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

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

Chapter 16

The SELinux Common Intermediate Language (CIL) is not an extension to SELinux that can be easily removed. It is at the heart of SELinux policy development and support, although mainly under the hood: all SELinux policy modules that are loaded on the system are first converted into CIL before actually being loaded in memory.
The CIL format is the only format used to interact with the Linux kernel and the SELinux subsystem. Because it is used as part of the SELinux user space utilities, it is not always as obvious to administrators or developers, but it is definitely a core component within SELinux.
No, it is not mandatory, but is recommended. The attribute is used to refer to types and roles in a modular fashion, and to ensure that these references are valid. CIL internally requires types and roles to be defined before they are used, and without using an attribute to force such declarations, the order of loading modules might result in failures.
While other attributes...