def test_validate_bitfield_padding_zero(committee_size):
bitfield = get_empty_bitfield(committee_size)
for index in range(committee_size):
bitfield = set_voted(bitfield, index)
if committee_size % 8 != 0:
bitfield = set_voted(bitfield, committee_size)
with pytest.raises(ValidationError):
validate_bitfield(bitfield, committee_size)
else:
validate_bitfield(bitfield, committee_size)
def test_validate_bitfield_bitfield_length(committee_size, is_valid):
if is_valid:
testing_committee_size = committee_size
else:
testing_committee_size = committee_size + 1
bitfield = get_empty_bitfield(testing_committee_size)
if not is_valid and len(bitfield) != get_bitfield_length(committee_size):
with pytest.raises(ValidationError):
validate_bitfield(bitfield, committee_size)
else:
validate_bitfield(bitfield, committee_size)
def get_members_from_bitfield(committee: Sequence[ValidatorIndex],
bitfield: Bitfield) -> Iterable[ValidatorIndex]:
"""
Return all indices in ``committee`` if they "voted" according to the
``bitfield``.
Raise ``ValidationError`` if the ``bitfield`` does not conform to some
basic checks around length and zero-padding based on the ``committee``
length.
"""
validate_bitfield(bitfield, len(committee))
# Extract committee members if the corresponding bit is set in the bitfield
for bitfield_index, validator_index in enumerate(committee):
if has_voted(bitfield, bitfield_index):
yield validator_index
def get_attesting_indices(state: BeaconState,
attestation_data: AttestationData,
bitfield: Bitfield,
config: CommitteeConfig) -> Iterable[ValidatorIndex]:
"""
Return the sorted attesting indices corresponding to ``attestation_data`` and ``bitfield``.
"""
committee = get_crosslink_committee(
state,
attestation_data.target_epoch,
attestation_data.crosslink.shard,
config,
)
validate_bitfield(bitfield, len(committee))
return sorted(index for i, index in enumerate(committee)
if has_voted(bitfield, i))
def validate_slashable_attestation(state: 'BeaconState',
slashable_attestation: 'SlashableAttestation',
max_indices_per_slashable_vote: int,
epoch_length: int) -> None:
"""
Verify validity of ``slashable_attestation`` fields.
Ensure that the ``slashable_attestation`` is properly assembled and contains the signature
we expect from the validators we expect. Otherwise, return False as
the ``slashable_attestation`` is invalid.
"""
# [TO BE REMOVED IN PHASE 1]
if not slashable_attestation.is_custody_bitfield_empty:
raise ValidationError(
"`slashable_attestation.custody_bitfield` is not empty."
)
if len(slashable_attestation.validator_indices) == 0:
raise ValidationError(
"`slashable_attestation.validator_indices` is empty."
)
if not slashable_attestation.is_validator_indices_ascending:
raise ValidationError(
"`slashable_attestation.validator_indices` "
f"({slashable_attestation.validator_indices}) "
"is not ordered in ascending."
)
validate_bitfield(
slashable_attestation.custody_bitfield,
len(slashable_attestation.validator_indices),
)
if len(slashable_attestation.validator_indices) > max_indices_per_slashable_vote:
raise ValidationError(
f"`len(slashable_attestation.validator_indices)` "
f"({len(slashable_attestation.validator_indices)}) greater than"
f"MAX_INDICES_PER_SLASHABLE_VOTE ({max_indices_per_slashable_vote})"
)
if not verify_slashable_attestation_signature(state, slashable_attestation, epoch_length):
raise ValidationError(
f"slashable_attestation.signature error"
)
def get_attestation_participants(state: 'BeaconState',
attestation_data: 'AttestationData',
bitfield: Bitfield,
genesis_epoch: EpochNumber, epoch_length: int,
target_committee_size: int,
shard_count: int) -> Iterable[ValidatorIndex]:
"""
Return the participant indices at for the ``attestation_data`` and ``bitfield``.
"""
# Find the committee in the list with the desired shard
crosslink_committees = get_crosslink_committees_at_slot(
state=state,
slot=attestation_data.slot,
genesis_epoch=genesis_epoch,
epoch_length=epoch_length,
target_committee_size=target_committee_size,
shard_count=shard_count,
)
if attestation_data.shard not in set(
[shard for _, shard in crosslink_committees]):
raise ValidationError(
"attestation_data.shard ({}) is not in crosslink_committees".
format(attestation_data.shard, ))
try:
# Filter by shard
committee = tuple(
_get_committee_for_shard(crosslink_committees,
attestation_data.shard))
except IndexError:
raise ValidationError(
"committee for shard={} should not be empty.".format(
attestation_data.shard, ))
validate_bitfield(bitfield, len(committee))
# Find the participating attesters in the committee
for bitfield_index, validator_index in enumerate(committee):
if has_voted(bitfield, bitfield_index):
yield validator_index