wstunnel

Establish a TCP socket tunnel over web socket connection, for circumventing strict firewalls.

Installation

npm install wstunnel

Usage

Run the websocket tunnel server at port 8080 on all interfaces:

wstunnel -s 0.0.0.0:8080

Run the websocket tunnel client:

wstunnel -t 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:
    wstunnel -s 0.0.0.0:8080 -t 2.2.2.2:33

Client:
    wstunnel -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.

To tell client to connect via http proxy, do:

wstunnel -t 33:2.2.2.2:33 -p http://[user:pass@]proxyhost:proxyport wss://server:443

When connecting to secure websocket server via "wss://", client might want to disable 'unauthorized' certificate rejection, via adding the '-c' option.

wstunnel -t 33:2.2.2.2:33 -c -p http://[user:pass@]proxyhost:proxyport wss://server:443

This also makes you vulnerable to MITM attack, so use with caution.

To get help, just run

wstunnel

reconnection support

With websocket, this code supports reconnection over network changes. To enable this, add --wsreconnect argument to both side(client/server). clients automatically reconnect after network interruption.

CAVEATS: this feature uses session id/secret to negotiation. In nature of this function, SSL setup is strongly recommended. your connection will be stolen when another person knows session id/secret.

example .ssh/config entry for continuous ssh session:

Host some-host-to-ssh
ProxyCommand path/to/wstunnel/bin/wstt.js --wsreconnect -t stdio:%h:%p wss://host/path/to/websocket
ServerAliveCountMax 24
ServerAliveInterval 300
# 300sec(5min) * 24 = 120min = 2hours

server side simply node path/to/wstunnel/bin/wstt.js --wsreconnect -s 8080 -t localhost:22 and use apache or nginx to SSL tunneling.

Use cases

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.

SSL setup

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

On server, listen on localhost:8080:

wstunnel -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:

wstunnel -t 99:targethost:targetport wss://mydomain.com

SSH Proxy

To use as a proxy for "ssh", run:

ssh -o ProxyCommand="wstunnel -c -t stdio:%h:%p https://wstserver" user@sshdestination

Above command will ssh to "user@sshdestination" via wstunnel server at "https://wstserver".

OpenVPN use case

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

wstunnel -s 8888 -t 127.0.0.1:1194

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

Now on client, you run:

wstunnel -t 1194 ws://server:8888

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

This setup won't work if you are behind a strict firewall because:

Non 80/443 ports are usually blocked by firewall.
Stateful packet inspection will be ablet detect the content of your websocket tunnel as OPENVPN traffic, then block it.

A more firewall proof setup would be to use wstunnel over SSL behind standard https port 443:

Run wstunnel server mode
```
 wstunnel -s 8888 -t 127.0.0.1:1194
```
Run NGINX on server, listen on 443 for https connection, forward to wstunnel server localhost:8888
On client, run wstunnel client mode using "wss://"
```
 wstunnel -t 1194 wss://server
```
Now on client, launch OPENVPN connection to localhost:1194.

topia/wstunnel