Tunneling TCP connections in WebSocket to circumvent firewall. It's light and can run on some PaaS (with SSL support).

• Encryption
• Proxy support (using HTTP CONNECT; test your proxy)
• Display error message in browser (plain HTTP only)
• SOCKS v5 and HTTP(S) in the same port (HTTP proxy is slower)

WARN: Do not rely it on security when not using SSL

wstan [-h] [-g] [-c | -s] [-d] [-z] [-p PORT] [-t TUN_ADDR]
      [-r TUN_PORT]
      [uri] [key]

positional arguments:
  uri                   URI of server
  key                   base64 encoded 16-byte key

optional arguments:
  -h, --help            show this help message and exit
  -g, --gen-key         generate a key and exit
  -c, --client          run as client (default, also act as SOCKS5/HTTP(S)
                        server)
  -s, --server          run as server
  -d, --debug
  -y PROXY, --proxy PROXY
                        let client use a HTTPS proxy (host:port)
  -z, --compatible      useful when server is behind WS proxy
  -p PORT, --port PORT  listen port of SOCKS5/HTTP(S) server at localhost
                        (defaults 1080)
  -t TUN_ADDR, --tun-addr TUN_ADDR
                        listen address of server, overrides URI
  -r TUN_PORT, --tun-port TUN_PORT
                        listen port of server, overrides URI

Example:

# generate a key using "wstan -g"
wstan ws://yourserver.com KEY -s  # server
wstan ws://yourserver.com KEY  # client
# now a proxy server is listening at localhost:1080 (at client side)

Example for OpenShift with SSL:

wstan wss://yours.rhcloud.com:8443 KEY -s -z -t $OPENSHIFT_PYTHON_IP -r $OPENSHIFT_PYTHON_PORT  # server
wstan wss://yours.rhcloud.com:8443 KEY -z  # client

• chisel
• https://github.com/mhzed/wstunnel
• https://github.com/ffalcinelli/wstunnel
• shadowsocks-dotcloud
• multitun (VPN)
• etherws (VPN)
• websockify (not for circumventing FW)
• gost
• v2ray

Original Goal: make active probing against server side more difficult while still keeping low latency of connection establishment and being stateless (inspired by shadowsocks).

Weakness: can't prevent MITM attack; client can't detect fake server (may receive garbage data); replay attack detection may fail

Tech Detail:

• request frame has HMAC and timestamp (data frame has nothing), and all frames are encrypted using AES-128-CTR
• server will save encryption nonce and timestamp when receiving valid request (to detect replay attack)
• the first request frame will be encoded into URI of WS handshake (to achieve low latency)
• it has a connection pool