if ((s = expand_string(US"$authenticated_id")) && *s)
req_str = string_append(req_str, 3, "User: ", s, "\r\n");
req_str = string_catn(req_str, US"\r\n", 2);
if ((s = expand_string(US"$authenticated_id")) && *s)
req_str = string_append(req_str, 3, "User: ", s, "\r\n");
req_str = string_catn(req_str, US"\r\n", 2);