The Duality of the Pluggable Authentication Module (PAM)

Introduction

Since its creation, Linux has been an operating system (OS) designed for simplicity, functionality, and flexibility. It enables users to modify and customize every component and module of the system.

In July 1991, Linus Torvalds announced on the comp.os.minix newsgroup that his operating system was designed to be easily modified and improved by tech professionals according to their needs.

Figure 1: Screenshot of Linus Torvald’s message on comp.os.minix.

Linux’s modular design offers users the flexibility to customize the OS by adding, removing, or altering components such as networking, security, system management, graphical user interfaces, and automation tools. This flexibility allows Linux to operate on a diverse range of devices, including smartphones, personal computers, and game consoles.

Modularity and simplicity are crucial in Linux, where security is a primary concern. As an open-source system, Linux benefits from the contributions of thousands of security experts who continuously work to address vulnerabilities and bugs, enhancing the OS’s security and making it one of the most secure systems available. The separation between the kernel and user space, along with MAC-based settings provided by the SELinux security module, helps prevent unauthorized root access and limits the spread of malware.

Linux security encompasses various aspects, including authentication, data encryption, and user anonymization.

This article will delve into one of the most intricate and important aspects of Linux security: Pluggable Authentication Modules (PAM).