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 3: Managing User Logins

When we log in to an SELinux-enabled system, we receive an SELinux context to work in. This context contains an SELinux user, an SELinux role, a domain, and optionally, a sensitivity range. As the SELinux user defines the roles and types that can be accessed, managing user logins and SELinux users is the first step in configuring end users on the system.

To enable properly configured users, we will learn to define users that have sufficient rights to do their jobs, ranging from regular users with strict SELinux protections to fully privileged administrative users with few SELinux protections. We will create and assign categories and sensitivities, as well as assign roles to users and use various tools to switch roles. At the end of the chapter, we will see how SELinux integrates with the Linux authentication process.

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

  • User-oriented SELinux contexts
  • SELinux users and...