FiddlerCore and HTTP 407: Proxy Authentication Required

[itaylor]

Hi, 

We are trying to install an application that includes FiddlerCode (in this case v2.3.01) and we are getting HTTP 407: Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied.  ) messages. I'm trying to get more details of the authentication protocols in use, but I'm having difficulty getting remote access to the site and I do not speak Italian, which makes it doubly difficult!

Before I spends ages trying, is this something that can be got around in FiddlerCore?

Many thanks

Ian

[itaylor]

NTLM, Kerberos and Negotiate, which seem fairly standard from some of your other posts.

[EricLaw]

I think you're saying that the server's Proxy-Authenticate headers contain NTLM, Kerberos, and Negotiate?

 

If so, yes, if the client itself can't handle proxy-authentication, you can use FiddlerCore to authenticate on the client's behalf. Basically, you just set the X-AuthAuth Session flag on the Session to either the string (default) or domain\username:password if the necessary credentials are different than the user's Windows logon credentials.

 

-Eric

[adam smith]

Hi.

Thanks for your service, Mr. Eric.

Fiddler is wonderful tool for Web debugging, so we are trying to implement MITM function using your FiddlerCore in our project.

I think FiddlerCore certainly will be of help to us.

But, I have encountered the same problem.

In my office web proxy is configured with basic authorization scheme, my application using FiddlerCore (v2.4.0.1) is receving the response [HTTP/1.0 407 Proxy Authentication Required].

The following is prototype of BeforeRequest() in our code.

            Fiddler.FiddlerApplication.BeforeRequest += delegate(Fiddler.Session oS)

            {

                        oS.oRequest["Proxy-Authorization"] = "Basic YWRhbToxMjM0NTY=";

                        // oS.oFlags["X-AutoAuth"] = "YWRhbToxMjM0NTY="; 

           if (oSession.HTTPMethodIs("CONNECT")) { oSession.oFlags["X-ReplyWithTunnel"] = "Fake for HTTPS Tunnel"; return; }

           // my custom code...

            }

I attached the saz file captured by Fiddler program. "X-AutoAuth" flag also have no effect.

How can I fix this problem ? 

Thanks.

[adam smith]

Eric,

Thanks again for your kindness.

Let me show what is the console output on the event handlers that I attached to the OnNotification and OnLogString events.

            Fiddler.FiddlerApplication.OnNotification += delegate(object sender, NotificationEventArgs oNEA) { Console.WriteLine("** NotifyUser: " + oNEA.NotifyString); };
            Fiddler.FiddlerApplication.Log.OnLogString += delegate(object sender, LogEventArgs oLEA) { Console.WriteLine("** LogString: " + oLEA.LogString); };

console output:
** LogString: fiddler.network.connect2> Unexpected response from upstream gateway HTTP/1.0 407 Proxy Authentication Required