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

Understanding the Linux system log files

You'll find the Linux log files in the /var/log directory. The structure of Linux log files is pretty much the same across all Linux distros. But, in the Linux tradition of trying to keep us all confused, the main log files have different names on different distros. On Red Hat-type systems, the main log file is the messages file, and the log for authentication-related events is the secure file. On Debian-type systems, the main log file is the syslog file, and the authentication log is the auth.log file. Other log files you'll see include the following:

  • /var/log/kern.log: On Debian-type systems, this log contains messages about what's going on with the Linux kernel. As we saw in Chapter 3, Securing Your Server with a Firewall - Part 1, and Chapter 4, Securing Your Server with a Firewall - Part 2, this includes messages about...