diff --git a/specs/_features/eip7251/beacon-chain.md b/specs/_features/eip7251/beacon-chain.md index 7d7e78d4a..ef61e3d3a 100644 --- a/specs/_features/eip7251/beacon-chain.md +++ b/specs/_features/eip7251/beacon-chain.md @@ -30,6 +30,8 @@ - [Extended Containers](#extended-containers) - [`BeaconState`](#beaconstate) - [`BeaconBlockBody`](#beaconblockbody) + - [`ExecutionPayload`](#executionpayload) + - [`ExecutionPayloadHeader`](#executionpayloadheader) - [Helpers](#helpers) - [Predicates](#predicates) - [Updated `is_eligible_for_activation_queue`](#updated-is_eligible_for_activation_queue) @@ -75,13 +77,14 @@ - [New `process_consolidation`](#new-process_consolidation) - [Voluntary exits](#voluntary-exits) - [Updated `process_voluntary_exit`](#updated-process_voluntary_exit) +- [Testing](#testing) ## Introduction -See [a modest proposal](https://notes.ethereum.org/@mikeneuder/increase-maxeb), the [diff view](https://github.com/michaelneuder/consensus-specs/pull/3/files) and +See [a modest proposal](https://notes.ethereum.org/@mikeneuder/increase-maxeb), the [diff view](https://github.com/michaelneuder/consensus-specs/pull/3/files) and [security considerations](https://notes.ethereum.org/@fradamt/meb-increase-security). *Note:* This specification is built upon [Deneb](../../deneb/beacon-chain.md). @@ -136,6 +139,7 @@ The following values are (non-configurable) constants used throughout the specif | Name | Value | Description | | - | - | - | +| `MAX_WITHDRAWAL_REQUESTS_PER_PAYLOAD` | `uint64(16)` | | `MAX_PARTIAL_WITHDRAWALS_PER_PAYLOAD` | `uint64(2**3)` (= 8) | Maximum amount of partial withdrawals allowed in each payload | ### State list lengths @@ -282,12 +286,64 @@ class BeaconBlockBody(Container): voluntary_exits: List[SignedVoluntaryExit, MAX_VOLUNTARY_EXITS] sync_aggregate: SyncAggregate # Execution - execution_payload: ExecutionPayload + execution_payload: ExecutionPayload bls_to_execution_changes: List[SignedBLSToExecutionChange, MAX_BLS_TO_EXECUTION_CHANGES] blob_kzg_commitments: List[KZGCommitment, MAX_BLOB_COMMITMENTS_PER_BLOCK] consolidations: List[SignedConsolidation, MAX_CONSOLIDATIONS] # [New in EIP-7251] ``` +#### `ExecutionPayload` + +```python +class ExecutionPayload(Container): + # Execution block header fields + parent_hash: Hash32 + fee_recipient: ExecutionAddress # 'beneficiary' in the yellow paper + state_root: Bytes32 + receipts_root: Bytes32 + logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM] + prev_randao: Bytes32 # 'difficulty' in the yellow paper + block_number: uint64 # 'number' in the yellow paper + gas_limit: uint64 + gas_used: uint64 + timestamp: uint64 + extra_data: ByteList[MAX_EXTRA_DATA_BYTES] + base_fee_per_gas: uint256 + # Extra payload fields + block_hash: Hash32 # Hash of execution block + transactions: List[Transaction, MAX_TRANSACTIONS_PER_PAYLOAD] + withdrawals: List[Withdrawal, MAX_WITHDRAWALS_PER_PAYLOAD] + blob_gas_used: uint64 + excess_blob_gas: uint64 + withdraw_requests: List[ExecutionLayerWithdrawRequest, MAX_WITHDRAWAL_REQUESTS_PER_PAYLOAD] # [New in EIP-7251] +``` + +#### `ExecutionPayloadHeader` + +```python +class ExecutionPayloadHeader(Container): + # Execution block header fields + parent_hash: Hash32 + fee_recipient: ExecutionAddress + state_root: Bytes32 + receipts_root: Bytes32 + logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM] + prev_randao: Bytes32 + block_number: uint64 + gas_limit: uint64 + gas_used: uint64 + timestamp: uint64 + extra_data: ByteList[MAX_EXTRA_DATA_BYTES] + base_fee_per_gas: uint256 + # Extra payload fields + block_hash: Hash32 # Hash of execution block + transactions_root: Root + withdrawals_root: Root + blob_gas_used: uint64 + excess_blob_gas: uint64 + withdraw_requests_root: Root # [New in EIP-7251] +``` + ## Helpers ### Predicates @@ -386,7 +442,7 @@ def get_churn_limit(state: BeaconState) -> Gwei: Return the churn limit for the current epoch. """ churn = max( - MIN_PER_EPOCH_CHURN_LIMIT_EIP7251, + MIN_PER_EPOCH_CHURN_LIMIT_EIP7251, get_total_active_balance(state) // CHURN_LIMIT_QUOTIENT ) return churn - churn % EFFECTIVE_BALANCE_INCREMENT @@ -472,7 +528,6 @@ def queue_excess_active_balance(state: BeaconState, index: ValidatorIndex) -> No #### New `compute_exit_epoch_and_update_churn` - ```python def compute_exit_epoch_and_update_churn(state: BeaconState, exit_balance: Gwei) -> Epoch: earliest_exit_epoch = compute_activation_exit_epoch(get_current_epoch(state)) @@ -566,16 +621,23 @@ def process_epoch(state: BeaconState) -> None: process_effective_balance_updates(state) # [Modified in EIP7251] process_slashings_reset(state) process_randao_mixes_reset(state) + process_historical_summaries_update(state) + process_participation_flag_updates(state) + process_sync_committee_updates(state) ``` #### Updated `process_registry_updates` +`process_registry_updates` uses the updated definition of `initiate_validator_exit` +and changes how the activation epochs are computed for eligible validators. + ```python def process_registry_updates(state: BeaconState) -> None: # Process activation eligibility and ejections for index, validator in enumerate(state.validators): if is_eligible_for_activation_queue(validator): validator.activation_eligibility_epoch = get_current_epoch(state) + 1 + if ( is_active_validator(validator, get_current_epoch(state)) and validator.effective_balance <= EJECTION_BALANCE @@ -607,7 +669,7 @@ def process_pending_balance_deposits(state: BeaconState) -> None: state.pending_balance_deposits = state.pending_balance_deposits[next_deposit_index:] if len(state.pending_balance_deposits) == 0: - state.deposit_balance_to_consume = 0 + state.deposit_balance_to_consume = Gwei(0) else: state.deposit_balance_to_consume = available_for_processing - processed_amount ``` @@ -638,6 +700,8 @@ def process_pending_consolidations(state: BeaconState) -> None: #### Updated `process_effective_balance_updates` +`process_effective_balance_updates` is updated with a new limit for the maximum effective balance. + ```python def process_effective_balance_updates(state: BeaconState) -> None: # Update effective balances with hysteresis @@ -760,7 +824,7 @@ def process_withdrawals(state: BeaconState, payload: ExecutionPayload) -> None: state.next_withdrawal_validator_index = next_validator_index ``` -#### Operations +#### Operations ##### Updated `process_operations` @@ -779,14 +843,16 @@ def process_operations(state: BeaconState, body: BeaconBlockBody) -> None: for_ops(body.deposits, process_deposit) # [Modified in EIP7251] for_ops(body.voluntary_exits, process_voluntary_exit) # [Modified in EIP7251] for_ops(body.bls_to_execution_changes, process_bls_to_execution_change) - for_ops(body.execution_payload.withdraw_requests, process_execution_layer_withdraw_request) # New in EIP7251 - for_ops(body.consolidations, process_consolidation) # New in EIP7251 + for_ops(body.execution_payload.withdraw_requests, process_execution_layer_withdraw_request) # [New in EIP7251] + for_ops(body.consolidations, process_consolidation) # [New in EIP7251] ``` ##### Deposits ###### Updated `apply_deposit` +*NOTE*: `process_deposit` is updated with a new definition of `apply_deposit`. + ```python def apply_deposit(state: BeaconState, pubkey: BLSPubkey, @@ -819,7 +885,7 @@ def apply_deposit(state: BeaconState, def is_valid_deposit_signature(pubkey: BLSPubkey, withdrawal_credentials: Bytes32, amount: uint64, - signature: BLSSignature) -> None: + signature: BLSSignature) -> bool: deposit_message = DepositMessage( pubkey=pubkey, withdrawal_credentials=withdrawal_credentials, @@ -862,7 +928,7 @@ def get_validator_from_deposit(pubkey: BLSPubkey, withdrawal_credentials: Bytes3 ) ``` -##### Withdrawals +##### Withdrawals ###### New `process_execution_layer_withdraw_request` @@ -874,7 +940,7 @@ def process_execution_layer_withdraw_request( amount = execution_layer_withdraw_request.amount