SELinux is a free open source software project that was developed by the U.S. National Security Agency. While it can theoretically be installed on any Linux distro, the Red Hat-type distros are the only ones that come with it already set up and enabled. It uses code in Linux kernel modules, along with filesystem-extended attributes, to help ensure that only authorized users and processes can access either sensitive files or system resources. There are three ways in which SELinux can be used:
- It can help prevent intruders from exploiting a system
- It can be used to ensure that only users with the proper security clearance can access files that are labeled with a security classification
- In addition to MAC, SELinux can also be used as a type of role-based access control
In this chapter, I'll only be covering the first of these...
