ok i am seeking to harden my system (and my brother's who is a linux
newbie), so I got John the Rippper (password cracker) and am learning to
use it to test my own system's passwords for strength. But the program
requires that I have a copy of /etc/shadow (shadowed passwords); well it
seems to me that in order to have that file one must have already cracked
some password to enter a PC system, so what is the point of Ripper other
than testing passwords? I mean, how does a cracker get into a system in
the first place using a password cracker since it seems to be a Catch22?
Mind you, I am no cracker, I just want to learn to harden my system, learn
to prevent crackers from getting in.