如何巧用PHP实现Des加密算法，代码是什么?

发布时间：2022-11-21 08:42 所属栏目：121 来源：互联网

导读：这篇文章主要介绍如何利用PHP实现Des加密算法，代码是什么?，有一些人在如何利用PHP实现Des加密算法，代码是什么?的问题上存在疑惑，接下来小编就给大家来介绍一下相关的内容，希望对大家解答有帮助，有这个方面学习需要的朋友就继续往下看吧。注：php7以上

　　这篇文章主要介绍“如何利用PHP实现Des加密算法，代码是什么?”，有一些人在如何利用PHP实现Des加密算法，代码是什么?的问题上存在疑惑，接下来小编就给大家来介绍一下相关的内容，希望对大家解答有帮助，有这个方面学习需要的朋友就继续往下看吧。

　　注：php7以上不支持了，因为php7去掉了某些函数，另外变量的{}要改为[]

　　<?php
　　class Des
　　{
　　 /**
　　 * 加密方法
　　 *
　　 * @param string $str 需要加密的内容
　　 * @param string $key 密钥
　　 * @param bool $toBase64 是否base64
　　 * return string
　　 */
　　    public function encrypt($str, $key, $toBase64=true)
　　    {
　　        if ($str == "") {
　　            return "";
　　        }
　　 if ($toBase64) {
　　   return base64_encode(self::_des($key,$str,1));
　　 }
　　 return self::_des($key,$str,1);
　　    }
　　
　　 /**
　　 * 解密方法
　　 *
　　 * @param string $str 需要加密的内容
　　 * @param string $key 密钥
　　 * @param bool $toBase64 是否base64
　　 * return string
　　 */
　　    public function decrypt($str, $key, $toBase64=true)
　　    {
　　        if ($str == "") {
　　            return "";
　　        }
　　 if ($toBase64) {
　　   return self::_des($key,base64_decode($str),0);
　　 }
　　 return self::_des($key,$str,0);
　　    }
　　
　　    private function _des($key, $message, $encrypt, $mode=0, $iv=null) {
　　      $spfunction1 = array (0x1010400,0,0x10000,0x1010404,0x1010004,0x10404,0x4,0x10000,0x400,0x1010400,0x1010404,0x400,0x1000404,0x1010004,0x1000000,0x4,0x404,0x1000400,0x1000400,0x10400,0x10400,0x1010000,0x1010000,0x1000404,0x10004,0x1000004,0x1000004,0x10004,0,0x404,0x10404,0x1000000,0x10000,0x1010404,0x4,0x1010000,0x1010400,0x1000000,0x1000000,0x400,0x1010004,0x10000,0x10400,0x1000004,0x400,0x4,0x1000404,0x10404,0x1010404,0x10004,0x1010000,0x1000404,0x1000004,0x404,0x10404,0x1010400,0x404,0x1000400,0x1000400,0,0x10004,0x10400,0,0x1010004);
　　      $spfunction2 = array (-0x7fef7fe0,-0x7fff8000,0x8000,0x108020,0x100000,0x20,-0x7fefffe0,-0x7fff7fe0,-0x7fffffe0,-0x7fef7fe0,-0x7fef8000,-0x80000000,-0x7fff8000,0x100000,0x20,-0x7fefffe0,0x108000,0x100020,-0x7fff7fe0,0,-0x80000000,0x8000,0x108020,-0x7ff00000,0x100020,-0x7fffffe0,0,0x108000,0x8020,-0x7fef8000,-0x7ff00000,0x8020,0,0x108020,-0x7fefffe0,0x100000,-0x7fff7fe0,-0x7ff00000,-0x7fef8000,0x8000,-0x7ff00000,-0x7fff8000,0x20,-0x7fef7fe0,0x108020,0x20,0x8000,-0x80000000,0x8020,-0x7fef8000,0x100000,-0x7fffffe0,0x100020,-0x7fff7fe0,-0x7fffffe0,0x100020,0x108000,0,-0x7fff8000,0x8020,-0x80000000,-0x7fefffe0,-0x7fef7fe0,0x108000);
　　      $spfunction3 = array (0x208,0x8020200,0,0x8020008,0x8000200,0,0x20208,0x8000200,0x20008,0x8000008,0x8000008,0x20000,0x8020208,0x20008,0x8020000,0x208,0x8000000,0x8,0x8020200,0x200,0x20200,0x8020000,0x8020008,0x20208,0x8000208,0x20200,0x20000,0x8000208,0x8,0x8020208,0x200,0x8000000,0x8020200,0x8000000,0x20008,0x208,0x20000,0x8020200,0x8000200,0,0x200,0x20008,0x8020208,0x8000200,0x8000008,0x200,0,0x8020008,0x8000208,0x20000,0x8000000,0x8020208,0x8,0x20208,0x20200,0x8000008,0x8020000,0x8000208,0x208,0x8020000,0x20208,0x8,0x8020008,0x20200);
　　      $spfunction4 = array (0x802001,0x2081,0x2081,0x80,0x802080,0x800081,0x800001,0x2001,0,0x802000,0x802000,0x802081,0x81,0,0x800080,0x800001,0x1,0x2000,0x800000,0x802001,0x80,0x800000,0x2001,0x2080,0x800081,0x1,0x2080,0x800080,0x2000,0x802080,0x802081,0x81,0x800080,0x800001,0x802000,0x802081,0x81,0,0,0x802000,0x2080,0x800080,0x800081,0x1,0x802001,0x2081,0x2081,0x80,0x802081,0x81,0x1,0x2000,0x800001,0x2001,0x802080,0x800081,0x2001,0x2080,0x800000,0x802001,0x80,0x800000,0x2000,0x802080);
