在图3-21中，微信公众平台在配置服务器时，提供了3种加解密模式供开发者选择，即“明文模式”、“兼容模式”、“安全模式（推荐）”。选择“兼容模式”和“安全模式（推荐）”前，需在开发者中心填写AES对称加密算法的消息加解密密钥EncodingAESKey。公众号用此密钥对收到的密文消息体进行解密，回复消息体也用此密钥加密。
·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。
消息体加解密的实现过程如下。
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3个参数。
/* 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'); 当用户向公众号发送消息时，微信公众号将会在URL中带上signature、timestamp、nonce、encrypt_type、msg_signature等参数，类似如下。
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+XDAQKEOjWTQIOp1p6kNsIV1Dd C3B+AtcKcKSNAeJDr7x7GHLx5DZYK09qQsYDOjP6R5NqebFjKt/NpEl/GU3gWFwG8LCtRNuIYdK5 axbFSfmXbh5CZ6Bk5wSwj5fu5aS90cMAgUhGsxrxZTY562QR6c+3ydXxb+GHI5w+qA+eqJjrQqR7 u5hS+1x5sEsA7vS+bZ5LYAR3+PZ243avQkGllQ+rg7a6TeSGDxxhvLw+mxxinyk88BNHkJnyK// hM 1k9PuvuLAASdaud4vzRQlAmnYOslZl8CN7gjCjV41skUTZv3wwGPxvEqtm/nf5fQ=]]></Encrypt></xml>
这时程序需要从URL中获得以下参数。这些参数将用于加解密过程。
$timestamp = $_GET['timestamp'];$nonce = $_GET["nonce"];$msg_signature = $_GET['msg_signature'];$encrypt_type = $_GET['encrypt_type'];
接口程序收到消息后，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>
对消息在自己的原有的代码流程中处理，完成之后，一个要回复的文本消息如下。
<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>
把上述消息加密，返回给微信公众号，加密过程如下。
// 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[pE6gp6qvVBMHwCXwnM7illFBrh9LmvlKFlPUDuyQo9EKNunqbUFMd2Kj iYoz+3K1B+93JbMWHt+19TI8awdRdyopRS4oUNg5M2jwpwXTmc6TtafkKNjvqlvPXIWmutw0tuMXke 1hDgsqz0SC8h/QjNLxECuwnczrfCMJlt+APHnX2yMMaq/aYUNcndOH387loQvl2suCGucXpglnbx f7frTCz9NQVgKiYrvKOhk6KFiVMnzuxy6WWmoe3GBiUCPTtYf5b1CxzN2IHViEBm28ilV9wWdNOM 9TPG7BSSAcpgY4pcwdIG5+4KhgYmnVU3bc/ZJkk42TIdidigOfFpJwET4UWVrLB/ldUud4aPexp 3aPCR3Fe53S2HHcl3tTxh4iRvDftUKP3svYPctt1MlYuYv/BZ4JyzUQV03H+0XrVyDY2tyVjimgC rA2c1mZMgHttOHTQ6VTnxrMq0GWlRlH0KPQKqtjUpNQzuOH4upQ8boPsEtuY3wDA2RaXQPJrX on]]></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。
完整的代码如下。
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, $encry ptMsg); 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"=>"", "Pic Url"=>"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"=>"", "Pic Url"=>"http:// d.hiphotos.bdimg.com/wisegame/pic/item/f3529822720e0cf3ac 9f1ada0846f21fbe09aaa3.jpg", "Url" =>"http:// m.cnblogs.com/?u=txw1958");112 $content = array("Title"=>"多图文3标题", "Description"=>"", "Pic Url"=>"http:// g.hiphotos.bdimg.com/wisegame/pic/item/18cb0a46f21fbe090d33 8acc6a600c338644adfd.jpg", "Url" =>"http:// m.cnblogs.com/?u=txw1958");113 }else if (strstr($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['Des cription'], $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_str195 </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($_SERVER['HTTP_APPNAME'])){ // SAE205 sae_set_display_errors(false);206 sae_debug($log_content);207 sae_set_display_errors(true);208 }else if($_SERVER['REMOTE_ADDR'] != "127.0.0.1"){ // LOCAL209 $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 ?>