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

Extending generated policies

When we assign a different policy to a new application, we are reusing and possibly extending existing policies. We can go a step further and generate new policies, after which we can further extend those policies, effectively moving into the realm of developing new policies ourselves.

In Chapter 15, Using the Reference Policy, and Chapter 16, Developing Policies with SELinux CIL, we will expand further into the policy development aspects for more fine-grained control. By using policy generation tools, however, we can quickly create a first-draft policy and adapt as needed.

An important caveat is that policy generation tools often limit themselves to a single-policy format, either being reference policy style or CIL style. Administrators and organizations should try to focus on a single style and stick with that so that the learning curve for new developers and administrators isn't too high.

Understanding the limitations of generated policies...