A Flutter plugin to store data in secure storage:

• Keychain is used for iOS
• AES encryption is used for Android. AES secret key is encrypted with RSA and RSA key is stored in KeyStore

Note KeyStore was introduced in Android 4.3 (API level 18). The plugin wouldn't work for earlier versions.

import 'package:flutter_secure_storage/flutter_secure_storage.dart';

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

// Read value 
String value = await storage.read(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);

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

android {
    ...
    
    defaultConfig {
        ...
        minSdkVersion 18
        ...
    }

}

Note By default Android backups data on Google Drive. It can cause exception java.security.InvalidKeyException:Failed to unwrap key. You need to

• disable autobackup, details
• exclude sharedprefs FlutterSecureStorage used by the plugin, details

Run the following command from example directory

flutter drive --target=test_driver/app.dart