Secure data in secure storage using biometrics

Question

I'm looking for a way to add biometric authentication for reading values from secure storage (KeyStore and KeyChain) in the Flutter app.

I have found that this is possible to do in Android, I have not managed to make it work though:
https://labs.f-secure.com/blog/how-secure-is-your-android-keystore-authentication/
https://riptutorial.com/android/example/29719/how-to-use-android-fingerprint-api-to-save-user-passwords

In iOS:
https://developer.apple.com/documentation/localauthentication/accessing_keychain_items_with_face_id_or_touch_id

Flutter secure storage package: https://pub.dev/packages/flutter_secure_storage

flutter_secure_storage is simple package and I have not seen any option to add biometric prompt on storage access.

Is there any way to add biometrics prompt on access to secure storage in from Flutter program using existing packages?

Answer 1

There is a Flutter package that does exactly what you're looking for called biometric_storage. It stores a string of data in Keystore/Keychain and the data is only accessible after authenticating with biometrics. It does require biometric authentication in order to write the file to Keystore/Keychain so when saving the data you will also be prompted for biometric authentication.