微信团队与2014年3月4日更新了公众平台sdk,点击打开链接,对排序算法进行了修改,原有的sort($tmpArr)修改为sort($tmpArr, SORT_STRING),php中sort()函数默认为SORT_REGULAR,即原来的数据类型。微信在接口验证时推送的数据为类似:signature=01e948890eb29696536d66a9aaa2943260b9f0cc&echostr=5989551905366037038×tamp=1394299438&nonce=1394551220
post时推送的为signature=c421f0190e6912339235e391a092ae9f30c08093×tamp=1394118446&nonce=244662140
php中通过$_GET获取的数据类型为string型,即$timestamp虽然为数字但数据格式仍为string,sort排序仍然会以SORT_STRING方式进行排序。其他一些语言如java需要声明变量类型时会产生差异,由于微信没有给出其他语言类型的示例代码,故加上SORT_STRING。通过把timestamp,token,nonce排序sha1加密后得到signature。对于简化验证,可以不进行验证,直接输出echostr,安全性稍差。大部分用户验证后对post数据类型直接改为$wechatObj->responseMsg(),不再对签名进行验证。由于post时仍有上述参数可以仍然调用验证签名,在responseMsg增加调用valid方法,以保证安全性。不过加上此类调用,对于调试就不太方便,微信官方的debug和宾果等均无法返回调试结果,代码如下:
<?php /** * wechat php test */ //define your token define("TOKEN", "weixin"); $wechatObj = new wechatCallbackapiTest(); if($_SERVER[‘REQUEST_METHOD‘]== "GET"){ $wechatObj->valid(); } elseif($_SERVER[‘REQUEST_METHOD‘]== "POST"){ $wechatObj->responseMsg(); } class wechatCallbackapiTest { public function valid() { $echoStr = $_GET["echostr"]; //valid signature , option if($this->checkSignature()){ echo $echoStr; exit; } } public function responseMsg() { if($this->checkSignature()){ //get post data, May be due to the different environments $postStr = $GLOBALS["HTTP_RAW_POST_DATA"]; //extract post data if (!empty($postStr)){ $postObj = simplexml_load_string($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() { $signature = $_GET["signature"]; $timestamp = $_GET["timestamp"]; $nonce = $_GET["nonce"]; $token = TOKEN; $tmpArr = array($token, $timestamp, $nonce); sort($tmpArr, SORT_STRING); $tmpStr = implode( $tmpArr ); $tmpStr = sha1( $tmpStr ); if( $tmpStr == $signature ){ return true; }else{ return false; } } } ?>