secure_biometric_storage

Description:

secure biometric storage

secure_biometric_storage #
Fork of biometric_storage with focus on security
Encrypted file store, optionally secured by a biometric lock
for Android and iOS.
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.
Uses similar encryption mechanism as in flutter_secure_storage

Android: Uses androidx with KeyStore.
iOS: LocalAuthentication with KeyChain.

Security Enhancements: #

On both Android and iOS keys are invalidated if new fingerprint/face are added.
Auth-per-use keys are used for storages secured by a biometric lock.
BIOMETRIC_STRONG used on Android.


An auth-per-use key requires the user to present a biometric credential
each time your app needs to access data that's guarded by that key. Auth-per-use keys can be useful
for high-value transactions, such as making a large payment or updating a person's health records.

Getting Started #
Android #

Requirements:


Android: API Level >= 23


MainActivity must extend FlutterFragmentActivity


Theme for the main activity must use Theme.AppCompat theme.
(Otherwise there will be crashes on Android < 29)
For example:
AndroidManifest.xml:
<activity
android:name=".MainActivity"
android:launchMode="singleTop"
android:theme="@style/LaunchTheme"
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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>
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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

Resources #

https://developer.android.com/topic/security/data
https://developer.android.com/topic/security/best-practices
https://developer.android.com/training/sign-in/biometric-auth