feat: Slash lists, store expiration, veto checks

Adds some missing features to slashing:

- Adds support for the slashValidatorNever and slashValidatorAlways
  config settings (now EthAddress lists) so that validators in those
lists are never/always slashed. All validators in the local keystore are
automatically added to the "never" list.

- Checks if a slash payload is vetoed before trying to execute it, to
  avoid running an unnecessary simulation. This is handled on the
slasher client directly.

- Adds expiration for offenses and payloads to avoid cluttering the
  local stores. Removes unused slashPayloadTtl setting.

- Avoids posting committee addresses during executeRound for committees
  that are not slashed, in order to save calldata gas.

Author: spalladino

yarn-project/aztec-node/src/aztec-node/server.ts

@@ -108,7 +108,7 @@ import {
   getTelemetryClient,
   trackSpan,
 } from '@aztec/telemetry-client';
-import { ValidatorClient, createValidatorClient } from '@aztec/validator-client';
+import { NodeKeystoreAdapter, ValidatorClient, createValidatorClient } from '@aztec/validator-client';
 import { createWorldStateSynchronizer } from '@aztec/world-state';
 
 import { createPublicClient, fallback, http } from 'viem';
@@ -373,13 +373,19 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, Traceable {
     if (!config.disableValidator) {
       // We create a slasher only if we have a sequencer, since all slashing actions go through the sequencer publisher
       // as they are executed when the node is selected as proposer.
+      const validatorAddresses = keyStoreManager
+        ? NodeKeystoreAdapter.fromKeyStoreManager(keyStoreManager).getAddresses()
+        : [];
+
       slasherClient = await createSlasher(
         config,
         config.l1Contracts,
         getPublicClient(config),
         watchers,
         dateProvider,
         epochCache,
+        validatorAddresses,
+        undefined, // logger
       );
       await slasherClient.start();
 

yarn-project/aztec-node/src/sentinel/sentinel.test.ts

@@ -45,13 +45,9 @@ describe('sentinel', () => {
   let epoch: bigint;
   let ts: bigint;
   let l1Constants: L1RollupConstants;
-  const config: Pick<
-    SlasherConfig,
-    'slashInactivityTargetPercentage' | 'slashInactivityPenalty' | 'slashPayloadTtlSeconds'
-  > = {
+  const config: Pick<SlasherConfig, 'slashInactivityTargetPercentage' | 'slashInactivityPenalty'> = {
     slashInactivityPenalty: 100n,
     slashInactivityTargetPercentage: 0.8,
-    slashPayloadTtlSeconds: 60 * 60,
   };
 
   beforeEach(async () => {
@@ -466,10 +462,7 @@ class TestSentinel extends Sentinel {
     archiver: L2BlockSource,
     p2p: P2PClient,
     store: SentinelStore,
-    config: Pick<
-      SlasherConfig,
-      'slashInactivityTargetPercentage' | 'slashInactivityPenalty' | 'slashPayloadTtlSeconds'
-    >,
+    config: Pick<SlasherConfig, 'slashInactivityTargetPercentage' | 'slashInactivityPenalty'>,
     protected override blockStream: L2BlockStream,
   ) {
     super(epochCache, archiver, p2p, store, config);

yarn-project/aztec-node/src/sentinel/sentinel.ts

@@ -44,10 +44,7 @@ export class Sentinel extends (EventEmitter as new () => WatcherEmitter) impleme
     protected archiver: L2BlockSource,
     protected p2p: P2PClient,
     protected store: SentinelStore,
-    protected config: Pick<
-      SlasherConfig,
-      'slashInactivityTargetPercentage' | 'slashInactivityPenalty' | 'slashPayloadTtlSeconds'
-    >,
+    protected config: Pick<SlasherConfig, 'slashInactivityTargetPercentage' | 'slashInactivityPenalty'>,
     protected logger = createLogger('node:sentinel'),
   ) {
     super();

yarn-project/aztec/src/cli/chain_l2_config.ts

@@ -69,7 +69,6 @@ export const testnetIgnitionL2ChainConfig: L2ChainConfig = {
   provingCostPerMana: 0n,
 
   slasherFlavor: 'none',
-  slashPayloadTtlSeconds: 0,
   slashAmountSmall: 0n,
   slashAmountMedium: 0n,
   slashAmountLarge: 0n,
@@ -153,7 +152,6 @@ export const alphaTestnetL2ChainConfig: L2ChainConfig = {
   slashAmountLarge: DefaultL1ContractsConfig.slashAmountLarge,
 
