def create_mock_signed_attestation(state, shard_committee,
voting_committee_indices,
attestation_data):
message = hash_eth2(
rlp.encode(attestation_data) + (0).to_bytes(1, "big"))
# participants sign message
signatures = [
bls.sign(message,
privkeys[shard_committee.committee[committee_index]],
domain=get_domain(
fork_data=state.fork_data,
slot=attestation_data.slot,
domain_type=SignatureDomain.DOMAIN_ATTESTATION,
)) for committee_index in voting_committee_indices
]
# aggregate signatures and construct participant bitfield
participation_bitfield, aggregate_signature = aggregate_votes(
bitfield=get_empty_bitfield(len(shard_committee.committee)),
sigs=(),
voting_sigs=signatures,
voting_committee_indices=voting_committee_indices,
)
# create attestation from attestation_data, particpipant_bitfield, and signature
return Attestation(
data=attestation_data,
participation_bitfield=participation_bitfield,
custody_bitfield=b'',
aggregate_signature=aggregate_signature,
)
def test_aggregate_votes(votes_count, random, privkeys, pubkeys):
bit_count = 10
pre_bitfield = get_empty_bitfield(bit_count)
pre_sigs = ()
random_votes = random.sample(range(bit_count), votes_count)
message = b'hello'
# Get votes: (committee_index, sig, public_key)
votes = [(committee_index, bls.sign(message, privkeys[committee_index]),
pubkeys[committee_index]) for committee_index in random_votes]
# Verify
sigs, committee_indices = verify_votes(message, votes)
# Aggregate the votes
bitfield, sigs = aggregate_votes(
bitfield=pre_bitfield,
sigs=pre_sigs,
voting_sigs=sigs,
voting_committee_indices=committee_indices)
try:
_, _, pubs = zip(*votes)
except ValueError:
pubs = ()
voted_index = [
committee_index for committee_index in random_votes
if has_voted(bitfield, committee_index)
]
assert len(voted_index) == len(votes)
aggregated_pubs = bls.aggregate_pubs(pubs)
assert bls.verify(message, aggregated_pubs, sigs)