Book Image

SELinux System Administration. - Second Edition

Book Image

SELinux System Administration. - Second Edition

Overview of this book

Do you have the crucial job of protecting your private and company systems from malicious attacks and undefined application behavior? Are you looking to secure your Linux systems with improved access controls? Look no further, intrepid administrator! This book will show you how to enhance your system’s secure state across Linux distributions, helping you keep application vulnerabilities at bay. This book covers the core SELinux concepts and shows you how to leverage SELinux to improve the protection measures of a Linux system. You will learn the SELinux fundamentals and all of SELinux’s configuration handles including conditional policies, constraints, policy types, and audit capabilities. These topics are paired with genuine examples of situations and issues you may come across as an administrator. In addition, you will learn how to further harden the virtualization offering of both libvirt (sVirt) and Docker through SELinux. By the end of the book you will know how SELinux works and how you can tune it to meet your needs.
Table of Contents (16 chapters)
SELinux System Administration - Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Summary


SELinux by default uses access controls based on the file representation of communication primitives or the sockets that are used. In the case of TCP and UDP ports, administrators have some leeway in handling the controls through the semanage command without resorting to SELinux policy updates. Once we go into the realms of network-based communication, more advanced communication control can be accomplished through Linux netfilter support, using the SECMARK labeling, and through peer labeling.

In the case of SECMARK labeling, local firewall rules are used to map contexts to packets, which are then governed through SELinux policy. In the case of peer labeling, either the application context itself (in the case of labeled IPsec) or its sensitivity level (in the case of netfilter/CIPSO support) is used. This allows an almost application-to-application network flow control through SELinux policies.

In the next chapter, we will take a look at two platforms that use SELinux for their additional...