private void checkAndSetSalt(final String salt) {
   if (TextUtils.isEmpty(salt)) {
     this.salt = CryptoHelper.getRandomBytes(AESCrypto.SALT_SIZE_DEFAULT);
   } else {
     this.salt = CryptoHelper.getRawBytes(salt);
   }
 }
 private void checkAndSetIV() {
   this.iv = CryptoHelper.getRandomBytes(AESCrypto.IV_SIZE_DEFAULT);
 }