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 15

  1. Many Linux distributions add services and tools that fit the distribution's purpose and principles, yet which might be contradictory to what the reference policy is about. For instance, Red Hat Enterprise Linux and its derived Linux distributions will enable unconfined domains for many applications, whereas the reference policy will strive toward confinement of all applications.

    As a result, many Linux distributions base their policy on the reference policy, but augment and adjust it for their specific purpose.

  2. The three main policy files are the following:

    - A type enforcement file, with the suffix .te, which contains the rules for the SELinux policy module, focusing on its owned domains.

    - An interface file, with the suffix .if, which exposes the interaction patterns and privileges vis-à-vis the domains and resources owned by this SELinux policy module. These interfaces are then used by other SELinux policy modules.

    - A context file, with the suffix .fc...