A sample that demonstrates to use registered fingerprints to authenticate the user in your app

This sample demonstrates how you can use registered fingerprints in your app to authenticate the user before proceeding some actions such as purchasing an item.

First you need to create a symmetric key in the Android Key Store using KeyGenerator which can be only be used after the user has authenticated with fingerprint and pass a KeyGenParameterSpec.

By setting KeyGenParameterSpec.Builder.setUserAuthenticationRequired to true, you can permit the use of the key only after the user authenticate it including when authenticated with the user's fingerprint.

Then start listening to a fingerprint on the fingerprint sensor by calling FingerprintManager.authenticate with a Cipher initialized with the symmetric key created. Or alternatively you can fall back to server-side verified password as an authenticator.

Once the fingerprint (or password) is verified, the FingerprintManager.AuthenticationCallback#onAuthenticationSucceeded() callback is called.

• Android SDK 27
• Android Support Repository

This sample uses the Gradle build system. To build this project, use the "gradlew build" command or use "Import Project" in Android Studio.

• Stack Overflow: http://stackoverflow.com/questions/tagged/android

If you've found an error in this sample, please file an issue: https://github.com/android/security

Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.