openrsync, a clean-room implementation of rsync, is being developed by Kristaps Dzonsons as part of the rpki-client(1) project [featured in an earlier article]. openrsync(1) has been imported into the tree (as "rsync") by Sebastian Benoit (benno@):
CVSROOT: /cvs Module name: src Changes by: firstname.lastname@example.org 2019/02/10 16:18:28 Added files: usr.bin/rsync : Makefile TODO.md blocks.c child.c client.c downloader.c extern.h fargs.c flist.c hash.c io.c log.c main.c md4.c md4.h mkpath.c receiver.c rsync.1 rsync.5 rsyncd.5 sender.c server.c session.c socket.c symlinks.c uploader.c Log message: Import Kristaps' openrsync into the tree. OK deraadt@
The "Security" section on the GitHub site contains a description of openrsync's use of OpenBSD's security features.
At the time of writing, rsync is not yet linked to the build.