<?php
/*
	[Phpup.Net!] (C)2009-2011 Phpup.net.
	This is NOT a freeware, use is subject to license terms

	$Id: global.func.php 2010-08-24 10:42 $
*/

if(!defined('IN_BIDCMS')) {
	exit('Access Denied');
}
//生成站点key
function mksitekey() {
	//16位
	$sitekey = substr(md5($_SERVER['SERVER_ADDR'].$_SERVER['HTTP_USER_AGENT'].$GLOBALS['dbhost'].$GLOBALS['dbuser'].$GLOBALS['dbpw'].$GLOBALS['dbname'].substr($GLOBALS['timestamp'], 0, 6)), 8, 6).random(10);
	return $sitekey;
}
function random($length, $numeric = 0) {
	PHP_VERSION < '4.2.0' && mt_srand((double)microtime() * 1000000);
	if($numeric) {
		$hash = sprintf('%0'.$length.'d', mt_rand(0, pow(10, $length) - 1));
	} else {
		$hash = '';
		$chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
		$max = strlen($chars) - 1;
		for($i = 0; $i < $length; $i++) {
			$hash .= $chars[mt_rand(0, $max)];
		}
	}
	return $hash;
}
function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {

	$ckey_length = 4;	//note 随机密钥长度 取值 0-32;
				//note 加入随机密钥，可以令密文无任何规律，即便是原文和密钥完全相同，加密结果也会每次不同，增大破解难度。
				//note 取值越大，密文变动规律越大，密文变化 = 16 的 $ckey_length 次方
				//note 当此值为 0 时，则不产生随机密钥

	$key = md5($key ? $key : UC_KEY);
	$keya = md5(substr($key, 0, 16));
	$keyb = md5(substr($key, 16, 16));
	$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';

	$cryptkey = $keya.md5($keya.$keyc);
	$key_length = strlen($cryptkey);

	$string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
	$string_length = strlen($string);

	$result = '';
	$box = range(0, 255);

	$rndkey = array();
	for($i = 0; $i <= 255; $i++) {
		$rndkey[$i] = ord($cryptkey[$i % $key_length]);
	}

	for($j = $i = 0; $i < 256; $i++) {
		$j = ($j + $box[$i] + $rndkey[$i]) % 256;
		$tmp = $box[$i];
		$box[$i] = $box[$j];
		$box[$j] = $tmp;
	}

	for($a = $j = $i = 0; $i < $string_length; $i++) {
		$a = ($a + 1) % 256;
		$j = ($j + $box[$a]) % 256;
		$tmp = $box[$a];
		$box[$a] = $box[$j];
		$box[$j] = $tmp;
		$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
	}

	if($operation == 'DECODE') {
		if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
			return substr($result, 26);
		} else {
			return '';
		}
	} else {
		return $keyc.str_replace('=', '', base64_encode($result));
	}
}

