libpassman : Library for interacting with passman++ database files. ( https://github.com/binex-dsk/libpassman )
olm : An implementation of a well known cryptographic ratchet in C++ ( https://gitlab.matrix.org/matrix-org/olm/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a swirl
For Paludis use this rsync : rsync://gentoo.zugaina.org/swirl-portage
If you have a problem : ycarus(-at-)zugaina.org