feat(engine, tree): witness invalid block hook

crates/engine/invalid-block-hooks/Cargo.toml

@@ -12,6 +12,20 @@ workspace = true
 
 [dependencies]
 # reth
+reth-chainspec.workspace = true
+reth-engine-primitives.workspace = true
+reth-evm.workspace = true
 reth-primitives.workspace = true
 reth-provider.workspace = true
-reth-trie.workspace = true
+reth-revm.workspace = true
+reth-tracing.workspace = true
+reth-trie = { workspace = true, features = ["serde"] }
+
+# alloy
+alloy-rlp.workspace = true
+alloy-rpc-types-debug.workspace = true
+
+# misc
+eyre.workspace = true
+pretty_assertions = "1.4"
+serde_json.workspace = true

crates/engine/invalid-block-hooks/src/lib.rs

@@ -2,4 +2,4 @@
 
 mod witness;
 
-pub use witness::witness;
+pub use witness::Witness;

crates/engine/invalid-block-hooks/src/witness.rs

@@ -1,13 +1,224 @@
-use reth_primitives::{Receipt, SealedBlockWithSenders, SealedHeader, B256};
-use reth_provider::BlockExecutionOutput;
-use reth_trie::updates::TrieUpdates;
+use std::{collections::HashMap, fmt::Debug, fs::File, io::Write, path::PathBuf};
+
+use alloy_rpc_types_debug::ExecutionWitness;
+use eyre::OptionExt;
+use pretty_assertions::Comparison;
+use reth_chainspec::ChainSpec;
+use reth_engine_primitives::InvalidBlockHook;
+use reth_evm::{
+    system_calls::{apply_beacon_root_contract_call, apply_blockhashes_contract_call},
+    ConfigureEvm,
+};
+use reth_primitives::{keccak256, Receipt, SealedBlockWithSenders, SealedHeader, B256, U256};
+use reth_provider::{BlockExecutionOutput, ChainSpecProvider, StateProviderFactory};
+use reth_revm::{
+    database::StateProviderDatabase,
+    db::states::bundle_state::BundleRetention,
+    primitives::{BlockEnv, CfgEnvWithHandlerCfg, EnvWithHandlerCfg},
+    DatabaseCommit, StateBuilder,
+};
+use reth_tracing::tracing::warn;
+use reth_trie::{updates::TrieUpdates, HashedPostState, HashedStorage};
 
