Book Image

Mastering Linux Security and Hardening - Third Edition

By : Donald A. Tevault
3.7 (7)
Book Image

Mastering Linux Security and Hardening - Third Edition

3.7 (7)
By: Donald A. Tevault

Overview of this book

The third edition of Mastering Linux Security and Hardening is an updated, comprehensive introduction to implementing the latest Linux security measures, using the latest versions of Ubuntu and AlmaLinux. In this new edition, you will learn how to set up a practice lab, create user accounts with appropriate privilege levels, protect sensitive data with permissions settings and encryption, and configure a firewall with the newest firewall technologies. You’ll also explore how to use sudo to set up administrative accounts with only the privileges required to do a specific job, and you’ll get a peek at the new sudo features that have been added over the past couple of years. You’ll also see updated information on how to set up a local certificate authority for both Ubuntu and AlmaLinux, as well as how to automate system auditing. Other important skills that you’ll learn include how to automatically harden systems with OpenSCAP, audit systems with auditd, harden the Linux kernel configuration, protect your systems from malware, and perform vulnerability scans of your systems. As a bonus, you’ll see how to use Security Onion to set up an Intrusion Detection System. By the end of this new edition, you will confidently be able to set up a Linux server that will be secure and harder for malicious actors to compromise.
Table of Contents (22 chapters)
1
Section 1: Setting up a Secure Linux System
9
Section 2: Mastering File and Directory Access Control (DAC)
12
Section 3: Advanced System Hardening Techniques
20
Other Books You May Enjoy
21
Index

Summary

In this chapter, we’ve seen that a default configuration of Secure Shell isn’t as secure as we’d like it to be, and we’ve seen what to do about it. We’ve looked at how to set up key-based authentication and two-factor authentication, and we’ve looked at lots of different options that can lock down the SSH server. We also looked at how to disable weak encryption algorithms, and at how the new system-wide crypto policies on RHEL 8/CentOS 8 and RHEL 9/AlmaLinux 9 make doing that really easy.

Along the way, we looked at setting up access controls, and at creating different configurations for different users, groups, and hosts. After demoing how to confine SFTP users to their own home directories, we used SSHFS to share a remote directory. We wrapped up this chapter by presenting a handy way to log in to our Linux servers from a Windows desktop machine.

Conspicuous by their absence are a couple of technologies that you may have...