Edit/Solved: Thank you for all the great input! Both on alternative solutions and on security implications. I’m going to make a draft on how I would setup the e-mail method as securely as possible as a programming/scripting exercise, but will IRL probably end up using either some reverse tunnel/shell variant.
Edit 2: or, as a hardware solution, install an extra NIC that I expose to the opennet - thus enabling remote port forwarding - while binding all my sensitive processes/traffic to my encrypted NIC.
I cannot ssh into my Linux box from outside of my LAN since I’m behind a VPN that doesn’t support port forwarding. Is it possible to make my Linux box receive, interpret and execute commands through e-mail instead? I’ve tried looking for answers through DuckDuckGo’s search engine, to no avail. If I may dream, I would like to setup an e-mail server with a systemd service or just run a script that continuously downloads the emails, prints their content to stdin and executes, perhaps through command substitution, whatever is in stdin.
@emotional_soup_88 possible, but sounds like an extremely bad idea. If you can send commands, then everybody else can.
True. Hadn’t thought of that. Maybe I could make the address extremely long and arbitrary? And “hide” it behind my e-mail alias service?
But I absolutely understand the security implications.
Security by obscurity as single line of defense is generally not a good idea.
And then there is user management and permissions that I could sprinkle on top that.
Yes but your script can check who the email is from and check its certs before doing any operations on it. The only security issue is the email being read in transit but that can be worked around by not sending sensitive info.