Implement Biometric Authentication in Android Using Kotlin

How to Implement Biometric Authentication in Android using Kotlin

Biometric authentication is an increasingly popular security feature amongst the developers due to its convenience and high level of security. It is an alternative to the traditional authentication systems such as passwords and pins. In this tutorial, we will be focusing on how to implement biometric authentication in Android applications using Kotlin.

Step 1: Add the Appropriate Dependencies in the Gradle File

The first step towards implementing biometric authentication in Android applications is to add the necessary dependencies in the gradle file. For this, open the build.gradle (Module: app) file and add the following line in the dependencies section:

implementation "androidx.biometric:biometric:1.0.1"

Step 2: Check for Biometric Support

In this step, we need to check if the device which the app is running on supports biometrics authentication or not. This can be done by making use of the class BiometricManager which is from the biometric library. To check if biometrics are supported, create an instance of BiometricManager and then call the canAuthenticate() method. The method returns an integer value corresponding to the type of biometric support available on the device. If the value is BIOMETRIC_SUCCESS then it means that the device supports biometric authentication.

Step 3: Initiate Authentication

In this step, we will use the same BiometricManager object to initiate the authentication process. This is achieved by making use of the authenticate() method. This method requires a BiometricPrompt.AuthenticationCallback object which is used to handle authentication events. The BiometricPrompt.AuthenticationCallback includes four methods - onAuthenticationSucceeded(), onAuthenticationError(), onAuthenticationFailed(), and onAuthenticationHelp() which are used to handle different scenarios based on the result of the authentication process.

Step 4: Create a Biometric Prompt Object

Now, it’s time to create a BiometricPrompt object that will display a prompt for the user to authenticate using biometrics. We need to send a few parameters along with the creation of the object. These parameters include a prompt title, a description message and also an optional callback. The callback is used to receive the results of the authentication.

Once the BiometricPrompt object is created, we can call the authenticate() method to prompt the user to authenticate using their biometric credentials.

Conclusion

Biometric authentication is becoming increasingly popular as a secure and fast way to log in to applications. In this tutorial, we have learned how to implement biometric authentication in Android applications using Kotlin. We covered all the steps required to set up biometric authentication in a few simple steps.