#Tunnel and Reverse Tunnel Client & Server on WebSocket Implementation for node

##Overview

Tools to establish a TCP socket tunnel over websocket connection, and to enstabilish a reverse tunnel over websocket connection, for circumventing the problems of direct connections to the host behind a strict firewalls or without a public IP.

##Installation npm install node-reverse-wstunnel

##Usage in node

###Server example

var wts = require("node-reverse-wstunnel");

server = new wts.server(); 
//the port of the websocket server 
server.start(port);

###Client example

var wts = require("node-reverse-wstunnel");

client = new wts.client();
//localport is the opened port of the localhost for the tunnel
//remotehost:port is the service that will be tunneled
client.start(localport,'ws://websocketserverhost:port', remotehost:port);

###Reverse Server example

var wts = require("node-reverse-wstunnel");

reverse_server = new wts.server_reverse(); 
//the port of the websocket server 
reverse_server.start(port);

###Reverse Client example

var wts = require("node-reverse-wstunnel");

reverse_client = new wts.client_reverse();
//portTunnel is the port that will be opened on the websocket server 
//remotehost:port is the service that will be reverse tunneled
reverse_client.start(portTunnel, 'ws://websocketserverhost:port', remotehost:port);

###Usage of wstt.js executable Using the wstt.js executable located in bin directory:

For running a websocket tunnel server:

./wstt.js -s 8080

For running a websocket tunnel client:

./wstt.js -tunnel 33:2.2.2.2:33 ws://host:8080

In the above example, client picks the final tunnel destination, similar to ssh tunnel. Alternatively for security reason, you can lock tunnel destination on the server end, example:

Server:

    ./wstt.js -s 8080 -t 2.2.2.2:33

Client:

    ./wstt.js -t 33 ws://server:8080

In both examples, connection to localhost:33 on client will be tunneled to 2.2.2.2:33 on server via websocket connection in between.

For running a websocket reverse tunnel server:

./wstt.js -r -s 8080

For running a websocket reverse tunnel client:

./wstt.js -r 6666:2.2.2.2:33 ws://server:8080

In the above example the client tells the server to open a TCP server on port 6666 and all connection on this port are tunneled to the client that is directely connected to 2.2.2.2:33

Use case

For tunneling over strict firewalls: WebSocket is a part of the HTML5 standard, any reasonable firewall will unlikely be so strict as to break HTML5.

The tunnel server currently supports plain tcp socket only, for SSL support, use NGINX, shown below:

On server: ./wstt.js -s 8080

On server, run nginx (>=1.3.13) with sample configuration:

server {
    listen   443;
    server_name  mydomain.com;

    ssl  on;
    ssl_certificate  /path/to/my.crt
    ssl_certificate_key  /path/to/my.key
    ssl_session_timeout  5m;
    ssl_protocols  SSLv2 SSLv3 TLSv1;
    ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
    ssl_prefer_server_ciphers   on;

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header        Host            $host;
        proxy_set_header        X-Real-IP       $remote_addr;
        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header        X-Forwarded-Proto $scheme;
    }
}

Then on client:

./wstt.js -t 99:targethost:targetport wss://mydomain.com

OpenVPN use case

Suppose on the server you have OpenVpn installed on the default port 1194, then run wstunnel as such:

./wstt.js -s 8888 -t 127.0.0.1:1194

Now on the server, you have a websocket server listening on 8888, any connection to 8888 will be forwarded to
127.0.0.1:1194, the OpenVpn port.

Now on client, you run:

./wstt.js -t 1194 ws://server:8888

Then launch the OpenVpn client, connect to localhost:1194 will be same as connect to server's 1194 port.

Suppose the firewall allows http traffic on target port 80 only, then setup a NGINX reverse proxy to listen on port 80, and proxy http traffic to localhost:8888 via host name.