We have reverse engineered CAL (for Fremantle) in CSSU repos so that shouldn't be a problem. That said, the only closed source blob left that use libcal and that isn't being dropped/replaced/cloned for other reasons is libdevlock.so.1.0.9, everything else using CAL is FOSS, needs to be cloned or needs to be dropped (e.g. softupd isn't something we can use on Neo900 because its too tied to N900 cellular modem)