Implementing Strong Password Policies in Linux using PAM Modules

This assignment delves into the Pluggable Authentication Module (PAM) framework in Linux systems, focusing on its role in determining password strength and acceptability. The solution outlines how PAM, particularly the pam_cracklib module, is utilized to enforce password complexity requirements, including minimum length, character diversity, and the avoidance of common passwords. The document details the parameters required for a "good" password in Linux, such as the use of uppercase, lowercase, numerical, and special characters. It provides step-by-step instructions on how to check for PAM usage and configure password policies using the /etc/pam.d/ directory and specific modules like pam_listfile.so and common-password files. The assignment also covers the rationale behind choosing specific authentication requirements and the edits made to PAM to achieve the desired password evaluation, including modifications to parameters like retry, minlen, lcredit, ucredit, dcredit, ocredit, difok, and reject_username. The solution emphasizes the importance of strong password policies for system security and provides practical examples of implementing these policies.