biometric_storage #

Encrypted file store, optionally secured by biometric lock for Android, iOS but android 5 not supported biometric but can use encrypt with random token

Meant as a way to store small data in a hardware encrypted fashion. E.g. to store passwords, secret keys, etc. but not massive amounts of data.

• Android: Uses androidx with KeyStore. but android 5 not supported biometric but can use encrypt with random token

• iOS LocalAuthentication with KeyChain.

Getting Started #

Installation #

Android

• Requirements:

  • Android: API Level >= 21 (android/app/build.gradle minSdkVersion 21)

  • Make sure to use the latest kotlin version:

    • android/build.gradle: ext.kotlin_version = '1.7.10' with gradle:7.3.0
    • classpath 'com.android.tools.build:gradle:7.3.0'

  • MainActivity must extend FlutterFragmentActivity

  • Theme for the main activity must use Theme.AppCompat thme. (Otherwise there will be crases on Android < 29) For example:

    AndroidManifest.xml:

    <activity
    android:name=".MainActivity"
    android:launchMode="singleTop"
    android:theme="@style/LaunchTheme">
    

    xml/styles.xml:

        <style name="LaunchTheme" parent="Theme.AppCompat.NoActionBar">
        <!-- Show a splash screen on the activity. Automatically removed when
             Flutter draws its first frame -->
        <item name="android:windowBackground">@drawable/launch_background</item>
    
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowActionBar">false</item>
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowContentOverlay">@null</item>
    </style>    
    

Resources

• https://developer.android.com/topic/security/data
• https://developer.android.com/topic/security/best-practices

iOS

https://developer.apple.com/documentation/localauthentication/logging_a_user_into_your_app_with_face_id_or_touch_id

• include the NSFaceIDUsageDescription key in your app’s Info.plist file
• Requires at least iOS 9

Known Issue: since iOS 15 the simulator seem to no longer support local authentication: https://developer.apple.com/forums/thread/685773

Usage #

You basically only need 4 methods.

1. Check whether biometric authentication is supported by the device

    final bool isBioSupported = await BiometricStorage().canAuth();

2. init AuthBio

 TBIBAuth().init(
      android: const AndroidAuthMessages(
        cancelButton: "Cancel",
        goToSettingsButton: "Settings",
        goToSettingsDescription: "Please set up your Touch IDs .",
        biometricHint: "Touch sensors",
        biometricNotRecognized: "Fingerprint not recognizeds.",
        deviceCredentialsRequiredTitle: "Fingerprint requireds",
        deviceCredentialsSetupDescription:
            "Please set up your Touch ID or Face IDs.",
      ),
      ios: const IOSAuthMessages(
          cancelButton: "Cancel",
          goToSettingsButton: "Settings",
          goToSettingsDescription: "Please set up your Touch ID.",
          lockOut: "Please reenable your Touch ID"));

3. need ask for auth before encrypt or decrypt data // need reason for auth

  await BiometricStorage().auth("Login to save data");

4. Write data // need send key , value

        await BiometricStorage().write("Login", "data to save");

5. Read data // need key

  await BiometricStorage().read("Login");