Error 502 (Bad Gateway) when sending a request with HttpWebRequest over SSL

Question

I have the following snippet in classic ASP, to send a command and retrieve the response over SSL:

Dim xmlHTTP
Set xmlHTTP = Server.CreateObject(\"Msxml2.Ser         


        

Answer 1

With the help of this I got a more detailed description of the problem: The proxy was returning the message: "The user agent is not recognized." So I set it manually. Also, I changed the code to use GlobalProxySelection.GetEmptyWebProxy(), as described here. The final working code is included below.

private static string SendRequest(string url, string postdata)
{
    if (String.IsNullOrEmpty(postdata))
        return null;
    HttpWebRequest rqst = (HttpWebRequest)HttpWebRequest.Create(url);
    // No proxy details are required in the code.
    rqst.Proxy = GlobalProxySelection.GetEmptyWebProxy();
    rqst.Method = "POST";
    rqst.ContentType = "application/x-www-form-urlencoded";
    // In order to solve the problem with the proxy not recognising the user
    // agent, a default value is provided here.
    rqst.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)";
    byte[] byteData = Encoding.UTF8.GetBytes(postdata);
    rqst.ContentLength = byteData.Length;

    using (Stream postStream = rqst.GetRequestStream())
    {
        postStream.Write(byteData, 0, byteData.Length);
        postStream.Close();
    }
    StreamReader rsps = new StreamReader(rqst.GetResponse().GetResponseStream());
    string strRsps = rsps.ReadToEnd();
    return strRsps;
}