Information
The pam_cracklib module checks the strength of passwords. It performs checks such as making sure a password is not a dictionary word, it is a certain length, contains a mix of characters (e.g. alphabet, numeric, other) and more. The following are definitions of the pam_cracklib.so options. retry=3 - Allow 3 tries before sending back a failure. minlen=14 - password must be 14 characters or more dcredit=-1 - provide at least one digit ucredit=-1 - provide at least one uppercase character ocredit=-1 - provide at least one special character lcredit=-1 - provide at least one lowercase character The setting shown above is one possible policy. Alter these values to conform to your own organization's password policies. Strong passwords protect systems from being hacked through brute force methods.
Solution
Install the libpam-cracklib package- # apt-get install libpam-cracklib Set the pam_cracklib.so parameters as follows in /etc/pam.d/ common-password- password required pam_cracklib.so retry=3 minlen=14 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1