HardenedBSD is a fork of FreeBSD, founded in 2014, that implements exploit mitigations and security hardening technologies. The primary goal of HardenedBSD is to perform a clean-room re-implementation of the grsecurity patchset for Linux to HardenedBSD.

Why Fork FreeBSD?

Work on HardenedBSD began in 2013 when Oliver Pinter and Shawn Webb started working on an implementation of Address Space Layout Randomization (ASLR), based on PaX’s publicly-available documentation, for FreeBSD. At that time, HardenedBSD was meant to be a staging area for experimental development on the ASLR patch. Over time, as the process of upstreaming ASLR to FreeBSD became more difficult, HardenedBSD naturally became a fork.

HardenedBSD completed its ASLR implementation in 2015 with the strongest form of ASLR in any of the BSDs. Since then, HardenedBSD has moved on to implementing other exploit mitigations and hardening technologies. OPNsense, an open source firewall based on FreeBSD, incorporated HardenedBSD’s ASLR implementation in 2016.

HardenedBSD exists today as a fork of FreeBSD that closely follows FreeBSD’s source code. HardenedBSD syncs with FreeBSD every six hours.

HardenedBSD’s Goals

HardenedBSD aims to provide the BSD community with a clean-room reimplementation of the publicly-documented portions of the grsecurity patchset for Linux.

Who is HardenedBSD?

HardenedBSD’s core team consists of Oliver Pinter and Shawn Webb. Contributions have been made by many individuals around the globe.

Cooperation with OPNsense

In May 2015, HardenedBSD announced collaboration with OPNSense. A HardenedBSD-flavored version of OPNsense was published early on as a proof-of-concept work. As the proof-of-concept proved stable, robust, and scalable, OPNsense migrated to HardenedBSD with the support of HardenedBSD’s core team.