IssueTracker

Some Xiaomi devices do not handle properly the credential fallback. Pressing the fallback button of the prompt or using the wrong finger to trigger the automatic credential fallback cause an immediate BiometricPrompt.ERROR_CANCELED (5) to be emitted. The credential activity starts regardless, but its result, be it success or failure, won't be passed back to the application.

I could work around this issue by forking the androidx library and forcing this condition to be true for Xiaomi devices. launchConfirmCredentialActivity() is going to show the BiometricPrompt and it will handle the credential fallback correctly.

So far I managed to reproduce the issue on a Redmi Note 8 Pro with Android 10. Not all the Xiaomi devices behave incorrectly, but I have no more info on this.

This appears to be the behavior of the native BiometricPrompt, so it is probably a vendor specific bug, but it is probably worth implementing some workaround in the library if feasible.

Here some information on the device affected by the issue:

[ro.build.characteristics]: [default]
[ro.build.date]: [Thu May 13 22:47:29 WIB 2021]
[ro.build.date.utc]: [1620920849]
[ro.build.description]: [begonia-user 10 QP1A.190711.020 V12.0.5.0.QGGEUXM release-keys]
[ro.build.display.id]: [QP1A.190711.020]
[ro.build.fingerprint]: [Redmi/begonia_eea/begonia:10/QP1A.190711.020/V12.0.5.0.QGGEUXM:user/release-keys]
[ro.build.flavor]: [begonia-user]
[ro.build.host]: [c5-miui-ota-bd169.bj]
[ro.build.id]: [QP1A.190711.020]
[ro.build.product]: [begonia]
[ro.build.system_root_image]: [false]
[ro.build.tags]: [release-keys]
[ro.build.type]: [user]
[ro.build.user]: [builder]
[ro.build.version.all_codenames]: [REL]
[ro.build.version.base_os]: [Redmi/begonia_eea/begonia:10/QP1A.190711.020/V12.0.4.0.QGGEUXM:user/release-keys]
[ro.build.version.codename]: [REL]
[ro.build.version.incremental]: [V12.0.5.0.QGGEUXM]
[ro.build.version.min_supported_target_sdk]: [23]
[ro.build.version.preview_sdk]: [0]
[ro.build.version.preview_sdk_fingerprint]: [REL]
[ro.build.version.release]: [10]
[ro.build.version.sdk]: [29]
[ro.build.version.security_patch]: [2021-04-01]