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

Communicating over D-Bus

The D-Bus daemon provides an inter-process communication channel between applications. Unlike traditional IPC methods, D-Bus is a higher-level communication channel that offers more than simple signaling or memory sharing. Applications that want to chat over D-Bus link with one of the many D-Bus-compatible libraries, such as those provided by the libdbus, sd-bus (part of systemd), GDBus, and QtDBus applications.

The D-Bus daemon is part of the systemd application suite.

Understanding D-Bus

Linux generally supports two D-Bus types – system-wide and session-specific D-Bus instances:

  • The system-wide D-Bus is the main instance used for system communication. Many services or daemons will associate themselves with the system D-Bus to allow others to communicate with them through D-Bus.
  • The session-specific D-Bus is an instance running for each logged-in user. It is commonly used by graphical applications to communicate with each other...