Weak password (weak password) There is no strict and precise definition, generally considered to be easy to be guessed by others (they may know you well) or cracked by cracking tools are weak passwords. Weak passwords refer to passwords that only contain simple numbers and letters, such as "123", "abc", etc., because such passwords can be easily cracked by others, thus putting the user's computer at risk, so it is not recommended for users.
john the Ripper is a password cracking tool. Let's use it to detect the strength of user passwords and crack account passwords with weak passwords.
1: First get the installation package. Get the installation package from the host through the shared file.
Scan the shared file and mount
it . 2: Unzip the installation package to the opt directory. 3: Enter the source code directory src of john-1.8.0. Installation Must be installed in this src directory 4: After mounting the CD-ROM drive to mnt, use yum to install gcc gcc++ compiler 5: Execute the compilation and installation process After the compilation completed, an executable application will be generated in the run subdirectory 6: Confirm This john program copies the password file to be cracked to root (the password file is stored in /etc/shadow) for brute force cracking. You can see that the password of root zkc1 is 123456 (weak password account), and you can also clear the cracked account list with the password dictionary. Violence Analysis