canyin-project/ybcy/common/helpers/wxBiz/Prpcrypt.php

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2024-11-01 16:07:54 +08:00
<?php
namespace app\common\helpers\wxBiz;
use app\common\helpers\wxBiz\ErrorCode;
use app\common\helpers\wxBiz\PKCS7Encoder;
/**
* Prpcrypt class
*
* 提供接收和推送给公众平台消息的加解密接口.
*/
class Prpcrypt
{
public $key;
function Prpcrypt($k)
{
$this->key = base64_decode($k . "=");
}
/**
* 对明文进行加密
* @param string $text 需要加密的明文
* @return string 加密后的密文
*/
public function encrypt($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->key, 0, 16);
//使用自定义的填充方式对明文进行补位填充
$pkc_encoder = new PKCS7Encoder;
$text = $pkc_encoder->encode($text);
mcrypt_generic_init($module, $this->key, $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(ErrorCode::$OK, base64_encode($encrypted));
} catch (Exception $e) {
//print $e;
return array(ErrorCode::$EncryptAESError, null);
}
}
/**
* 对密文进行解密
* @param string $encrypted 需要解密的密文
* @return string 解密得到的明文
*/
public function decrypt($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->key, 0, 16);
mcrypt_generic_init($module, $this->key, $iv);
//解密
$decrypted = mdecrypt_generic($module, $ciphertext_dec);
mcrypt_generic_deinit($module);
mcrypt_module_close($module);
} catch (Exception $e) {
return array(ErrorCode::$DecryptAESError, null);
}
try {
//去除补位字符
$pkc_encoder = new PKCS7Encoder;
$result = $pkc_encoder->decode($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 $e;
return array(ErrorCode::$IllegalBuffer, null);
}
if ($from_appid != $appid)
return array(ErrorCode::$ValidateAppidError, null);
return array(0, $xml_content);
}
/**
* 随机生成16位字符串
* @return string 生成的字符串
*/
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;
}
}