　　      $spfunction5 = array (0x100,0x2080100,0x2080000,0x42000100,0x80000,0x100,0x40000000,0x2080000,0x40080100,0x80000,0x2000100,0x40080100,0x42000100,0x42080000,0x80100,0x40000000,0x2000000,0x40080000,0x40080000,0,0x40000100,0x42080100,0x42080100,0x2000100,0x42080000,0x40000100,0,0x42000000,0x2080100,0x2000000,0x42000000,0x80100,0x80000,0x42000100,0x100,0x2000000,0x40000000,0x2080000,0x42000100,0x40080100,0x2000100,0x40000000,0x42080000,0x2080100,0x40080100,0x100,0x2000000,0x42080000,0x42080100,0x80100,0x42000000,0x42080100,0x2080000,0,0x40080000,0x42000000,0x80100,0x2000100,0x40000100,0x80000,0,0x40080000,0x2080100,0x40000100);
　　      $spfunction6 = array (0x20000010,0x20400000,0x4000,0x20404010,0x20400000,0x10,0x20404010,0x400000,0x20004000,0x404010,0x400000,0x20000010,0x400010,0x20004000,0x20000000,0x4010,0,0x400010,0x20004010,0x4000,0x404000,0x20004010,0x10,0x20400010,0x20400010,0,0x404010,0x20404000,0x4010,0x404000,0x20404000,0x20000000,0x20004000,0x10,0x20400010,0x404000,0x20404010,0x400000,0x4010,0x20000010,0x400000,0x20004000,0x20000000,0x4010,0x20000010,0x20404010,0x404000,0x20400000,0x404010,0x20404000,0,0x20400010,0x10,0x4000,0x20400000,0x404010,0x4000,0x400010,0x20004010,0,0x20404000,0x20000000,0x400010,0x20004010);
　　      $spfunction7 = array (0x200000,0x4200002,0x4000802,0,0x800,0x4000802,0x200802,0x4200800,0x4200802,0x200000,0,0x4000002,0x2,0x4000000,0x4200002,0x802,0x4000800,0x200802,0x200002,0x4000800,0x4000002,0x4200000,0x4200800,0x200002,0x4200000,0x800,0x802,0x4200802,0x200800,0x2,0x4000000,0x200800,0x4000000,0x200800,0x200000,0x4000802,0x4000802,0x4200002,0x4200002,0x2,0x200002,0x4000000,0x4000800,0x200000,0x4200800,0x802,0x200802,0x4200800,0x802,0x4000002,0x4200802,0x4200000,0x200800,0,0x2,0x4200802,0,0x200802,0x4200000,0x800,0x4000002,0x4000800,0x800,0x200002);
　　      $spfunction8 = array (0x10001040,0x1000,0x40000,0x10041040,0x10000000,0x10001040,0x40,0x10000000,0x40040,0x10040000,0x10041040,0x41000,0x10041000,0x41040,0x1000,0x40,0x10040000,0x10000040,0x10001000,0x1040,0x41000,0x40040,0x10040040,0x10041000,0x1040,0,0,0x10040040,0x10000040,0x10001000,0x41040,0x40000,0x41040,0x40000,0x10041000,0x1000,0x40,0x10040040,0x1000,0x41040,0x10001000,0x40,0x10000040,0x10040000,0x10040040,0x10000000,0x40000,0x10001040,0,0x10041040,0x40040,0x10000040,0x10040000,0x10001000,0x10001040,0,0x10041040,0x41000,0x41000,0x1040,0x1040,0x40040,0x10000000,0x10041000);
　　      $masks = array (4294967295,2147483647,1073741823,536870911,268435455,134217727,67108863,33554431,16777215,8388607,4194303,2097151,1048575,524287,262143,131071,65535,32767,16383,8191,4095,2047,1023,511,255,127,63,31,15,7,3,1,0);
　　
　　      $keys = self::_createKeys ($key);
　　      $m=0;
　　      $len = strlen($message);
　　      $chunk = 0;
　　
　　      $iterations = ((count($keys) == 32) ? 3 : 9);
　　      if ($iterations == 3) {$looping = (($encrypt) ? array (0, 32, 2) : array (30, -2, -2));}
　　      else {$looping = (($encrypt) ? array (0, 32, 2, 62, 30, -2, 64, 96, 2) : array (94, 62, -2, 32, 64, 2, 30, -2, -2));}
　　
　　      $message .= (chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0));
　　
　　      $result = "";
　　      $tempresult = "";
　　
　　      if ($mode == 1) {
　　        $cbcleft = (ord($iv[$m++]) << 24) | (ord($iv[$m++]) << 16) | (ord($iv[$m++]) << 8) | ord($iv[$m++]);
　　        $cbcright = (ord($iv[$m++]) << 24) | (ord($iv[$m++]) << 16) | (ord($iv[$m++]) << 8) | ord($iv[$m++]);
　　        $m=0;
　　      }
　　
　　      while ($m < $len) {
　　        $left = (ord($message[$m++]) << 24) | (ord($message[$m++]) << 16) | (ord($message[$m++]) << 8) | ord($message[$m++]);
　　        $right = (ord($message[$m++]) << 24) | (ord($message[$m++]) << 16) | (ord($message[$m++]) << 8) | ord($message[$m++]);
　　
