In this tutorial, we will show you how to add fingerprint authentication to your app.

What are the advantages of fingerprint authentication?

• Fast and easy to use

• Secure: fingerprint uniquely identifies you

• Online transactions are safer

How to implement fingerprint authentication in your app:

• Verify that the lock screen is secure, or in other words, it is protected by a PIN, password, or pattern.

• Verify that at least one fingerprint is registered on the smartphone.

• Get access to the Android keystore to store the key used to encrypt/decrypt an object.

• Generate an encryption key and cipher.

• Start the authentication process.

• Implement a callback class to handle authentication events.

These are several steps to follow to enable fingerprint authentication. But still, you have to write lots of code to implement that.

Well, here is an easy way to implement this in your app by writing 5 – 10 lines in your code.

I have created a module library which will do all of the above for you, and by writing very little code, you can implement fingerprint authentication in your app in just five minutes and in any way you want.

Follow these steps:

Step 1) Add Dependency to Gradle

Add this dependency to your module's Gradle file:

implementation 'com.sa.hardik:fingerprintauthentication:0.1'

Step 2) Implement Callback

You can either implement this in your class and override the methods, or you can pass it as a constructor parameter.

Class MainActivity: AppcompactActivity(), FingerprintHandlerCallback {……

 override fun success() {
  //Todo on successful fingerprint authentication
 }

 override fun error(errorMsg: String) {
  //Todo on error in fingerprint authentication
 }

}

Step 3) Initialize the Fingerprint Authentication

val fManager = FingerprintManagerHelper(context, "MYKEY", callback)
fManager.initFingerprint()

Here,
context - Context reference of your activity or application
MYKEY - Encryption KEY
Callback - Reference of‘ FingerprintHandlerCallback’ implemented in library to get
success and error callback

That’s it! You have successfully implemented the fingerprint authentication in your app. You can use the same for payment authentication as well.

You can download the full demo from this GitHub URL.

Note: There are many devices which do not have a fingerprint sensor. In that case, you will receive an error callback at the time of initialization.