SSH tunnelling using dynamic proxy

Proxy-README.md

SSH Proxy Script by Red Moses

http://redmoses.me

This script connects to a SSH server to create a dynamic tunnel proxy. I'm assuming you use a private key for authenticating to the server.

Script configuration

To use this script you must first configure it according to your details. I have supplied some dummy values for the configuration fields to start with.

# SSH user
USER=johndoe

# Server domain/ip
SERVER=proxyserver.com

# Private key for authenticating to the server
KEY=~/.ssh/id_rsa

# SSH port of the server
SSH_PORT=22

# Local port to be used for proxy
PROXY_PORT=8999

Script usage

# Start tunnel
./tunnel.sh start

# Stop tunnel
./tunnel.sh stop

# Restart tunnel
./tunnel.sh restart

# Tunnel status
./tunnel.sh status

SSH Example

Suppose you want to connect to server.com using the proxy service you've started using the script. Open your 'ssh_config' file (for Ubuntu),

sudo vim /etc/ssh/ssh_config

and enter the following at the end of the file. I'm using an example configuration. Please change the fields according to your own specifications.

Host server.ssh
  Hostname      example.com
  Port          2020
  IdentityFile  ~/.ssh/server
  User          admin
  ProxyCommand  nc -x localhost:8999 %h %p

From now on you can ssh to the above server by using the following command,

ssh server.ssh

Firefox or other browsers

For using the proxy with firefox or other browsers just use the following configuration as Socks v5 proxy,

Server: 127.0.0.1
Port: 8999

proxy.sh

#!/bin/bash

## A script by RedMoses, redmoses.me ##

## Proxy Configuration ##
# Please change it accordingly
USER=johndoe
SERVER=proxyserver.com
KEY=~/.ssh/id_rsa
SSH_PORT=22
PROXY_PORT=8999
#########################

# start, stop, or restart
ACTION=$1

## MESSAGES ##
start_msg="Proxy service started."
stop_msg="Proxy service stopped."
status_msg="Proxy service is "
usage_msg="* Usage: ./proxy.sh {start|stop|restart|status}"

function tunnel_start {
  ssh -C -c blowfish -f -N -D $PROXY_PORT -p $SSH_PORT -i $KEY $USER@$SERVER
  echo "$start_msg"
}

function tunnel_stop {
  sudo kill 9 $(sudo lsof -t -i:$PROXY_PORT)
  echo "$stop_msg"
}

function tunnel_status {
  PID=$(sudo lsof -t -i:$PROXY_PORT)
  if [[ "$PID" = "" ]]; then
    echo "$status_msg not running."
  elif [[ condition ]]; then
    echo "$status_msg running."
  fi
}

if [ ! -z "$ACTION" ]; then

  # start tunnel
  if [ "$ACTION" = "start" ]; then
    tunnel_start
  # stop tunnel
  elif [ "$ACTION" = "stop" ]; then
    tunnel_stop
  # restart tunnel
  elif [[ "$ACTION" = "restart" ]]; then
    tunnel_stop
    sleep 3
    tunnel_start
  # tunnel status
  elif [[ "$ACTION" = "status" ]]; then
    tunnel_status
  else
    echo "$usage_msg"
  fi

else
  echo "$usage_msg"
fi