   // Slashing stuff
-  slashPayloadTtlSeconds: 36 * 32 * 6 * 6, // 6 rounds (a bit longer than lifetime)
   slashMinPenaltyPercentage: 0.5,
   slashMaxPenaltyPercentage: 2.0,
   slashInactivityTargetPercentage: 0.7,
@@ -325,7 +323,6 @@ export async function enrichEnvironmentWithChainConfig(networkName: NetworkNames
   enrichEthAddressVar('AZTEC_SLASHING_VETOER', config.slashingVetoer.toString());
 
   // Slashing
-  enrichVar('SLASH_PAYLOAD_TTL_SECONDS', config.slashPayloadTtlSeconds.toString());
   enrichVar('SLASH_MIN_PENALTY_PERCENTAGE', config.slashMinPenaltyPercentage.toString());
   enrichVar('SLASH_MAX_PENALTY_PERCENTAGE', config.slashMaxPenaltyPercentage.toString());
   enrichVar('SLASH_PRUNE_PENALTY', config.slashPrunePenalty.toString());

yarn-project/ethereum/src/contracts/index.ts

@@ -11,3 +11,4 @@ export * from './registry.js';
 export * from './rollup.js';
 export * from './empire_slashing_proposer.js';
 export * from './tally_slashing_proposer.js';
+export * from './slasher_contract.js';

yarn-project/ethereum/src/contracts/rollup.ts

@@ -27,6 +27,7 @@ import type { ViemClient } from '../types.js';
 import { formatViemError } from '../utils.js';
 import { EmpireSlashingProposerContract } from './empire_slashing_proposer.js';
 import { GSEContract } from './gse.js';
+import { SlasherContract } from './slasher_contract.js';
 import { TallySlashingProposerContract } from './tally_slashing_proposer.js';
 import { checkBlockTag } from './utils.js';
 
@@ -267,6 +268,14 @@ export class RollupContract {
     return this.rollup.read.getSlasher();
   }
 
+  /**
+   * Returns a SlasherContract instance for interacting with the slasher contract.
+   */
+  async getSlasherContract(): Promise<SlasherContract> {
+    const slasherAddress = await this.getSlasher();
+    return new SlasherContract(this.client, EthAddress.fromString(slasherAddress));
+  }
+
   getOwner() {
     return this.rollup.read.owner();
   }

