Just found out about these interesting links I had loved to use years ago, but alas, now I know (:
- How HTML5 Web Sockets Interact With Proxy Servers
- Vpn-ws – A VPN system over websockets | Hacker News
It looks similar to SSL VPN sometimes also called WebVPN:
Then there are non-VPN tunnels through WebSockets:
- covertcodes/multitun: Tunnel arbitrary traffic through an innocuous WebSocket. Clients can ‘see’ each other, resulting in a stealth WebSocket VPN.
- mhzed/wstunnel: tunnel over websocket
Since WebSockets can run over a proxy server you could route any kind of binary traffic through them even in places that disallow non-web protocols or layer-7 inspect https traffic.
Although ops might restrict stuff even further:
- firewalls – How does a network admin block the reverse SSH in company? – Information Security Stack Exchange
- SSH across a Layer 7 Filter · System Overlord
–jeroen