1 2Android FingerprintDialog Sample (Kotlin) 3========================================= 4 5A sample that demonstrates to use registered fingerprints to authenticate the user in your app 6 7Introduction 8------------ 9 10This sample demonstrates how you can use registered fingerprints in your app to authenticate the 11user before proceeding some actions such as purchasing an item. 12 13First you need to create a symmetric key in the Android Key Store using [KeyGenerator][1] 14which can be only be used after the user has authenticated with fingerprint and pass 15a [KeyGenParameterSpec][2]. 16 17By setting [KeyGenParameterSpec.Builder.setUserAuthenticationRequired][3] to true, you can permit 18the use of the key only after the user authenticate it including when authenticated with the user's 19fingerprint. 20 21Then start listening to a fingerprint on the fingerprint sensor by calling 22[FingerprintManager.authenticate][4] with a [Cipher][5] initialized with the symmetric key created. 23Or alternatively you can fall back to server-side verified password as an authenticator. 24 25Once the fingerprint (or password) is verified, the 26[FingerprintManager.AuthenticationCallback#onAuthenticationSucceeded()][6] callback is called. 27 28[1]: https://developer.android.com/reference/javax/crypto/KeyGenerator.html 29[2]: https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.html 30[3]: https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.Builder.html#setUserAuthenticationRequired%28boolean%29 31[4]: https://developer.android.com/reference/android/hardware/fingerprint/FingerprintManager.html#authenticate%28android.hardware.fingerprint.FingerprintManager.CryptoObject,%20android.os.CancellationSignal,%20int,%20android.hardware.fingerprint.FingerprintManager.AuthenticationCallback,%20android.os.Handler%29 32[5]: https://developer.android.com/reference/javax/crypto/Cipher.html 33[6]: https://developer.android.com/reference/android/hardware/fingerprint/FingerprintManager.AuthenticationCallback.html#onAuthenticationSucceeded%28android.hardware.fingerprint.FingerprintManager.AuthenticationResult%29 34 35Pre-requisites 36-------------- 37 38- Android SDK 27 39- Android Support Repository 40 41Screenshots 42------------- 43 44<img src="screenshots/1-purchase-screen.png" height="400" alt="Screenshot"/> 45<img src="screenshots/2-fingerprint-dialog.png" height="400" alt="Screenshot"/> 46<img src="screenshots/3-fingerprint-authenticated.png" height="400" alt="Screenshot"/> 47<img src="screenshots/4-new-fingerprint-enrolled.png" height="400" alt="Screenshot"/> 48 49Getting Started 50--------------- 51 52This sample uses the Gradle build system. To build this project, use the 53"gradlew build" command or use "Import Project" in Android Studio. 54 55Support 56------- 57 58- Google+ Community: https://plus.google.com/communities/105153134372062985968 59- Stack Overflow: http://stackoverflow.com/questions/tagged/android 60 61If you've found an error in this sample, please file an issue: 62https://github.com/googlesamples/android-FingerprintDialog 63 64Patches are encouraged, and may be submitted by forking this project and 65submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details. 66 67License 68------- 69 70Copyright 2017 The Android Open Source Project, Inc. 71 72Licensed to the Apache Software Foundation (ASF) under one or more contributor 73license agreements. See the NOTICE file distributed with this work for 74additional information regarding copyright ownership. The ASF licenses this 75file to you under the Apache License, Version 2.0 (the "License"); you may not 76use this file except in compliance with the License. You may obtain a copy of 77the License at 78 79http://www.apache.org/licenses/LICENSE-2.0 80 81Unless required by applicable law or agreed to in writing, software 82distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 83WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 84License for the specific language governing permissions and limitations under 85the License. 86
