Implementations
SELinux is available with commercial support as part of Red Hat Enterprise Linux (RHEL) version 4 and all future releases. This presence is also reflected in corresponding versions of CentOS and Scientific Linux. The supported policy in RHEL4 is the targeted policy which aims for maximum ease of use and thus is not as restrictive as it might be. Future versions of RHEL are planned to have more targets in the targeted policy which will mean more restrictive policies.
In free community supported GNU/Linux distributions, Fedora was one of the earliest adopters, including support for it by default since Fedora Core 2. Other distributions include support for it such as Debian as of the etch release, Ubuntu as of 8.04 Hardy Heron, Hardened Gentoo, and Yellow Dog Linux. It is also supported in EnGarde Secure Linux. As of version 11.1, openSUSE contains SELinux "basic enablement". SUSE Linux Enterprise 11 will feature SELinux as a "technology preview".
The earliest work directed toward standardizing an approach toward provision of mandatory and discretionary access controls (MAC and DAC) within a UNIX (more precisely, POSIX) computing environment can be attributed to the National Security Agency's Trusted UNIX (TRUSIX) Working Group, which met from 1987 to 1991 and published one Rainbow Book (#020A) and produced a formal model and associated evaluation evidence prototype (#020B) that was ultimately unpublished. It was sponsored by Chet Coates and Mario Tinto of the NSA's National Computer Security Center, and managed by Dr. Charles Testa and Bruce Wilner of Infosystems Technology (Greenbelt, Maryland; later, Falls Church, Virginia), the crucial architects of the TRUSIX project, and members of its Modeling Subcommittee — Steve Bunch, Dr. Frank Knowles, Dr. J. Eric Roskos, Larry Wehr, and Bruce Wilner. Their efforts, particularly as critics of the less technically profound work of the TRUSIX Access Control List (ACL) Subcommittee, survive in the IEEE POSIX 1003.6 "security extensions for portable operating systems environments" specification.
Read more about this topic: Security-Enhanced Linux