def test_capsule_is_hashable(alices_keys):
delegating_sk, _signing_sk = alices_keys
delegating_pk = delegating_sk.public_key()
capsule1, key1 = Capsule.from_public_key(delegating_pk)
capsule2, key2 = Capsule.from_public_key(delegating_pk)
assert capsule1 != capsule2
assert key1 != key2
assert hash(capsule1) != hash(capsule2)
new_capsule = Capsule.from_bytes(bytes(capsule1))
assert hash(new_capsule) == hash(capsule1)
def test_capsule_serialization(alices_keys):
delegating_sk, _signing_sk = alices_keys
delegating_pk = delegating_sk.public_key()
capsule, _key = Capsule.from_public_key(delegating_pk)
new_capsule = Capsule.from_bytes(bytes(capsule))
assert capsule == new_capsule
# Deserializing a bad capsule triggers verification error
capsule.point_e = CurvePoint.random()
capsule_bytes = bytes(capsule)
with pytest.raises(ValueError):
Capsule.from_bytes(capsule_bytes)
def test_open_original(alices_keys):
delegating_sk, _signing_sk = alices_keys
delegating_pk = delegating_sk.public_key()
capsule, key = Capsule.from_public_key(delegating_pk)
key_back = capsule.open_original(delegating_sk)
assert key == key_back
def test_open_reencrypted(alices_keys, bobs_keys):
threshold = 6
shares = 10
delegating_sk, signing_sk = alices_keys
receiving_sk, receiving_pk = bobs_keys
signer = Signer(signing_sk)
delegating_pk = delegating_sk.public_key()
capsule, key = Capsule.from_public_key(delegating_pk)
kfrags = generate_kfrags(delegating_sk=delegating_sk,
signer=signer,
receiving_pk=receiving_pk,
threshold=threshold,
shares=shares)
cfrags = [reencrypt(capsule, kfrag).cfrag for kfrag in kfrags]
key_back = capsule.open_reencrypted(receiving_sk, delegating_pk,
cfrags[:threshold])
assert key_back == key
# No cfrags at all
with pytest.raises(ValueError, match="Empty CapsuleFrag sequence"):
capsule.open_reencrypted(receiving_sk, delegating_pk, [])
# Not enough cfrags
with pytest.raises(ValueError, match="Internal validation failed"):
capsule.open_reencrypted(receiving_sk, delegating_pk,
cfrags[:threshold - 1])
# Repeating cfrags
with pytest.raises(ValueError,
match="Some of the CapsuleFrags are repeated"):
capsule.open_reencrypted(receiving_sk, delegating_pk,
[cfrags[0]] + cfrags[:threshold - 1])
# Mismatched cfrags
kfrags2 = generate_kfrags(delegating_sk=delegating_sk,
signer=signer,
receiving_pk=receiving_pk,
threshold=threshold,
shares=shares)
cfrags2 = [reencrypt(capsule, kfrag).cfrag for kfrag in kfrags2]
with pytest.raises(ValueError,
match="CapsuleFrags are not pairwise consistent"):
capsule.open_reencrypted(receiving_sk, delegating_pk,
[cfrags2[0]] + cfrags[:threshold - 1])
def test_cfrag_with_wrong_capsule(verification_keys, kfrags, capsule_and_ciphertext, message):
capsule, ciphertext = capsule_and_ciphertext
verifying_pk, delegating_pk, receiving_pk = verification_keys
capsule_alice1 = capsule
capsule_alice2, _unused_key2 = Capsule.from_public_key(delegating_pk)
cfrag = reencrypt(capsule_alice2, kfrags[0])
cfrag = CapsuleFrag.from_bytes(bytes(cfrag)) # de-verify
with pytest.raises(VerificationError):
cfrag.verify(capsule_alice1,
verifying_pk=verifying_pk,
delegating_pk=delegating_pk,
receiving_pk=receiving_pk,
)