接收到SSRS 2008的HttpWebRequest中的“未经授权（401）”错误

Question

I'm using HttpWebRequest to programatically export an SSRS 2008 report in PDF format. My problem however, is my NetworkCredentials don't seem to be working. I'm receiving an Unauthorized (401) error when trying access SSRS.

I know the NetworkCredentials I supplied are correct. If I log into our SSRS web service manually, these are the exact credentials I use. Also, this works fine locally, just not up on our server.

The report is run on our asp.net 4.0 website. When the user clicks the "Generate Report" button, the following code is executed (the error occurs on my 2nd line, on WebRequest.Create) to try to connect to my SSRS 2008:

string sTargetURL = "MY_REPORT_SERVER?/REPORT_NAME&rs:format=pdf&rs:command=render&rc:parameters=Collapsed";

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(sTargetURL);
req.PreAuthenticate = true;

 req.Credentials = new NetworkCredential("Username", "Password", "Domain");

  HttpWebResponse HttpWResp = (HttpWebResponse)req.GetResponse();
  Stream fStream = HttpWResp.GetResponseStream();

 byte[] fileBytes = ReadFully(fStream);
 HttpWResp.Close();

 System.Web.HttpContext.Current.Response.Clear();
 System.Web.HttpContext.Current.Response.ContentType = "application/pdf";

 System.Web.HttpContext.Current.Response.AddHeader("content-disposition", "attachment; filename=\"" + reportName + ".pdf"\"");
 System.Web.HttpContext.Current.Response.BinaryWrite(fileBytes);
 System.Web.HttpContext.Current.Response.Flush();
 System.Web.HttpContext.Current.Response.End();

Answer 1

Outside the application, are you able to run the report locally and in the Report Manager/Server? If so, what type of data source does the report use? It could be that the data source does not accept the credentials double-hopping from the Report Server. You may need to create a domain account with the necessary read rights and configure the data source on the Report Server to impersonate these credentials.