hotp.py 文件源码

def __init__(self, key, length, algorithm, backend):
        if not isinstance(backend, HMACBackend):
            raise UnsupportedAlgorithm(
                "Backend object does not implement HMACBackend.",
                _Reasons.BACKEND_MISSING_INTERFACE
            )

        if len(key) < 16:
            raise ValueError("Key length has to be at least 128 bits.")

        if not isinstance(length, six.integer_types):
            raise TypeError("Length parameter must be an integer type.")

        if length < 6 or length > 8:
            raise ValueError("Length of HOTP has to be between 6 to 8.")

        if not isinstance(algorithm, (SHA1, SHA256, SHA512)):
            raise TypeError("Algorithm must be SHA1, SHA256 or SHA512.")

        self._key = key
        self._length = length
        self._algorithm = algorithm
        self._backend = backend