<?php

/**********************************************************\

|                                                          |

| The implementation of PHPRPC Protocol 3.0                |

|                                                          |

| xxtea.php                                                |

|                                                          |

| Release 3.0.1                                            |

| Copyright by Team-PHPRPC                                 |

|                                                          |

| WebSite:  http://www.phprpc.org/                         |

|           http://www.phprpc.net/                         |

|           http://www.phprpc.com/                         |

|           http://sourceforge.net/projects/php-rpc/       |

|                                                          |

| Authors:  Ma Bingyao <andot@ujn.edu.cn>                  |

|                                                          |

| This file may be distributed and/or modified under the   |

| terms of the GNU General Public License (GPL) version    |

| 2.0 as published by the Free Software Foundation and     |

| appearing in the included file LICENSE.                  |

|                                                          |

\**********************************************************/



/* XXTEA encryption arithmetic library.

 *

 * Copyright: Ma Bingyao <andot@ujn.edu.cn>

 * Version: 1.6

 * LastModified: Apr 12, 2010

 * This library is free.  You can redistribute it and/or modify it under GPL.

 */

if (!extension_loaded('xxtea')) {

    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);

    }

}

?>