def test_der_serialization_backend(self): backend = MultiBackend([DummyDERSerializationBackend()]) backend.load_der_private_key(b"keydata", None) backend.load_der_public_key(b"keydata") backend = MultiBackend([]) with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_SERIALIZATION): backend.load_der_private_key(b"keydata", None) with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_SERIALIZATION): backend.load_der_public_key(b"keydata")