extensions.py 文件源码

def _key_identifier_from_public_key(public_key):
    if isinstance(public_key, RSAPublicKey):
        data = public_key.public_bytes(
            serialization.Encoding.DER,
            serialization.PublicFormat.PKCS1,
        )
    elif isinstance(public_key, EllipticCurvePublicKey):
        data = public_key.public_numbers().encode_point()
    else:
        # This is a very slow way to do this.
        serialized = public_key.public_bytes(
            serialization.Encoding.DER,
            serialization.PublicFormat.SubjectPublicKeyInfo
        )
        spki, remaining = decoder.decode(
            serialized, asn1Spec=_SubjectPublicKeyInfo()
        )
        assert not remaining
        # the univ.BitString object is a tuple of bits. We need bytes and
        # pyasn1 really doesn't want to give them to us. To get it we'll
        # build an integer and convert that to bytes.
        bits = 0
        for bit in spki.getComponentByName("subjectPublicKey"):
            bits = bits << 1 | bit

        data = utils.int_to_bytes(bits)

    return hashlib.sha1(data).digest()