A program to tunnel TCP connection through HTTP connection

The program is useful when you has a client behind a firewall which only allows HTTP connections or connections to standard ports such as port 80 of HTTP. You will need a remote server outside of the firewall.

Start the tunneld server on a remote machine. The server listens on a port specified by parameter -p for HTTP connection from a client program. The -s parameter enables SSL.

python tunneld.py [-s] -p <listen_port>

The server then reads the HTTP payload and sends it to the target using TCP connection. The target is specified by the client when establishing the tunnel.

Usually, tunneling will actually be useful when you use the default HTTP port 80 so that the connection from tunnel client to tunnel server is not blocked by firewall.

Start the tunnel client which listens on the local machine. The command needs local port parameter, the remote tunnel server and its port, and the target that the client wants to connect to. The -s parameter enables SSL.

python tunnel.py -p <client_port> -r <tunnel_server_host>:<tunnel_server_port> <target_host>:<target_port>

When this command is executed, the client sends a http request to establish the tunnel with the remote tunnel server. The tunnel server will then establish a TCP connection with the target server. When you don't specify a port with the -p parameter, the client reads traffic from stdin and writes responses to stdout.

To connect to irc server using the tunnel:

# 1. on server machine (remote_host)
python tunneld.py -p 80

# 2. on client machine: 
python tunnel.py -p 8765 -r remote_host:80 irc.freenode.net:6667

# 3. on the client machine, test the tunnel connection using netcat
nc 127.0.0.1 8765
# send irc NICK command to the connection and see the response back from
the irc server
NICK abc

To use the HTTP tunnel to encapsulate ssh connections:

ssh user@host -o "ProxyCommand=python tunnel.py -r <tunnel_server_host:tunnel_server_port> -o <proxy_addr:proxy_port> %h:%p"

This project was inspired by supertunnel project