PHP 的DES加密解密源码

DES.class.php

<?php 
class DES{           
public static function Encrypt($key,$text){         
$size = mcrypt_get_block_size('des','ecb');  
$text = self::pkcs5_pad($text, $size);  
$td = mcrypt_module_open('des', '', 'ecb', '');  
//srand((double)microtime() * 1000000); 
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);  
mcrypt_generic_init($td, $key, $iv);  
$data = mcrypt_generic($td, $text);  
mcrypt_generic_deinit($td);  
mcrypt_module_close($td);  
$data = base64_encode($data);  
return $data;  
} 

public static function Decrypt($key,$encrypted){         
$encrypted = base64_decode($encrypted);  
$td = mcrypt_module_open('des','','ecb',''); 
//srand((double)microtime() * 1000000);     
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);  
$ks = mcrypt_enc_get_key_size($td);  
mcrypt_generic_init($td, $key, $iv);              
$decrypted = mdecrypt_generic($td, $encrypted);  
mcrypt_generic_deinit($td);     
mcrypt_module_close($td);  
$plain_text=self::pkcs5_unpad($decrypted);  
return $plain_text;     
}         
public static function pkcs5_pad ($text, $blocksize){         
$pad = $blocksize - (strlen($text) % $blocksize);  
return $text . str_repeat(chr($pad), $pad);  
} 

public static function pkcs5_unpad($text){         
$pad = ord($text{strlen($text)-1});  
if ($pad > strlen($text)){  
return false;  
}  
if (strspn($text, chr($pad), strlen($text) - $pad) != $pad){  
return false;  
}  
return substr($text, 0, -1 * $pad);  
}  
}