在 curl 请求 https 网址，响应为 false 的排查分析

$json = Helper::curlRequest("https://api.weixin.qq.com/sns/jscode2session?appid={$config['id']}&secret={$config['secret']}&js_code={$code}&grant_type=authorization_code");


    public static function curlRequest($url, $params = array(), $isreturn = true, $ispost = 0, $referer = '', $need_header = false, $user_agent = 'Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)')
    {
        if (empty($referer)) {
            $urlinfo = parse_url($url);
            if (isset($urlinfo['scheme'])) {
                $referer = $urlinfo['scheme'] . '://' . $urlinfo['host'] . '/';
            } else {
                $referer = '//' . $urlinfo['host'] . '/';
            }
        }

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        //curl_setopt($ch, CURLOPT_AUTOREFERER, $referer);
        curl_setopt($ch, CURLOPT_REFERER, $referer);
        curl_setopt($ch, CURLOPT_HEADER, $need_header);
        curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
        //curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36');
        if ($ispost) {
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $params);
        }
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $rst = curl_exec($ch);
        curl_close($ch);
        if ($isreturn) {
            return $rst;
        }
    }

openssl.cafile = /etc/ssl/certs/cacert.pem