HUProxy

This is not a Google product.

HTTP(S)-Upgrade Proxy — Tunnel anything (but primarily SSH) over HTTP websockets.

Why

The reason for not simply using a SOCKS proxy or similar is that they tend to take up an entire port, while huproxy only takes up a single URL subdirectory.

There's also SSL/SSH multiplexers but they:

Take over the port and front both the web server and SSH, instead of letting the web server be the primary owner of port 443.
For SSH don't look like SSL for packet inspectors, because they're not.
Hide the original client address from the web server (without some interesting iptables magic).
Only allow connecting to the server itself, not treat it as a proxy jumpgate.

Setup

nginx

Create user

sudo htpasswd -c /etc/nginx/users.proxy thomas

Add config to nginx

map $http_upgrade $connection_upgrade {
    default upgrade;
         '' close;
}

server {
    # ... other config
    location /proxy {
        auth_basic "Proxy";
        auth_basic_user_file /etc/nginx/users.proxy;
        proxy_pass http://127.0.0.1:8086;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        # proxy_set_header Connection "upgrade";
        proxy_set_header Connection $connection_upgrade;
    }
    # ... other config
}

Start proxy:

./huproxy

Start proxy with specific IP:port:

./huproxy -listen 10.1.2.3:8086

Running

These commands assume that HTTPS is used. If not, then change "wss://" to "ws://".

echo thomas:secretpassword > ~/.huproxy.pw
chmod 600 ~/.huproxy.pw
cat >> ~/.ssh/config << EOF
Host shell.example.com
    ProxyCommand /path/to/huproxyclient -auth=@$HOME/.huproxy.pw wss://proxy.example.com/proxy/%h/%p
EOF

ssh shell.example.com

Or manually with these commands:

ssh -o 'ProxyCommand=./huproxyclient -auth=thomas:secretpassword wss://proxy.example.com/proxy/%h/%p' shell.example.com
ssh -o 'ProxyCommand=./huproxyclient -auth=@<(echo thomas:secretpassword) wss://proxy.example.com/proxy/%h/%p' shell.example.com
ssh -o 'ProxyCommand=./huproxyclient -auth=@$HOME/.huproxy.pw wss://proxy.example.com/proxy/%h/%p' shell.example.com

If remote server uses self-signed or invalid certificate then use -insecure_conn, for example:

ssh -o 'ProxyCommand=./huproxyclient -insecure_conn wss://proxy.example.com/proxy/%h/%p' shell.example.com