HttpWebRequest收到“WebException：请求超时”

Question

After endless research and testing of different combinations, I'm clueless right now.

I receive an WebException: The request timed out only if I my byteArray gets filled by something else than System.Text.Encoding.UTF8.GetBytes(""). (Like "hello")

The server setup is a https-request to a Google Load Balancer, which communicates with the backend via HTTP. The backend is an Apache with PHP.

For testing purposes (self-signed SSL-Cert) I have this:

System.Net.ServicePointManager.ServerCertificateValidationCallback = 
        delegate (object s,  
            System.Security.Cryptography.X509Certificates.X509Certificate certificate,  
            System.Security.Cryptography.X509Certificates.X509Chain chain, 
            System.Net.Security.SslPolicyErrors sslPolicyErrors){ 
        return true; 
    };

• If I enter the URL in my web-browser (Chrome), I get a response.
• If I use the HTTP-requester from Mozilla with or without content to send, I get the correct response data (after adding an SSL-Security exception)
• If I run my code below with System.Text.Encoding.UTF8.GetBytes("") everything works (except I cannot send data and therefore receive what I want)

Here's the code I'm using.

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("https://someurl.com/some.php");
webRequest.Proxy = null;
webRequest.Credentials = CredentialCache.DefaultCredentials;
webRequest.Method = "POST";
webRequest.Timeout = 3000;

byte[] byteArray = System.Text.Encoding.UTF8.GetBytes("someData");  //works if empty
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.ContentLength = byteArray.Length;

Stream postData = webRequest.GetRequestStream();
postData.Write(byteArray, 0, byteArray.Length);
postData.Close();

HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse(); //ERROR MESSAGE
Stream dataStream = webResponse.GetResponseStream();
reader = new StreamReader(dataStream);
string data = reader.ReadToEnd(); //output data

reader.Close ();
dataStream.Close ();
webResponse.Close ();

The exact error (btw, all this happens in the Unity3D editor):

WebException: The request timed out System.Net.HttpWebRequest.EndGetResponse (IAsyncResult asyncResult) System.Net.HttpWebRequest.GetResponse ()

So why on earth is it not working, once there is something the GetRequestStream has to write?

Thanks and all the best, Kruegbert

---

..::Addendum

• if I increase the timeout, it just takes longer until the same msg appears.
• If I write webRequest.ContentLength = byteArray.Length+1 I receive a response, but it's a WebException error: ProtocolError
• If I write webRequest.ContentLength = byteArray.Length-1 I get the ProtocolViolationException
• I already tried the same with try/catch/using resulting in the same behaviour

Answer 1

I figured out, why it was not working - still I don't know why it behaves like this. (Maybe a UnityEditor thing)

I added

webRequest.ProtocolVersion = HttpVersion.Version10;

and everything worked. No more timeout errors. And yes webRequest.ProtocolVersion = HttpVersion.Version11; results in the timeout error.

However, making a HttpRequest from the web succeeds with either of these: HTTP/1.1, HTTP/1.0 (with Host header), HTTP/1.0 (without Host header)