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

Configuring PAM services

systemd and D-Bus are SELinux-aware applications, with explicit SELinux support built in. Several other services exist on a Linux system that play nicely together with SELinux yet are not SELinux-aware themselves. Many of these services have an affinity with SELinux through their PAM integration.

We covered PAM integration in Chapter 3, Managing User Logins. In this section, we'll cover three example services using PAM, and how SELinux can be further fine-tuned to support these services.

Cockpit

Cockpit is a simple, browser-based management application that allows administrators to easily see system resources (monitoring) as well as to interact with the system. It also allows users to log into the system through the browser.

It is this browser-based terminal that we want to configure: by tuning the target SELinux roles for the SELinux users, we can selectively put users in a specific role. This effectively defines what the users can accomplish...