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

Using labeled IPsec with SELinux

Although setting up and maintaining an IPsec setup is far beyond the scope of this book, let's look at a simple IPsec example to show how to enable labeled IPsec on a system. Remember that the labeled network controls on the interface, node, and peer levels, as mentioned earlier, are automatically enabled the moment we use labeled IPsec.

In an IPsec setup, there are three important concepts to be aware of:

  • The security policy database (SPD) contains the rules and information for the kernel to know when communication should be handled by an IP policy (and, as a result, handled through a security association).
  • A security association (SA) is a one-way channel between two hosts and contains all the security information about the channel. When labeled IPsec is in use, it also contains the context information of the client that caused the security association to materialize.
  • The security association database (SAD) contains the individual...