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

Creating roles and user domains


One of the best features of SELinux is its ability to confine end users and only grant them the rights they need to do their job. To accomplish this, we need to create a restricted user domain that these users should use (either immediately or after switching from their standard role to the more privileged role).

Such user domains and roles need to be created through SELinux policy enhancements. These enhancements, however, require a deep understanding of the available permission checks, reference policy macros, and more, which one can only obtain through experience (or assistance). Still, that shouldn't prevent us from providing a working example of how to create a special end user role and domain for the PostgreSQL administration.

Creating the pgsql_admin.te file

First, let's look at the SELinux policy file that includes our user related rules. Each line is commented to explain why the next policy line is used.

The pgsql_admin.te file looks as follows:

# cat...