Flutter secure file storage

An implementation for flutter secure file storage. For example keychain has a soft limit of 4kb. Using the file system instead we can store much larger content.

AES/GCM/NoPadding encryption is used to encrypt the data. The keys are generated using Random.secureand stored using the flutter_secure_storage package, the values are encrypted by the pointycastle package or native for Android

Usage

It's implemented to use the same structure as FlutterSecureStorage and therefore you can switch easily between them. But we also support Uint8List as input/output

import 'package:flutter_secure_file_storage/flutter_secure_file_storage.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';

// Create storage
final storage = FlutterSecureFileStorage(FlutterSecureStorage());

// Read value
final value = await storage.read<String>(key: key);

// Read all values
Map<String, String> allValues = await storage.readAll();

// Delete value
await storage.delete(key: key);

// Delete all
await storage.deleteAll();

// Write value
await storage.write(key: key, value: value);

Configure Android version

In project/android/app/build.gradle set minSdkVersion to >= 18.

android {
    ...

    defaultConfig {
        ...
        minSdkVersion 18
        ...
    }

}