一、消息体加解密
微信公众平台在配置服务器时,提供了3种加解密的模式供开发者选择,即明文模式、兼容模式、安全模式,选择兼容模式和安全模式前,需在开发者中心填写消息加解密密钥EncodingAESKey。
- 明文模式:维持现有模式,没有适配加解密新特性,消息体明文收发,默认设置为明文模式
- 兼容模式:公众平台发送消息内容将同时包括明文和密文,消息包长度增加到原来的3倍左右;公众号回复明文或密文均可,不影响现有消息收发;开发者可在此模式下进行调试
- 安全模式(推荐):公众平台发送消息体的内容只含有密文,公众账号回复的消息体也为密文,建议开发者在调试成功后使用此模式收发消息
什么是EncodingAESKey?
- 微信公众平台采用AES对称加密算法对推送给公众帐号的消息体对行加密,EncodingAESKey则是加密所用的秘钥。公众帐号用此秘钥对收到的密文消息体进行解密,回复消息体也用此秘钥加密。AES对称加密算法的原理可以参考 http://www.cnblogs.com/txw1958/p/aes.html
加解密的详细技术方案可以参考官方文档 http://mp.weixin.qq.com/wiki/index.php?title=%E6%8A%80%E6%9C%AF%E6%96%B9%E6%A1%88
适用公众账号类型
不能用于未认证订阅号,因为其没有appid参数
二、开发实现及数据分析
1. 配置
假设本次的开发配置中URL为
http://www.fangbei.org/index.php
接口程序中需要配置以下三项参数
/*
方倍工作室 http://www.cnblogs.com/txw1958/
CopyRight 2014 All Rights Reserved
*/
define("TOKEN", "weixin");
define("AppID", "wxbad0b45542aa0b5e");
define("EncodingAESKey", "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFG");
require_once('wxBizMsgCrypt.php');
2. 加解密实现
当用户向公众账号发送消息时,微信公众账号将会在URL中带上signature、timestamp、nonce、encrypt_type、msg_signature等参数,如下所示
http://www.fangbei.org/index.php?signature=35703636de2f9df2a77a662b68e521ce17c34db4×tamp=1414243737&nonce=1792106704&encrypt_type=aes&msg_signature=6147984331daf7a1a9eed6e0ec3ba69055256154
同时向该接口推送如下XML消息 ,即一个已加密的消息
<xml>
<ToUserName><![CDATA[gh_680bdefc8c5d]]></ToUserName>
<Encrypt><![CDATA[MNn4+jJ/VsFh2gUyKAaOJArwEVYCvVmyN0iXzNarP3O6vXzK62ft1/KG2/XPZ4y5bPWU/jfIfQxODRQ7sLkUsrDRqsWimuhIT8Eq+w4E/28m+XDAQKEOjWTQIOp1p6kNsIV1DdC3B+AtcKcKSNAeJDr7x7GHLx5DZYK09qQsYDOjP6R5NqebFjKt/NpEl/GU3gWFwG8LCtRNuIYdK5axbFSfmXbh5CZ6Bk5wSwj5fu5aS90cMAgUhGsxrxZTY562QR6c+3ydXxb+GHI5w+qA+eqJjrQqR7u5hS+1x5sEsA7vS+bZ5LYAR3+PZ243avQkGllQ+rg7a6TeSGDxxhvLw+mxxinyk88BNHkJnyK//hM1k9PuvuLAASdaud4vzRQlAmnYOslZl8CN7gjCjV41skUTZv3wwGPxvEqtm/nf5fQ=]]></Encrypt>
</xml>
这时,程序需要从url中获得以下参数
$timestamp = $_GET['timestamp'];
$nonce = $_GET["nonce"];
$msg_signature = $_GET['msg_signature'];
$encrypt_type = $_GET['encrypt_type'];
这些参数将用于加解密过程
收到消息后,先进行解密,解密部分代码如下
$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
if ($encrypt_type == 'aes'){
$pc = new WXBizMsgCrypt(TOKEN, EncodingAESKey, AppID);
$this->logger(" D \r\n".$postStr);
$decryptMsg = ""; //解密后的明文
$errCode = $pc->DecryptMsg($msg_signature, $timestamp, $nonce, $postStr, $decryptMsg);
$postStr = $decryptMsg;
}
解密完成后,把解密内容又返回给$postStr,这是为了保证将消息中解密后的内容和明文模式时的消息统一,方便后续处理,解密后的XML如下
<xml>
<ToUserName><![CDATA[gh_680bdefc8c5d]]></ToUserName>
<FromUserName><![CDATA[oIDrpjpQ8j8mBuQ8nM26HWzNEZgg]]></FromUserName>
<CreateTime>1414243737</CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[?]]></Content>
<MsgId>6074130599188426998</MsgId>
</xml>
对消息在自己的原来代码中处理,完成之后,要回复的消息如下
<xml>
<ToUserName><![CDATA[oIDrpjpQ8j8mBuQ8nM26HWzNEZgg]]></ToUserName>
<FromUserName><![CDATA[gh_680bdefc8c5d]]></FromUserName>
<CreateTime>1414243733</CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[2014-10-25 21:28:53
技术支持 方倍工作室
http://www.fangbei.org/]]></Content>
</xml>
把上述消息进行加密,返回给微信公众账号
//加密
if ($encrypt_type == 'aes'){
$encryptMsg = ''; //加密后的密文
$errCode = $pc->encryptMsg($result, $timeStamp, $nonce, $encryptMsg);
$result = $encryptMsg;
$this->logger(" E \r\n".$result);
}
加密后的内容如下
<xml>
<Encrypt><![CDATA[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]]></Encrypt>
<MsgSignature><![CDATA[6c46904dc1f58b2ddf2dd0399f1c6cf41f33ecb9]]></MsgSignature>
<TimeStamp>1414243733</TimeStamp>
<Nonce><![CDATA[1792106704]]></Nonce>
