Send files over HTTPWebRequest and receive on web-server from $_FILES

Question

My .NET application sends a single simple text file to web-server over HttpWebRequest. But at the web-server side I am always getting an empty $_FILES array.

I read all this questions and articles:

• POSTING MULTIPART/FORM-DATA USING .NET WEBREQUEST
• Upload files with HTTPWebrequest (multipart/form-data)
• How to recieve POST data sent using “application/octet-stream” in PHP?
• and PHP manual of course: Handling file uploads

Here is the test code:

public static void UploadFile()
{
    var boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");

    var httpRequest = (HttpWebRequest)WebRequest.Create(@"https://test.com/upload.php");
    httpRequest.Credentials = CredentialCache.DefaultNetworkCredentials;
    httpRequest.AllowAutoRedirect = true;
    httpRequest.MaximumAutomaticRedirections = 1;
    httpRequest.Method = "POST";
    httpRequest.ContentType = "multipart/form-data; boundary=" + boundary;
    httpRequest.KeepAlive = true;

    using (var requestStream = httpRequest.GetRequestStream())
    {
        var data = Encoding.UTF8.GetBytes("--" + boundary + "\r\n\r\n");
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("Content-Disposition: form-data; name=\"MAX_FILE_SIZE\"\r\n\r\n");
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("1048576"); // 1Mb
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("--" + boundary + "\r\n");
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("Content-Disposition: form-data; name=\"uploadedfile\"; filename=\"upload.txt\"\r\n");
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("Content-Type: application/octet-stream\r\n\r\n");
        requestStream.Write(data, 0, data.Length);

        data = File.ReadAllBytes(@"D:\upload.txt");
        requestStream.Write(data, 0, data.Length);

        data = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--");
        requestStream.Write(data, 0, data.Length);
    }

    using (var response = (HttpWebResponse)httpRequest.GetResponse())
    using (var sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
        Console.WriteLine(sr.ReadToEnd());
}

The /upload.php:

exit (var_dump($_FILES));

In console the output is always: array(0){}
Please, help.

Answer 1

Writing up an answer according to comments.

Fiddler lets you inspect the data sent over the wire when making requests and retrieving responses. It is a proxy and it's free (for now) :-)

When one encounter problems like this one, it is essential to make it work manually, then try to recreate the request programmatically and inspect the request to see that it is built the correct way.