Courtesy: GitHub

Android FingerprintDialog Sample

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 26
  • Android Build Tools v26.0.2
  • Android Support Repository


Screenshot Screenshot Screenshot Screenshot

Getting Started

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


If you've found an error in this sample, please file an issue:

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


Copyright 2017 The Android Open Source Project, Inc.

Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

compile ""

compile ""

compile ""

compile ""

compileSdkVersion 26

minSdkVersion 23

targetSdkVersion 26


versionCode 1

versionName 1.0


  • android.permission.USE_FINGERPRINT


Main entry point for the sample, showing a backpack and "Purchase" button.

Initialize the {@link Cipher} instance with the created key in the {@link #createKey(String, boolean)} method. * @param keyName the key name to init the cipher @return {@code true} if initialization is successful, {@code false} if the lock screen has been disabled or reset after the key was generated, or if a fingerprint got enrolled after the key was generated.

Proceed the purchase operation * @param withFingerprint {@code true} if the purchase was made by using a fingerprint @param cryptoObject the Crypto object

Tries to encrypt some data with the generated key in {@link #createKey} which is only works if the user has just authenticated via fingerprint.

Creates a symmetric key in the Android Key Store which can only be used after the user has authenticated with fingerprint. @param keyName the name of the key to be created @param invalidatedByBiometricEnrollment if {@code false} is passed, the created key will not be invalidated even if a new fingerprint is enrolled. The default value is {@code true}, so passing {@code true} doesn't change the behavior (the key will be invalidated if a new fingerprint is enrolled.). Note that this parameter is only valid if the app works on Android N developer preview.


Fragment for settings.