IssueTracker

Hi.
The problem is that in my app, i have some logic for the BIOMETRIC_ERROR_NONE_ENROLLED case.
On Android 9, this error is not returned when it should be.

BUILD INFO
- Device type: Huawei P20 Lite (ANE-LX1)
- OS version: Android 9 - EMUI 9.1.0
- Biometric library version: 1.1.0 and also 1.2.0-alpha3

STEPS TO REPRODUCE
1. Remove all fingerprints saved but not device credentials
2. Use BiometricManager.from(this).canAuthenticate(BIOMETRIC_STRONG)

EXPECTED RESULTS: 11 (BIOMETRIC_ERROR_NONE_ENROLLED)
OBSERVED RESULTS: -1 (BIOMETRIC_STATUS_UNKNOWN)
NUMBER OF TIMES YOU WERE ABLE TO REPRODUCE: 10/10

When you show the BiometricPrompt, the error code returned in the BiometricPrompt.AuthenticationCallback is 11.
When you delete all the fingerprints AND the device credentials, canAuthenticate returns 11.

I saw the source code of BiometricManager, in the method canAuthenticateWithFingerprintOrUnknownBiometric()

// Check for definite availability of fingerprint. Otherwise, return "unknown" to allow for
// non-fingerprint biometrics (e.g. iris) that may be available via BiometricPrompt.
return canAuthenticateWithFingerprint() == BIOMETRIC_SUCCESS
                ? BIOMETRIC_SUCCESS
                : BIOMETRIC_STATUS_UNKNOWN;

canAuthenticateWithFingerprint() returns BIOMETRIC_ERROR_NONE_ENROLLED, but this value is ignored, and all the errors returned are mapped in BIOMETRIC_STATUS_UNKNOWN.

This is for the "iris" biometric authentication, but for this, I'm forced to use the method hasEnrolledFingerprints() of the FingerprintManagerCompat, even if deprecated, to have the correct error.

Isn't there a way to have the BIOMETRIC_ERROR_NONE_ENROLLED error from the "canAuthenticate(BIOMETRIC_STRONG)" method in Android 9?

Thank you for your time.

Regards,
Francesco.