常用对称加密类

对称加密
  1 <?php
  2 
  3 /**
  4  * 常用对称加密算法类
  5  * 支持密钥：64/128/256 bit（字节长度8/16/32）
  6  * 支持算法：DES/AES（根据密钥长度自动匹配使用：DES:64bit AES:128/256bit）
  7  * 支持模式：CBC/ECB/OFB/CFB
  8  * 密文编码：base64字符串/十六进制字符串/二进制字符串流
  9  * 填充方式: PKCS5Padding（DES）
 10  *
 11  * @author: linvo
 12  * @version: 1.0.0
 13  * @date: 2013/1/10
 14  */
 15 class Xcrypt{
 16 
 17     private $mcrypt;
 18     private $key;
 19     private $mode;
 20     private $iv;
 21     private $blocksize;
 22 
 23     /**
 24      * 构造函数
 25      *
 26      * @param string 密钥
 27      * @param string 模式
 28      * @param string 向量（"off":不使用 / "auto":自动 / 其他:指定值，长度同密钥）
 29      */
 30     public function __construct($key, $mode = 'cbc', $iv = "off"){
 31         switch (strlen($key)){
 32             case 8:
 33                 $this->mcrypt = MCRYPT_DES;
 34                 break;
 35             case 16:
 36                 $this->mcrypt = MCRYPT_RIJNDAEL_128;
 37                 break;
 38             case 32:
 39                 $this->mcrypt = MCRYPT_RIJNDAEL_256;
 40                 break;
 41             default:
 42                 die("Key size must be 8/16/32");
 43         }
 44 
 45         $this->key = $key;
 46 
 47         switch (strtolower($mode)){
 48             case 'ofb':
 49                 $this->mode = MCRYPT_MODE_OFB;
 50                 if ($iv == 'off') die('OFB must give a IV'); //OFB必须有向量
 51                 break;
 52             case 'cfb':
 53                 $this->mode = MCRYPT_MODE_CFB;
 54                 if ($iv == 'off') die('CFB must give a IV'); //CFB必须有向量
 55                 break;
 56             case 'ecb':
 57                 $this->mode = MCRYPT_MODE_ECB;
 58                 $iv = 'off'; //ECB不需要向量
 59                 break;
 60             case 'cbc':
 61             default:
 62                 $this->mode = MCRYPT_MODE_CBC;
 63         }
 64 
 65         switch (strtolower($iv)){
 66             case "off":
 67                 $this->iv = null;
 68                 break;
 69             case "auto":
 70                 $source = PHP_OS=='WINNT' ? MCRYPT_RAND : MCRYPT_DEV_RANDOM;
 71                 $this->iv = mcrypt_create_iv(mcrypt_get_block_size($this->mcrypt, $this->mode), $source);
 72                 break;
 73             default:
 74                 $this->iv = $iv;
 75         }
 76 
 77 
 78     }
 79 
 80     /**
 81      * 获取向量值
 82      * @param string 向量值编码（base64/hex/bin）
 83      * @return string 向量值
 84      */
 85     public function getIV($code = 'base64'){
 86         switch ($code){
 87             case 'base64':
 88                 $ret = base64_encode($this->iv);
 89                 break;
 90             case 'hex':
 91                 $ret = bin2hex($this->iv);
 92                 break;
 93             case 'bin':
 94             default:
 95                 $ret = $this->iv;
 96         }
 97         return $ret;
 98     }
 99 
100     /**
101      * 加密
102      * @param string 明文
103      * @param string 密文编码（base64/hex/bin）
104      * @return string 密文
105      */
106     public function encrypt($str, $code = 'base64'){
107         if ($this->mcrypt == MCRYPT_DES) $str = $this->_pkcs5Pad($str);
108 
109         if (isset($this->iv)) {
110             $result = mcrypt_encrypt($this->mcrypt, $this->key, $str, $this->mode, $this->iv);
111         } else {
112             @$result = mcrypt_encrypt($this->mcrypt, $this->key, $str, $this->mode);
113         }
114 
115         switch ($code){
116             case 'base64':
117                 $ret = base64_encode($result);
118                 break;
119             case 'hex':
120                 $ret = bin2hex($result);
121                 break;
122             case 'bin':
123             default:
124                 $ret = $result;
125         }
126 
127         return $ret;
128 
129     }
130 
131     /**
132      * 解密
133      * @param string 密文
134      * @param string 密文编码（base64/hex/bin）
135      * @return string 明文
136      */
137     public function decrypt($str, $code = "base64"){
138         $ret = false;
139 
140         switch ($code){
141             case 'base64':
142                 $str = base64_decode($str);
143                 break;
144             case 'hex':
145                 $str = $this->_hex2bin($str);
146                 break;
147             case 'bin':
148             default:
149         }
150 
151         if ($str !== false){
152             if (isset($this->iv)) {
153                 $ret = mcrypt_decrypt($this->mcrypt, $this->key, $str, $this->mode, $this->iv);
154             } else {
155                 @$ret = mcrypt_decrypt($this->mcrypt, $this->key, $str, $this->mode);
156             }
157             if ($this->mcrypt == MCRYPT_DES) $ret = $this->_pkcs5Unpad($ret);
158             $ret = trim($ret);
159         }
160 
161         return $ret;
162     }
163 
164     private function _pkcs5Pad($text){
165         $this->blocksize = mcrypt_get_block_size($this->mcrypt, $this->mode);
166         $pad = $this->blocksize - (strlen($text) % $this->blocksize);
167         return $text . str_repeat(chr($pad), $pad);
168     }
169 
170     private function _pkcs5Unpad($text){
171         $pad = ord($text{strlen($text) - 1});
172         if ($pad > strlen($text)) return false;
173         if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
174         $ret = substr($text, 0, -1 * $pad);
175         return $ret;
176     }
177 
178     private function _hex2bin($hex = false){
179         $ret = $hex !== false && preg_match('/^[0-9a-fA-F]+$/i', $hex) ? pack("H*", $hex) : false;
180         return $ret;
181     }
182 
183 
184 
185 }
186 
187 
188 
189 header('Content-Type:text/html;Charset=utf-8;');
190 
191 echo '<pre>';
192 //////////////////////////////////////
193 $a = isset($_GET['a']) ? $_GET['a'] : '<uid>441323198511201032</uid><pswd>851120</pswd><gid>12682</gid><date>2018-11-30</date>';
194 
195 //密钥
196 $key = 'EW2sdfkj'; //64 bit
197 
198 //设置模式和IV
199 $m = new Xcrypt($key, 'ecb', 'auto');
200 //加密
201 $b = $m->encrypt($a, 'hex');
202 
203 echo '加密后：';
204 var_dump($b);