In this document, you'll find the necessary stuff to bypass proxies that allow only ports 80 and 443, to go to the internet without any port-limitation or stupid filtering. Most of the “Client Part” is for an Android-based client, but should be easily adapted to other platforms.

For a basic OpenVPN setup, you should have a look here.

The proxy we need to bypass only allows web protocols; so we'll setup our openvpn to listen on TCP-443 port:

proto tcp-server
port 443

Since version 2.1, OpenVPN provides a nice feature: proxying HTTPS requests. It is able to listen on the 443 port, and to forward non-VPN traffic to another webserver. Just write the webserver IP and port to forward traffic to:

port-share remoteserver 443

OpenVPN provides an option to route all trafic, instead of just the VPN one. Just happen the following line:

push "redirect-gateway def1"

Warning: for most of this operations, you need to be root.

• Install busybox from here.
• Get the OpenVPN binary here.

Manually install archive's contents:

adb push libcrypto.so /system/lib/
adb push liblzo.so /system/lib/
adb push libssl.so /system/lib/
adb push openssl /system/bin/
adb push openvpn /system/bin/
adb shell chmod 4755 /system/bin/openssl
adb shell chmod 4755 /system/bin/openvpn

You'll also need the tun driver for your appropriate kernel. I downloaded mine there. Copy it to /system/lib/modules/, and load it:

adb push tun.ko /system/lib/modules/
adb shell insmod /system/lib/modules/tun.ko

Here are the lines you need to happen to your client file to use a famous French ISP's proxy:

http-proxy-option AGENT "Series60/3.1" # some user-agent to fool the proxy
http-proxy-retry # restart connexion if it breaks
http-proxy 195.115.25.129 8080 # Proxy Name
keepalive 5 600 # keep the connexion alive