public function getKeyPair($file = false)
    {
        $pk = $this->_generatePK();

        openssl_pkey_export($pk, $privKey, null, $this->certConfigure);
        $pubKey = openssl_pkey_get_details($pk);

        $keys = new KeyPair();
        $keys->setPrivateKey($privKey)->setPublicKey($pubKey['key']);

        if ($file) {
            file_put_contents($this->fileName . static::PRIV_KEY_FILENAME , $keys->getPrivateKey());
            file_put_contents($this->fileName . static::PUB_KEY_FILENAME , $keys->getPublicKey());
        }

        return $keys;
    }