I'd like to setup
sudo in such a way that it doesn't prompt me for a password when I authenticate to
sshd with a key; but do otherwise.
I don't want an answer of "it doesn't work like that" because obviously that's the reason why I asked the question in the first place. I don't want the suggestion of creating two users for this.
Consider that for my personal servers I use Fedora, maybe there might be a hack with a temporal SELinux role based on authentication method, which can be then used in the sudoers file?