NTLM authentication - How to ?

[bartt]

I am develping a C# app that has to pull over some XML from an https site.
My code seems to work fine with standard html (at least getting it) from http sites
(like google.com). But when I change the site to an https site our local proxy server emits 407 errors (indicating that it cannot authenticate the connection). I am using and HttpWebRequest object to perform all the steps.
I have tried Basic, NTLM and Negotiate in the CredentialCache Add method, they all fall over on the https connection.

At this point I am wondering several things:

1) Does the HttpWebRequest.proxy really perform the needed NTLM negotiation?
2) If so, why is it picky about https vs http?
3) Do I need to write my own code to perform the negotiation with the proxy?
4) If so, do I do it in response to the exceptions I am getting at this point, or is there a way to circumvent the exceptions?

Here is a code snippet:
all the required params are passed into the constructor of this object method.

        public string SendRequest()
        // run the request and return a string response
        {
            string FinalResponse = "";
            string Cookie = "";
 
            NameValueCollection collHeader = new NameValueCollection();
 
            HttpWebResponse webresponse;
 
             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URI);
 
             request.KeepAlive = true;
            request.Timeout = 10000;
            request.Method = "POST";
            request.AllowAutoRedirect = false;
            request.Proxy = WebProxy.GetDefaultProxy();
 
            string addr = "http://" + ProxyServer + ":" + String.Format("{0:D}", ProxyPort);
            Uri u = new Uri(addr);
 
            CredentialCache wrCache = new CredentialCache();
            wrCache.Add(u, "Negotiate", System.Net.CredentialCache.DefaultNetworkCredentials);
 
            request.Proxy.Credentials = wrCache;
 
            try
            {
                byte[] bytes = Encoding.ASCII.GetBytes(Request);
                request.ContentLength = bytes.Length;
 
                Stream oStreamOut = request.GetRequestStream();
                oStreamOut.Write(bytes, 0, bytes.Length);
                oStreamOut.Close();
 
                webresponse = (HttpWebResponse)request.GetResponse();
                if (null == webresponse)
                {
                    FinalResponse = "No Response from " + URI;
                }
                else
                {
                    Encoding enc = System.Text.Encoding.GetEncoding(1252);
                    StreamReader rdr = new StreamReader(webresponse.GetResponseStream(),enc);
                    FinalResponse = rdr.ReadToEnd();
                }
 
            }//End of Try Block
 
            catch (WebException e)
            {
                // some kind of error..
                if (407 == (int)e.Status)
                {
                }
 
                throw CatchHttpExceptions(FinalResponse = e.Message);
            }
            catch (System.Exception e)
            {
                throw new Exception(FinalResponse = e.Message);
            }
            finally
            {
                // BaseHttp = null;
            }
            return FinalResponse;
        } //End of SendRequestTo method
 

[iripka]

Hi,

I have completely the same issue.
Additonally I tried to test this scenario using the demonstration tool from Microsoft (http://support.microsoft.com/kb/303436) . The result is the same - success in case of HTTP and 407 error in case of HTTPS.

Thanks,

[iripka]

One update.

I have found this http://support.microsoft.com/kb/928563.

The files on my machine are of version *832. As I understand they are newer than version *428 mentioned in the hotfix.

Nevertheless the issue appears.