I saw I should include some line breaks....


echo "deb http://deb.torproject.org/torproject.org stretch main"|sudo tee /etc/apt/sources.list.d/tor.list

sudo apt-get update

sudo apt-get install dirmngr

sudo gpg --keyserver keyserver.ubuntu.com --recv A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89

sudo gpg --export A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 | sudo apt-key add -

sudo apt-get install tor tor-arm gpgv2 deb.torproject.org-keyring

echo 'SOCKSPort 9050
RunAsDaemon 1
ControlPort 9051
ExitPolicy reject *:* # no exits allowed
HiddenServiceDir /var/lib/tor/sshd/
HiddenServicePort 22 127.0.0.1:22
CookieAuthentication 1'|sudo tee /etc/tor/torrc

sudo systemctl enable tor --now


*each line contains a new command*

If you want to be able to run "arm" with your user then run "sudo usermod -a -G debian-tor $your_user".

sudo cat /var/lib/tor/sshd/hostname will output the .onion of the device.

"ssh $your_user@xyz.onion will open a ssh connection even if the computer is behind a firewall (as long as tor found some way to connect to the outside, in tricky cases you can use obfs or so).

Any service running on the computer can be made available, but also ssh should be enough to connect to any locally available service.

Downside is the speed. Upside, if you crashed the router or DynDNS is not working for any reason you can still connect to the machine via the hidden service.

You can also run commands from that end that will use the usual internet connection to transfer some data to your computer.

Disclaimer:
Be careful, think before execute the command, do no trust me with the above given keys but check if these are the correct ones.