TrustedBSD Mandatory Access Control (MAC) Framework
Mandatory access controls extend operating system access control
policy by allowing administrators to enforce additional constraints
on user and application behavior.
The TrustedBSD MAC Framework is a kernel programming interface
allowing loadable modules to augment the system security policy in
order to implement mandatory access control in a flexible manner.
The TrustedBSD MAC Framework first shipped in FreeBSD 5.0, with
significant functionality, quality, and performance enhancements in
later releases. Supported policy modules include rule-based file
system firewall support, TCP/UDP port access control lists,
inter-user process visibility controls, as well as classic mandatory
access control policies such as Multi-Level Security (MLS) with
compartments, and fixed- and floating-label Biba integrity policies.
Third party policy modules include cryptographic checksums on system
binaries, and SEBSD, a port of the NSA
FLASK/SELinux policy to FreeBSD. A number of commercial
FreeBSD-based products make use of the TrustedBSD MAC Framework to
locally modify the operating system security policy.
MAC Framework and general MAC user documentation and a number of
implementation papers may be found on the documentation page.
The TrustedBSD MAC Framework is also present in Mac
OS X as of the Leopard release, where it is used to implement
Seatbelt and other system security services. The port of the MAC
Framework was performed initially as part of SEDarwin, which also included a port of
FLASK and SELinux to the Mac OS X platform.