　　        if ($mode == 1) {if ($encrypt) {$left ^= $cbcleft; $right ^= $cbcright;} else {$cbcleft2 = $cbcleft; $cbcright2 = $cbcright; $cbcleft = $left; $cbcright = $right;}}
　　
　　        $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4);
　　        $temp = (($left >> 16 & $masks[16]) ^ $right) & 0x0000ffff; $right ^= $temp; $left ^= ($temp << 16);
　　        $temp = (($right >> 2 & $masks[2]) ^ $left) & 0x33333333; $left ^= $temp; $right ^= ($temp << 2);
　　        $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8);
　　        $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1);
　　
　　        $left = (($left << 1) | ($left >> 31 & $masks[31]));
　　        $right = (($right << 1) | ($right >> 31 & $masks[31]));
　　
　　        for ($j=0; $j<$iterations; $j+=3) {
　　          $endloop = $looping[$j+1];
　　          $loopinc = $looping[$j+2];
　　          for ($i=$looping[$j]; $i!=$endloop; $i+=$loopinc) {
　　            $right1 = $right ^ $keys[$i];
　　            $right2 = (($right >> 4 & $masks[4]) | ($right << 28)) ^ $keys[$i+1];
　　            $temp = $left;
　　            $left = $right;
　　            $right = $temp ^ ($spfunction2[($right1 >> 24 & $masks[24]) & 0x3f] | $spfunction4[($right1 >> 16 & $masks[16]) & 0x3f]
　　                  | $spfunction6[($right1 >> 8 & $masks[8]) & 0x3f] | $spfunction8[$right1 & 0x3f]
　　                  | $spfunction1[($right2 >> 24 & $masks[24]) & 0x3f] | $spfunction3[($right2 >> 16 & $masks[16]) & 0x3f]
　　                  | $spfunction5[($right2 >> 8 & $masks[8]) & 0x3f] | $spfunction7[$right2 & 0x3f]);
　　          }
　　          $temp = $left; $left = $right; $right = $temp;
　　        }
　　
　　        $left = (($left >> 1 & $masks[1]) | ($left << 31));
　　        $right = (($right >> 1 & $masks[1]) | ($right << 31));
　　
　　        $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1);
　　        $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8);
　　        $temp = (($right >> 2 & $masks[2]) ^ $left) & 0x33333333; $left ^= $temp; $right ^= ($temp << 2);
　　        $temp = (($left >> 16 & $masks[16]) ^ $right) & 0x0000ffff; $right ^= $temp; $left ^= ($temp << 16);
　　        $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4);
　　
　　        if ($mode == 1) {if ($encrypt) {$cbcleft = $left; $cbcright = $right;} else {$left ^= $cbcleft2; $right ^= $cbcright2;}}
　　        $tempresult .= (chr($left>>24 & $masks[24]) . chr(($left>>16 & $masks[16]) & 0xff) . chr(($left>>8 & $masks[8]) & 0xff) . chr($left & 0xff) . chr($right>>24 & $masks[24]) . chr(($right>>16 & $masks[16]) & 0xff) . chr(($right>>8 & $masks[8]) & 0xff) . chr($right & 0xff));
　　
　　        $chunk += 8;
　　        if ($chunk == 512) {$result .= $tempresult; $tempresult = ""; $chunk = 0;}
　　      }
　　
　　      return ($result . $tempresult);
　　    }
　　
　　    private function _createKeys ($key) {
　　      $pc2bytes0 = array (0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204);
　　      $pc2bytes1 = array (0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101);
　　      $pc2bytes2 = array (0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808);
　　      $pc2bytes3 = array (0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000);
　　      $pc2bytes4 = array (0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010);
　　      $pc2bytes5 = array (0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420);
　　      $pc2bytes6 = array (0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002);
　　      $pc2bytes7 = array (0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800);
　　      $pc2bytes8 = array (0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002);
　　      $pc2bytes9 = array (0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408);
