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。
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
- 已认证订阅号
- 服务号
- 企业号
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/aes/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 ?>