//关键代码如下
        $postUrl = $url;
        $curlPost = $param;
        $ch = curl_init();                                      //初始化curl
        curl_setopt($ch, CURLOPT_URL, $postUrl);                 //抓取指定网页
        $headerArray = array("Content-Type:text/xml", "charset=utf-8","Cache-Control: no-cache");
        curl_setopt($ch, CURLOPT_HEADER, FALSE);                    //设置header，使用$headerArray 也无用
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);            //要求结果为字符串且输出到屏幕上
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);        // 终止从服务端进行验证
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_AUTOREFERER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);                      //post提交方式
        curl_setopt($ch, CURLOPT_POSTFIELDS, $curlPost);           // 增加 HTTP Header（头）里的字段
        curl_setopt($ch, CURLOPT_SSLCERTTYPE,'PEM');
        curl_setopt($ch, CURLOPT_SSLCERT,IA_ROOT . "/路径/" . 'apiclient_cert_' . $_W['uniacid'] . '.pem'); //这个是证书的位置绝对路径
        curl_setopt($ch, CURLOPT_SSLKEYTYPE,'PEM');
        curl_setopt($ch, CURLOPT_SSLKEY, IA_ROOT . "/路径/" . 'apiclient_key_' . $_W['uniacid'] . '.pem'); //这个也是证书的位置绝对路径
//        curl_setopt($ch,CURLOPT_SSLKEYPASSWD,$password);  //
        $data = curl_exec($ch);                                 //运行curl
        if($data)
        {
            curl_close($ch);
            return $data;
        }
        else{
            $error_msg = curl_error($ch);
            $error = curl_errno($ch);
            curl_close($ch);
            message("打款失败，CURL出错，错误码：".$error."，错误信息：<br />$error_msg");exit;
        }
// 最后错误信息为：could not load PEM client certificate, OpenSSL error error:0906D06C:
  //PEM routines:PEM_read_bio:no start line, 
//(no key found, wrong pass phrase, or wrong file format?)