);
+
+		// Check that setting the next sync committee for period 0 is free (it is not set yet).
+		let result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), sync_committee_update.clone());
+		assert_ok!(result);
+		assert_eq!(result.unwrap().pays_fee, Pays::No);
+		assert_eq!(<LatestSyncCommitteeUpdatePeriod<Test>>::get(), 0);
+
+		// Check that setting the next sync committee for period 0 again is not free.
+		let second_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), second_sync_committee_update);
+		assert_eq!(second_result.unwrap().pays_fee, Pays::Yes);
+		assert_eq!(<LatestSyncCommitteeUpdatePeriod<Test>>::get(), 0);
+
+		// Check that setting an update with a sync committee that has already been set, but with a
+		// newer finalized header, is free.
+		let third_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), third_sync_committee_update);
+		assert_eq!(third_result.unwrap().pays_fee, Pays::No);
+		assert_eq!(<LatestSyncCommitteeUpdatePeriod<Test>>::get(), 0);
+
+		// Check that setting the next sync committee for period 0 again with an earlier slot is not
+		// free.
+		let fourth_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), fourth_sync_committee_update);
+		assert_err!(fourth_result, Error::<Test>::IrrelevantUpdate);
+		assert_eq!(fourth_result.unwrap_err().post_info.pays_fee, Pays::Yes);
+
+		// Check that setting the next sync committee for period 1 is free.
+		let fith_result =
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), fith_sync_committee_update);
+		assert_eq!(fith_result.unwrap().pays_fee, Pays::No);
+		assert_eq!(<LatestSyncCommitteeUpdatePeriod<Test>>::get(), 1);
+	});
+}
+
+/* IMPLS */
+
+#[test]
+fn verify_message() {
+	let (event_log, proof) = get_message_verification_payload();
+
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_ok!(EthereumBeaconClient::verify(&event_log, &proof));
+	});
+}
+
+#[test]
+fn verify_message_invalid_proof() {
+	let (event_log, mut proof) = get_message_verification_payload();
+	proof.receipt_proof.1[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_err!(
+			EthereumBeaconClient::verify(&event_log, &proof),
+			VerificationError::InvalidProof
+		);
+	});
+}
+
+#[test]
+fn verify_message_invalid_receipts_root() {
+	let (event_log, mut proof) = get_message_verification_payload();
+	let mut payload = deneb::ExecutionPayloadHeader::default();
+	payload.receipts_root = TEST_HASH.into();
+	proof.execution_proof.execution_header = VersionedExecutionPayloadHeader::Deneb(payload);
+
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_err!(
+			EthereumBeaconClient::verify(&event_log, &proof),
+			VerificationError::InvalidExecutionProof(
+				Error::<Test>::BlockBodyHashTreeRootFailed.into()
+			)
+		);
+	});
+}
+
+#[test]
+fn verify_message_invalid_log() {
+	let (mut event_log, proof) = get_message_verification_payload();
+	event_log.topics = vec![H256::zero(); 10];
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_err!(
+			EthereumBeaconClient::verify(&event_log, &proof),
+			VerificationError::LogNotFound
+		);
+	});
+}
+
+#[test]
+fn verify_message_receipt_does_not_contain_log() {
+	let (mut event_log, proof) = get_message_verification_payload();
+	event_log.data = hex!("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").to_vec();
+
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_err!(
+			EthereumBeaconClient::verify(&event_log, &proof),
+			VerificationError::LogNotFound
+		);
+	});
+}
+
+#[test]
+fn set_operating_mode() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let update = Box::new(load_finalized_header_update_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+
+		assert_ok!(EthereumBeaconClient::set_operating_mode(
+			RuntimeOrigin::root(),
+			snowbridge_core::BasicOperatingMode::Halted
+		));
+
+		assert_noop!(
+			EthereumBeaconClient::submit(RuntimeOrigin::signed(1), update),
+			Error::<Test>::Halted
+		);
+	});
+}
+
+#[test]
+fn set_operating_mode_root_only() {
+	new_tester().execute_with(|| {
+		assert_noop!(
+			EthereumBeaconClient::set_operating_mode(
+				RuntimeOrigin::signed(1),
+				snowbridge_core::BasicOperatingMode::Halted
+			),
+			DispatchError::BadOrigin
+		);
+	});
+}
+
+#[test]
+fn verify_execution_proof_invalid_ancestry_proof() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_header_update = Box::new(load_finalized_header_update_fixture());
+	let mut execution_header_update = Box::new(load_execution_proof_fixture());
+	if let Some(ref mut ancestry_proof) = execution_header_update.ancestry_proof {
+		ancestry_proof.header_branch[0] = TEST_HASH.into()
+	}
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_header_update));
+		assert_err!(
+			EthereumBeaconClient::verify_execution_proof(&execution_header_update),
+			Error::<Test>::InvalidAncestryMerkleProof
+		);
+	});
+}
+
+#[test]
+fn verify_execution_proof_invalid_execution_header_proof() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_header_update = Box::new(load_finalized_header_update_fixture());
+	let mut execution_header_update = Box::new(load_execution_proof_fixture());
+	execution_header_update.execution_branch[0] = TEST_HASH.into();
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_header_update));
+		assert_err!(
+			EthereumBeaconClient::verify_execution_proof(&execution_header_update),
+			Error::<Test>::InvalidExecutionHeaderProof
+		);
+	});
+}
+
+#[test]
+fn verify_execution_proof_that_is_also_finalized_header_which_is_not_stored() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_header_update = Box::new(load_finalized_header_update_fixture());
+	let mut execution_header_update = Box::new(load_execution_proof_fixture());
+	execution_header_update.ancestry_proof = None;
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_header_update));
+		assert_err!(
+			EthereumBeaconClient::verify_execution_proof(&execution_header_update),
+			Error::<Test>::ExpectedFinalizedHeaderNotStored
+		);
+	});
+}
+
+#[test]
+fn submit_execution_proof_that_is_also_finalized_header_which_is_stored_but_slots_dont_match() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_header_update = Box::new(load_finalized_header_update_fixture());
+	let mut execution_header_update = Box::new(load_execution_proof_fixture());
+	execution_header_update.ancestry_proof = None;
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_header_update));
+
+		let block_root: H256 = execution_header_update.header.hash_tree_root().unwrap();
+
+		<FinalizedBeaconState<Test>>::insert(
+			block_root,
+			CompactBeaconState {
+				slot: execution_header_update.header.slot + 1,
+				block_roots_root: Default::default(),
+			},
+		);
+		LatestFinalizedBlockRoot::<Test>::set(block_root);
+
+		assert_err!(
+			EthereumBeaconClient::verify_execution_proof(&execution_header_update),
+			Error::<Test>::ExpectedFinalizedHeaderNotStored
+		);
+	});
+}
+
+#[test]
+fn verify_execution_proof_not_finalized() {
+	let checkpoint = Box::new(load_checkpoint_update_fixture());
+	let finalized_header_update = Box::new(load_finalized_header_update_fixture());
+	let update = Box::new(load_execution_proof_fixture());
+
+	new_tester().execute_with(|| {
+		assert_ok!(EthereumBeaconClient::process_checkpoint_update(&checkpoint));
+		assert_ok!(EthereumBeaconClient::submit(RuntimeOrigin::signed(1), finalized_header_update));
+
+		<FinalizedBeaconState<Test>>::mutate(<LatestFinalizedBlockRoot<Test>>::get(), |x| {
+			let prev = x.unwrap();
+			*x = Some(CompactBeaconState { slot: update.header.slot - 1, ..prev });
+		});
+
+		assert_err!(
+			EthereumBeaconClient::verify_execution_proof(&update),
+			Error::<Test>::HeaderNotFinalized
+		);
+	});
+}
+
+#[test]
+fn verify_message_invalid_topic() {
+	let (event_log, proof) = get_message_verification_payload();
+	let mut event_log_muted = event_log.clone();
+	event_log_muted.topics[0] = H256::default();
+
+	new_tester().execute_with(|| {
+		assert_ok!(initialize_storage());
+		assert_err!(
+			EthereumBeaconClient::verify(&event_log_muted, &proof),
+			VerificationError::LogNotFound
+		);
+	});
+}

