function postData($url,$postfields){

   $ch = curl_init();
   $params[CURLOPT_URL] = $url;    //请求url地址
   $params[CURLOPT_HEADER] = false; //是否返回响应头信息
   $params[CURLOPT_RETURNTRANSFER] = true; //是否将结果返回
   $params[CURLOPT_FOLLOWLOCATION] = true; //是否重定向
   $params[CURLOPT_POST] = true;
   $params[CURLOPT_POSTFIELDS] = $postfields;
   $params[CURLOPT_SSL_VERIFYPEER] = false;
   $params[CURLOPT_SSL_VERIFYHOST] = false;
   //以下是证书相关代码
    $params[CURLOPT_SSLCERTTYPE] = 'PEM';
    $params[CURLOPT_SSLCERT] = '证书路径';
    $params[CURLOPT_SSLKEYTYPE] = 'PEM';
    $params[CURLOPT_SSLKEY] = '秘钥路径';

     curl_setopt_array($ch, $params); //传入curl参数
     $content = curl_exec($ch); //执行
     curl_close($ch); //关闭连接
     return $content;
}