PIN Scrambling Bug

banjo8389

Recently installed GrapheneOS. I enabled fingerprint + PIN scrambling. Worked for 2 days.

Booted up my phone yesterday and noticed the numbers were no longer scrambled. GrapheneOS is saying that I am entering my PIN incorrectly.

Feels possible that this is a serious lockout bug with GrapheneOS where it's scrambling the numbers under the hood then displaying the unscrambled numbers to the user, locking the user out.

nandohyphen1

banjo8389 are Developer Options enabled?

banjo8389

nandohyphen1 Yes they are enabled

nandohyphen1

banjo8389 not saying it is, but that could be the problem right there. Developer Options can cause all sorts of weird things to happen that nothing except a factory reset can fix.

banjo8389

@nandohyphen1 Rebooted the phone several times, no dice. I eventually had to reinstall GrapheneOS, which was painful.

Symptoms are that the user sets fingerprint + scrambled pin -> something happens without user interaction -> device no longer scrambles pin. User locked out.

nandohyphen1

banjo8389 sorry to hear that you reinstalled GrapheneOS. If you haven't yet restored or re set it up, to figure out if this was an issue with developer options or not, perform this test. Turn developer options OFF. Set a PIN and enable PIN scrambling. Reboot the phone and try unlocking. If it works, it likely was related to developer options. And from now on, I strongly recommend you leave Developer Options off at all times so stuff like this doesn't happen anymore.