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

OpenSSL and the Public Key Infrastructure

With OpenSSL, we can encrypt information on the fly as it goes across the network. There’s no need to manually encrypt our data before we send them across the network because OpenSSL encryption happens automatically. This is important because online commerce and banking couldn’t exist without it.

The Secure Sockets Layer (SSL) is the original in-transit encryption protocol. Ironically, even though we’re using the OpenSSL suite of programs and libraries, we no longer want to use SSL. Instead, we now want to use the Transport Layer Security (TLS) protocol. SSL is full of legacy code and a lot of vulnerabilities that go along with that legacy code. TLS is newer, and is much more secure. But, even when working with TLS, we can still use the OpenSSL suite.

One reason that the older SSL protocol is so bad is because of past government regulations, especially here in the U.S., that prohibited the use of strong encryption...