Discuz security.inc.php 代码解释

<?php

/*

[Discuz!] (C)2001-2009 Comsenz Inc.

This is NOT a freeware, use is subject to license terms

$Id: security.inc.php 16688 2008-11-14 06:41:07Z cnteacher $

*/

//如果没有设定 IN_DISCUZ ，则访问出错

if(!defined('IN_DISCUZ')) {

exit('Access Denied');

}

// 使用位移 $attackevasive 来设定 论坛防御级别 ，如果是 1 或者是 4 的话， 1=cookie 刷新限制 ， 4=二次请求

// 读取上次时间到当前存放cookies数组，并将现在时间放置cookies

// 将$_DCOOKIE['lastrequest'] 不断加密 存放last访问时间到 lastrequest_cookies

if($attackevasive & 1 || $attackevasive & 4) {

$_DCOOKIE['lastrequest'] = authcode($_DCOOKIE['lastrequest'], 'DECODE');

dsetcookie('lastrequest', authcode($timestamp, 'ENCODE'), $timestamp + 816400, 1, true);

}

//如果确认被攻击，则展示提示语 1

if($attackevasive & 1) {

if($timestamp - $_DCOOKIE['lastrequest'] < 1) {

securitymessage('attachsave_1_subject', 'attachsave_1_message');

}

}

//如检查到 HTTP_X_FORWARDED_FOR 有以下 参数 ，将提示 使用代理

if(($attackevasive & 2) && ($_SERVER['HTTP_X_FORWARDED_FOR'] ||

$_SERVER['HTTP_VIA'] || $_SERVER['HTTP_PROXY_CONNECTION'] ||

$_SERVER['HTTP_USER_AGENT_VIA'] || $_SERVER['HTTP_CACHE_INFO'] ||

$_SERVER['HTTP_PROXY_CONNECTION'])) {

securitymessage('attachsave_2_subject', 'attachsave_2_message', FALSE);

}

//如果在限定的时间内访问多次，将判断为二次请求

if($attackevasive & 4) {

if(empty($_DCOOKIE['lastrequest']) || $timestamp - $_DCOOKIE['lastrequest'] > 300) {

securitymessage('attachsave_4_subject', 'attachsave_4_message');

}

}

//如果需要回答问题，则判断为8

if($attackevasive & 8) {

list($questionkey, $questionanswer, $questiontime) = explode('|', authcode($_DCOOKIE['secqcode'], 'DECODE'));

include_once DISCUZ_ROOT.'./forumdata/cache/cache_secqaa.php';

if(!$questionanswer || !$questiontime || $_DCACHE['secqaa'][$questionkey]['answer'] != $questionanswer) {

if(empty($_POST['secqsubmit']) || (!empty($_POST['secqsubmit']) && $_DCACHE['secqaa'][$questionkey]['answer'] != md5($_POST['answer']))) {

$questionkey = array_rand($_DCACHE['secqaa']);

dsetcookie('secqcode', authcode($questionkey.'||'.$timestamp, 'ENCODE'), $timestamp + 816400, 1, true);

securitymessage($_DCACHE['secqaa'][$questionkey]['question'], '<input type="text" name="answer" size="8" maxlength="150" /><input class="button" type="submit" name="secqsubmit" value=" Submit " />', FALSE, TRUE);

} else {

dsetcookie('secqcode', authcode($questionkey.'|'.$_DCACHE['secqaa'][$questionkey]['answer'].'|'.$timestamp, 'ENCODE'), $timestamp + 816400, 1, true);

}

}

}

/**

* 输出被攻击提示语言，如果是ajax，展示一個错误層， 如果是請求， 則展示错误頁面

* @param $subject

* @param $message

* @param $reload

* @param $form

* @return unknown_type

*/

function securitymessage($subject, $message, $reload = TRUE, $form = FALSE) {

$scuritylang = array(

'attachsave_1_subject' => '&#x9891;&#x7e41;&#x5237;&#x65b0;&#x9650;&#x5236;',

'attachsave_1_message' => '&#x60a8;&#x8bbf;&#x95ee;&#x672c;&#x7ad9;&#x901f;&#x5ea6;&#x8fc7;&#x5feb;&#x6216;&#x8005;&#x5237;&#x65b0;&#x95f4;&#x9694;&#x65f6;&#x95f4;&#x5c0f;&#x4e8e;&#x4e24;&#x79d2;&#xff01;&#x8bf7;&#x7b49;&#x5f85;&#x9875;&#x9762;&#x81ea;&#x52a8;&#x8df3;&#x8f6c;&#x20;&#x2e;&#x2e;&#x2e;',

