1 2 Android AsymmetricFingerprintDialog Sample 3 =================================== 4 5 A sample that demonstrates to use registered fingerprints to authenticate the user in your app 6 7 Introduction 8 ------------ 9 10 This sample demonstrates how you can use registered fingerprints in your app to authenticate the 11 user before proceeding some actions such as purchasing an item. 12 13 First you need to create an asymmetric key pair in the Android Key Store using [KeyPairGenerator][1] 14 in the way that its private key can only be used after the user has authenticated with fingerprint 15 and transmit the public key to your backend with the user verified password (In a real world, the 16 app should show proper UIs). 17 18 By setting [KeyGenParameterSpec.Builder.setUserAuthenticationRequired][2] to true, you can permit the 19 use of the key only after the user authenticate it including when authenticated with the user's 20 fingerprint. 21 22 Then start listening to a fingerprint on the fingerprint sensor by calling 23 [FingerprintManager.authenticate][3] with a [Signature][4] initialized with the asymmetric key pair 24 created. Or alternatively you can fall back to server-side verified password as an authenticator. 25 26 Once the fingerprint (or password) is verified, the 27 [FingerprintManager.AuthenticationCallback#onAuthenticationSucceeded()][5] callback is called. 28 29 Then you can verify the purchase transaction on server side with the public key passed from the 30 client, by verifying the piece of data signed by the Signature. 31 32 [1]: https://developer.android.com/reference/java/security/KeyPairGenerator.html 33 [2]: https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.Builder.html#setUserAuthenticationRequired%28boolean%29 34 [3]: 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 35 [4]: https://developer.android.com/reference/java/security/Signature.html 36 [5]: https://developer.android.com/reference/android/hardware/fingerprint/FingerprintManager.AuthenticationCallback.html#onAuthenticationSucceeded%28android.hardware.fingerprint.FingerprintManager.AuthenticationResult%29 37 38 Pre-requisites 39 -------------- 40 41 - Android SDK 24 42 - Android Build Tools v24.0.1 43 - Android Support Repository 44 45 Screenshots 46 ------------- 47 48 <img src="screenshots/1-purchase-screen.png" height="400" alt="Screenshot"/> <img src="screenshots/2-fingerprint-dialog.png" height="400" alt="Screenshot"/> <img src="screenshots/3-fingerprint-authenticated.png" height="400" alt="Screenshot"/> <img src="screenshots/4-new-fingerprint-enrolled.png" height="400" alt="Screenshot"/> 49 50 Getting Started 51 --------------- 52 53 This sample uses the Gradle build system. To build this project, use the 54 "gradlew build" command or use "Import Project" in Android Studio. 55 56 Support 57 ------- 58 59 - Google+ Community: https://plus.google.com/communities/105153134372062985968 60 - Stack Overflow: http://stackoverflow.com/questions/tagged/android 61 62 If you've found an error in this sample, please file an issue: 63 https://github.com/googlesamples/android-AsymmetricFingerprintDialog 64 65 Patches are encouraged, and may be submitted by forking this project and 66 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details. 67 68 License 69 ------- 70 71 Copyright 2016 The Android Open Source Project, Inc. 72 73 Licensed to the Apache Software Foundation (ASF) under one or more contributor 74 license agreements. See the NOTICE file distributed with this work for 75 additional information regarding copyright ownership. The ASF licenses this 76 file to you under the Apache License, Version 2.0 (the "License"); you may not 77 use this file except in compliance with the License. You may obtain a copy of 78 the License at 79 80 http://www.apache.org/licenses/LICENSE-2.0 81 82 Unless required by applicable law or agreed to in writing, software 83 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 84 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 85 License for the specific language governing permissions and limitations under 86 the License. 87
