flutter_app_shield 0.2.0

Flutter security wrapper: screenshot/recording prevention, capture detection, biometric lock, inactivity auto-lock, and per-screen SecureScope.

Flutter App Shield

A powerful Flutter security wrapper for screenshot/recording prevention, capture detection, biometric lock, inactivity auto-lock, and per-screen protection.

Features

• Prevent Screenshots & Recordings – Native prevention via no_screenshot
• Capture Detection – Callbacks when a screenshot or recording starts/stops
• Blur in Background – Frosted overlay in the app switcher (secure_application)
• Resume / Launch Auth – Require biometrics or PIN on resume and/or first launch
• Inactivity Auto-Lock – Lock after a configurable idle timeout
• Runtime Controller – Lock, unlock, and toggle prevention without rebuilding
• SecureScope – Protect only a sensitive page/subtree (reference-counted)
• Root / Jailbreak & Developer Mode – Separate policy flags
• Highly Customizable – Custom lock screens, max attempts, exit-on-fail, and more

Installation

dependencies:
  flutter_app_shield: ^0.2.0

flutter pub get

Required Configuration

iOS – Add to Info.plist:

<key>NSFaceIDUsageDescription</key>
<string>This app uses biometric authentication to protect your sensitive data.</string>

Android – No extra permissions needed for core features.

Quick start

import 'package:flutter/material.dart';
import 'package:flutter_app_shield/flutter_app_shield.dart';

void main() {
  runApp(
    AppShield(
      preventScreenshot: true,
      requireAuthOnResume: true,
      requireAuthOnLaunch: false,
      inactivityTimeout: const Duration(minutes: 1),
      blockOnJailbreak: true,
      blockOnDeveloperMode: false,
      listenToCaptureEvents: true,
      onScreenshot: (e) => debugPrint('Screenshot at ${e.timestamp}'),
      child: const MaterialApp(home: HomeScreen()),
    ),
  );
}

Runtime controller

final controller = AppShieldController();

AppShield(
  controller: controller,
  requireAuthOnResume: true,
  child: MyApp(),
);

// Later:
await controller.lock();
await controller.unlock(); // runs biometric when wired by AppShield
await controller.setScreenshotPrevention(false);
print(controller.isLocked);

Per-screen protection

Navigator.push(
  context,
  MaterialPageRoute(
    builder: (_) => SecureScope(
      child: SensitivePage(),
    ),
  ),
);

Nested SecureScope / AppShield prevention claims share a reference count, so protection stays on until the last holder is disposed.

Customization

AppShield(
  maxAuthAttempts: 5,
  maxAttemptsMessage: 'Too many failed attempts. App locked for security.',
  authLocalizedReason: 'Unlock to continue',
  compromisedDeviceBuilder: const Scaffold(
    backgroundColor: Colors.black,
    body: Center(
      child: Text(
        'This app cannot run on rooted or jailbroken devices.',
        style: TextStyle(color: Colors.red, fontSize: 20),
        textAlign: TextAlign.center,
      ),
    ),
  ),
  lockedBuilder: (context, secureController) => Center(
    child: ElevatedButton(
      onPressed: () => secureController?.unlock(),
      child: const Text('Unlock'),
    ),
  ),
  child: MaterialApp(...),
);

Breaking change in 0.2.0

blockOnJailbreak: true no longer blocks Android developer mode by itself. Use blockOnDeveloperMode: true if you need that behavior.

Development & Testing

• Test screenshot prevention and root detection on real devices
• Ensure biometrics or a device PIN is set up for auth testing
• exitOnMaxAttempts is disabled on Flutter Web

Contributing

Contributions are welcome.

• Report bugs or request features via Issues
• Submit Pull Requests with improvements

License

This project is licensed under the MIT License – see the LICENSE file for details.