</xml>
这样,一个安全模式下的加解密消息就完成了。
三、完整代码
1 <?php
2 /*
3 方倍工作室 http://www.cnblogs.com/txw1958/
4 CopyRight 2014 All Rights Reserved
5 */
6 define("TOKEN", "weixin");
7 define("AppID", "wxbad0b45542aa0b5e");
8 define("EncodingAESKey", "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFG");
9 require_once('wxBizMsgCrypt.php');
10
11 $wechatObj = new wechatCallbackapiTest();
12 if (!isset($_GET['echostr'])) {
13 $wechatObj->responseMsg();
14 }else{
15 $wechatObj->valid();
16 }
17
18 class wechatCallbackapiTest
19 {
20 //验证签名
21 public function valid()
22 {
23 $echoStr = $_GET["echostr"];
24 $signature = $_GET["signature"];
25 $timestamp = $_GET["timestamp"];
26 $nonce = $_GET["nonce"];
27 $tmpArr = array(TOKEN, $timestamp, $nonce);
28 sort($tmpArr);
29 $tmpStr = implode($tmpArr);
30 $tmpStr = sha1($tmpStr);
31 if($tmpStr == $signature){
32 echo $echoStr;
33 exit;
34 }
35 }
36
37 //响应消息
38 public function responseMsg()
39 {
40 $timestamp = $_GET['timestamp'];
41 $nonce = $_GET["nonce"];
42 $msg_signature = $_GET['msg_signature'];
43 $encrypt_type = (isset($_GET['encrypt_type']) && ($_GET['encrypt_type'] == 'aes')) ? "aes" : "raw";
44
45 $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
46 if (!empty($postStr)){
47 //解密
48 if ($encrypt_type == 'aes'){
49 $pc = new WXBizMsgCrypt(TOKEN, EncodingAESKey, AppID);
50 $this->logger(" D \r\n".$postStr);
51 $decryptMsg = ""; //解密后的明文
52 $errCode = $pc->DecryptMsg($msg_signature, $timestamp, $nonce, $postStr, $decryptMsg);
53 $postStr = $decryptMsg;
54 }
55 $this->logger(" R \r\n".$postStr);
56 $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
57 $RX_TYPE = trim($postObj->MsgType);
58
59 //消息类型分离
60 switch ($RX_TYPE)
61 {
62 case "event":
63 $result = $this->receiveEvent($postObj);
64 break;
65 case "text":
66 $result = $this->receiveText($postObj);
67 break;
68 }
69 $this->logger(" R \r\n".$result);
70 //加密
71 if ($encrypt_type == 'aes'){
72 $encryptMsg = ''; //加密后的密文
73 $errCode = $pc->encryptMsg($result, $timeStamp, $nonce, $encryptMsg);
74 $result = $encryptMsg;
75 $this->logger(" E \r\n".$result);
76 }
77 echo $result;
78 }else {
79 echo "";
80 exit;
81 }
82 }
83
84 //接收事件消息
85 private function receiveEvent($object)
86 {
87 $content = "";
88 switch ($object->Event)
89 {
90 case "subscribe":
91 $content = "欢迎关注方倍工作室 ";
92 break;
93 }
94
95 $result = $this->transmitText($object, $content);
96 return $result;
97 }
98
99 //接收文本消息
100 private function receiveText($object)
101 {
102 $keyword = trim($object->Content);
103 if (strstr($keyword, "文本")){
104 $content = "这是个文本消息";
105 }else if (strstr($keyword, "单图文")){
106 $content = array();
107 $content[] = array("Title"=>"单图文标题", "Description"=>"单图文内容", "PicUrl"=>"http://discuz.comli.com/weixin/weather/icon/cartoon.jpg", "Url" =>"http://m.cnblogs.com/?u=txw1958");
108 }else if (strstr($keyword, "图文") || strstr($keyword, "多图文")){
109 $content = array();
110 $content[] = array("Title"=>"多图文1标题", "Description"=>"", "PicUrl"=>"http://discuz.comli.com/weixin/weather/icon/cartoon.jpg", "Url" =>"http://m.cnblogs.com/?u=txw1958");
111 $content[] = array("Title"=>"多图文2标题", "Description"=>"", "PicUrl"=>"http://d.hiphotos.bdimg.com/wisegame/pic/item/f3529822720e0cf3ac9f1ada0846f21fbe09aaa3.jpg", "Url" =>"http://m.cnblogs.com/?u=txw1958");
