<?php
//1.將timestamp,nonce,toke按字典順序排序
$timestamp?=?$_GET['timestamp'];
$nonce?=?$_GET['nonce'];
$token?=?'weixin';
$signature?=?$_GET['signature'];
$array?=?array($timestamp,$nonce,$token);
//2.將排序后的三個參數(shù)拼接之后用sha1加密
$tmpstr?=?implode('',$array);
$tmpstr?=?sha1($tmpstr);
//3.將加密后的字符串與signature進行對比，判斷該請求是否來自微信
if($tmpstr?==?$signature){
????header('content-type:text');
????echo?$_GET['echostr'];
????exit;
}