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

Supporting CIPSO with NetLabel and SELinux

NetLabel/CIPSO labels and transmits sensitivities across the network. Unlike labeled IPsec, no other context information is sent or synchronized. So, when we consider the communication flows between two points, they will have a default, common SELinux type (rather than the SELinux type associated with the source or target) but will have sensitivity labels based on the sensitivity label of the remote side.

Part of NetLabel's configuration are mapping definitions that inform the system which communication flows (from selected interfaces, or even from configured IP addresses) are for a certain Domain of Interpretation (DOI). The CIPSO standard defines the DOI as a collection of systems that interpret the CIPSO label similarly, or, in our case, use the same SELinux policy and configuration of sensitivity labels.

Once these mappings have been established, NetLabel/CIPSO will pass on the sensitivity information (and categories) between...