Category: Unix

I’m working in a coffee shop today. I used SSH and SOCKS to browse the Internet securely, but today I decided to take it a step further and automate the process with a shell script. Here’s the script, for what it’s worth:

#!/bin/bash
disable_proxy()
{
        networksetup -setsocksfirewallproxystate Wi-Fi off
        networksetup -setsocksfirewallproxystate Ethernet off
        echo "SOCKS proxy disabled."
}
trap disable_proxy INT

networksetup -setsocksfirewallproxy Wi-Fi 127.0.0.1 9999
networksetup -setsocksfirewallproxy Ethernet 127.0.0.1 9999
networksetup -setsocksfirewallproxystate Wi-Fi on
networksetup -setsocksfirewallproxystate Ethernet on
echo "SOCKS proxy enabled."
echo "Tunneling..."
ssh -ND 9999 MYHOST.macminicolo.net

Instructions:

1. Save this to a file. I saved it to “/Users/richard/bin/ssh_tunnel”.
2. Make it executable and run it.

   $ chmod a+x /Users/richard/bin/ssh_tunnel
   $ /Users/richard/bin/ssh_tunnel
   

3. It creates an SSH tunnel to my dedicated server at macminicolo.net and routes Internet traffic through that server.
4. Hit Control-C to quit. The proxy is disabled. No need to fiddle with Network Preferences manually.

UPDATE March 18, 2011: I haven’t tried it, but Sidestep appears to be a free Mac OS X app that will enable SSH tunneling automatically when you connect to an insecure network.