SSH has no Host header
We have a challenge with ssh. Every VM has a standard URL that we use for both HTTPS and SSH, e.g. undefined-behavior.exe.xyz. Just as you can type the domain into a web browser (and have TLS and auth taken care of for you), you can run: ssh undefined-behavior.exe.xyz To get a shell in your VM. This is very straightforward to implement if you give each machine its own IP address, but exe.dev gives you many VMs on a flat rate subscription. We cannot issue an IPv4 address to each machine without blowing out the cost of the subscription. We cannot use IPv6-only as that means some of the internet cannot reach the VM over the web. That means we have to share IPv4 addresses between VMs. For the web, this is a long-solved problem. Many sites can and do have the same IP address. Web browsers send…