yarn-project/ethereum/src/contracts/slasher_contract.ts

@@ -0,0 +1,67 @@
+import { EthAddress } from '@aztec/foundation/eth-address';
+import { createLogger } from '@aztec/foundation/log';
+import { SlasherAbi } from '@aztec/l1-artifacts/SlasherAbi';
+
+import { type GetContractReturnType, getContract } from 'viem';
+
+import type { ViemClient } from '../types.js';
+
+/**
+ * Typescript wrapper around the Slasher contract.
+ */
+export class SlasherContract {
+  private contract: GetContractReturnType<typeof SlasherAbi, ViemClient>;
+
+  constructor(
+    private readonly client: ViemClient,
+    private readonly address: EthAddress,
+    private readonly log = createLogger('slasher-contract'),
+  ) {
+    this.contract = getContract({
+      address: this.address.toString(),
+      abi: SlasherAbi,
+      client: this.client,
+    });
+  }
+
+  /**
+   * Checks if a slash payload is vetoed.
+   * @param payloadAddress - The address of the payload to check
+   * @returns True if the payload is vetoed, false otherwise
+   */
+  public async isPayloadVetoed(payloadAddress: EthAddress): Promise<boolean> {
+    try {
+      return await this.contract.read.vetoedPayloads([payloadAddress.toString()]);
+    } catch (error) {
+      this.log.error(`Error checking if payload ${payloadAddress} is vetoed`, error);
+      throw error;
+    }
+  }
+
+  /**
+   * Gets the current vetoer address.
+   * @returns The vetoer address
+   */
+  public async getVetoer(): Promise<EthAddress> {
+    const vetoer = await this.contract.read.VETOER();
+    return EthAddress.fromString(vetoer);
+  }
+
+  /**
+   * Gets the current governance address.
+   * @returns The governance address
+   */
+  public async getGovernance(): Promise<EthAddress> {
+    const governance = await this.contract.read.GOVERNANCE();
+    return EthAddress.fromString(governance);
+  }
+
+  /**
+   * Gets the current proposer address.
+   * @returns The proposer address
+   */
+  public async getProposer(): Promise<EthAddress> {
+    const proposer = await this.contract.read.PROPOSER();
+    return EthAddress.fromString(proposer);
+  }
+}

yarn-project/ethereum/src/contracts/tally_slashing_proposer.ts

@@ -97,21 +97,20 @@ export class TallySlashingProposerContract extends EventEmitter {
   public async getPayload(
     round: bigint,
   ): Promise<{ actions: { slashAmount: bigint; validator: EthAddress }[]; address: EthAddress }> {
-    const result = await this.getTallyFromContract(round);
-    const address = await this.contract.read.getPayloadAddress([round, result]);
-    const actions = this.mapSlashActions(result);
+    const { result: committees } = await this.contract.simulate.getSlashTargetCommittees([round]);
+    const tally = await this.contract.read.getTally([round, committees]);
+    const address = await this.contract.read.getPayloadAddress([round, tally]);
+    const actions = this.mapSlashActions(tally);
     return { actions, address: EthAddress.fromString(address) };
   }
 
   /** Returns the slash actions to be executed for a given round based on votes */
-  public async getTally(round: bigint): Promise<{ slashAmount: bigint; validator: EthAddress }[]> {
-    const result = await this.getTallyFromContract(round);
-    return this.mapSlashActions(result);
-  }
-
-  private async getTallyFromContract(round: bigint): Promise<readonly { slashAmount: bigint; validator: Hex }[]> {
+  public async getTally(
+    round: bigint,
+  ): Promise<{ actions: { slashAmount: bigint; validator: EthAddress }[]; committees: EthAddress[][] }> {
     const { result: committees } = await this.contract.simulate.getSlashTargetCommittees([round]);
-    return await this.contract.read.getTally([round, committees]);
+    const tally = await this.contract.read.getTally([round, committees]);
+    return { actions: this.mapSlashActions(tally), committees: committees.map(c => c.map(EthAddress.fromString)) };
   }
 
   private mapSlashActions(

yarn-project/foundation/src/config/env_var.ts

@@ -208,7 +208,6 @@ export type EnvVar =
   | 'SLASH_INACTIVITY_TARGET_PERCENTAGE'
   | 'SLASH_INVALID_BLOCK_PENALTY'
   | 'SLASH_OVERRIDE_PAYLOAD'
-  | 'SLASH_PAYLOAD_TTL_SECONDS'
   | 'SLASH_PROPOSE_INVALID_ATTESTATIONS_PENALTY'
   | 'SLASH_ATTEST_DESCENDANT_OF_INVALID_PENALTY'
   | 'SLASH_UNKNOWN_PENALTY'

yarn-project/slasher/README.md

@@ -32,6 +32,7 @@ Key characteristics:
 - Requires quorum to execute slashing
 - L1 contract determines which offenses reach consensus
 - Execution happens after a delay period for review
+- Slash payloads can be vetoed during the execution delay period
 
