Download file using Tor in C#

Question

I want to download a file using Tor. Most solutions I found require that additional software (e.g. privoxy) is installed and running, but I don't want to have an additional software running all the time even when I don't use my program.

So I tried the Tor.NET library, but I can't get it using Tor. This example shouldn't return my IP-address, but it does:

ClientCreateParams createParams = new ClientCreateParams(@"D:\tor.exe", 9051);
Client client = Client.Create(createParams);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.icanhazip.com/");
request.Proxy = client.Proxy.WebProxy;
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
    var reader = new StreamReader(response.GetResponseStream());
    Console.WriteLine(reader.ReadToEnd());
}

Console.WriteLine("Press enter to exit...");
Console.ReadLine();

There are already multiple comments about this but unfortunally the author of the library isn't active anymore.

Maybe you know what I'm doing wrong (is more configuration neccessary?) or have an idea for an alternative way to download a file using tor.

Answer 1

You follow the Tor project manual, command line HTTPTunnelPort, that you find here: first you must start an HTTP tunnel with

Tor.exe --HTTPTunnelPort 4711

It supplies you with a HTTP tunnel at 127.0.0.1:4711 (see also here). Now you can connect to this proxy:

WebProxy oWebProxy = new WebProxy (IPAddress.Loopback.ToString (), 4711);
WebClient oWebClient = new WebClient ();
oWebClient.Proxy = oWebProxy;
oWebClient.DownloadFile ("https://myUri", "myFilename");

By now, Microsoft recommends the use of the HttpClient for new developments. Here is the code:

// we must configure the HttpClient
HttpClientHandler oHttpClientHandler = new HttpClientHandler ();
oHttpClientHandler.UseProxy = true;
oHttpClientHandler.Proxy = 
  new WebProxy (IPAddress.Loopback.ToString (), 4711);
// we start an HttpClient with the handler; Microsoft recommends to start
// one HttpClient per application
HttpClient oHttpClient = new HttpClient (oHttpClientHandler);
// we request the resource by the GET method
HttpRequestMessage oHttpRequestMessage = 
  new HttpRequestMessage (HttpMethod.Get, "https://myUri");
// we make the request and we do only wait for the headers and not for
// content
Task<HttpResponseMessage> 
  oTaskSendAsync = 
    oHttpClient.SendAsync 
      (oHttpRequestMessage, HttpCompletionOption.ResponseHeadersRead);
// we wait for the arrival of the headers
oTaskSendAsync.Wait ();
// the function throws an exception if something went wrong
oTaskSendAsync.Result.EnsureSuccessStatusCode ();
// we can act on the returned headers
HttpResponseHeaders oResponseHeaders = oTaskSendAsync.Result.Headers;
HttpContentHeaders  oContentHeaders  = oTaskSendAsync.Result.Content.Headers;
// we fetch the content stream
Task<Stream> oTaskResponseStream = 
    oTaskSendAsync.Result.Content.ReadAsStreamAsync ();
// we open a file for the download data
FileStream oFileStream = File.OpenWrite ("myFilename");
// we delegate the copying of the content to the file
Task oTaskCopyTo = oTaskResponseStream.Result.CopyToAsync (oFileStream);
// and wait for its completion
oTaskCopyTo.Wait ();
// now we can close the file
oFileStream.Close ();

Please heed the following in using Tor.exe:

• If the port is already in use Tor.exe will not be able to supply a proxy. It does not even necessarily inform you about this failure.
• Make sure that nobody spoofs your program Tor.exe so that it is Tor that supplies you with this proxy. Hence, Tor.exe should be at a secure place in your file system.
• Inform yourself about other precautions with respect to using Tor.

At least, you might want to check that your proxy has a different IP address from your local internet connection.

Answer 2

In the end I used https://github.com/Ogglas/SocksWebProxy by @Ogglas to download a file using Tor.

The project has an example which is not working (the first time you start it waits infinitely for Tor to exit, but when you start the program again it can use the Tor process startet by your first try), so I changed it.

I made a Start() method to start Tor:

public async void Start(IProgress<int> progress)
{
    torProcess = new Process();
    torProcess.StartInfo.FileName = @"D:\...\tor.exe";
    torProcess.StartInfo.Arguments = @"-f ""D:\...\torrc""";
    torProcess.StartInfo.UseShellExecute = false;
    torProcess.StartInfo.RedirectStandardOutput = true;
    torProcess.StartInfo.CreateNoWindow = true;
    torProcess.Start();
    var reader = torProcess.StandardOutput;
    while (true)
    {
        var line = await reader.ReadLineAsync();
        if (line == null)
        {
            // EOF
            Environment.Exit(0);
        }
        // Get loading status
        foreach (Match m in Regex.Matches(line, @"Bootstrapped (\d+)%"))
        {
            progress.Report(Convert.ToInt32(m.Groups[1].Value));
        }

        if (line.Contains("100%: Done"))
        {
            // Tor loaded
            break;
        }
        if (line.Contains("Is Tor already running?"))
        {
            // Tor already running
            break;
        }
    }

    proxy = new SocksWebProxy(new ProxyConfig(
        //This is an internal http->socks proxy that runs in process
        IPAddress.Parse("127.0.0.1"),
        //This is the port your in process http->socks proxy will run on
        12345,
        //This could be an address to a local socks proxy (ex: Tor / Tor Browser, If Tor is running it will be on 127.0.0.1)
        IPAddress.Parse("127.0.0.1"),
        //This is the port that the socks proxy lives on (ex: Tor / Tor Browser, Tor is 9150)
        9150,
        //This Can be Socks4 or Socks5
        ProxyConfig.SocksVersion.Five
    ));
    progress.Report(100);
}

Afterwards you can use something like this to download something:

public static string DownloadString(string url)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
    request.Proxy = proxy;
    using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
    {
        return new StreamReader(response.GetResponseStream()).ReadToEnd();
    }
}

And when you exit the program you should also kill the Tor process.