PHPRPC Code

<?php
/**
 * @author      Ma Bingyao(andot@ujn.edu.cn)
 * @copyright   CoolCode.CN
 * @package     XXTEA
 * @version     1.4
 * @lastupdate  2006-07-23
 * @link        http://www.coolcode.cn/?p=128
 */
 
function long2str($v, $w) {
    $len = count($v);
    $s = array();
    for ($i = 0; $i < $len; $i++)
    {
        $s[$i] = pack("V", $v[$i]);
    }
    if ($w) {
        return substr(join('', $s), 0, $v[$len - 1]);
    }
    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);
}
?>