Security Series - Password Aging!!!

Did I say "password aging"? Yes I did. There is a counter which reads from a config file...what??? About the password aging information. The next question which strikes the mind is - which file?, what info?, does that file really exist???.

Here's your answers:
Characteristics of a Strong Password:
--> Should have minimum character defined
--> Should be a combination of characters(including special characters) and digits
--> Should have expiration date.

You can view the password aging information of a particular user by executing the following command.

#chage -l username

The password expire information can be set with the following command.
#chage username

for example:
sudo chage -E 01/31/2011 -m 5 -M 90 -I 30 -W 14 username

which means - date (-E) to 01/31/2008, minimum password age (-m) of 5 days, maximum password age (-M) of 90 days, inactivity period (-I) of 5 days after password expiration, and a warning time period (-W) of 14 days before password expiration.

Cheers