Book Image

Practical Linux Security Cookbook - Second Edition

By : Tajinder Kalsi
Book Image

Practical Linux Security Cookbook - Second Edition

By: Tajinder Kalsi

Overview of this book

Over the last few years, system security has gained a lot of momentum and software professionals are focusing heavily on it. Linux is often treated as a highly secure operating system. However, the reality is that Linux has its share of security ?aws, and these security ?aws allow attackers to get into your system and modify or even destroy your important data. But there’s no need to panic, since there are various mechanisms by which these ?aws can be removed, and this book will help you learn about different types of Linux security to create a more secure Linux system. With a step-by-step recipe approach, the book starts by introducing you to various threats to Linux systems. Then, this book will walk you through customizing the Linux kernel and securing local files. Next, you will move on to managing user authentication both locally and remotely and mitigating network attacks. Later, you will learn about application security and kernel vulnerabilities. You will also learn about patching Bash vulnerability, packet filtering, handling incidents, and monitoring system logs. Finally, you will learn about auditing using system services and performing vulnerability scanning on Linux. By the end of this book, you will be able to secure your Linux systems and create a robust environment.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Contributors
Packt Upsell
Preface
Index

Login authentication using a USB device and PAM


When a Linux user wants to secure the system, the most common method is always using their login password. However, we know this method is not very reliable as there are many methods to hack a traditional password. To increase the security level, we can use a USB device like an authentication token, which will be used to log in to the system.

Getting ready

To follow these steps, we need to have a USB storage device and Pluggable Authentication Modules (PAM) downloaded on the Linux system. Most Linux systems have PAM in the form of precompiled packages, which can be accessed from the relevant repository.

How to do it...

By using any type of USB storage device and PAM, we can create the authentication token:

  1. To start with, we first need to install the packages required for PAM USB authentication. To do so, we run this command:
$ sudo apt-get install pamusb-tools libpam-usb

  1. Once the packages are installed, we have to configure the USB device to use PAM...