def _verifying_key_from_pubkey(cls, pubkey):
""" Converts a 33-byte compressed pubkey into an coincurve.PublicKey object. """
if not isinstance(pubkey, (bytes, bytearray)):
raise TypeError('pubkey must be raw bytes')
if len(pubkey) != 33:
raise ValueError('pubkey must be 33 bytes')
if pubkey[0] not in (2, 3):
raise ValueError('invalid pubkey prefix byte')
return cPublicKey(pubkey)
def is_signature_valid(signature, digest, public_key_bytes):
signature = cdata_to_der(deserialize_compact(signature))
public_key = cPublicKey(public_key_bytes)
is_valid = public_key.verify(signature, digest, None)
if not is_valid: # try old way
# ytsync signed claims don't seem to validate with coincurve
try:
pk = ec.EllipticCurvePublicKey.from_encoded_point(
ec.SECP256K1(), public_key_bytes)
pk.verify(signature, digest,
ec.ECDSA(Prehashed(hashes.SHA256())))
return True
except (ValueError, InvalidSignature):
pass
return is_valid
def public_key_bytes(self) -> bytes:
if len(self.message.public_key) == 33:
return self.message.public_key
public_key_info = PublicKeyInfo.load(self.message.public_key)
public_key = cPublicKey(public_key_info.native['public_key'])
return public_key.format(compressed=True)