　　      $pc2bytes10 = array (0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020);
　　      $pc2bytes11 = array (0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200);
　　      $pc2bytes12 = array (0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010);
　　      $pc2bytes13 = array (0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105);
　　      $masks = array (4294967295,2147483647,1073741823,536870911,268435455,134217727,67108863,33554431,16777215,8388607,4194303,2097151,1048575,524287,262143,131071,65535,32767,16383,8191,4095,2047,1023,511,255,127,63,31,15,7,3,1,0);
　　
　　      $iterations = ((strlen($key) >= 24) ? 3 : 1);
　　      $keys = array ();
　　      $shifts = array (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0);
　　      $m=0;
　　      $n=0;
　　
　　      for ($j=0; $j<$iterations; $j++) {
　　        $left = (ord($key[$m++]) << 24) | (ord($key[$m++]) << 16) | (ord($key[$m++]) << 8) | ord($key[$m++]);
　　        $right = (ord($key[$m++]) << 24) | (ord($key[$m++]) << 16) | (ord($key[$m++]) << 8) | ord($key[$m++]);
　　
　　        $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4);
　　        $temp = (($right >> 16 & $masks[16]) ^ $left) & 0x0000ffff; $left ^= $temp; $right ^= ($temp << -16);
　　        $temp = (($left >> 2 & $masks[2]) ^ $right) & 0x33333333; $right ^= $temp; $left ^= ($temp << 2);
　　        $temp = (($right >> 16 & $masks[16]) ^ $left) & 0x0000ffff; $left ^= $temp; $right ^= ($temp << -16);
　　        $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1);
　　        $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8);
　　        $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1);
　　
　　        $temp = ($left << 8) | (($right >> 20 & $masks[20]) & 0x000000f0);
　　        $left = ($right << 24) | (($right << 8) & 0xff0000) | (($right >> 8 & $masks[8]) & 0xff00) | (($right >> 24 & $masks[24]) & 0xf0);
　　        $right = $temp;
　　
　　        for ($i=0; $i < count($shifts); $i++) {
　　          if ($shifts[$i] > 0) {
　　             $left = (($left << 2) | ($left >> 26 & $masks[26]));
　　             $right = (($right << 2) | ($right >> 26 & $masks[26]));
　　          } else {
　　             $left = (($left << 1) | ($left >> 27 & $masks[27]));
　　             $right = (($right << 1) | ($right >> 27 & $masks[27]));
　　          }
　　          $left = $left & -0xf;
　　          $right = $right & -0xf;
　　
　　          $lefttemp = $pc2bytes0[$left >> 28 & $masks[28]] | $pc2bytes1[($left >> 24 & $masks[24]) & 0xf]
　　                  | $pc2bytes2[($left >> 20 & $masks[20]) & 0xf] | $pc2bytes3[($left >> 16 & $masks[16]) & 0xf]
　　                  | $pc2bytes4[($left >> 12 & $masks[12]) & 0xf] | $pc2bytes5[($left >> 8 & $masks[8]) & 0xf]
　　                  | $pc2bytes6[($left >> 4 & $masks[4]) & 0xf];
　　          $righttemp = $pc2bytes7[$right >> 28 & $masks[28]] | $pc2bytes8[($right >> 24 & $masks[24]) & 0xf]
　　                    | $pc2bytes9[($right >> 20 & $masks[20]) & 0xf] | $pc2bytes10[($right >> 16 & $masks[16]) & 0xf]
　　                    | $pc2bytes11[($right >> 12 & $masks[12]) & 0xf] | $pc2bytes12[($right >> 8 & $masks[8]) & 0xf]
　　                    | $pc2bytes13[($right >> 4 & $masks[4]) & 0xf];
　　          $temp = (($righttemp >> 16 & $masks[16]) ^ $lefttemp) & 0x0000ffff;
　　          $keys[$n++] = $lefttemp ^ $temp; $keys[$n++] = $righttemp ^ ($temp << 16);
　　        }
　　      }
　　      return $keys;
　　    }
　　}
　　
　　// 使用方式
　　$Des = new Des();
　　$string = 'hello leven';
　　$key = '123456';
　　$encode = $Des->encrypt($string,$key,true);
　　$decode = $Des->decrypt($encode,$key,true);
　　echo $encode;
　　echo "<br />";
　　echo $decode;
　　?>
　　另一个DES加密算法

