code: function encrypt($data, $password) {
          // Set a random salt
          $salt = openssl_random_pseudo_bytes(16);
          $salted = '';
          $dx = '';
          while (strlen($salted) < 48) {
              $dx = hash('sha256', $dx.$password.$salt, true);
              $salted .= $dx;
          }
      
          $key = substr($salted, 0, 32);
          $iv  = substr($salted, 32,16);
      
          $encrypted_data = openssl_encrypt($data, 'AES-256-CBC', $key, true, $iv);
          return base64_encode($salt . $encrypted_data);
      }
docs: session crypt AES 256
  
  @param data $data
  @param string $password
  @return base64 encrypted data