<?php
/**
- 对公众平台发送给公众账号的消息加解密示例代码.
- @copyright Copyright © 1998-2014 Tencent Inc.
*/
namespace app\common\library\wechat;
/**
-
1.第三方回复加密消息给公众平台;
-
2.第三方收到公众平台发送的消息,验证消息的安全性,并对消息进行解密。
*/
class WxBizMsgCrypt
{
private $token;
private $encodingAesKey;
private $appId;private $block_size = 32;
private $keys;private $OK = 0;
private $ValidateSignatureError = -40001; //签名验证错误
private $ParseXmlError = -40002; //xml解析失败
private $ComputeSignatureError = -40003; //sha加密生成签名失败
private $IllegalAesKey = -40004; //encodingAesKey 非法
private $ValidateAppidError = -40005; //appid 校验错误
private $EncryptAESError = -40006; //aes 加密失败
private $DecryptAESError = -40007; //aes 解密失败
private $IllegalBuffer = -40008; //解密后得到的buffer非法
private $EncodeBase64Error = -40009; //base64加密失败
private $DecodeBase64Error = -40010; //base64解密失败
private $GenReturnXmlError = -40011; //生成xml失败/**
- 构造函数
- @param $token string 公众平台上,开发者设置的token
- @param $encodingAesKey string 公众平台上,开发者设置的EncodingAESKey
- @param $appId string 公众平台的appId
*/
public function __construct($token, $encodingAesKey, $appId)
{
$this->token = $token;
$this->encodingAesKey = $encodingAesKey;
$this->appId = $appId;
$this->keys = base64_decode($encodingAesKey . “=”);
}
/**
-
将公众平台回复用户的消息加密打包.
-
<ol>
-
<li>对要发送的消息进行AES-CBC加密</li>
-
<li>生成安全签名</li>
-
<li>将消息密文和安全签名打包成xml格式</li>
-
</ol>
-
@param $replyMsg string 公众平台待回复用户的消息,xml格式的字符串
-
@param $timeStamp string 时间戳,可以自己生成,也可以用URL参数的timestamp
-
@param $nonce string 随机串,可以自己生成,也可以用URL参数的nonce
-
@param &$encryptMsg string 加密后的可以直接回复用户的密文,包括msg_signature, timestamp, nonce, encrypt的xml格式的字符串,
-
当return返回0时有效
-
@return int 成功0,失败返回对应的错误码
*/
public function encryptMsg($replyMsg, $timeStamp, $nonce, &$encryptMsg)
{
//加密
$array = $this->encrypt($replyMsg, $this->appId);
$ret = $array[0];
if ($ret != 0) {
return $ret;
}if ($timeStamp == null) {
$timeStamp = time();
}
$encrypt = $array[1];//生成安全签名
$array = $this->getSHA1($this->token, $timeStamp, $nonce, $encrypt);
$ret = $array[0];
if ($ret != 0) {
return $ret;
}
$signature = $array[1];//生成发送的xml
$encryptMsg = $this->generate($encrypt, $signature, $timeStamp, $nonce);
return $this->OK;
}
/**
-
检验消息的真实性,并且获取解密后的明文.
-
<ol>
-
<li>利用收到的密文生成安全签名,进行签名验证</li>
-
<li>若验证通过,则提取xml中的加密消息</li>
-
<li>对消息进行解密</li>
-
</ol>
-
@param $msgSignature string 签名串,对应URL参数的msg_signature
-
@param $timestamp string 时间戳 对应URL参数的timestamp
-
@param $nonce string 随机串,对应URL参数的nonce
-
@param $postData string 密文,对应POST请求的数据
-
@param &$msg string 解密后的原文,当return返回0时有效
-
@return int 成功0,失败返回对应的错误码
*/
public function decryptMsg($msgSignature, $timestamp = null, $nonce, $postData, &$msg)
{
if (strlen($this->encodingAesKey) != 43) {
return $this->IllegalAesKey;
}
//提取密文
$array = $this->extracts($postData);
$ret = $array[0];
if ($ret != 0) {
return $ret;
}
if ($timestamp == null) {
$timestamp = time();
}
$encrypt = $array[1];
$app_id = $array[2];
//验证安全签名
$array = $this->getSHA1($this->token, $timestamp, $nonce, $encrypt);
$ret = $array[0];if ($ret != 0) {
return $ret;
}
$signature = $array[1];
if ($signature != $msgSignature) {
return $this->ValidateSignatureError;
}
$result = $this->decrypt($encrypt,$this->appId);
if ($result[0] != 0) {
return $result[0];
}
$msg = $result[1];
return $this->OK;
}
/**
- 用SHA1算法生成安全签名
- @param string $token 票据
- @param string $timestamp 时间戳
- @param string $nonce 随机字符串
- @param string $encrypt 密文消息
*/
private function getSHA1($token, $timestamp, $nonce, $encrypt_msg)
{
//排序
try {
$array = array($encrypt_msg, $token, $timestamp, $nonce);
sort($array, SORT_STRING);
$str = implode($array);
return array($this->OK, sha1($str));
} catch (Exception $e) {
//print $e . “\n”;
return array($this->ComputeSignatureError, null);
}
}
/**
- 提取出xml数据包中的加密消息
