When using libaacs to decrypt Blu-ray discs, it will ask for a keyfile, and look for KEYDB.cfg in your ~/.config/aacs/ directory.

The KEYDB.2017-09-02.cfg was the last one available at http://labdv.com/aacs/ (they have since removed it the site).

The KEYDB.2017-12-12.cfg was downloaded from http://vlc-bluray.whoknowsmy.name/ and the place I'd recommend always getting the most current.