112 $content[] = array("Title"=>"多图文3标题", "Description"=>"", "PicUrl"=>"http://g.hiphotos.bdimg.com/wisegame/pic/item/18cb0a46f21fbe090d338acc6a600c338644adfd.jpg", "Url" =>"http://m.cnblogs.com/?u=txw1958");
113 }else if (strstr($keyword, "音乐")){
114 $content = array();
115 $content = array("Title"=>"最炫民族风", "Description"=>"歌手:凤凰传奇", "MusicUrl"=>"http://121.199.4.61/music/zxmzf.mp3", "HQMusicUrl"=>"http://121.199.4.61/music/zxmzf.mp3");
116 }else{
117 $content = date("Y-m-d H:i:s",time())."\n".$object->FromUserName."\n技术支持 方倍工作室";
118 }
119
120 if(is_array($content)){
121 if (isset($content[0])){
122 $result = $this->transmitNews($object, $content);
123 }else if (isset($content['MusicUrl'])){
124 $result = $this->transmitMusic($object, $content);
125 }
126 }else{
127 $result = $this->transmitText($object, $content);
128 }
129 return $result;
130 }
131
132 //回复文本消息
133 private function transmitText($object, $content)
134 {
135 $xmlTpl = "<xml>
136 <ToUserName><![CDATA[%s]]></ToUserName>
137 <FromUserName><![CDATA[%s]]></FromUserName>
138 <CreateTime>%s</CreateTime>
139 <MsgType><![CDATA[text]]></MsgType>
140 <Content><![CDATA[%s]]></Content>
141 </xml>";
142 $result = sprintf($xmlTpl, $object->FromUserName, $object->ToUserName, time(), $content);
143 return $result;
144 }
145
146 //回复图文消息
147 private function transmitNews($object, $newsArray)
148 {
149 if(!is_array($newsArray)){
150 return;
151 }
152 $itemTpl = " <item>
153 <Title><![CDATA[%s]]></Title>
154 <Description><![CDATA[%s]]></Description>
155 <PicUrl><![CDATA[%s]]></PicUrl>
156 <Url><![CDATA[%s]]></Url>
157 </item>
158 ";
159 $item_str = "";
160 foreach ($newsArray as $item){
161 $item_str .= sprintf($itemTpl, $item['Title'], $item['Description'], $item['PicUrl'], $item['Url']);
162 }
163 $xmlTpl = "<xml>
164 <ToUserName><![CDATA[%s]]></ToUserName>
165 <FromUserName><![CDATA[%s]]></FromUserName>
166 <CreateTime>%s</CreateTime>
167 <MsgType><![CDATA[news]]></MsgType>
168 <ArticleCount>%s</ArticleCount>
169 <Articles>
170 $item_str </Articles>
171 </xml>";
172
173 $result = sprintf($xmlTpl, $object->FromUserName, $object->ToUserName, time(), count($newsArray));
174 return $result;
175 }
176
177 //回复音乐消息
178 private function transmitMusic($object, $musicArray)
179 {
180 $itemTpl = "<Music>
181 <Title><![CDATA[%s]]></Title>
182 <Description><![CDATA[%s]]></Description>
183 <MusicUrl><![CDATA[%s]]></MusicUrl>
184 <HQMusicUrl><![CDATA[%s]]></HQMusicUrl>
185 </Music>";
186
187 $item_str = sprintf($itemTpl, $musicArray['Title'], $musicArray['Description'], $musicArray['MusicUrl'], $musicArray['HQMusicUrl']);
188
189 $xmlTpl = "<xml>
190 <ToUserName><![CDATA[%s]]></ToUserName>
191 <FromUserName><![CDATA[%s]]></FromUserName>
192 <CreateTime>%s</CreateTime>
193 <MsgType><![CDATA[music]]></MsgType>
194 $item_str
195 </xml>";
196
197 $result = sprintf($xmlTpl, $object->FromUserName, $object->ToUserName, time());
198 return $result;
199 }
200
201 //日志记录
202 public function logger($log_content)
203 {
204 if(isset($_SERVER['HTTP_APPNAME'])){ //SAE
205 sae_set_display_errors(false);
206 sae_debug($log_content);
207 sae_set_display_errors(true);
208 }else if($_SERVER['REMOTE_ADDR'] != "127.0.0.1"){ //LOCAL
209 $max_size = 500000;
210 $log_filename = "log.xml";
211 if(file_exists($log_filename) and (abs(filesize($log_filename)) > $max_size)){unlink($log_filename);}
212 file_put_contents($log_filename, date('Y-m-d H:i:s').$log_content."\r\n", FILE_APPEND);
213 }
214 }
215 }
216 ?>