PLEASE NOTE:

If your project has minSDK 23 and should support only basic Fingerprint Authorization on most devices - take a look first at the AndroidX's Biometric .

If you still need advanced Biometric authentication use Fingerpint, Face or Iris on the wide range of devices - see doc below.

Advanced BiometricPromptCompat

Introduction

What is BiometricPrompt API?

This is a new API that declares that the system takes care of a unified way to use different biometric identification methods - fingerprint, face, iris, etc., as well as a unified way to display the UI on all devices.

To learn more, read BiometricPrompt Reference in Android Developers site.

Unfortunately, this simplification hides a number of problems.

• On Android 9, there is no way to simply get information about whether there is available biometric hardware and whether biometric data is enrolled. Android 10 provides BiometricManager that partially solves this problem.
• Some manufacturers have removed/do not display the biometric UI
• Biometric Auth solutions like Samsung Pass SDK or Meizu Fingerprint need to implement separately
• No way to identify what types of biometric auth available on the device.

How to use BiometricPromptCompat in old devices?

BiometricPromptCompat is designed to be compatible with the largest number of Android devices.
Its interface is very close to the original BiometricPrompt.
Minimal supported SDK - Android 4.1 JellyBean (API 16)

Key features

• Unified UI for all devices - starts from Android 4.1 and to Android 11
• Contains fix for devices WITHOUT system BiometricPrompt UI (like LG G8 or OnePlus 6T)
• Dark/Light themes supported; Also you able to get the background color of the current Biometric dialog
• Auth in Split-Screen Mode supported
• Wide range of supported biometrics

Supported types of biometric authentication

Screenshots:

Xiaomi Pocophone F1

Samsung Galaxy S5

Huawei Mate P40 Pro

Prestigio PAP3400

Video from Xiaomi Pocophone F1

Setup

VERSION =

Add dependency to Gradle

dependencies {
 implementation 'dev.skomlach:biometric:${VERSION}' 
}

Usage

BiometricPromptCompat API

At first, better in Application.onCreate(), call

BiometricPromptCompat.init(callback);//Callback - null or Runnable{ do_something_after_init(); }     

BiometricManagerCompat

static boolean hasEnrolled() - returns true if specified biometric enrolled

static boolean isBiometricSensorPermanentlyLocked() - returns true if specified biometric permanently locked; Device lock-unlock or reboot required from the user

static boolean isHardwareDetected() - returns true if specified biometric hardware available

static boolean isLockOut() - returns true if specified biometric temporarily locked; Usually need to wait for 30 seconds and the system will reset this lock

static boolean isNewBiometricApi() - returns true if BiometricPrompt API used for specified biometric

static boolean openSettings(Activity) - returns true if open the "Enroll biometric" settings screen for specified biometric

static boolean isBiometricEnrollChanged - returns true if enrollment changed for specified biometric.

NOTE!!! Be careful using 'isBiometricEnrollChanged' - due to technical limitations, it can return incorrect result in some cases

BiometricAuthRequest

Allows you to configure the type of target biometrics.
It can be any combination of BiometricApi and BiometricType;
Default is BiometricAuthRequest(BiometricApi.AUTO, BiometricType.BIOMETRIC_ANY, BiometricConfirmation.ANY) - means any available BiometricApi and BiometricType

BiometricConfirmation:

BiometricConfirmation.ANY - any biometric confirm the user

BiometricConfirmation.ALL - all (one-by-one) biometrics confirm the user

BiometricApi:

BiometricApi.AUTO - the library will peek at the best-matched API

BiometricApi.LEGACY_API - forced usage of legacy biometric APIs like Fingerprint or FaceUnlock, and custom UI

BiometricApi.BIOMETRIC_API - forced usage of new BiometricPrompt API

BiometricType:

BiometricType.BIOMETRIC_FINGERPRINT - Use only Fingerprint biometric, ignore others

BiometricType.BIOMETRIC_FACE - Use only FaceId biometric, ignore others

BiometricType.BIOMETRIC_IRIS - Use only Iris biometric, ignore others

BiometricType.BIOMETRIC_ANY - use any available biometric (multiple types supported)

BiometricPromptCompat.Builder

BiometricPromptCompat.Builder builder =  
 new BiometricPromptCompat.Builder(getActivity()) .setTitle("Biometric demo") .setNegativeButton("Cancel", null); BiometricPromptCompat biometricPromptCompat = builder.build();    

Please note:
Methods builder.setTitle() and builder.setNegativeButton() are mandatory.

BiometricPromptCompat:

void authenticate(BiometricPromptCompat.Result resultCallback) - start biometric auth workflow

void cancelAuthenticate() - cancel active biometric auth workflow

boolean cancelAuthenticateBecauseOnPause() - Useful if you need to allow biometric auth in Split-Screen mode; Recommended to call this method in onPause() and use returned value to avoid biometric auth restart.
Returns false and keep biometric auth on display if the app in Split-Screen mode, returns true and cancel active biometric auth otherwise

@ColorRes int getDialogMainColor() - returns dialog background color

BiometricPromptCompat.Result

void onSucceeded(Set<BiometricType> confirmed) - User successfully authenticated

void onCanceled() - Biometric authentication was canceled

void onFailed(AuthenticationFailureReason reason) - Error happens, see details in AuthenticationFailureReason

void onUIOpened()/void onUIClosed - Biometric UI on display or closed

False-positive and/or False-negative detection

On pure API28 implementation (built-in BiometricPrompt API) is no way to get 'isBiometricEnrolled' results for specific biometric, like Iris/Face, etc. So, some tricks have used that try to determine by indirect signs which biometric data are used (like "if NOT fingerprint, BUT something enrolled in the System Settings").

There are edge cases where we cannot tell exactly what type of biometrics is enrolled - for example, if it is Samsung with Face and Iris - in this case, the code can give a incorrect result. It can happen if you set BiometricApi.BIOMETRIC_API + BiometricType.BIOMETRIC_FACE or BiometricApi.BIOMETRIC_API + BiometricType.BIOMETRIC_IRIS

Fortunately, for Samsung with Face and Iris, the 'legacy' check should work correctly, so for general cases when you use BiometricApi.AUTO/LEGACY_API + BiometricType.BIOMETRIC_FACE/BIOMETRIC_IRIS all should work fine.

I have a device that can be unlocked using Fingerprint/Face/Iris and(or) I can use this biometric type in pre-installed apps. But it doesn't work on 3rd party apps. Can you help?

Yes, this is, unfortunately, happening very often. Many functions demanded by the market are often implemented by device manufacturers before the same API appears in the official Android SDK.

The device manufacturer has implemented biometric authentication via fingerprint/face/iris, but "forgot" to provide access to this implementation for third-party developers. Therefore, preinstalled (system) applications developed by the device manufacturer can use biometrics, while banking applications, password managers, and other third-party applications cannot.

And unfortunately, sometimes manufacturers create such implementations that it is impossible to access using any known technic.

Anyway, research and testing required for each case, so feel free to create issues or contact directly with me.

Types of Biometrics

https://www.biometricsinstitute.org/what-is-biometrics/types-of-biometrics/

HOWTO SETUP

FaceUnlock: https://www.xda-developers.com/face-unlock/

Fingerprint: https://www.wikihow.com/Set-Up-the-Fingerprint-Scanner-on-an-Android-Device

IrisUnlock: https://www.samsung.com/ph/support/mobile-devices/what-is-iris-scanning-and-how-to-use-it-on-my-samsung-galaxy-device/

Contact author

Telegram: @SergeyKomlach

Twitter: @SergejKomlach

License

Apache License 2.0