Updated keystore branch

Author: chun-baoluo

android/src/main/java/br/com/classapp/RNSensitiveInfo/RNSensitiveInfoModule.java

@@ -22,6 +22,7 @@
 import com.facebook.react.bridge.WritableNativeMap;
 import com.facebook.react.modules.core.DeviceEventManagerModule;
 
+import java.security.Key;
 import java.security.KeyStore;
 import java.util.HashMap;
 import java.util.Map;
@@ -30,6 +31,7 @@
 import javax.crypto.KeyGenerator;
 import javax.crypto.SecretKey;
 import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.GCMParameterSpec;
 import javax.crypto.spec.IvParameterSpec;
 
 import br.com.classapp.RNSensitiveInfo.utils.AppConstants;
@@ -47,8 +49,12 @@ public class RNSensitiveInfoModule extends ReactContextBaseJavaModule {
                     KeyProperties.BLOCK_MODE_CBC + "/" +
                     KeyProperties.ENCRYPTION_PADDING_PKCS7;
 
+    private static final byte[] FIXED_IV = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1};
+    private static final String KEY_ALIAS = "MySharedPreferenceKeyAlias";
     private static final String KEY_ALIAS_AES = "MyAesKeyAlias";
     private static final String DELIMITER = "]";
+    private static final String AES_GCM = "AES/GCM/NoPadding";
+    private static final String AES_ECB = "AES/ECB/PKCS7Padding";
 
     private FingerprintManager mFingerprintManager;
     private KeyStore mKeyStore;
@@ -133,7 +139,11 @@ public void getItem(String key, ReadableMap options, Promise pm) {
 
             decryptWithAes(value, showModal, strings, pm, null);
         } else {
-            pm.resolve(value);
+            try {
+                pm.resolve(decrypt(value));
+            } catch (Exception e) {
+                pm.reject(e);
+            }
         }
     }
 
@@ -149,7 +159,7 @@ public void setItem(String key, String value, ReadableMap options, Promise pm) {
             putExtraWithAES(key, value, prefs(name), showModal, strings, pm, null);
         } else {
             try {
-                putExtra(key, value, prefs(name));
+                putExtra(key, encrypt(value), prefs(name));
                 pm.resolve(value);
             } catch (Exception e) {
                 Log.d("RNSensitiveInfo", e.getCause().getMessage());
@@ -208,19 +218,9 @@ private String sharedPreferences(ReadableMap options) {
     }
 
 
-    private void putExtra(String key, Object value, SharedPreferences mSharedPreferences) {
+    private void putExtra(String key, String value, SharedPreferences mSharedPreferences) {
         SharedPreferences.Editor editor = mSharedPreferences.edit();
-        if (value instanceof String) {
-            editor.putString(key, (String) value).apply();
-        } else if (value instanceof Boolean) {
-            editor.putBoolean(key, (Boolean) value).apply();
-        } else if (value instanceof Integer) {
-            editor.putInt(key, (Integer) value).apply();
-        } else if (value instanceof Long) {
-            editor.putLong(key, (Long) value).apply();
-        } else if (value instanceof Float) {
-            editor.putFloat(key, (Float) value).apply();
-        }
+        editor.putString(key, value).apply();
     }
 
     /**
@@ -232,6 +232,17 @@ private void initKeyStore() {
             mKeyStore = KeyStore.getInstance(ANDROID_KEYSTORE_PROVIDER);
             mKeyStore.load(null);
 
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, ANDROID_KEYSTORE_PROVIDER);
+                keyGenerator.init(
+                        new KeyGenParameterSpec.Builder(KEY_ALIAS,
+                                KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
+                                .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+                                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+                                .setRandomizedEncryptionRequired(false)
+                                .build());
+                keyGenerator.generateKey();
+            }
             // Check if a generated key exists under the KEY_ALIAS_AES .
             if (!mKeyStore.containsAlias(KEY_ALIAS_AES)) {
                 prepareKey();
@@ -244,6 +255,7 @@ private void prepareKey() throws Exception {
         if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.M) {
             return;
         }
+        
         KeyGenerator keyGenerator = KeyGenerator.getInstance(
                 KeyProperties.KEY_ALGORITHM_AES, ANDROID_KEYSTORE_PROVIDER);
 
@@ -477,4 +489,45 @@ public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult re
             pm.reject("Fingerprint not supported", "Fingerprint not supported");
         }
     }
+    
+    public String encrypt(String input) throws Exception {
+        
+        Key secretKey = ((KeyStore.SecretKeyEntry) mKeyStore.getEntry(KEY_ALIAS, null)).getSecretKey();
+        byte[] bytes = input.getBytes();
+
+        Cipher c;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            c = Cipher.getInstance(AES_GCM);
+            c.init(Cipher.ENCRYPT_MODE, secretKey, new GCMParameterSpec(128, FIXED_IV));
+        } else {
+            c = Cipher.getInstance(AES_ECB, "BC");
+            c.init(Cipher.ENCRYPT_MODE, secretKey);
+        }
+        byte[] encodedBytes = c.doFinal(bytes);
+        String encryptedBase64Encoded = Base64.encodeToString(encodedBytes, Base64.DEFAULT);
+        return encryptedBase64Encoded;
+    }
+
+
+    public String decrypt(String encrypted) throws Exception {
+        if (encrypted == null) {
+            Exception cause = new RuntimeException("Invalid argument at decrypt function");
+            throw new RuntimeException("encrypted argument can't be null", cause);
+        }
+
+        Cipher c;
+        KeyStore keyStore = KeyStore.getInstance(ANDROID_KEYSTORE_PROVIDER);
+        keyStore.load(null);
+        Key secretKey = ((KeyStore.SecretKeyEntry) mKeyStore.getEntry(KEY_ALIAS, null)).getSecretKey();
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            c = Cipher.getInstance(AES_GCM);
+            c.init(Cipher.DECRYPT_MODE, secretKey, new GCMParameterSpec(128, FIXED_IV));
+        } else {
+            c = Cipher.getInstance(AES_ECB, "BC");
+            c.init(Cipher.DECRYPT_MODE, secretKey);
+        }
+        byte[] decodedBytes = c.doFinal(Base64.decode(encrypted, Base64.DEFAULT));
+        return new String(decodedBytes);
+    }
 }