- @param string $xmltext 待提取的xml字符串
- @return string 提取出的加密消息字符串
*/
private function extracts($xmltext)
{
try {
$xml = new \DOMDocument();
$xml->loadXML($xmltext);
$array_e = $xml->getElementsByTagName(‘AppId’);
$array_a = $xml->getElementsByTagName(‘Encrypt’);
$AppId = $array_e->item(0)->nodeValue;
$Encrypt = $array_a->item(0)->nodeValue;
return array(0,$Encrypt,$AppId);
} catch (Exception $e) {
//print $e . “\n”;
return array($this->ParseXmlError, null, null);
}
}
/**
- 生成xml消息
- @param string $encrypt 加密后的消息密文
- @param string $signature 安全签名
- @param string $timestamp 时间戳
- @param string $nonce 随机字符串
*/
private function generate($encrypt, $signature, $timestamp, $nonce)
{
$format = “<xml>
<Encrypt><![CDATA[%s]]></Encrypt>
<MsgSignature><![CDATA[%s]]></MsgSignature>
<TimeStamp>%s</TimeStamp>
<Nonce><![CDATA[%s]]></Nonce>
</xml>”;
return sprintf($format, $encrypt, $signature, $timestamp, $nonce);
}
/**
- 对需要加密的明文进行填充补位
- @param $text 需要进行填充补位操作的明文
- @return 补齐明文字符串
*/
private function encode($text)
{
$block_size = $this->block_size;
$text_length = strlen($text);
//计算需要填充的位数
$amount_to_pad = $this->block_size - ($text_length % $this->block_size);
if ($amount_to_pad == 0) {
$amount_to_pad = $this->block_size;
}
//获得补位所用的字符
$pad_chr = chr($amount_to_pad);
$tmp = “”;
for ($index = 0; $index < $amount_to_pad; $index++) {
$tmp .= $pad_chr;
}
return $text . $tmp;
}
/**
-
对解密后的明文进行补位删除
-
@param decrypted 解密后的明文
-
@return 删除填充补位后的明文
*/
private function decode($text)
{$pad = ord(substr($text, -1));
if ($pad < 1 || $pad > 32) {
$pad = 0;
}
return substr($text, 0, (strlen($text) - $pad));
}
/**
-
对明文进行加密
-
@param string $text 需要加密的明文
-
@return string 加密后的密文
*/
private function encrypt($text, $appid)
{try {
//获得16位随机字符串,填充到明文之前
$random = $this->getRandomStr();
$text = $random . pack(“N”, strlen($text)) . $text . $appid;
// 网络字节序
$size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, ‘’, MCRYPT_MODE_CBC, ‘’);
$iv = substr($this->keys, 0, 16);
//使用自定义的填充方式对明文进行补位填充
$text = $this->encode($text);
mcrypt_generic_init($module, $this->keys, $iv);
//加密
$encrypted = mcrypt_generic($module, $text);
mcrypt_generic_deinit($module);
mcrypt_module_close($module);//print(base64_encode($encrypted)); //使用BASE64对加密后的字符串进行编码 return array($this->OK, base64_encode($encrypted));
} catch (Exception $e) {
//print $e;
return array($this->EncryptAESError, null);
}
}
/**
-
对密文进行解密
-
@param string $encrypted 需要解密的密文
-
@return string 解密得到的明文
*/
private function decrypt($encrypted, $appid)
{try {
//使用BASE64对需要解密的字符串进行解码
$ciphertext_dec = base64_decode($encrypted);
$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, ‘’, MCRYPT_MODE_CBC, ‘’);
$iv = substr($this->keys, 0, 16);
mcrypt_generic_init($module, $this->keys, $iv);
//解密
$decrypted = mdecrypt_generic($module, $ciphertext_dec);
mcrypt_generic_deinit($module);
mcrypt_module_close($module);
} catch (Exception $e) {
return array($this->DecryptAESError, null);
}try {
//去除补位字符
$result = $this->decode($decrypted);
//去除16位随机字符串,网络字节序和AppId
if (strlen($result) < 16)
return “”;
$content = substr($result, 16, strlen($result));
$len_list = unpack(“N”, substr($content, 0, 4));
$xml_len = $len_list[1];
$xml_content = substr($content, 4, $xml_len);
$from_appid = substr($content, $xml_len + 4);
} catch (Exception $e) {
//print $e;
return array($this->IllegalBuffer, null);
}
if ($from_appid != $appid)
return array($this->ValidateAppidError, null);
return array(0, $xml_content);
}
/**
-
随机生成16位字符串
-
@return string 生成的字符串
*/
private function getRandomStr()
{$str = “”;
$str_pol = “ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz”;
$max = strlen($str_pol) - 1;
for ($i = 0; $i < 16; $i++) {
$str .= $str_pol[mt_rand(0, $max)];
}
return $str;
}
}
官方提供的DEMO,在PHP7.0以上版本不能用。