/biometric_storage

Flutter plugin to store data behind biometric authentication (ie. fingerprint)

Primary LanguageDartMIT LicenseMIT

biometric_storage

Pub

Encrypted file store, optionally secured by biometric lock for Android, iOS, MacOS and partial support for Linux, Windows and Web.

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.
  • iOS and MacOS: LocalAuthentication with KeyChain.
  • Linux: Stores values in Keyring using libsecret. (No biometric authentication support).
  • Windows: Uses wincreds.h to store into read/write into credential store.
  • Web: Warning Uses unauthenticated, unencrypted storage in localStorage. If you have a better idea for secure storage on web platform, please open an Issue.

Check out AuthPass Password Manager for a app which makes heavy use of this plugin.

Getting Started

Android

  • Requirements:

    • Android: API Level >= 23

    • 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>

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

Mac OS

  • include the NSFaceIDUsageDescription key in your app’s Info.plist file
  • enable keychain sharing and signing. (not sure why this is required. but without it You will probably see an error like:

    SecurityError, Error while writing data: -34018: A required entitlement isn't present.

  • Requires at least Mac OS 10.12

Resources