The user panel let you enroll the same finger several times

[PRASAD HEGDE]

We are able to enroll the same finger for all 10 available options. (No error like 'Fingerprint is already enrolled' is observed). In windows it doesn’t allow to enroll the same finger, it has a duplicate check API. Here we have all 10 finger options are shown in GUI itself, so whichever finger is enrolled atleast the same finger can be grayed out so that user cannot enroll the same finger again.

The release of Ubuntu: Ubuntu 20.04

[Sebastien Bacher (seb128)]

Thank you for your bug report, does it create any issue in practice or any buggy situation? It would probably be nicer if the UI was warning you about that but it seems pretty minor. I've forwarded it upstream anyway
https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/1023

[PRASAD HEGDE (prasad-hegde-nagapati)]

Hi Sebastian,

I am just referring s per windows implementation here. So the user may try to enroll the same finger several times and since the templates are stored in device(Not the host) it may run out of memory. Hence this duplicate check is necessary for those devices which stores the templates in device memory itself.

The other thing is you need to provide an API in the libfprint to do the duplicate check when enrolling a new finger. So this command goes to the device all through and device itself sees whether the finger is already enrolled or not. Depending on this output further enrollment process can be continued or a warning message can be displayed(As in windows).

You can refer the windows WBF API's for the same.

[Sebastien Bacher (seb128)]

Right, thanks for the details

[prafulla chandra kota (prafullakota)]

FP_DEVICE_ERROR_DATA_DUPLICATE error is added in libfprint 1.90.3 version, but when driver is returned this error, UI is not showing as duplicate finger error and showing Fingerprint enroll is failed, UI should show proper error here.

And also, post this failure, next finger enrollment is failed until system restart.

[prafulla chandra kota (prafullakota)]

Duplicate FP enrollment support is added in latest release 22.04, it is working fine now, defect can be closed.