EINVAL: Valid solutions for invalid problems

Secondary login credentials

Sometimes I need to access my files on my servers using SSH/SCP from an untrusted device and/or application. Usually I would create a new SSH key pair so that I can easily revoke these credentials later if such need arises. But what if the used application doesn’t support SSH keys or we do not want to use them for some reason? There is a trick supposedly used by sysadmins in the olden days, before sudo was around.