Book Image

SELinux System Administration, Third Edition - Third Edition

By : Sven Vermeulen
Book Image

SELinux System Administration, Third Edition - Third Edition

By: Sven Vermeulen

Overview of this book

Linux is a dominant player in many organizations and in the cloud. Securing the Linux environment is extremely important for any organization, and Security-Enhanced Linux (SELinux) acts as an additional layer to Linux system security. SELinux System Administration covers basic SELinux concepts and shows you how to enhance Linux system protection measures. You will get to grips with SELinux and understand how it is integrated. As you progress, you’ll get hands-on experience of tuning and configuring SELinux and integrating it into day-to-day administration tasks such as user management, network management, and application maintenance. Platforms such as Kubernetes, system services like systemd, and virtualization solutions like libvirt and Xen, all of which offer SELinux-specific controls, will be explained effectively so that you understand how to apply and configure SELinux within these applications. If applications do not exert the expected behavior, you’ll learn how to fine-tune policies to securely host these applications. In case no policies exist, the book will guide you through developing custom policies on your own. By the end of this Linux book, you’ll be able to harden any Linux system using SELinux to suit your needs and fine-tune existing policies and develop custom ones to protect any app and service running on your Linux systems.
Table of Contents (22 chapters)
1
Section 1: Using SELinux
8
Section 2: SELinux-Aware Platforms
14
Section 3: Policy Management

Chapter 1: Fundamental SELinux Concepts

Security-Enhanced Linux (SELinux) brings additional security measures to your Linux system to further protect its resources. As part of the Linux kernel, it is a mandatory access control system supported by major Linux distributions. In this book, we cover all aspects of SELinux, from basic fundamentals to resolving SELinux issues, configuring applications to deal with SELinux, and even writing our own policies.

Before we embark on the details of SELinux, let's first cover the concepts of this technology: why SELinux uses labels to identify resources, how SELinux differs from traditional Linux access controls, how SELinux enforces security rules, and other mandatory access control systems that are supported in the Linux kernel. We will also see how the access control rules enforced by SELinux are provided through policy files. At the end of the chapter, we will cover an overview of the differences between SELinux implementations across Linux distributions.

In this chapter, we're going to cover the following main topics:

  • Providing more security for Linux
  • Labeling all resources and objects
  • Defining and distributing policies
  • Distinguishing between policies