is_full_exit_request = amount == FULL_EXIT_REQUEST_AMOUNT - # If partial withdrawal queue is full, only full exits are processed + # If partial withdrawal queue is full, only full exits are processed if len(state.pending_partial_withdrawals) >= PENDING_PARTIAL_WITHDRAWALS_LIMIT and not is_full_exit_request: return @@ -947,7 +1013,7 @@ def process_consolidation(state: BeaconState, signed_consolidation: SignedConsol assert source_validator.exit_epoch == FAR_FUTURE_EPOCH assert target_validator.exit_epoch == FAR_FUTURE_EPOCH # Consolidations must specify an epoch when they become valid; they are not valid before then - assert current_epoch >= consolidation.epoch + assert current_epoch >= consolidation.epoch # Verify the source and the target have Execution layer withdrawal credentials assert has_execution_withdrawal_credential(source_validator) @@ -989,12 +1055,70 @@ def process_voluntary_exit(state: BeaconState, signed_voluntary_exit: SignedVolu assert get_current_epoch(state) >= voluntary_exit.epoch # Verify the validator has been active long enough assert get_current_epoch(state) >= validator.activation_epoch + SHARD_COMMITTEE_PERIOD - # Verify signature - domain = get_domain(state, DOMAIN_VOLUNTARY_EXIT, voluntary_exit.epoch) - signing_root = compute_signing_root(voluntary_exit, domain) - assert bls.Verify(validator.pubkey, signing_root, signed_voluntary_exit.signature) # Only exit validator if it has no pending withdrawals in the queue assert get_pending_balance_to_withdraw(state, voluntary_exit.validator_index) == 0 # [New in EIP7251] + # Verify signature + domain = compute_domain(DOMAIN_VOLUNTARY_EXIT, CAPELLA_FORK_VERSION, state.genesis_validators_root) + signing_root = compute_signing_root(voluntary_exit, domain) + assert bls.Verify(validator.pubkey, signing_root, signed_voluntary_exit.signature) # Initiate exit initiate_validator_exit(state, voluntary_exit.validator_index) ``` + +## Testing + +*Note*: The function `initialize_beacon_state_from_eth1` is modified for pure EIP-7251 testing only. + +```python +def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32, + eth1_timestamp: uint64, + deposits: Sequence[Deposit], + execution_payload_header: ExecutionPayloadHeader=ExecutionPayloadHeader() + ) -> BeaconState: + fork = Fork( + previous_version=EIP7251_FORK_VERSION, # [Modified in EIP-7251] for testing only + current_version=EIP7251_FORK_VERSION, # [Modified in EIP-7251] + epoch=GENESIS_EPOCH, + ) + state = BeaconState( + genesis_time=eth1_timestamp + GENESIS_DELAY, + fork=fork, + eth1_data=Eth1Data(block_hash=eth1_block_hash, deposit_count=uint64(len(deposits))), + latest_block_header=BeaconBlockHeader(body_root=hash_tree_root(BeaconBlockBody())), + randao_mixes=[eth1_block_hash] * EPOCHS_PER_HISTORICAL_VECTOR, # Seed RANDAO with Eth1 entropy + ) + + # Process deposits + leaves = list(map(lambda deposit: deposit.data, deposits)) + for index, deposit in enumerate(deposits): + deposit_data_list = List[DepositData, 2**DEPOSIT_CONTRACT_TREE_DEPTH](*leaves[:index + 1]) + state.eth1_data.deposit_root = hash_tree_root(deposit_data_list) + process_deposit(state, deposit) + + # Process deposit balance updates + for deposit in state.pending_balance_deposits: + increase_balance(state, deposit.index, deposit.amount) + state.pending_balance_deposits = [] + + # Process activations + for index, validator in enumerate(state.validators): + balance = state.balances[index] + validator.effective_balance = min(balance - balance % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE) + if validator.effective_balance == MAX_EFFECTIVE_BALANCE: + validator.activation_eligibility_epoch = GENESIS_EPOCH + validator.activation_epoch = GENESIS_EPOCH + + # Set genesis validators root for domain separation and chain versioning + state.genesis_validators_root = hash_tree_root(state.validators) + + # Fill in sync committees + # Note: A duplicate committee is assigned for the