PHP实现的XXTEA加密解密算法示例

本文实例讲述了PHP实现的XXTEA加密解密算法。分享给大家供大家参考，具体如下：

<?php
/**
* Xxtea 加密实现类
*/
class xxtea {
 private 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]);
   return $w ? substr(implode('', $s), 0, $n) : implode('', $s);
 }
 private function str2long($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 $v;
 }
 private function int32($n) {
   while ($n >= 2147483648)
     $n -= 4294967296;
   while ($n <= 2147483649)
     $n += 4294967296;
   return (int) $n;
 }
 public function encrypt($str, $key) {
   if ($str == '')
     return '';
   $v = $this->str2long($str, true);
   $k = $this->str2long($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 = $this->int32($sum + $delta);
     $e = $sum >> 2 & 3;
     for ($p = 0; $p < $n; $p++) {
       $y = $v[$p +1];
       $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
       $z = $v[$p] = $this->int32($v[$p] + $mx);
     }
     $y = $v[0];
     $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
     $z = $v[$n] = $this->int32($v[$n] + $mx);
   }
   return $this->long2str($v, false);
 }
 public function decrypt($str, $key) {
   if ($str == '')
     return '';
   $v = $this->str2long($str, false);
   $k = $this->str2long($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 = $this->int32($q * $delta);
   while ($sum != 0) {
     $e = $sum >> 2 & 3;
     for ($p = $n; $p > 0; $p--) {
       $z = $v[$p -1];
       $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
       $y = $v[$p] = $this->int32($v[$p] - $mx);
     }
     $z = $v[$n];
     $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
     $y = $v[0] = $this->int32($v[0] - $mx);
     $sum = $this->int32($sum - $delta);
   }
   return $this->long2str($v, true);
 }
}
//用法测试：
$strDemo = "www.aspxhome.com";
$key = "123456";
$pwd = new Xxtea();
$pwdrel = $pwd->encrypt($strDemo, $key);
echo $pwdrel;
echo "<br/>";
echo $pwd->decrypt($pwdrel, $key);
?>

运行结果：

{���H(�S��7*�u7U
www.aspxhome.com

希望本文所述对大家PHP程序设计有所帮助。

来源：https://blog.csdn.net/yafeikf/article/details/6341703