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

Summary

SELinux has quite a few analysis tools that we can use to analyze policies. We've seen how to use sesearch to do in-depth assessments of the current policy, but noticed that it fails to validate the more dynamic analysis requirements.

With apol, we have seen a graphical application that is able to do more dynamic analysis, including the domain transitions (examining which domains can be reached from a current point) and information flow analysis (investigating how information can flow from one domain to another). From this experience, we've learned that such analysis is intensive and requires lots of interpretation to be done correctly.

Next to apol, we also learned that command-line utilities exist with similar capabilities: sedta for domain transition analysis, seinfoflow for information flow analysis, and sepolicy, which has a few out-of-the-box functionalities, but not as extensive or flexible as the other options we looked at.

In the end, we learned...