app\Certificate::showCertificateFile PHP Method

    public function showCertificateFile($name)
    {
        $name = preg_replace('/[^A-Za-z0-9_\\-\\.]/', '', $name);
        $path = $this->getPath() . "/" . $name;
        if (!is_readable($path)) {
            throw new \RuntimeException('File not available');
        }
        return file_get_contents($path);
    }