基于Discuzsecurity.inc.php代码的深入分析_php实例

代码如下所示：

代码如下:

/*
[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'][$questionkey]['question'], '', FALSE, TRUE);
} else {
dsetCOOKIE('secqcode', authcode($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 '

'.$subject.'

'.$message.'

';
ajaxshowfooter();
} else {
echo '';
echo '';
echo '';
echo '';
echo '';
if($reload) {
echo '';
}
if($form) {
echo '';
}
echo '';
echo ' ';
echo ' ';
echo ' ';
echo '

'; echo ' '; echo ' '; echo ' '; echo ' '; echo ' '; echo ' '.$subject.' '; echo $message; echo ' '; echo ' '; echo '

';
if($form) {
echo '';
}
echo '';
echo '';
}
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 "/n}

function ajaxshowfooter() {
echo ']]>';
}

?>