libxslt should be ported to use NSS library for cryptography. See the tracking bug for details and links on how it could be done.
I happen to be the upstream maintainer for that package, so I might actually be able to do this the correct way i.e. as an upstream patch. I would however appreciate if you could log that request as a bug in the upstream bugzilla.gnome.org for the module libxslt. Note however the concerns that I made as comment #5 on the tracking bug, thanks, Daniel
Has the upstream bug been filed? If so it might be helpful to include a link here.