Biometric Authentication Demo

A modern, secure Android application demonstrating the implementation of biometric authentication (Fingerprint, Face, Iris) using Jetpack Biometric and Jetpack Compose.

🚀 Key Features

• Standardized Auth: Uses BiometricPrompt for a consistent system-level experience.
• Compose Integration: Seamlessly bridges the FragmentActivity-based biometric API with a modern Compose UI.
• Robust State Handling: Manages authentication lifecycle states:
  • Idle: Initial state.
  • Success: Authentication confirmed.
  • Failed: Incorrect credential (allows retry).
  • Error: Hardware issues or user cancellation.
• Hardware Validation: Pre-flight checks using BiometricManager to verify hardware availability and enrollment.

🛠 Tech Stack & Requirements

• Kotlin 2.0+: Primary language with the modern Compose Compiler.
• Jetpack Compose: Declarative UI implementation.
• AndroidX Biometric (1.2.0-alpha05): Standard library for secure authentication.
• Min SDK: 24
• Target SDK: 36
• Architecture: MVVM with ViewModel and StateFlow.

📂 Architecture Overview

• MainActivity: Inherits from FragmentActivity (required for BiometricPrompt) and handles the authentication callback.
• MainViewModel: Encapsulates the AuthStatus logic, ensuring UI consistency during configuration changes.
• BiometricAuthScreen: A reactive UI that observes the ViewModel and triggers the system prompt.

🚀 Getting Started

1. Clone & Open: Open the project in the latest Android Studio.
2. Device Setup:
   • Use a physical device with a fingerprint or face scanner.
   • For Emulators, go to Settings > Security > Fingerprint and register a dummy print (usually by clicking the "..." menu in the emulator and selecting the Fingerprint tab).
3. Run: Deploy the :app module.

🔒 Security Note

The app uses BIOMETRIC_STRONG by default, ensuring that only Class 3 (formerly "Strong") biometrics are used, providing a high level of security suitable for sensitive data.