XXTEA 加密算法的 PHP 实现

<?php
    /* XXTEA encryption arithmetic library.
    *
    * Copyright (C) 2006 Ma Bingyao <[email protected]>
    * Version:      1.5
    * LastModified: Dec 5, 2006
    * This library is free.  You can redistribute it and/or modify it.
    */

   function long2str($v, $w) {
       $len = count($v);
       $n = ($len - 1) << 2;
       if ($w) {
           $m = $v[$len - 1];
           if (($m < $n - 3) || ($m > $n)) return false;
           $n = $m;
       }
       $s = array();
       for ($i = 0; $i < $len; $i++) {
           $s[$i] = pack("V", $v[$i]);
       }
       if ($w) {
           return substr(join('', $s), 0, $n);
       }
       else {
           return join('', $s);
       }

   }

   function str2long($s, $w) {
       $v = unpack("V*", $s. str_repeat("\0", (4 - strlen($s) % 4) & 3));
       $v = array_values($v);
       if ($w) {
           $v[count($v)] = strlen($s);
       }

       return $v;
   }

   function int32($n) {
       while ($n >= 2147483648) $n -= 4294967296;
       while ($n <= -2147483649) $n += 4294967296;
       return (int)$n;
   }

   function xxtea_encrypt($str, $key) {
       if ($str == "") {
           return "";
       }
       $v = str2long($str, true);
       $k = str2long($key, false);
       if (count($k) < 4) {
           for ($i = count($k); $i < 4; $i++) {
               $k[$i] = 0;
           }
       }
       $n = count($v) - 1;

       $z = $v[$n];
       $y = $v[0];
       $delta = 0x9E3779B9;
       $q = floor(6 + 52 / ($n + 1));
       $sum = 0;
       while (0 < $q--) {
           $sum = int32($sum + $delta);
           $e = $sum >> 2 & 3;
           for ($p = 0; $p < $n; $p++) {
               $y = $v[$p + 1];
               $mx = int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4))
               		^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
               $z = $v[$p] = int32($v[$p] + $mx);
           }
           $y = $v[0];
           $mx = int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4))
           		^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
           $z = $v[$n] = int32($v[$n] + $mx);
       }
       return long2str($v, false);
   }

   function xxtea_decrypt($str, $key) {
       if ($str == "") {
           return "";
       }
       $v = str2long($str, false);
       $k = str2long($key, false);
       if (count($k) < 4) {
           for ($i = count($k); $i < 4; $i++) {
               $k[$i] = 0;
           }
       }
       $n = count($v) - 1;

       $z = $v[$n];
       $y = $v[0];
       $delta = 0x9E3779B9;
       $q = floor(6 + 52 / ($n + 1));
       $sum = int32($q * $delta);
       while ($sum != 0) {
           $e = $sum >> 2 & 3;
           for ($p = $n; $p > 0; $p--) {
               $z = $v[$p - 1];
              $mx = int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) 
^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
              $y = $v[$p] = int32($v[$p] - $mx);
          }
          $z = $v[$n];
          $mx = int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) 
^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
          $y = $v[0] = int32($v[0] - $mx);
          $sum = int32($sum - $delta);
      }
      return long2str($v, true);
  }


$key = '1234567890123456';
$SS = unpack('H*', 'pl00:00:00:00:00:001120000501182001120500020');
foreach($SS as $key){
	echo $key."<br>";
}
$e = base64_encode(xxtea_encrypt($SS, $key));
echo $e."<br>";

$d = xxtea_decrypt(base64_decode($e), $key);
echo  $d."<br>";

?>

 

 

原作者：andot
原文网址：http://www.coolcode.cn/show-128-1.html