Book Image

Mastering Linux Security and Hardening - Second Edition

By : Donald A. Tevault
Book Image

Mastering Linux Security and Hardening - Second Edition

By: Donald A. Tevault

Overview of this book

From creating networks and servers to automating the entire working environment, Linux has been extremely popular with system administrators for the last couple of decades. However, security has always been a major concern. With limited resources available in the Linux security domain, this book will be an invaluable guide in helping you get your Linux systems properly secured. Complete with in-depth explanations of essential concepts, practical examples, and self-assessment questions, this book begins by helping you set up a practice lab environment and takes you through the core functionalities of securing Linux. You'll practice various Linux hardening techniques and advance to setting up a locked-down Linux server. As you progress, you will also learn how to create user accounts with appropriate privilege levels, protect sensitive data by setting permissions and encryption, and configure a firewall. The book will help you set up mandatory access control, system auditing, security profiles, and kernel hardening, and finally cover best practices and troubleshooting techniques to secure your Linux environment efficiently. By the end of this Linux security book, you will be able to confidently set up a Linux server that will be much harder for malicious actors to compromise.
Table of Contents (20 chapters)
1
Section 1: Setting up a Secure Linux System
8
Section 2: Mastering File and Directory Access Control (DAC)
11
Section 3: Advanced System Hardening Techniques

Locking down users' home directories the Red Hat or CentOS way

This is another area where different Linux distribution families do business differently from each other. As we shall see, each distribution family comes with different default security settings. A security administrator who oversees a mixed environment of different Linux distributions will need to take this into account.

One beautiful thing about Red Hat Enterprise Linux and all of its offspring, such as CentOS, is that they have better out-of-the-box security than any other Linux distribution. This makes it quicker and easier to harden Red Hat-type systems because much of the work has already been done. One thing that's already been done for us is locking down users' home directories:

 [donnie@localhost home]$ sudo useradd charlie
[sudo] password for donnie:
[donnie@localhost home]$
[donnie@localhost...