Category: Wifi Security

Refer: http://www.mattlestock.com/
Software goodie: plink.exe

For episode 416 of HAK5, I showed how easy it really is to tunnel all kinds of traffic from HTTP, FTP, and more over a secure SSH Socks proxy.

What you’ll need is:

• An SSH server to act as your proxy.
  Simple enough really! If you’re using windows I highly recommend freeSSHd. If you’re on a mac check out this page for instructions on how to enable remote logon. Linux users, you should know how to do this.
• An SSH client on the computer you’re using.
  Mac and *nix machines have SSH built right in at the command line. Windows users can do like I did in the episode and download plink (available here). There are other people out there that will recommend Cygwin, but for this purpose, it’s really overkill.

How proxies work

In a nutshell, what you’re doing with a proxy is setting up a middle-person (no not a pineapple, but close) between you and the internet. Using the proxy, your browser hands off web page requests to the proxy server, which handles the request and fetches the page for you from the internet. The web site actually thinks the request is coming from the proxy server, not your computer, which is a good way to obscure your originating IP address.

Additionally, the connection between your computer and the proxy happens over SSH, an encrypted protocol. This prevents wifi sniffers from seeing what you’re doing online.

Start your SSH tunnel

So you’ve got your ssh server setup at your house or workplace. Great! To connect to it we’re going to setup a local proxy server on your client that you’ll be browsing the internet from, which will then “tunnel” web traffic from your local machine to the remote server over SSH. The command to run on your linux / mac client in a terminal window is : ssh -ND 9999 you@example.com

For Windows it’s as simple as browsing to the directory you saved plink to and running
plink.exe -N -D 9999 you@example.com

Of course, you’re going to replace the you with your username on your SSH server and example.com with your server domain name or IP address. What that command does is accept requests from your local machine on port 9999 and hands that request off to your server at example.com for processing.

When you execute either of those commands, you’ll be prompted for your password. After you authenticate, nothing will happen. The -N tells ssh not to open an interactive prompt, so it will just hang there, waiting. That’s exactly what you want.

Set Firefox to use SOCKS proxy

Once your proxy’s up and running, configure Firefox to use it. From Firefox’s Tools menu, choose Options, and from the Advanced section choose the Network tab. Next to “Configure how Firefox connects to the Internet” hit the “Settings” button and enter the SOCKS information, which is the server name (localhost) and the port you used (in the example above, 9999.)

Save those settings and hit up a web page. When it loads, visit http://www.ipchicken.com to see if it’s using your remote ssh server to tunnel traffic. If you are, GOLDEN!

If you feel there’s something I’ve missed, hit me up here (http://www.mattlestock.com)

PS: Remember that you’ll need to open your firewall a bit by cracking open port 9999 on your local machine and port 22 on your server for SSH.