secure_content 3.0.0

Protect Flutter screens with screenshot detection, recording obscuring, biometric re-auth, inactivity lock, integrity checks, risk watermarks, and secure clipboard controls.

Secure Content

Protect sensitive Flutter UI from recording visibility, app switcher previews, and runtime risk states on Android and iOS. On iOS, screenshot events are detected and reported.

Screenshots

Android - Screen recording demo

https://user-images.githubusercontent.com/60510869/154502746-830d9198-8f11-46ba-9246-784def00f610.mp4

iOS - Screenshot detection result

iOS - Screen recording demo

https://github.com/user-attachments/assets/0b4e10ac-d592-4b5b-92bf-72f51b2cf570

iOS - App switcher demo

https://github.com/user-attachments/assets/b6ef5914-eb3a-4e17-be0c-2f00538cffec

Features

• Screenshot detection and recording obscuring
• App switcher protection with configurable color and optional branding image (iOS)
• Android 14+ screenshot callback support
• Biometric/device credential re-auth hooks
• Inactivity auto-lock for secure areas
• Integrity risk checks (root/jailbreak/debugger/emulator heuristics)
• Soft mode events and optional hard-block mode
• Sensitive clipboard with TTL-based auto-clear
• Risk-state watermark overlay (only shown when needed)

Installation

Requires Flutter 3.44+, Dart 3.11+, Android API 23+, and iOS 13+. iOS builds require a Swift 6 compiler (Xcode 16 or newer). Android host apps must compile against SDK 37 or later. The example uses AGP 9.3.3. The example and CI use Flutter 3.47.4, which requires iOS 15+. See the native toolchain for compiler versions and compatibility. AndroidX Core is constrained to 1.17.0 because newer releases remove the fingerprint implementation required by stable Biometric on Android 23–27.

dependencies:
  secure_content: ^3.0.0

For Face ID authentication, add a usage description to the host app's ios/Runner/Info.plist:

<key>NSFaceIDUsageDescription</key>
<string>Authenticate to access protected content.</string>

For biometric authentication on Android 23–27, the host activity must extend FlutterFragmentActivity. The example uses this activity on all Android versions:

import io.flutter.embedding.android.FlutterFragmentActivity

class MainActivity : FlutterFragmentActivity()

On Android 23–27, the activity theme must also inherit from Theme.AppCompat.DayNight.NoActionBar or another AppCompat theme. Set this parent for LaunchTheme and NormalTheme in both values/styles.xml and values-night/styles.xml. The example includes these themes.

Quick Start

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

SecureContentScope(
  enabled: true,
  protectInAppSwitcher: true,
  appSwitcherColor: Colors.black,
  policy: const SecureContentPolicy(
    requireBiometricOnResume: true,
    inactivityTimeout: Duration(seconds: 30),
    enableIntegrityChecks: true,
    hardBlockOnIntegrityRisk: false,
    enableRiskWatermark: true,
    watermarkText: 'CONFIDENTIAL',
  ),
  onEvent: (event) {
    debugPrint('Secure event: ${event.type.name}');
  },
  child: const YourSensitiveWidget(),
)

Scope and Native Protection

SecureContentScope scopes the Flutter overlay, lock screen, and risk watermark to its child. When the scope is enabled, it also enables native capture protection for the current app window. Native protection is not limited to the scope's child.

While a scope is locked or hard-blocked, its child cannot receive focus, pointer input, or accessibility actions. Its accessibility content is hidden until access is restored. Custom lock and hard-block builders must paint an opaque cover that fills the scope.

App Switcher Branding (iOS)

On iOS, when the app moves to the background, the multitasking snapshot and biometric re-auth moment are covered by a privacy overlay. By default this is a flat appSwitcherColor fill. Pass appSwitcherImageName to center one of your host app's native asset-catalog images on that overlay, rendered as a white-tinted template:

SecureContentScope(
  enabled: true,
  protectInAppSwitcher: true,
  appSwitcherColor: Colors.black,
  // Name of an image in the iOS app's asset catalog (Assets.xcassets).
  appSwitcherImageName: 'AppSwitcherLogo',
  child: const YourSensitiveWidget(),
)

The native iOS privacy cover always uses an opaque background. The alpha component of appSwitcherColor does not make protected content visible.

Note: appSwitcherImageName is iOS-only. Android uses FLAG_SECURE for capture and app-switcher protection. When protectInAppSwitcher is true, Android also sets the navigation-bar color to appSwitcherColor. Android does not add a branded app-switcher overlay, and it ignores the image name.

Global Protection

await SecureContent.setGlobalProtection(
  true,
  protectInAppSwitcher: true,
  appSwitcherColor: Colors.black,
);

Clipboard TTL

await SecureContent.setSensitiveClipboard(
  'one-time code: 123456',
  clearAfter: const Duration(seconds: 10),
);

iOS uses system pasteboard expiration and keeps sensitive copies local to the device. Automatic cleanup preserves newer clipboard entries, including a new copy of the same text. A zero or negative clearAfter disables automatic expiry.

Android restricts clipboard access while an app is in the background. If cleanup cannot access the clipboard, it remains pending until the app can access it again. The requested TTL is not a guaranteed background deletion deadline on Android. Process termination can also prevent app-scheduled cleanup.

Events

Listen to all secure events globally:

SecureContent.events.listen((event) {
  debugPrint('Secure event: ${event.type.name}');
});

Key event types include:

• screenshotCaptured
• recordingStarted / recordingStopped
• biometricAuthSucceeded / biometricAuthFailed / biometricUnavailable
• integritySafe / integrityRiskDetected
• clipboardSet / clipboardCleared
• idleLockActivated / idleLockReleased

Platform Support

Feature	iOS	Android
Screenshot Prevention	❌	✅
Screen Recording Obscuring	✅	✅
Screenshot Detection Callback	✅	✅ (Android 14+)
Screen Recording Start Callback	✅	❌
Screen Recording Stop Callback	✅	❌
Biometric Re-Auth	✅	✅
Inactivity Auto-Lock	✅	✅
Integrity Risk Check	✅	✅
Hard Block Mode	✅	✅
Sensitive Clipboard TTL	✅	✅
Risk-State Watermark	✅	✅
App Switcher Protection	✅	✅
Dynamic Security Toggle	✅	✅
Full App Protection	✅	✅

Notes

• Android screenshot callback requires Android 14+.
• Visual capture protection does not mute audio in a screen recording. Mute audio separately in the recording or media layer.
• Android system clipboard "Copied to clipboard" toast is controlled by the OS and cannot be disabled by apps.
• Integrity checks are heuristic signals, not a guaranteed anti-tamper boundary.
• The iOS plugin supports CocoaPods and Swift Package Manager. Its native window integration uses UIKit; it does not require SwiftUI.

Example

See example/lib/main.dart for a complete implementation including:

• global protection toggle
• biometric trigger
• integrity check trigger
• clipboard TTL action
• hard-block mode toggle
• secure scope with policy

License

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