fix(app): add check for strongbox

Author: Numoy

flutter_secure_storage/android/src/main/java/com/it_nomads/fluttersecurestorage/FlutterSecureStorage.java

@@ -94,40 +94,6 @@ public void delete(String key) {
     public void deleteAll() {
         encryptedPreferences.edit().clear().apply();
     }
-
-    public boolean isStrongBoxAvailable() {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
-            try {
-                // Check if the device supports StrongBox
-                KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
-                keyStore.load(null);
-    
-                String keyAlias = "strongboxCheck";
-                KeyGenParameterSpec keyGenParameterSpec = new KeyGenParameterSpec.Builder(keyAlias,
-                        KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
-                        .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
-                        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
-                        .setKeySize(256)
-                        .build();
-    
-                KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
-                keyGenerator.init(keyGenParameterSpec);
-                keyGenerator.generateKey();
-    
-                // Check if the key was generated in StrongBox
-                KeyInfo keyInfo = (KeyInfo) KeyFactory.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")
-                        .getKeySpec(keyGenerator.generateKey(), KeyInfo.class);
-    
-                return keyInfo.isInsideStrongBox();
-    
-            } catch (Exception e) {
-                Log.e(TAG, "StrongBox check failed", e);
-                return false;
-            }
-        }
-    
-        return false;
-    }
 
 
     public Map<String, String> readAll() {

flutter_secure_storage/android/src/main/java/com/it_nomads/fluttersecurestorage/FlutterSecureStoragePlugin.java

@@ -1,5 +1,6 @@
 package com.it_nomads.fluttersecurestorage;
 
+import android.content.pm.PackageManager;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
@@ -24,6 +25,7 @@ public class FlutterSecureStoragePlugin implements MethodCallHandler, FlutterPlu
     private HandlerThread workerThread;
     private Handler workerThreadHandler;
     private FlutterPluginBinding binding;
+    private boolean isStrongBoxAvailable;
 
     @Override
     public void onAttachedToEngine(FlutterPluginBinding binding) {
@@ -52,6 +54,7 @@ private boolean initSecureStorage(Result result, Map<String, Object> options) {
         if (secureStorage != null) return true;
 
         try {
+            isStrongBoxAvailable = getContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_STRONGBOX_KEYSTORE);
             secureStorage = new FlutterSecureStorage(binding.getApplicationContext(), options);
             return true;
         } catch (Exception e) {
@@ -168,7 +171,7 @@ private void handleDeleteAll(Result result) {
         }
 
         private void handleStrongBoxAvailable(Result result) {
-            result.success(secureStorage.isStrongBoxAvailable());
+            result.success(isStrongBoxAvailable);
         }
 
         @SuppressWarnings("unchecked")