public async Task Signature(String Base, String id, HttpResponseBase Response, Action <ExpandoObject> setParams) { try { var url = $"/_attachment{Base}/{id}"; var si = await _baseController.DownloadSignature(url, setParams); if (si == null) { throw new RequestModelException($"Signature not found. (Id:{id})"); } Response.ContentType = "application/octet-stream"; Response.BinaryWrite(si.Stream); } catch (Exception ex) { _baseController.WriteExceptionStatus(ex, Response); } }