Why is WebRequest timeout not honored for SSL over a proxy?

Question

If I run the following code, which tries to GET a HTTPS URL on an endpoint that is not answering (notice the port); then it throws a timeout WebException when a second has passed, as I would expect:

var request = WebRequest.CreateHttp("https://stackoverflow.com:81");
request.Timeout = 1000; // ms
Stopwatch watch = Stopwatch.StartNew();
try 
{
    using(var response = request.GetResponse()) 
    {
        new StreamReader(response.GetResponseStream()).ReadToEnd();
    }
}
catch(Exception ex)
{
    Console.WriteLine(ex);
}
watch.Stop();
Console.WriteLine(watch.Elapsed);

Now, if I connect via a proxy (for instance, by opening Fiddler), the timeout is not honored, and the exception only occurs after 21 seconds has passed (!). I suspect the timeout is proxy-specific (the actual duration is larger when I try to connect via another proxy we have internally).

This does not happen if the server is listening on the port and returns an error.
This does not happen for HTTP, only HTTPS
I tried it on .NET 4.5 and 4.5.1 with same results.

Why does this happen ? Is is a bug in HttpWebRequest ?

Is there any way to work around this (which preferably does not involve setting up my own timer thread for enforcing a timeout) ?

Why is WebRequest timeout not honored for SSL over a proxy?

0 Answers0