src/Auth/CookieAuth.php
protected function getEncryptKey($cookieName)
    {
        if (isset($_SERVER['HTTP_USER_AGENT'])) {
            $agent = strtolower($_SERVER['HTTP_USER_AGENT']);
        } else {
            $agent = 'agent';
        }

        return md5($agent . $this->key . $cookieName);
    }
protected function getEncryptKey($cookieName)
    {
        if (isset($_SERVER['HTTP_USER_AGENT'])) {
            $agent = strtolower($_SERVER['HTTP_USER_AGENT']);
        } else {
            $agent = 'agent';
        }

        return md5($agent . $this->key . $cookieName);
    }
生成密钥

@param string $cookieName
@return string