from copy import deepcopy from py_ecc import bls import build.phase0.spec as spec from build.phase0.utils.minimal_ssz import signed_root from build.phase0.spec import ( # constants EMPTY_SIGNATURE, ZERO_HASH, # SSZ Attestation, AttestationData, AttestationDataAndCustodyBit, BeaconBlockHeader, Deposit, DepositData, Eth1Data, ProposerSlashing, VoluntaryExit, # functions get_active_validator_indices, get_attestation_participants, get_block_root, get_crosslink_committee_for_attestation, get_crosslink_committees_at_slot, get_current_epoch, get_domain, get_empty_block, get_epoch_start_slot, get_genesis_beacon_state, slot_to_epoch, verify_merkle_branch, hash, ) from build.phase0.utils.merkle_minimal import ( calc_merkle_tree_from_leaves, get_merkle_proof, get_merkle_root, ) privkeys = [i + 1 for i in range(1000)] pubkeys = [bls.privtopub(privkey) for privkey in privkeys] pubkey_to_privkey = {pubkey: privkey for privkey, pubkey in zip(privkeys, pubkeys)} def create_mock_genesis_validator_deposits(num_validators, deposit_data_leaves=None): if not deposit_data_leaves: deposit_data_leaves = [] proof_of_possession = b'\x33' * 96 deposit_data_list = [] for i in range(num_validators): pubkey = pubkeys[i] deposit_data = DepositData( pubkey=pubkey, # insecurely use pubkey as withdrawal key as well withdrawal_credentials=spec.BLS_WITHDRAWAL_PREFIX_BYTE + hash(pubkey)[1:], amount=spec.MAX_DEPOSIT_AMOUNT, proof_of_possession=proof_of_possession, ) item = hash(deposit_data.serialize()) deposit_data_leaves.append(item) tree = calc_merkle_tree_from_leaves(tuple(deposit_data_leaves)) root = get_merkle_root((tuple(deposit_data_leaves))) proof = list(get_merkle_proof(tree, item_index=i)) assert verify_merkle_branch(item, proof, spec.DEPOSIT_CONTRACT_TREE_DEPTH, i, root) deposit_data_list.append(deposit_data) genesis_validator_deposits = [] for i in range(num_validators): genesis_validator_deposits.append(Deposit( proof=list(get_merkle_proof(tree, item_index=i)), index=i, data=deposit_data_list[i] )) return genesis_validator_deposits, root def create_genesis_state(num_validators, deposit_data_leaves=None): initial_deposits, deposit_root = create_mock_genesis_validator_deposits( num_validators, deposit_data_leaves, ) return get_genesis_beacon_state( initial_deposits, genesis_time=0, genesis_eth1_data=Eth1Data( deposit_root=deposit_root, deposit_count=len(initial_deposits), block_hash=spec.ZERO_HASH, ), ) def force_registry_change_at_next_epoch(state): # artificially trigger registry update at next epoch transition state.finalized_epoch = get_current_epoch(state) - 1 for crosslink in state.latest_crosslinks: crosslink.epoch = state.finalized_epoch state.validator_registry_update_epoch = state.finalized_epoch - 1 def build_empty_block_for_next_slot(state): empty_block = get_empty_block() empty_block.slot = state.slot + 1 previous_block_header = deepcopy(state.latest_block_header) if previous_block_header.state_root == spec.ZERO_HASH: previous_block_header.state_root = state.hash_tree_root() empty_block.previous_block_root = signed_root(previous_block_header) return empty_block def build_deposit_data(state, pubkey, privkey, amount): deposit_data = DepositData( pubkey=pubkey, # insecurely use pubkey as withdrawal key as well withdrawal_credentials=spec.BLS_WITHDRAWAL_PREFIX_BYTE + hash(pubkey)[1:], amount=amount, proof_of_possession=EMPTY_SIGNATURE, ) proof_of_possession = bls.sign( message_hash=signed_root(deposit_data), privkey=privkey, domain=get_domain( state.fork, get_current_epoch(state), spec.DOMAIN_DEPOSIT, ) ) deposit_data.proof_of_possession = proof_of_possession return deposit_data def build_attestation_data(state, slot, shard): assert state.slot >= slot block_root = build_empty_block_for_next_slot(state).previous_block_root epoch_start_slot = get_epoch_start_slot(get_current_epoch(state)) if