wstunnel

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

Installation

npm install -g 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

For dev/test purpose, client can set '-c' option to disable ssl certificate check.

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

To get help, just run

wstunnel

Docker

A public docker image "mhzed/wstunnel" is now available.

Example:

# run as client to connect to wss://server.com, tunnel localhost:2244 to target.ip:22
docker run --rm -d -p 2244:2244 mhzed/wstunnel -t 0.0.0.0:2244:target.ip:22 wss://server.com

Notice "-t 0.0.0.0:2244..." above. By default wstunnel binds to localhost which is unreachable inside a docker container, so make sure to specify "0.0.0.0" to bind to all local IPs.

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

Currently wstunnel in server mode supports plain tcp socket only. For SSL support (highly recommended), setup a NGINX reverse proxy.

On server, wstunnel listens 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 -t stdio:%h:%p https://server" user@sshDestination

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

RDP use case

Let's say you want to use a Remote Desktop connection to a machine with IP 2.2.2.2
Run the wstunnel server on a different machine, tunneling to the destination on the RDP port 3389:

     wstunnel -s 0.0.0.0:8080 -t 2.2.2.2:3389

On the destination, you need to tweak some registry settings to relax the security policy for Remote Desktop.

    Open RegEdit, and navigate to the following key:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
    Change "SecurityLayer" to 0
    Change "SelectNetworkDetect" to 0
    Reboot

On the client, first start wstunnel:

    wstunnel -t 3389 ws://server:8080

Now you can just open Remote Desktop Connection and connect to localhost

Proxy

When using socks proxy, ensure the host is IP address only, DNS name is not supported. For example:

# "localhost" won't work
wstunnel -t 2255:sshhost:22 --proxy socks://localhost:3111 http://wsserver
# instead, do:
wstunnel -t 2255:sshhost:22 --proxy socks://127.0.0.1:3111 https://wsserver

Http tunnel

An http tunnel will be established if websocket connection fails. Two long live http connections are established for sending and receiving data.