'attachsave_2_subject' => '&#x4ee3;&#x7406;&#x670d;&#x52a1;&#x5668;&#x8bbf;&#x95ee;&#x9650;&#x5236;',

'attachsave_2_message' => '&#x672c;&#x7ad9;&#x73b0;&#x5728;&#x9650;&#x5236;&#x4f7f;&#x7528;&#x4ee3;&#x7406;&#x670d;&#x52a1;&#x5668;&#x8bbf;&#x95ee;&#xff0c;&#x8bf7;&#x53bb;&#x9664;&#x60a8;&#x7684;&#x4ee3;&#x7406;&#x8bbe;&#x7f6e;&#xff0c;&#x76f4;&#x63a5;&#x8bbf;&#x95ee;&#x672c;&#x7ad9;&#x3002;',

'attachsave_4_subject' => '&#x9875;&#x9762;&#x91cd;&#x8f7d;&#x5f00;&#x542f;',

'attachsave_4_message' => '&#x6b22;&#x8fce;&#x5149;&#x4e34;&#x672c;&#x7ad9;&#xff0c;&#x9875;&#x9762;&#x6b63;&#x5728;&#x91cd;&#x65b0;&#x8f7d;&#x5165;&#xff0c;&#x8bf7;&#x7a0d;&#x5019;&#x20;&#x2e;&#x2e;&#x2e;'

);

$subject = $scuritylang[$subject] ? $scuritylang[$subject] : $subject;

$message = $scuritylang[$message] ? $scuritylang[$message] : $message;

if($_GET['inajax']) {

ajaxshowheader();

echo '<div id="attackevasive_1" class="popupmenu_option"><b style="font-size: 16px">'.$subject.'</b><br /><br />'.$message.'</div>';

ajaxshowfooter();

} else {

echo '<html>';

echo '<head>';

echo '<title>'.$subject.'</title>';

echo '</head>';

echo '<body bgcolor="#FFFFFF">';

if($reload) {

echo '<script language="JavaScript">';

echo 'function reload() {';

echo ' document.location.reload();';

echo '}';

echo 'setTimeout("reload()", 1001);';

echo '</script>';

}

if($form) {

echo '<form action="'.$_SERVER['PHP_SELF'].'" method="POST">';

}

echo '<table cellpadding="0" cellspacing="0" border="0" width="700" align="center" height="85%">';

echo ' <tr align="center" valign="middle">';

echo ' <td>';

echo ' <table cellpadding="10" cellspacing="0" border="0" width="80%" align="center" style="font-family: Verdana, Tahoma; color: #666666; font-size: 11px">';

echo ' <tr>';

echo ' <td valign="middle" align="center" bgcolor="#EBEBEB">';

echo ' <br /><br /> <b style="font-size: 16px">'.$subject.'</b> <br /><br />';

echo $message;

echo ' <br /><br />';

echo ' </td>';

echo ' </tr>';

echo ' </table>';

echo ' </td>';

echo ' </tr>';

echo '</table>';

if($form) {

echo '</form>';

}

echo '</body>';

echo '</html>';

}

exit();

}

function ajaxshowheader() {

global $charset, $inajax;

ob_end_clean();

@header("Expires: -1");

@header("Cache-Control: no-store, private, post-check=0, pre-check=0, max-age=0", FALSE);

@header("Pragma: no-cache");

header("Content-type: application/xml");

echo "<?xml version=/"1.0/" encoding=/"$charset/"?>/n<root><![CDATA[";

}

function ajaxshowfooter() {

echo ']]></root>';

}

?>