　　class CryptDes {
　　 function __construct(){
　　 $this->key = 'codelovers'; //密钥
　　 $this->iv = '15548632'; //偏移量
　　 }
　　 /*
　　 * 加密
　　 */
　　 function encrypt($input){
　　 $size = mcrypt_get_block_size(MCRYPT_DES,MCRYPT_MODE_CBC); //3DES加密将MCRYPT_DES改为MCRYPT_3DES
　　 $input = $this->pkcs5_pad($input, $size); //如果采用PaddingPKCS7，请更换成PaddingPKCS7方法。
　　 $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
　　 $td = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_CBC, '');
　　 if( $this->iv == '' )
　　 {
　　   $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
　　 }
　　 else
　　 {
　　   $iv = $this->iv;
　　 }
　　 @mcrypt_generic_init($td, $key, $iv);
　　 $data = mcrypt_generic($td, $input);
　　 mcrypt_generic_deinit($td);
　　 mcrypt_module_close($td);
　　 $data = base64_encode($data);//如需转换二进制可改成 bin2hex 转换
　　 return $data;
　　 }
　　 /*
　　 * 解密
　　 */
　　 function decrypt($encrypted){
　　 $encrypted = base64_decode($encrypted); //如需转换二进制可改成 bin2hex 转换
　　 $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
　　 $td = mcrypt_module_open(MCRYPT_DES,'',MCRYPT_MODE_CBC,'');//3DES加密将MCRYPT_DES改为MCRYPT_3DES
　　 if( $this->iv == '' )
　　 {
　　   $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
　　 }
　　 else
　　 {
　　   $iv = $this->iv;
　　 }
　　 $ks = mcrypt_enc_get_key_size($td);
　　 @mcrypt_generic_init($td, $key, $iv);
　　 $decrypted = mdecrypt_generic($td, $encrypted);
　　 mcrypt_generic_deinit($td);
　　 mcrypt_module_close($td);
　　 $y=$this->pkcs5_unpad($decrypted);
　　 return $y;
　　 }
　　 function pkcs5_pad ($text, $blocksize) {
　　 $pad = $blocksize - (strlen($text) % $blocksize);
　　 return $text . str_repeat(chr($pad), $pad);
　　 }
　　 function pkcs5_unpad($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 * $pad);
　　 }
　　 function PaddingPKCS7($data) {
　　 $block_size = mcrypt_get_block_size(MCRYPT_DES, MCRYPT_MODE_CBC);//3DES加密将MCRYPT_DES改为MCRYPT_3DES
　　 $padding_char = $block_size - (strlen($data) % $block_size);
　　 $data .= str_repeat(chr($padding_char),$padding_char);
　　 return $data;
　　 }
　　}
　　用法如下：

　　$str = 'www.jb51.net';
　　$des = new CryptDes();
　　$mres = $des->encrypt($str); //加密
　　echo $mres."<br/>";
　　$jres = $des->decrypt($mres); //解密
　　echo $jres."<br/>";

　　关于“如何利用PHP实现Des加密算法，代码是什么?”就介绍到这了。

（编辑：ASP站长网）