 ### Empire Model
 
@@ -56,13 +57,14 @@ Common interface implemented by both tally and empire clients. Provides methods
 #### SlashOffensesCollector
 Collects slashable offenses from watchers and stores them in the offenses store. Features:
 - Subscribes to `WANT_TO_SLASH_EVENT` from watchers
-- Manages offense lifecycle and expiration
+- Manages offense lifecycle and automatic expiration
 
 #### SlasherOffensesStore
 Persistent storage for offenses. Tracks:
 - Pending offenses awaiting slashing
 - Executed offenses to prevent double slashing
 - Round-based offense organization
+- Automatic expiration of old offenses based on configurable rounds
 
 #### SlashRoundMonitor
 Monitors slashing rounds and triggers actions on round transitions:
@@ -85,6 +87,15 @@ Actions returned by the slasher client to the SequencerPublisher:
 4. **Action Execution**: SequencerPublisher receives actions and executes them on L1
 5. **Round Monitoring**: SlashRoundMonitor tracks rounds and triggers execution when conditions are met
 
+## Vetoing
+
+The slashing system includes a veto mechanism that allows designated vetoers to block slash payloads during the execution delay period. When a slash payload is ready for execution, the system first checks if it has been vetoed before proceeding.
+
+Key features:
+- Slash payloads can be vetoed by authorized addresses on the L1 slasher contract
+- Veto checks are performed automatically before execution attempts
+- The veto mechanism provides a safety valve for incorrectly proposed slashes
+
 ## Slashable Offenses
 
 ### DATA_WITHHOLDING
@@ -132,15 +143,27 @@ Actions returned by the slasher client to the SequencerPublisher:
 
 ## Configuration
 
-### Slasher Configuration
-- `slashGracePeriodL2Slots`: Number of initial L2 slots where slashing is disabled
-- `slashMaxPayloadSize`: Maximum size of slash payloads (empire model)
-- `slashingRoundSize`: Number of slots per slashing round
+### L1 System Settings (L1ContractsConfig)
+These settings are deployed with the L1 contracts and apply system-wide to the protocol:
+
+- `slashingRoundSize`: Number of slots per slashing round (default: 192, must be multiple of epochs)
 - `slashingQuorumSize`: Votes required to slash (tally model)
 - `slashingOffsetInRounds`: How many rounds to look back for offenses (tally model)
 - `slashingExecutionDelayInRounds`: Rounds to wait before execution
 - `slashingLifetimeInRounds`: Maximum age of executable rounds
-- `slashingUnit`: Base slashing amount per unit
+- `slashingAmounts`: Valid values for each individual slash (tally model)
+
+### Local Node Configuration (SlasherConfig)
+These settings are configured locally on each validator node:
 
-### Environment Variables
-- `SLASHER_CLIENT_TYPE`: Select between 'tally' or 'empire' (default: 'tally')
+- `slashGracePeriodL2Slots`: Number of initial L2 slots where slashing is disabled
+- `slashMaxPayloadSize`: Maximum size of slash payloads (empire model)
+- `slashOffenseExpirationRounds`: Number of rounds after which pending offenses expire
+- `slashValidatorsAlways`: Array of validator addresses that should always be slashed
+- `slashValidatorsNever`: Array of validator addresses that should never be slashed (own validator addresses are automatically added to this list)
+- `slashPrunePenalty`: Penalty for DATA_WITHHOLDING and VALID_EPOCH_PRUNED offenses
+- `slashInactivityPenalty`: Penalty for INACTIVITY offenses
+- `slashBroadcastedInvalidBlockPenalty`: Penalty for broadcasting invalid blocks
+- `slashProposeInvalidAttestationsPenalty`: Penalty for proposing with insufficient/incorrect attestations
+- `slashAttestDescendantOfInvalidPenalty`: Penalty for attesting to descendants of invalid blocks
+- `slashUnknownPenalty`: Default penalty for unknown offense types