Android Tutorial => Adding the Fingerprint Scanner in Android...

Example

Android supports fingerprint api from Android 6.0 (Marshmallow) SDK 23

To use this feature in your app, first add the USE_FINGERPRINT permission in your manifest.

<uses-permission
        android:name="android.permission.USE_FINGERPRINT" />

Here the procedure to follow

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.

KeyPairGenerator.getInstance(KeyProperties.KEY_ALGORITHM_EC, "AndroidKeyStore");
keyPairGenerator.initialize(
        new KeyGenParameterSpec.Builder(KEY_NAME,
                KeyProperties.PURPOSE_SIGN)
                .setDigests(KeyProperties.DIGEST_SHA256)
                .setAlgorithmParameterSpec(new ECGenParameterSpec("secp256r1"))
                .setUserAuthenticationRequired(true)
                .build());
keyPairGenerator.generateKeyPair();

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.

KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
keyStore.load(null);
PublicKey publicKey =
        keyStore.getCertificate(MainActivity.KEY_NAME).getPublicKey();

KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
keyStore.load(null);
PrivateKey key = (PrivateKey) keyStore.getKey(KEY_NAME, null);

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.

Create and initialise the FingerprintManger from fingerprintManger.class

getContext().getSystemService(FingerprintManager.class)

To authenticate use FingerprintManger api and create subclass using

FingerprintManager.AuthenticationCallback and override the methods

onAuthenticationError
onAuthenticationHelp
onAuthenticationSucceeded
onAuthenticationFailed

To Start

To startListening the fingerPrint event call authenticate method with crypto

fingerprintManager
              .authenticate(cryptoObject, mCancellationSignal, 0 , this, null);

Cancel

to stop listenting the scanner call

android.os.CancellationSignal;

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

@Override

public void onAuthenticationSucceeded(AuthenticationResult result) {
               
            }

PDF - Download Android for free

Previous Next

Android

Fastest Entity Framework Extensions

Example

Got any Android Question?

Android

Android Fingerprint API in android Adding the Fingerprint Scanner in Android application

Fastest Entity Framework Extensions

Example

Got any Android Question?