PHP 数据加密

<?php

/**

 *

 * 加密

 *

 */

function lock_url($txt, $key = "aiteng") {

    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";

    $nh = rand(0, 64);

    $ch = $chars[$nh];

    $mdKey = md5($key . $ch);

    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);

    $txt = base64_encode($txt);

    $tmp = '';

    $i = 0;

    $j = 0;

    $k = 0;

    for ($i = 0; $i < strlen($txt); $i++) {

        $k = $k == strlen($mdKey) ? 0 : $k;

        $j = ($nh + strpos($chars, $txt[$i]) + ord($mdKey[$k++])) % 64;

        $tmp.= $chars[$j];

    }

    return urlencode($ch . $tmp);

}

/**

 *

 * 解密

 *

 */

function unlock_url($txt, $key = "aiteng") {

    $txt = urldecode($txt);

    $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";

    $ch = $txt[0];

    $nh = strpos($chars, $ch);

    $mdKey = md5($key . $ch);

    $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);

    $txt = substr($txt, 1);

    $tmp = '';

    $i = 0;

    $j = 0;

    $k = 0;

    for ($i = 0; $i < strlen($txt); $i++) {

        $k = $k == strlen($mdKey) ? 0 : $k;

        $j = strpos($chars, $txt[$i]) - $nh - ord($mdKey[$k++]);

        while ($j < 0) $j+= 64;

        $tmp.= $chars[$j];

    }

    return base64_decode($tmp);

}

?>