Test: TOR and the Mule --- HELP

[Nick Mathewson]

On Thu, Aug 26, 2004 at 05:43:08PM +0200, D.manea.forums wrote:
> I'm trying to use eMule with TOR.
> 
> So i tried setting port 9050 of localhost, pointing at TOR, as socks4a from
>  eMule, results:
> ---
> Aug 26 17:31:22.609 [warn] Your application (using socks4 on port 4662) is
> givin
> g Tor only an IP address. Applications that do DNS resolves themselves may
> leak
> ---

Right.  It looks as though your application is using socks4, not
socks4a as it claims.

> I tried setting port 8118 of localhost,pointing at privoxy, as
> socks4a,socks4,
> socks5 and http from eMule, results:
> 
> NOTHING HAPPEN

This is as expected; privoxy only handles HTTP requests, not SOCKS
requests.

Here's a little diagram.  (You might need to use a fixed-width font to
view this properly.

When you use Privoxy and socks4a, your requests look like this:

---------------
I Web browser I
---------------
     I  "GET http://servername/resource"
     V
-----------
I Privoxy I
-----------
     I "Connect to servername"   (socks4a)
     V
  -------
  I Tor I
  -------

And when you use an application that uses socks4a correctly, it works
like this:

---------------
I Application I
---------------
     I "Connect to servername"   (socks4a)
     V
  -------
  I Tor I
  -------

But what emule seems to be doing is:

---------------
I Application I-----------------
---------------                I
 I  "Lookup servername"        I "Connect to IP address" (socks4)
 I                             I
 V                             V
-----------------------     -------
I External DNS server I     I Tor I
-----------------------     -------

So privoxy can't help you, if you aren't using HTTP.  If you want to
avoid leaking your destinations to your DNS server, you need to do one
of the following:
   - Make your application use socks4a correctly.

   - Resolve the server name to an IP though some safe means.  I don't
     know whether the tor-resolve script works cleanly on windows; if
     it does, you can try to manually resolve server names to IPs and
     see if you can point your application to them directly.  (You
     might need Python to make it run; the next version of Tor will
     include a standalone version that doesn't need python.)

It's possible that some future socks interface application might be
able to replace your application's calls to the windows DNS stack with
request to Tor instead, but this feature isn't implemented in any that
I'm aware of right now.


Hope this helps,
-- 
Nick Mathewson
(PGP key changed on 15Aug2004; see http://wangafu.net/key.txt)
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