user password are password of a user stored in the secure shadow file.
The password is the second field of the shadow file
It's 13 character encrypted
To set/change a password, use the passwd command
Options:
passwd
Changing password for user gerardnico.
Changing password for gerardnico
(current) UNIX password:
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully.
To change the password for the user 'gerardnico' (only if you are logged in as root)…
passwd gerardnico
Changing password for user gerardnico.
New UNIX password:
BAD PASSWORD: it is based on a dictionary word
Retype new UNIX password:
passwd: all authentication tokens updated successfully.