multibackend.py 文件源码

def derive_pbkdf2_hmac(self, algorithm, length, salt, iterations,
                           key_material):
        for b in self._filtered_backends(PBKDF2HMACBackend):
            try:
                return b.derive_pbkdf2_hmac(
                    algorithm, length, salt, iterations, key_material
                )
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "{0} is not a supported hash on this backend.".format(
                algorithm.name),
            _Reasons.UNSUPPORTED_HASH
        )