php对称加密算法（DES/AES）类代码

1. /**
2. * 常用对称加密算法类
3. * 支持密钥：64/128/256 bit（字节长度8/16/32）
4. * 支持算法：DES/AES（根据密钥长度自动匹配使用：DES:64bit AES:128/256bit）
5. * 支持模式：CBC/ECB/OFB/CFB
6. * 密文编码：base64字符串/十六进制字符串/二进制字符串流
7. * 填充方式: PKCS5Padding（DES）
8. *
9. * @author: linvo
10. * @version: 1.0.0
11. * @date: 2013/1/10
12. */
13. class Xcrypt{
15. private $mcrypt;
16. private $key;
17. private $mode;
18. private $iv;
19. private $blocksize;
21. /**
22. * 构造函数
23. *
24. * @param string 密钥
25. * @param string 模式
26. * @param string 向量（"off":不使用 / "auto":自动 / 其他:指定值，长度同密钥）
27. */
28. public function __construct($key, $mode = 'cbc', $iv = "off"){
29. switch (strlen($key)){
30. case 8:
31. $this->mcrypt = MCRYPT_DES;
32. break;
33. case 16:
34. $this->mcrypt = MCRYPT_RIJNDAEL_128;
35. break;
36. case 32:
37. $this->mcrypt = MCRYPT_RIJNDAEL_256;
38. break;
39. default:
40. die("Key size must be 8/16/32");
41. }
43. $this->key = $key;
45. switch (strtolower($mode)){
46. case 'ofb':
47. $this->mode = MCRYPT_MODE_OFB;
48. if ($iv == 'off') die('OFB must give a IV'); //OFB必须有向量
49. break;
50. case 'cfb':
51. $this->mode = MCRYPT_MODE_CFB;
52. if ($iv == 'off') die('CFB must give a IV'); //CFB必须有向量
53. break;
54. case 'ecb':
55. $this->mode = MCRYPT_MODE_ECB;
56. $iv = 'off'; //ECB不需要向量
57. break;
58. case 'cbc':
59. default:
60. $this->mode = MCRYPT_MODE_CBC;
61. }
63. switch (strtolower($iv)){
64. case "off":
65. $this->iv = null;
66. break;
67. case "auto":
68. $source = PHP_OS=='WINNT' ? MCRYPT_RAND : MCRYPT_DEV_RANDOM;
69. $this->iv = mcrypt_create_iv(mcrypt_get_block_size($this->mcrypt, $this->mode), $source);
70. break;
71. default:
72. $this->iv = $iv;
73. }
76. }
79. /**
80. * 获取向量值
81. * @param string 向量值编码（base64/hex/bin）
82. * @return string 向量值
83. */
84. public function getIV($code = 'base64'){
85. switch ($code){
86. case 'base64':
87. $ret = base64_encode($this->iv);
88. break;
89. case 'hex':
90. $ret = bin2hex($this->iv);
91. break;
92. case 'bin':
93. default:
94. $ret = $this->iv;
95. }
96. return $ret;
97. }
100. /**
101. * 加密
102. * @param string 明文
103. * @param string 密文编码（base64/hex/bin）
104. * @return string 密文
105. */
106. public function encrypt($str, $code = 'base64'){
107. if ($this->mcrypt == MCRYPT_DES) $str = $this->_pkcs5Pad($str);
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, $this->mode);
113. }
115. switch ($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. }
127. return $ret;
129. }
131. /**
132. * 解密
133. * @param string 密文
134. * @param string 密文编码（base64/hex/bin）
135. * @return string 明文
136. */
137. public function decrypt($str, $code = "base64"){
138. $ret = false;
140. switch ($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. }
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. }
160. return $ret;
161. }
165. private function _pkcs5Pad($text){
166. $this->blocksize = mcrypt_get_block_size($this->mcrypt, $this->mode);
167. $pad = $this->blocksize - (strlen($text) % $this->blocksize);
168. return $text . str_repeat(chr($pad), $pad);
169. }
171. private function _pkcs5Unpad($text){
172. $pad = ord($text{strlen($text) - 1});
173. if ($pad > strlen($text)) return false;
174. if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
175. $ret = substr($text, 0, -1 * $pad);
176. return $ret;
177. }
179. private function _hex2bin($hex = false){
180. $ret = $hex !== false && preg_match('/^[0-9a-fA-F]+$/i', $hex) ? pack("H*", $hex) : false;
181. return $ret;
182. }
186. }

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使用示例：

1. header('Content-Type:text/html;Charset=utf-8;');
3. include "xcrypt.php";
5. echo '

   '; 

6. //////////////////////////////////////
7. $a = isset($_GET['a']) ? $_GET['a'] : '测试123';
9. //密钥
10. $key = '12345678123456781234567812345678'; //256 bit
11. $key = '1234567812345678'; //128 bit
12. $key = '12345678'; //64 bit
14. //设置模式和IV
15. $m = new Xcrypt($key, 'cbc', 'auto');
17. //获取向量值
18. echo '向量：';
19. var_dump($m->getIV());
21. //加密
22. $b = $m->encrypt($a, 'base64');
23. //解密
24. $c = $m->decrypt($b, 'base64');
26. echo '加密后：';
27. var_dump($b);
28. echo '解密后：';
29. var_dump($c);
32. /////////////////////////////////////////
33. echo '';

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php, DES, AES