Question

I’m using this code, to make a request to a given URL:

private static string GetWebRequestContent(string url) {   string sid = String.Empty;    HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);   req.KeepAlive = false;    using (HttpWebResponse res = (HttpWebResponse)req.GetResponse())   {     using (StreamReader sr = new StreamReader(res.GetResponseStream()))     {       sid = sr.ReadToEnd().Trim();     }   }    return sid; } 

I’m using it to test the stickyness of a Work Load Balancer, with 3 servers behind it. They all have a static HTM file called sid.htm, where the server’s Server ID is written.

For URL’s with HTTP this works fine. But with HTTPS it doesn’t work. I get this exception:

The request was aborted: Could not create SSL/TLS secure channel.

At the moment, I have only 2 servers behind the WLB and one on its own with a public IP behind a firewall. HTTPS requests works fine if I hit the stand-alone server – but when I hit the WLB I get the above error.

One thing: In order to switch between hitting the single server, and the WLB I use my hosts file. The DNS records for my domain points to the single server at the moment. So I put a record in my hosts file to hit the WLB. This shouldn’t be causing problems…

My question: Which SSL credentials/certificates does the HttpWebRequest use? If it uses 40 bit DES or 56 bit DES, that’s the reason, because those are disabled in the WLB. But those certificates haven’t been used in browsers since IE3 and Netscape 1 and 2.

Answer 1

It works perfectly in my browser.

I found the solution 1 minute after i posted the question:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3; 

And that means the HttpWebRequest was using TLS 1.0 – I don’t know, but I assume that is 40 bit DES or 56 bit DES, which is disabled in the WLB.