Password security is important subject in IT. We call it password but actually it is a key to enter systems. Making authentication password-less by using key-based authentication is more secure but it is not always possible. So for the password-based authentication password strength is important.

How Can We Make Passwords Strong

Actually making passwords strong is easy. The important thing is making this a default behavior. Just typing more 5 characters will make our systems like a castle.

At least use 14 characters

Use easy to remember the expression

Use . , ; ” ! more than 3 times

Install Cracklib

Ubuntu, Debian, Kali, Mint:

We will install cracklib-runtime package with the following command for Ubuntu, Debian, Kali, and Mint.

$ sudo apt-get install cracklib-runtime -y

Fedora, CentOS, RedHat:

cracklib is the package we will install in Fedora, CentOS, RedHat.

$ yum install cracklib -y

Check Given Password

There are different tools provided by cracklib but the most useful and important one is cracklib-check command. We will provide the password we want to check to the cracklib-check command as standard input.

Simplistic/systematic

We will check the password 123456 which is insecure as we know.

$echo "123456" | cracklib-check

Too Short

it is too short message means we need to use more characters than given password.

$ echo "admin" | cracklib-check

Ok or Password Is Secure

If the given password is secure the OK message is printed to the screen.

$ echo "3dAmI12." | cracklib-check

Check Multiple Password From File

If checking passwords one by one is long process we can check password with a single run by providing them from a file. In this example we will write all passwords into file named pass and redirect to the cracklib-check command like below.

$ cat pass | cracklib-check

How To Check Password Strength In Linux With Cracklib? Infografic