BABE Randomness using PreRuntime digests (#2929)

* Initial work on exposing pre-runtime digests

This provides the primitive API, as well as exposing it from BABE.

* Initial work on using pre-digests in runtimes

This includes both code to expose them from `srml_system`, as well as
using it in (currently dead) code in `srml_babe`.

* Bump `{spec,impl}_version`

* Add `u64_backend` feature to curve25519-dalek

Otherwise, it errors out at compile-time.

* Bump `Cargo.lock`

* Do not depend on the schnorrkel crate in the runtime

The schnorrkel crate does not work on `#![no_std]`, but the runtime only
needs constants from it.  This adds our own definitions of those
constants, and checks them for correctness at compile-time.

* Actually implement storage of VRF outputs

* Trivial formatting change

* Provide a `hash_randomness` function in BABE

for processing VRF outputs.

* Implement a basic randomness generating function

It just XORs the VRF outputs together.

* Actually implement on-chain randomness

Blake2b is used for hashing.

* Update dependencies

* Run `cargo update` where needed

* Re-add a newline at EOF

* Remove broken and unsafe code

XOR is not a hash function, and must not be used as such.  The
implementation was also needlessly unsafe.

* Run `cargo update` where needed

* Remove spurious dependency

* Document security guarantees of BABE randomness

* Add a `RandomnessBeacon` trait

* Document `RandomnessBeacon::random`

* Fix silly compile error (unexpected type arguments)

* Fix BABE randomness

* Implement `FindAuthor` for `babe::Module`

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>
Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Respond to suggestions from code review and fix bugs

* Store an authority index, not the authority itself.
* Avoid unnecessary decoding.
* Implement relative slots and BABE randomness fully and correctly.

* Remove spurious dependency

* Fix error reported by rust-analyzer

* Update Cargo.lock files

* `wrapping_add` → `checked_add`

The epoch index will not overflow.  Panic if it does.

* Move randomness documentation to trait

* Fix compile error in test suite

* Explain 2^64 limit

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>
This commit is contained in:
DemiMarie-parity
2019-07-03 08:49:08 -04:00
committed by Gavin Wood
parent dcb1a590e2
commit 81d8a5d01d
18 changed files with 1810 additions and 1916 deletions
+17 -17
View File
@@ -15,7 +15,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "byteorder"
version = "1.3.1"
version = "1.3.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
@@ -33,12 +33,12 @@ dependencies = [
[[package]]
name = "hash-db"
version = "0.12.2"
version = "0.12.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "hash256-std-hasher"
version = "0.12.2"
version = "0.12.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"crunchy 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -82,7 +82,7 @@ dependencies = [
"proc-macro-crate 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
"proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
"quote 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
"syn 0.15.34 (registry+https://github.com/rust-lang/crates.io-index)",
"syn 0.15.39 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
@@ -157,14 +157,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "serde"
version = "1.0.91"
version = "1.0.94"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "sr-io"
version = "2.0.0"
dependencies = [
"hash-db 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)",
"hash-db 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)",
"parity-codec 4.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
"sr-std 2.0.0",
@@ -197,9 +197,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
name = "substrate-primitives"
version = "2.0.0"
dependencies = [
"byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
"hash-db 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)",
"hash256-std-hasher 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)",
"byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
"hash-db 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)",
"hash256-std-hasher 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)",
"num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
"parity-codec 4.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
"primitive-types 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -209,7 +209,7 @@ dependencies = [
[[package]]
name = "syn"
version = "0.15.34"
version = "0.15.39"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -222,7 +222,7 @@ name = "toml"
version = "0.5.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"serde 1.0.91 (registry+https://github.com/rust-lang/crates.io-index)",
"serde 1.0.94 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
@@ -230,7 +230,7 @@ name = "uint"
version = "0.8.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
"byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
"crunchy 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
]
@@ -243,11 +243,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
[metadata]
"checksum arrayvec 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "92c7fb76bc8826a8b33b4ee5bb07a247a81e76764ab4d55e8f73e3a4d8808c71"
"checksum autocfg 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "0e49efa51329a5fd37e7c79db4621af617cd4e3e5bc224939808d076077077bf"
"checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
"checksum crunchy 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"
"checksum fixed-hash 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "516877b7b9a1cc2d0293cbce23cd6203f0edbfd4090e6ca4489fecb5aa73050e"
"checksum hash-db 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ba7fb417e5c470acdd61068c79767d0e65962e70836cf6c9dfd2409f06345ce0"
"checksum hash256-std-hasher 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f8b2027c19ec91eb304999abae7307d225cf93be42af53b0039f76e98ed5af86"
"checksum hash-db 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3c95a428c86ed4633d83e07ef9e0a147a906da01e931f07e74a85bedce5a43"
"checksum hash256-std-hasher 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)" = "663ce20dae36902c16d12c6aaae400ca40d922407a8cf2b4caf8cae9b39b4f03"
"checksum impl-codec 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "62ed8ff267bc916dd848a800b96d3129aec73d5b23a5e3d018c83655d0c55371"
"checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
"checksum num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
@@ -261,9 +261,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
"checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
"checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
"checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
"checksum serde 1.0.91 (registry+https://github.com/rust-lang/crates.io-index)" = "a72e9b96fa45ce22a4bc23da3858dfccfd60acd28a25bcd328a98fdd6bea43fd"
"checksum serde 1.0.94 (registry+https://github.com/rust-lang/crates.io-index)" = "076a696fdea89c19d3baed462576b8f6d663064414b5c793642da8dfeb99475b"
"checksum static_assertions 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "c19be23126415861cb3a23e501d34a708f7f9b2183c5252d690941c2e69199d5"
"checksum syn 0.15.34 (registry+https://github.com/rust-lang/crates.io-index)" = "a1393e4a97a19c01e900df2aec855a29f71cf02c402e2f443b8d2747c25c5dbe"
"checksum syn 0.15.39 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d960b829a55e56db167e861ddb43602c003c7be0bee1d345021703fac2fb7c"
"checksum toml 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b8c96d7873fa7ef8bdeb3a9cda3ac48389b4154f32b9803b4bc26220b677b039"
"checksum uint 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f5375d2c574f89adad4108ad525c93e39669853a602560bf5ed4ca9943b10799"
"checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"