解密

    //解密
    public function decrypt()
    {
        $appId = config('wechat.yqcf.app_id');
        $encodingAesKey = config('wechat.yqcf.symmetric_key');
        $token = config('wechat.yqcf.verify_token');
        $timeStamp = $_POST['timestamp'];
        $nonce = $_POST['nonce'];

        $pc = new WXBizMsgCrypt($token, $encodingAesKey, $appId);
        $encryptMsg = file_get_contents("php://input");
        $xml_tree = new DOMDocument();
        $xml_tree->loadXML($encryptMsg);
        $array_e = $xml_tree->getElementsByTagName('Encrypt');
        $array_s = $xml_tree->getElementsByTagName('MsgSignature');
//        $array_t = $xml_tree->getElementsByTagName('TimeStamp');
//        $array_n = $xml_tree->getElementsByTagName('Nonce');

        $encrypt = $array_e->item(0)->nodeValue;
        $msg_sign = $array_s->item(0)->nodeValue;
//        $timeStamp = $array_t->item(0)->nodeValue;
//        $nonce = $array_n->item(0)->nodeValue;


        $format = "<xml><ToUserName><![CDATA[toUser]]></ToUserName><Encrypt><![CDATA[%s]]></Encrypt></xml>";
        $from_xml = sprintf($format, $encrypt);
        // 第三方收到公众号平台发送的消息
        $msg = '';
        $errCode = $pc->decryptMsg($msg_sign, $timeStamp, $nonce, $from_xml, $msg);
        if ($errCode == 0) {
            print("解密后: " . $msg . "\n");
        } else {
            print($errCode . "\n");
        }

    }