SOCKS Proxy Example

As an example of the options the native API opens up, this demonstrates the ability to modify the system proxy settings based on runtime information to enable the use of an OpenSSH Dynamic Proxy when the user is not on the campus network:

Prerequisites

1. Configure public key authentication for your account so it can be used without interaction (i.e. 10.5's SSH agent for authentication, username set in ~/.ssh/config, etc.). As long as something like ssh myserver.example.org date works you should be fine.
2. Register a LaunchAgent so launchd will keep your SSH connection open as long as you're logged in:
1. Copy org.openssh.dynamic-proxy.plist to ~/Library/LaunchAgents (note that you must already have public key authentication configured)
2. Change server.example.org to your server
3. Register the LaunchAgent with launchd for interactive (aqua) sessions: launchctl -w -S aqua load ~/Library/LaunchAgents/org.openssh.dynamic-proxy.plist

Manual Install

1. Copy or symlink crankd.py in /usr/local/sbin
2. Copy or symlink the http://pymacadmin.googlecode.com/svn/trunk/lib/PyMacAdmin/PyMacAdmin to /Library/Application Support/crankd/PyMacAdmin
3. Copy or symlink the ProxyManager.py to /Library/Application Support/crankd/
4. Copy com.googlecode.pymacadmin.crankd.plist to /Library/Preferences
5. Copy com.googlecode.pymacadmin.crankd.LaunchDaemon.plist to /Library/LaunchDaemons
6. Register the launch daemon with launchd: launchctl load -w /Library/LaunchDaemons/com.googlecode.pymacadmin.crankd.LaunchDaemon.plist
7. Open Console.app - you should see various startup messages as crankd loads
8. Put your system to sleep and wake it. After it wakes, your network preferences should have the SOCKS proxy enabled using localhost:1080