COW (Climb Over the Wall) proxy

COW is a HTTP proxy that tries to automatically identify blocked web sites and use a parent proxy when visiting those sites. For non-blocked sites, COW will use direct access. COW can also generate PAC file to tell the client use direct access for non-blocked sites.

Features

• Automatically identify blocked websites
• Record which sites are blocked, which can be directly accessed
  • Can also manually specify blocked and direct sites
• Generate and serve PAC file
  • The PAC file tells the browser to use direct connection for non-blocked sites
• Convert socks proxy to HTTP proxy
  • Can start socks proxy through ssh, requires public key authentication

Limitations

• Designed to run on your own computer
• No caching, cow just passes traffic between the browser and web servers
  • Browsers have cache
• Alpha quality now

Installation

Install go, then run

go get github.com/cyfdecyf/cow

Usage

Configuration file is located at ~/.cow/rc. Here's an example:

# proxy listen address
listen = 127.0.0.1:7777
# parent socks proxy address
socks = 127.0.0.1:1080
# Nubmer of cores to use
core = 2
# ssh to the given server to start socks proxy
sshServer = gfw
# Update blocked site list (~/.cow/auto-blocked)
updateBlocked = true
# Update direct accessable site list (~/.cow/auto-direct)
updateDirect = true
# empty path means stdout, use /dev/null to disable output
logFile = ~/.cow/log

To start cow, just execute cow on the command line.

• The PAC file can be access at the same address as proxy listen address
  • For the above example, accessing http://127.0.0.1:7777/anypath will get the generated PAC file
• You can manually specify blocked and direct accessable sites. Just edit ~/.cow/blocked and ~/.cow/direct
  • One line for each domain
• When update blocked/direct sites is enabled, cow will update ~/.cow/auto-blocked and ~/.cow/auto-direct
• For sites which will be temporarily blocked, they should always go through cow and thus should not appear in blocked or direct site lists. Put them in ~/.cow/chou. (If you are Chinese, this stands for 抽风.)
• Command line options can override options in configuration file. For more details, see the output of cow -h

OS X: Automatic start COW upon login

• Put doc/osx/info.chenyufei.cow.plist into ~/Library/LaunchAgents
• Edit this plist file, change the COW executable path to the one on your system

After this, COW will be started when you login. It will also be automatically restarted upon exit by launchd (if network is avaiable).