 /// Generates a witness for the given block and saves it to a file.
-pub fn witness(
-    _block: &SealedBlockWithSenders,
-    _header: &SealedHeader,
-    _output: &BlockExecutionOutput<Receipt>,
-    _trie_updates: Option<(&TrieUpdates, B256)>,
-) {
-    unimplemented!("witness generation is not supported")
+#[derive(Debug)]
+pub struct Witness<P, EvmConfig> {
+    /// The directory to write the witness to. Additionally, diff files will be written to this
+    /// directory in case of failed sanity checks.
+    output_directory: PathBuf,
+    /// The provider to read the historical state and do the EVM execution.
+    provider: P,
+    /// The EVM configuration to use for the execution.
+    evm_config: EvmConfig,
+}
+
+impl<P, EvmConfig> Witness<P, EvmConfig> {
+    /// Creates a new witness hook.
+    pub const fn new(output_directory: PathBuf, provider: P, evm_config: EvmConfig) -> Self {
+        Self { output_directory, provider, evm_config }
+    }
+}
+
+impl<P, EvmConfig> Witness<P, EvmConfig> {
+    /// Compares two values and saves the diff if they are different.
+    ///
+    /// Returns the path of the saved diff file if the values are different.
+    fn compare_and_save_diff<T: PartialEq + Debug>(
+        &self,
+        filename: String,
+        original: &T,
+        new: &T,
+    ) -> Option<PathBuf> {
+        if original == new {
+            return None
+        }
+
+        let path = self.output_directory.join(filename);
+        let diff = Comparison::new(original, new);
+        File::options()
+            .write(true)
+            .create_new(true)
+            .open(&path)
+            .unwrap()
+            .write_all(diff.to_string().as_bytes())
+            .unwrap();
+
+        Some(path)
+    }
+}
+
+impl<P, EvmConfig> InvalidBlockHook for Witness<P, EvmConfig>
+where
+    P: StateProviderFactory + ChainSpecProvider<ChainSpec = ChainSpec> + Send + Sync + 'static,
+    EvmConfig: ConfigureEvm,
+{
+    fn on_invalid_block(
+        &self,
+        parent_header: &SealedHeader,
+        block: &SealedBlockWithSenders,
+        output: &BlockExecutionOutput<Receipt>,
+        trie_updates: Option<(&TrieUpdates, B256)>,
+    ) -> eyre::Result<()> {
+        // TODO(alexey): unify with `DebugApi::debug_execution_witness`
+
+        // Setup database.
+        let mut db = StateBuilder::new()
+            .with_database(StateProviderDatabase::new(
+                self.provider.state_by_block_hash(parent_header.hash())?,
+            ))
+            .with_bundle_update()
+            .build();
+
+        // Setup environment for the execution.
+        let mut cfg = CfgEnvWithHandlerCfg::new(Default::default(), Default::default());
+        let mut block_env = BlockEnv::default();
+        self.evm_config.fill_cfg_and_block_env(
+            &mut cfg,
+            &mut block_env,
+            &self.provider.chain_spec(),
+            block.header(),
+            U256::MAX,
+        );
+
+        // Setup EVM
+        let mut evm = self.evm_config.evm_with_env(
+            &mut db,
+            EnvWithHandlerCfg::new_with_cfg_env(cfg, block_env, Default::default()),
+        );
+
+        // Apply pre-block system contract calls.
+        apply_beacon_root_contract_call(
+            &self.evm_config,
+            &self.provider.chain_spec(),
+            block.timestamp,
+            block.number,
+            block.parent_beacon_block_root,
+            &mut evm,
+        )?;
+        apply_blockhashes_contract_call(
+            &self.evm_config,
+            &self.provider.chain_spec(),
+            block.timestamp,
+            block.number,
+            block.parent_hash,
+            &mut evm,
+        )?;
+
+        // Re-execute all of the transactions in the block to load all touched accounts into
+        // the cache DB.
+        for tx in block.transactions() {
+            self.evm_config.fill_tx_env(
+                evm.tx_mut(),
+                tx,
+                tx.recover_signer().ok_or_eyre("failed to recover sender")?,
+            );
+            let result = evm.transact()?;
+            evm.db_mut().commit(result.state);
+        }
+
+        drop(evm);
+
+        // Merge all state transitions
+        db.merge_transitions(BundleRetention::Reverts);
+
+        // Take the bundle state
+        let bundle_state = db.take_bundle();
+
+        // Initialize a map of preimages.
+        let mut state_preimages = HashMap::new();
+
+        // Grab all account proofs for the data accessed during block execution.
+        //
+        // Note: We grab *all* accounts in the cache here, as the `BundleState` prunes
+        // referenced accounts + storage slots.
+        let mut hashed_state = HashedPostState::from_bundle_state(&bundle_state.state);
+        for (address, account) in db.cache.accounts {
+            let hashed_address = keccak256(address);
+            hashed_state
+                .accounts
+                .insert(hashed_address, account.account.as_ref().map(|a| a.info.clone().into()));
+
+            let storage = hashed_state
+                .storages
+                .entry(hashed_address)
+                .or_insert_with(|| HashedStorage::new(account.status.was_destroyed()));
+
+            if let Some(account) = account.account {
+                state_preimages.insert(hashed_address, alloy_rlp::encode(address).into());
+
+                for (slot, value) in account.storage {
+                    let slot = B256::from(slot);
+                    let hashed_slot = keccak256(slot);
+                    storage.storage.insert(hashed_slot, value);
+
+                    state_preimages.insert(hashed_slot, alloy_rlp::encode(slot).into());
+                }
+            }
+        }
+
+        // Generate an execution witness for the aggregated state of accessed accounts.
+        // Destruct the cache database to retrieve the state provider.
+        let state_provider = db.database.into_inner();
+        let witness = state_provider.witness(HashedPostState::default(), hashed_state.clone())?;
+
+        // Write the witness to the output directory.
+        let mut file = File::options()
+            .write(true)
+            .create_new(true)
+            .open(self.output_directory.join(format!("{}_{}.json", block.number, block.hash())))?;
+        let response = ExecutionWitness { witness, state_preimages: Some(state_preimages) };
+        file.write_all(serde_json::to_string(&response)?.as_bytes())?;
+
+        // The bundle state after re-execution should match the original one.
+        if let Some(path) = self.compare_and_save_diff(
+            format!("{}_{}.bundle_state.diff", block.number, block.hash()),
+            &bundle_state,
+            &output.state,
+        ) {
+            warn!(target: "engine::invalid_block_hooks::witness", path = %path.display(), "Bundle state mismatch after re-execution");
+        }
+
+        // Calculate the state root and trie updates after re-execution. They should match
+        // the original ones.
+        let (state_root, trie_output) = state_provider.state_root_with_updates(hashed_state)?;
+        if let Some(trie_updates) = trie_updates {
+            if let Some(path) = self.compare_and_save_diff(
+                format!("{}_{}.state_root.diff", block.number, block.hash()),
+                &state_root,
+                &trie_updates.1,
+            ) {
+                warn!(target: "engine::invalid_block_hooks::witness", path = %path.display(), "State root mismatch after re-execution");
+            }
+
+            if let Some(path) = self.compare_and_save_diff(
+                format!("{}_{}.trie_updates.diff", block.number, block.hash()),
+                &trie_output,
+                trie_updates.0,
+            ) {
+                warn!(target: "engine::invalid_block_hooks::witness", path = %path.display(), "Trie updates mismatch after re-execution");
+            }
+        }
+
+        Ok(())
+    }
 }

crates/engine/primitives/Cargo.toml

@@ -13,7 +13,11 @@ workspace = true
 [dependencies]
 # reth
 reth-chainspec.workspace = true
+reth-execution-types.workspace = true
 reth-payload-primitives.workspace = true
+reth-primitives.workspace = true
+reth-trie.workspace = true
 
 # misc
-serde.workspace = true
+eyre.workspace = true
+serde.workspace = true