epoch_start_slot == slot: epoch_boundary_root = block_root else: get_block_root(state, epoch_start_slot) if slot < epoch_start_slot: justified_block_root = state.previous_justified_root else: justified_block_root = state.current_justified_root return AttestationData( slot=slot, shard=shard, beacon_block_root=block_root, source_epoch=state.current_justified_epoch, source_root=justified_block_root, target_root=epoch_boundary_root, crosslink_data_root=spec.ZERO_HASH, previous_crosslink=deepcopy(state.latest_crosslinks[shard]), ) def build_voluntary_exit(state, epoch, validator_index, privkey): voluntary_exit = VoluntaryExit( epoch=epoch, validator_index=validator_index, signature=EMPTY_SIGNATURE, ) voluntary_exit.signature = bls.sign( message_hash=signed_root(voluntary_exit), privkey=privkey, domain=get_domain( fork=state.fork, epoch=epoch, domain_type=spec.DOMAIN_VOLUNTARY_EXIT, ) ) return voluntary_exit def build_deposit(state, deposit_data_leaves, pubkey, privkey, amount): deposit_data = build_deposit_data(state, pubkey, privkey, amount) item = hash(deposit_data.serialize()) index = len(deposit_data_leaves) deposit_data_leaves.append(item) tree = calc_merkle_tree_from_leaves(tuple(deposit_data_leaves)) root = get_merkle_root((tuple(deposit_data_leaves))) proof = list(get_merkle_proof(tree, item_index=index)) assert verify_merkle_branch(item, proof, spec.DEPOSIT_CONTRACT_TREE_DEPTH, index, root) deposit = Deposit( proof=list(proof), index=index, data=deposit_data, ) return deposit, root, deposit_data_leaves def get_valid_proposer_slashing(state): current_epoch = get_current_epoch(state) validator_index = get_active_validator_indices(state.validator_registry, current_epoch)[-1] privkey = pubkey_to_privkey[state.validator_registry[validator_index].pubkey] slot = state.slot header_1 = BeaconBlockHeader( slot=slot, previous_block_root=ZERO_HASH, state_root=ZERO_HASH, block_body_root=ZERO_HASH, signature=EMPTY_SIGNATURE, ) header_2 = deepcopy(header_1) header_2.previous_block_root = b'\x02' * 32 header_2.slot = slot + 1 domain = get_domain( fork=state.fork, epoch=get_current_epoch(state), domain_type=spec.DOMAIN_BEACON_BLOCK, ) header_1.signature = bls.sign( message_hash=signed_root(header_1), privkey=privkey, domain=domain, ) header_2.signature = bls.sign( message_hash=signed_root(header_2), privkey=privkey, domain=domain, ) return ProposerSlashing( proposer_index=validator_index, header_1=header_1, header_2=header_2, ) def get_valid_attestation(state, slot=None): if slot is None: slot = state.slot shard = state.latest_start_shard attestation_data = build_attestation_data(state, slot, shard) crosslink_committee = get_crosslink_committee_for_attestation(state, attestation_data) committee_size = len(crosslink_committee) bitfield_length = (committee_size + 7) // 8 aggregation_bitfield = b'\xC0' + b'\x00' * (bitfield_length - 1) custody_bitfield = b'\x00' * bitfield_length attestation = Attestation( aggregation_bitfield=aggregation_bitfield, data=attestation_data, custody_bitfield=custody_bitfield, aggregate_signature=EMPTY_SIGNATURE, ) participants = get_attestation_participants( state, attestation.data, attestation.aggregation_bitfield, ) assert len(participants) == 2 signatures = [] for validator_index in participants: privkey = privkeys[validator_index] signatures.append( get_attestation_signature( state, attestation.data, privkey ) ) attestation.aggregation_signature = bls.aggregate_signatures(signatures) return attestation def get_attestation_signature(state, attestation_data, privkey, custody_bit=0b0): message_hash = AttestationDataAndCustodyBit( data=attestation_data, custody_bit=custody_bit, ).hash_tree_root() return bls.sign( message_hash=message_hash, privkey=privkey, domain=get_domain( fork=state.fork, epoch=slot_to_epoch(attestation_data.slot), domain_type=spec.DOMAIN_ATTESTATION, ) )