Maybe one of you guys know this.
No complaints here, just doing experiments.
XA2 4.3
I made a backup by dding mmcblk0p76 partition (as proposed by DrYak in the [xa2] Full-backup in terminal thread (click “see more comments” near the end)).
/dev/mmcblk0p76 contains / and /home if I got it correctly.
Then, I restored this on another XA2 freshly installed with 4.3.
Everything seems to be back (calendar, contacts, pictures, messages)
Except fingerprints, and I can’t record new ones. (“Error, your fingerprint could not be captured”).
So, I went to this question: Where are they stored, outside of / and /home ?
Optional side questions:
-are they uploaded somewhere on any cloud?
-could I convert them to images to see my digitalized fingerprints?
There is some variance between devices but basically fingerprint data storage / handling at least ought to be dictated by Android rules for biometric data - which is roughly: data acquired from biometric sensors is never available in raw/usable form. Access to sensors, data acquisition, processing, and matching is done in hardware backed trusted execution environment. When/if data is stored outside tee, it is encrypted in a way that makes it accessible only by tee sw on the device where it was originally recorded.
Data is signed with a device specific key and thus by design is not transferable from one device to another.
There probably is fingerprint data in the backup (under /var/lib/sailfish-fpd/) and - since it is invalid due to originating from another device - it is confusing some parts of the sw stack. You probably need to get rid of it. Something like:
