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
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.
We will check the password
123456 which is insecure as we know.
$echo "123456" | cracklib-check
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