multibackend.py 文件源码

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