In today’s fast-paced digital landscape, security is paramount, particularly in mobile applications that handle sensitive information such as personal data or financial accounts. One effective way to enhance security is by integrating biometric authentication options like FaceID and TouchID. This not only offers users a quick and seamless method for logging into apps but also adds an extra layer of protection. This guide will walk you through the implementation of biometric authentication in an Ionic app, outlining the steps necessary for protecting your application after it has been sent to the background or after a defined period of inactivity.

Understanding the Basics of Biometric Authentication in Ionic

Biometric authentication uses a person’s physical characteristics—like fingerprints or facial features—to grant access to devices or applications. Implementing biometric authentication in your Ionic application can be particularly useful for password managers or banking apps, where security is essential. This method provides a secure alternative to traditional login methods, eliminating the need for users to remember complex passwords.

Why Use Biometric Authentication?

• Enhanced Security: Biometric data is difficult to replicate compared to passwords.
• User Convenience: Unlocking apps through biometrics is faster and simpler, improving the overall user experience.
• Reduced Password Fatigue: Users do not need to remember multiple passwords, which encourages the usage of apps.

Getting Started with Your Ionic Application

Setting Up Your Ionic Project

1. Create a New Ionic Application: Start by setting up a blank Ionic app if you haven’t already. Use the command:

   ionic start MyApp blank

2. Install the Biometric Authentication Plugin: Use the Capacitor plugin for biometric authentication, which can handle the integration seamlessly.

   npm install capacitor-biometric-auth

Creating Necessary Pages in Your App

In this implementation, you will create three primary pages: a login page, an inside area page, and a lock screen page.

• Login Page: Central to your application’s initial access point.
• Inside Area Page: For active app usage post-login.
• Lock Screen Modal: To appear when the application is inactive, requiring the user to authenticate again.

Configuring Your App for iOS and Android

For Android: Modify the MainActivity.java file to import the biometric authentication plugin and implement necessary functionalities.
For iOS: Add the NSFaceIDUsageDescription key in your project settings to ensure proper permissions are granted for biometric data usage.

Implementing the Lock Functionality

Timer and Lockout Mechanism

1. Create a Lockout Timer: This timer will count down after user inactivity.

   private lockoutTimer: BehaviorSubject<number>;

2. Resetting the Timer: Every time the user performs an action, reset this timer to prevent the app from locking too soon. For example, after a successful HTTP request, trigger the reset.
3. Decreasing the Timer: Implement a function to decrement this timer until it reaches zero, at which point the lock screen should be displayed.

   decreaseTimer() {
       setTimeout(() => {
           // Logic to decrease the timer
       }, 1000);
   }

Handling App State Changes

Listen for platform pause events to lock the application when it goes into the background:

this.platform.pause.subscribe(() => this.lockApplication());

This ensures that your application remains secure if the user inadvertently leaves it open.

Integrating Biometric Authentication

Verifying the User’s Identity

Utilizing the biometric authentication plugin, check if the device supports this feature and then prompt the user for authentication. During initialization, check for biometric availability:

if (biometricAuth.isAvailable()) {
    biometricAuth.verify().then(result => {
        if (result.verified) {
            // Dismiss lock screen
        }
    });
}

Implementing a Fallback Mechanism

In case biometric verification fails, it’s essential to have a fallback login method, like an alternative password entry. This ensures that users can still access their accounts in case of issues with biometrics.

Finalizing Your Application

After finishing the coding and configuration, run your Ionic application on a real device, as biometric authentication does not function within a browser environment. Test functionality in various scenarios, such as.

1. Logging in.
2. Switching the app to the background and reopening it (the lock screen should appear).
3. Failing biometric authentication while having a fallback option.

Conclusion

Integrating biometric authentication into your Ionic app significantly strengthens its security while enhancing user experience. This tutorial has covered the essential steps for implementing FaceID or TouchID, providing a framework that ensures your app is not only user-friendly but secure. Keep in mind that while biometric authentication adds a layer of protection, it should complement existing authentication methods rather than replace them entirely.

If you’re looking to improve your skills further or explore more in-depth tutorials, consider joining the Ionic Academy. Happy coding!