Biometric Auth Plugin (Premium)

This premium plugin allows you to add an extra layer of security by requiring biometric authentication (fingerprint, face recognition) before granting access to your app or specific features.

Secure, Non-Bypassable Gate

The authentication flow is designed to be a true security gate, not just a dismissible prompt.

• Blocking Overlay: When authentication is triggered, a full-screen overlay immediately blocks all app content, preventing any “glimpses” of the underlying UI.
• Non-Dismissible: The biometric prompt cannot be dismissed by tapping outside of it. The user must either authenticate successfully or explicitly exit the app.
• Persistent Lock: If the user sends the app to the background and then resumes it, the authentication flow is automatically re-triggered, preventing bypass through the “recents” screen.

Setup and Configuration

1. Obtain the Plugin: Acquire the BiometricPlugin.java file through a GitHub sponsorship.

2. Add to Project: Place the file in the plugins/ directory.

3. Enable Plugin: Ensure the plugin is enabled in SmartWebView.java:

   put("BiometricPlugin", true);
   

4. Configure Auth on Launch: To enable authentication every time the app starts, go to Playground.java and set the authOnAppLaunch config to true.

   // In Playground.java -> configurePlugins()
   runPluginAction("BiometricPlugin", plugin -> {
       Map<String, Object> config = SmartWebView.getPluginManager().getPluginConfig("BiometricPlugin");
       if (config != null) {
           config.put("authOnAppLaunch", true); // Set to true to enable
       }
   });
   

   If false (the default), authentication will only be triggered manually from your JavaScript.

Usage

The plugin is primarily controlled via a JavaScript interface.

Triggering Authentication from JavaScript

The plugin injects a window.Biometric object into your web page. You can call this to lock a specific feature or section of your app.

// Request biometric authentication
window.Biometric.authenticate();

Callbacks in JavaScript

Define callback functions in your JavaScript to handle the result of the authentication attempt.

// Called on successful authentication
window.Biometric.onAuthSuccess = function() {
  console.log("Authentication successful!");
  // Unlock feature or proceed with login
};

// Called if there's an error (e.g., no hardware, lock screen not set up)
// This is NOT called for simple failed attempts (fingerprint not recognized).
window.Biometric.onAuthError = function(errorMessage) {
  console.error("Authentication error:", errorMessage);
};

// Called when the fingerprint/face is not recognized. The prompt will remain
// visible for the user to try again.
window.Biometric.onAuthFailed = function() {
  console.warn("Authentication failed. Please try again.");
};