I have access to a CentOS server with a user that its not root but belongs to the sudoers list. I do not have the password of root, nor I can't find out what it is (policies of the people who gave me access to the server). 

I want to enable SSH login with root, meaning I don't want to keep logging in to the server with some user, and always do `sudo su -` in order to do about anything. So far I was able to enable SSH login with my user and a passphrase, which is nice, but I would like to be able to login directly in the root user.

Can I do this without the password of root? How? Any links/books or information would be appreciated.