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

@@ -0,0 +1,28 @@
+// 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 = snowbridge_beacon_primitives::SyncCommittee<SC_SIZE>;
+pub type SyncCommitteePrepared = snowbridge_beacon_primitives::SyncCommitteePrepared<SC_SIZE>;
+pub type SyncAggregate = snowbridge_beacon_primitives::SyncAggregate<SC_SIZE, SC_BITS_SIZE>;
+pub type CheckpointUpdate = snowbridge_beacon_primitives::CheckpointUpdate<SC_SIZE>;
+pub type Update = snowbridge_beacon_primitives::Update<SC_SIZE, SC_BITS_SIZE>;
+pub type NextSyncCommitteeUpdate = snowbridge_beacon_primitives::NextSyncCommitteeUpdate<SC_SIZE>;
+
+pub use snowbridge_beacon_primitives::{AncestryProof, ExecutionProof};
+
+/// FinalizedState ring buffer implementation
+pub type FinalizedBeaconStateBuffer<T> = RingBufferMapImpl<
+	u32,
+	crate::MaxFinalizedHeadersToKeep<T>,
+	crate::FinalizedBeaconStateIndex<T>,
+	crate::FinalizedBeaconStateMapping<T>,
+	crate::FinalizedBeaconState<T>,
+	OptionQuery,
+>;

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

@@ -0,0 +1,61 @@
+//! 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-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;
+}
+
+// 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))
+	}
+}