With regards to running Linux remotely (SSH) I'd like to employ two levels of authentication for accessing the system with root privileges.
I have the root account disabled / locked out so direct access to the system is not possible with root user.
I access the system with a normal user, and then from their I can sudo. Of course, it is merely the same password to gain root privileges.
/etc/sudoers, you can set the directive
Default rootpw which will prompt for a root (second) password. However, I have the root account locked and so there is no password.
My question is, how can I have the user enter a 2nd DIFFERENT password to access the root account or to sudo?