The result of a blogging accident

Bypassing Proxy Filters using Tor

Note: This was written some time ago, and Torpark is now known as xB Browser. The xB Browser supports a commercial anonymity network run by XeroBank, as well as Tor. There is no torrc file in this version, therefore the instructions cannot apply to xB Browser.

xB Browser has it’s own graphical configuration utility which allows you to connect through a HTTP or HTTPS proxy, and also supports authenticated proxies.

The remainder of the text of this page is kept here for historical reasons.

I’m in a situation where I’m often behind a proxy server in an educational institution. I find that the administrators will often block random websites and content types (eg: executables, MP3, etc.), even when the desired content is part of my curriculum. Of course, I also really don’t like the administrator watching what I’m browsing. So this is a little mini-HOWTO on how I break past this proxy using Tor. Of course, these instructions are aimed at Win32 machines, seeing as where I’m trying to use the internet fear Linux - although they use it on the proxy server.

A couple of things to bear in mind is that many administrators are lazy. They’ll often leave default settings alone. This happens to work in my favour, as I’m behind a Squid proxy. The great thing about SQUID’s default configuration is that it’ll let you use HTTP CONNECT to port 443 (https), and also make normal HTTP requests to ports 80 and those higher than 1024 - at least last time I checked. So, many ShoutCast internet radio stations work fine for me, with no filtering applied or bypassing needed. You shouldn’t use Tor to listen to internet radio anyway, as it’ll be unreliable and needlessly clogs up the Tor network.

Many people would have heard about Portable Firefox and the Portable Apps project. They allow you to run a self-contained copy of some good open source applications from a USB mass storage device (like, a flash disk or a MP3 player). There’s another interesting app that I found in my searches called Torpark (think: Tor+Deer Park, aka Firefox 1.5). This is Portable Firefox, plus some useful privacy-related extensions, and Tor, all bundled in one nice neat package.

So, download Torpark and extract it. It’s generally a good idea to do this part at home, incase your administrator blocks access to the Torpark website.

Now, if you ran the application, chances are if you are behind a proxy, it won’t work. To get around this you’ll need to add it to the settings for Tor. Go into the folder English\Torpark\Tor and open the file torrc in a text editor (like Notepad). Then you’ll need to add the following lines to the end of the file:

ReachableDirAddresses *:80
ReachableORAddresses *:443

You’ll need to replace with the IP address of the HTTP proxy server, and 8080 with it’s correct port - though normally it is 8080, or on occasion, 3128. You can get this information from the Internet Options control panel. Under the Connections tab, press LAN Settings, then you should see the address for the proxy server. If you cannot access it via the Internet Options control panel, try accessing it from the Tools > Internet Options menu in Internet Explorer. Do not change the Reachable addresses at all!

Finally, run Torpark.exe. Wait a couple of minutes for it to try to connect to the Tor network. Once that is done, Firefox will load automatically. You can then surf wherever you please, securely. Of course, due to the fact that the connection is bounced off of several hosts before it reaches you, it will be a bit slower than normal. So be patient - remember slow internet is better than no internet!

If you find Torpark useful, consider running a Tor Server or Donating to the Tor project