current and next committee at genesis + state.current_sync_committee = get_next_sync_committee(state) + state.next_sync_committee = get_next_sync_committee(state) + + # Initialize the execution payload header + # If empty, will initialize a chain that has not yet gone through the Merge transition + state.latest_execution_payload_header = execution_payload_header + + return state +``` diff --git a/specs/_features/eip7251/fork.md b/specs/_features/eip7251/fork.md index 02d73deb1..49e01ea7e 100644 --- a/specs/_features/eip7251/fork.md +++ b/specs/_features/eip7251/fork.md @@ -131,8 +131,7 @@ def upgrade_to_eip7251(pre: deneb.BeaconState) -> BeaconState: # Ensure early adopters of compounding credentials go through the activation churn for index, validator in enumerate(post.validators): if has_compounding_withdrawal_credential(validator): - queue_excess_active_balance(post, index) + queue_excess_active_balance(post, ValidatorIndex(index)) return post ``` - diff --git a/specs/_features/eip7251/validator.md b/specs/_features/eip7251/validator.md new file mode 100644 index 000000000..455699383 --- /dev/null +++ b/specs/_features/eip7251/validator.md @@ -0,0 +1,73 @@ +# EIP-7251 -- Honest Validator + +## Table of contents + + + + + +- [Introduction](#introduction) +- [Prerequisites](#prerequisites) +- [Beacon chain responsibilities](#beacon-chain-responsibilities) + - [Block and sidecar proposal](#block-and-sidecar-proposal) + - [Constructing the `BeaconBlockBody`](#constructing-the-beaconblockbody) + - [ExecutionPayload](#executionpayload) + + + + +## Introduction + +This document represents the changes to be made in the code of an "honest validator". + +## Prerequisites + +This document is an extension of the [Deneb -- Honest Validator](../deneb/validator.md) guide. +All behaviors and definitions defined in this document, and documents it extends, carry over unless explicitly noted or overridden. + +All terminology, constants, functions, and protocol mechanics defined in the updated [Beacon Chain doc of EIP-7251](./beacon-chain.md) are requisite for this document and used throughout. +Please see related Beacon Chain doc before continuing and use them as a reference throughout. + +## Beacon chain responsibilities + +All validator responsibilities remain unchanged other than those noted below. + +### Block and sidecar proposal + +#### Constructing the `BeaconBlockBody` + +##### ExecutionPayload + +`prepare_execution_payload` is updated from the Deneb specs. + +*Note*: In this section, `state` is the state of the slot for the block proposal _without_ the block yet applied. +That is, `state` is the `previous_state` processed through any empty slots up to the assigned slot using `process_slots(previous_state, slot)`. + +*Note*: The only change to `prepare_execution_payload` is the new definition of `get_expected_withdrawals`. + +```python +def prepare_execution_payload(state: BeaconState, + safe_block_hash: Hash32, + finalized_block_hash: Hash32, + suggested_fee_recipient: ExecutionAddress, + execution_engine: ExecutionEngine) -> Optional[PayloadId]: + # Verify consistency of the parent hash with respect to the previous execution payload header + parent_hash = state.latest_execution_payload_header.block_hash + + # Set the forkchoice head and initiate the payload build process + withdrawals, _ = get_expected_withdrawals(state) # [Modified in EIP-7251] + + payload_attributes = PayloadAttributes( + timestamp=compute_timestamp_at_slot(state, state.slot), + prev_randao=get_randao_mix(state, get_current_epoch(state)), + suggested_fee_recipient=suggested_fee_recipient, + withdrawals=withdrawals, + parent_beacon_block_root=hash_tree_root(state.latest_block_header), + ) + return execution_engine.notify_forkchoice_updated( + head_block_hash=parent_hash, + safe_block_hash=safe_block_hash, + finalized_block_hash=finalized_block_hash, + payload_attributes=payload_attributes, + ) +```