You're reading from SELinux System Administration, Third Edition Implement mandatory access control to secure applications, users, and information flows on Linux

Product type Paperback

Published in Dec 2020

Publisher Packt

ISBN-13 9781800201477

Length 458 pages

Edition 3rd Edition

Tools

Docker

Concepts

System Administration

Author (1):

Sven Vermeulen

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Table of Contents (22) Chapters

Preface

1. Section 1: Using SELinux

2. Chapter 1: Fundamental SELinux Concepts FREE CHAPTER

3. Chapter 2: Understanding SELinux Decisions and Logging

4. Chapter 3: Managing User Logins

5. Chapter 4: Using File Contexts and Process Domains

6. Chapter 5: Controlling Network Communications

7. Chapter 6: Configuring SELinux through Infrastructure-as-Code Orchestration

8. Section 2: SELinux-Aware Platforms

9. Chapter 7: Configuring Application-Specific SELinux Controls

10. Chapter 8: SEPostgreSQL – Extending PostgreSQL with SELinux

11. Chapter 9: Secure Virtualization

12. Chapter 10: Using Xen Security Modules with FLASK

13. Chapter 11: Enhancing the Security of Containerized Workloads

14. Section 3: Policy Management

15. Chapter 12: Tuning SELinux Policies

16. Chapter 13: Analyzing Policy Behavior

17. Chapter 14: Dealing with New Applications

18. Chapter 15: Using the Reference Policy

19. Chapter 16: Developing Policies with SELinux CIL

20. Assessments

21. Other Books You May Enjoy

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Introducing CIL

CIL has been designed to be the main language to have policies built in, and is the lowest readable format. After CIL, the SELinux code is transformed in binary to send off to the Linux kernel (and SELinux subsystem) for loading in memory.

Administrators might be inclined to think that the binary files, generated when building a SELinux policy module using the reference policy method, are the final binaries. However, as we've seen in Chapter 1, Fundamental SELinux Concepts, the semodule command converts and translates this into CIL before building the final format.

Let's see how these translations work and what we can learn from them.

Translating .pp files to CIL

When a non-CIL SELinux policy module is loaded, the semodule command is designed to first consider the module as an unknown format, and extract the High Level Language (HLL) information from it. HLL is an abstract term that the SELinux utilities use to define any SELinux source format...