4bd2b777ec
## Issue Addressed Recent discussions with other client devs about optimistic sync have revealed a conceptual issue with the optimisation implemented in #3738. In designing that feature I failed to consider that the execution node checks the `blockHash` of the execution payload before responding with `SYNCING`, and that omitting this check entirely results in a degradation of the full node's validation. A node omitting the `blockHash` checks could be tricked by a supermajority of validators into following an invalid chain, something which is ordinarily impossible. ## Proposed Changes I've added verification of the `payload.block_hash` in Lighthouse. In case of failure we log a warning and fall back to verifying the payload with the execution client. I've used our existing dependency on `ethers_core` for RLP support, and a new dependency on Parity's `triehash` crate for the Merkle patricia trie. Although the `triehash` crate is currently unmaintained it seems like our best option at the moment (it is also used by Reth, and requires vastly less boilerplate than Parity's generic `trie-root` library). Block hash verification is pretty quick, about 500us per block on my machine (mainnet). The optimistic finalized sync feature can be disabled using `--disable-optimistic-finalized-sync` which forces full verification with the EL. ## Additional Info This PR also introduces a new dependency on our [`metastruct`](https://github.com/sigp/metastruct) library, which was perfectly suited to the RLP serialization method. There will likely be changes as `metastruct` grows, but I think this is a good way to start dogfooding it. I took inspiration from some Parity and Reth code while writing this, and have preserved the relevant license headers on the files containing code that was copied and modified.
36 lines
1.0 KiB
Rust
36 lines
1.0 KiB
Rust
// Copyright 2017, 2018 Parity Technologies
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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use hash256_std_hasher::Hash256StdHasher;
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use hash_db::Hasher;
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use types::Hash256;
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pub fn keccak256(bytes: &[u8]) -> Hash256 {
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Hash256::from(ethers_core::utils::keccak256(bytes))
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}
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/// Keccak hasher.
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#[derive(Default, Debug, Clone, PartialEq)]
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pub struct KeccakHasher;
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impl Hasher for KeccakHasher {
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type Out = Hash256;
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type StdHasher = Hash256StdHasher;
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const LENGTH: usize = 32;
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fn hash(x: &[u8]) -> Self::Out {
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keccak256(x)
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}
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}
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