wx_sample.php

<?php

/**

  * wechat php test

  */

//define your token

define("TOKEN", "weixin");

$wechatObj = new wechatCallbackapiTest();

$wechatObj->valid();

class wechatCallbackapiTest

{

public function valid()

    {

        $echoStr = $_GET["echostr"];

        //valid signature , option

        if($this->checkSignature()){

        echo $echoStr;

        exit;

        }

    }

    public function responseMsg()

    {

//get post data, May be due to the different environments

$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

      //extract post data

if (!empty($postStr)){

                /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,

                   the best way is to check the validity of xml by yourself */

                libxml_disable_entity_loader(true);

              $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);

                $fromUsername = $postObj->FromUserName;

                $toUsername = $postObj->ToUserName;

                $keyword = trim($postObj->Content);

                $time = time();

                $textTpl = "<xml>

<ToUserName><![CDATA[%s]]></ToUserName>

<FromUserName><![CDATA[%s]]></FromUserName>

<CreateTime>%s</CreateTime>

<MsgType><![CDATA[%s]]></MsgType>

<Content><![CDATA[%s]]></Content>

<FuncFlag>0</FuncFlag>

</xml>";             

if(!empty( $keyword ))

                {

              $msgType = "text";

                $contentStr = "Welcome to wechat world!";

                $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);

                echo $resultStr;

                }else{

                echo "Input something...";

                }

        }else {

        echo "";

        exit;

        }

    }

private function checkSignature()

{

        // you must define TOKEN by yourself

        if (!defined("TOKEN")) {

            throw new Exception('TOKEN is not defined!');

        }

        

        $signature = $_GET["signature"];

        $timestamp = $_GET["timestamp"];

        $nonce = $_GET["nonce"];

       

$token = TOKEN;

$tmpArr = array($token, $timestamp, $nonce);

        // use SORT_STRING rule

sort($tmpArr, SORT_STRING);

$tmpStr = implode( $tmpArr );

$tmpStr = sha1( $tmpStr );

if( $tmpStr == $signature ){

return true;

}else{

return false;

}

}

}

?>