serialization.py 文件源码

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _read_next_string(decoded_data)
    data, rest = _read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    numbers = ec.EllipticCurvePublicNumbers.from_encoded_point(curve, data)
    return numbers.public_key(backend)