def test_get_attestation_participants(monkeypatch, num_validators,
epoch_length, committee,
participation_bitfield, expected,
sample_state):
from eth.beacon import helpers
def mock_get_shard_committees_at_slot(state, slot, epoch_length):
return (ShardCommittee(
shard=0,
committee=committee,
total_validator_count=num_validators,
), )
monkeypatch.setattr(helpers, 'get_shard_committees_at_slot',
mock_get_shard_committees_at_slot)
if isinstance(expected, Exception):
with pytest.raises(ValidationError):
get_attestation_participants(
state=sample_state,
slot=0,
shard=0,
participation_bitfield=participation_bitfield,
epoch_length=epoch_length,
)
else:
result = get_attestation_participants(
state=sample_state,
slot=0,
shard=0,
participation_bitfield=participation_bitfield,
epoch_length=epoch_length,
)
assert result == expected
def validate_serenity_attestation_aggregate_signature(
state: BeaconState, attestation: Attestation,
epoch_length: int) -> None:
"""
Validate ``aggregate_signature`` field of ``attestation``.
Raise ``ValidationError`` if it's invalid.
Note: This is the phase 0 version of `aggregate_signature`` validation.
All proof of custody bits are assumed to be 0 within the signed data.
This will change to reflect real proof of custody bits in the Phase 1.
"""
participant_indices = get_attestation_participants(
state=state,
slot=attestation.data.slot,
shard=attestation.data.shard,
participation_bitfield=attestation.participation_bitfield,
epoch_length=epoch_length,
)
pubkeys = tuple(state.validator_registry[validator_index].pubkey
for validator_index in participant_indices)
group_public_key = bls.aggregate_pubkeys(pubkeys)
# TODO: change to tree hashing when we have SSZ
# TODO: Replace with AttestationAndCustodyBit data structure
message = hash_eth2(rlp.encode(attestation.data) + (0).to_bytes(1, "big"))
is_valid_signature = bls.verify(
message=message,
pubkey=group_public_key,
signature=attestation.aggregate_signature,
domain=get_domain(
fork_data=state.fork_data,
slot=attestation.data.slot,
domain_type=SignatureDomain.DOMAIN_ATTESTATION,
),
)
if not is_valid_signature:
raise ValidationError(
"Attestation ``aggregate_signature`` is invalid.")