Creates SAML metadata strings for the configured front- and backends.
    :param satosa_config: configuration of the proxy
    :return: a tuple of the frontend metadata (containing IdP entities) and the backend metadata (containing SP
             entities).

    :type satosa_config: satosa.satosa_config.SATOSAConfig
    :rtype: Tuple[str, str]

def create_entity_descriptors(satosa_config):
    """
    Creates SAML metadata strings for the configured front- and backends.
    :param satosa_config: configuration of the proxy
    :return: a tuple of the frontend metadata (containing IdP entities) and the backend metadata (containing SP
             entities).

    :type satosa_config: satosa.satosa_config.SATOSAConfig
    :rtype: Tuple[str, str]
    """
    frontend_modules = load_frontends(satosa_config, None, satosa_config["INTERNAL_ATTRIBUTES"])
    backend_modules = load_backends(satosa_config, None, satosa_config["INTERNAL_ATTRIBUTES"])
    logger.info("Loaded frontend plugins: {}".format([frontend.name for frontend in frontend_modules]))
    logger.info("Loaded backend plugins: {}".format([backend.name for backend in backend_modules]))

    backend_metadata = _create_backend_metadata(backend_modules)
    frontend_metadata = _create_frontend_metadata(frontend_modules, backend_modules)

    return frontend_metadata, backend_metadata