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

About SELinux file contexts


Throughout this chapter, we will be using a web-based application deployment as an example: DokuWiki. This is a popular PHP wiki that uses files rather than a database as its backend system and is easy to install and manage.

Getting context information

Let's assume that the DokuWiki application is hosted at /srv/web/localhost/htdocs/dokuwiki and stores its wiki pages (user content) in subdirectories of the data/ directory. This can be accomplished by downloading the latest DokuWiki tarball from the project site and extracting it in this location. Some distributions might have a different location for the DokuWiki application (such as /var/lib/dokuwiki) which is correctly labeled already. The example here generally follows the same labeling regardless of the distribution, allowing us to show various context related actions.

The contexts of files can easily be acquired using the -Z option of the ls command. Most utilities that are able to provide feedback on contexts...