TrustedBSD provides a file system access control list implementation that provides enhanced discretionary access control as required by the CC CAPP specification at higher assurance levels. This implementation is based on the POSIX.1eD17 draft specification, and is API-compatible with the ACL implementations found on many other UNIX systems. The TrustedBSD implementation stores access control lists in file system extended attributes, as found in the UFS1 and UFS2 file systems on FreeBSD. The TrustedBSD POSIX.1e ACL library may also found in Mac OS X, although wrapping NTFS-style ACLs, and portions of the ACL library documentation may be found in Linux. TrustedBSD ACLs are present in FreeBSD 5.0 and greater, and are supported by Samba, KDE, and a number of other applications.

Currently, prototyping work is being performed relating to adding support for NFSv4-style ACLs behind the existing APIs in FreeBSD, in a manner similar to Mac OS X. This may provide improved compatibility with NFSv4 and NTFS. Check back on this web page for future updates as this work continues.