Book Image

SELinux System Administration, Third Edition - Third Edition

By : Sven Vermeulen
Book Image

SELinux System Administration, Third Edition - Third Edition

By: Sven Vermeulen

Overview of this book

Linux is a dominant player in many organizations and in the cloud. Securing the Linux environment is extremely important for any organization, and Security-Enhanced Linux (SELinux) acts as an additional layer to Linux system security. SELinux System Administration covers basic SELinux concepts and shows you how to enhance Linux system protection measures. You will get to grips with SELinux and understand how it is integrated. As you progress, you’ll get hands-on experience of tuning and configuring SELinux and integrating it into day-to-day administration tasks such as user management, network management, and application maintenance. Platforms such as Kubernetes, system services like systemd, and virtualization solutions like libvirt and Xen, all of which offer SELinux-specific controls, will be explained effectively so that you understand how to apply and configure SELinux within these applications. If applications do not exert the expected behavior, you’ll learn how to fine-tune policies to securely host these applications. In case no policies exist, the book will guide you through developing custom policies on your own. By the end of this Linux book, you’ll be able to harden any Linux system using SELinux to suit your needs and fine-tune existing policies and develop custom ones to protect any app and service running on your Linux systems.
Table of Contents (22 chapters)
1
Section 1: Using SELinux
8
Section 2: SELinux-Aware Platforms
14
Section 3: Policy Management

Chapter 13

  1. The seinfo application is used to query the policy for its type content, but not for its rules. For instance, you list the types within the policy with seinfo, but you don't query what these types can do.

    The sesearch application, on the other hand, is used to query the rules within the policy, but does not reveal anything about the various definitions inside the policy that are not really rules (such as attribute definitions and supported classes).

    Hence, the main difference is that seinfo focuses on the structure of the policy, whereas sesearch focuses on the enforcements defined within the policy.

  2. Reaching a domain implies domain transitions. Hence, what we are looking for is how you can transition from your current domain (say staff_t) to the target domain (say unconfined_t) and through which means—generally, this is done by executing a binary or script that triggers a type transition.

    Analyzing domain transitions can be done using apol (the graphical...