In kernel stackable cryptographic filesystem (ownfs)

by Gleb Kurtsov for The FreeBSD Project

FreeBSD supports only whole filesystem encryption at device level (with GELI or GBDE), but lacks in kernel cryptographic filesystem that can be used transparently atop of other filesystem. Some progress has been seen here recently with userlevel cryptographic filesystems, but userlevel implementations are slow and relay and 3rd party software not included in base system (namely fuse kmod and library). I propose to implement in kernel cryptographic filesystem utilizing stackable VFS layers (like nullfs+crypto).