CI框架源码阅读---------Security.php
'[removed]',
'document.write' => '[removed]',
'.parentNode' => '[removed]',
'.innerHTML' => '[removed]',
'window.location' => '[removed]',
'-moz-binding' => '[removed]',
'' => '-->',
' '' => ''
);
/* never allowed, regex replacement */
/**
* List of never allowed regex replacement
* 不允许的正则替换字符串列表
* @var array
* @access protected
*/
protected $_never_allowed_regex = array(
'javascript\s*:',
'expression\s*(\(|&\#40;)', // CSS and IE
'vbscript\s*:', // IE, surprise!
'Redirect\s+302',
"([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
);
/**
* Constructor
*
* @return void
*/
public function __construct()
{
// Is CSRF protection enabled?
// csrf 是否开启
if (config_item('csrf_protection') === TRUE)
{
// CSRF config 读取CSRF 配置并赋值给本类下的对应的属性
foreach (array('csrf_expire', 'csrf_token_name', 'csrf_cookie_name') as $key)
{
if (FALSE !== ($val = config_item($key)))
{
$this->{'_'.$key} = $val;
}
}
// Append application specific cookie prefix
// 添加应用指定的cookie前缀
if (config_item('cookie_prefix'))
{
$this->_csrf_cookie_name = config_item('cookie_prefix').$this->_csrf_cookie_name;
}
// Set the CSRF hash
// 设置CSRF hash
$this->_csrf_set_hash();
}
log_message('debug', "Security Class Initialized");
}
// --------------------------------
/**
* Verify Cross Site Request Forgery Protection
* 验证跨站请求伪造保护
* @return object
*/
public function csrf_verify()
{
// If it's not a POST request we will set the CSRF cookie
// 如果不是post请求我们要设置 CSRF cookie
if (strtoupper($_SERVER['REQUEST_METHOD']) !== 'POST')
{
return $this->csrf_set_cookie();
}
// Do the tokens exist in both the _POST and _COOKIE arrays?
// 如果请求令牌不存在，调用csrf_show_error 报错
if ( ! isset($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name]))
{
$this->csrf_show_error();
}
// Do the tokens match?
// 如果令牌不对，报错。
if ($_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name])
{
$this->csrf_show_error();
}
// We kill this since we're done and we don't want to
// polute the _POST array
// 销毁领牌子，因为我们不想污染_POST 数组
unset($_POST[$this->_csrf_token_name]);
// Nothing should last forever
// 销毁cookie名 并重新设置hash和cookie
unset($_COOKIE[$this->_csrf_cookie_name]);
$this->_csrf_set_hash();
$this->csrf_set_cookie();
log_message('debug', 'CSRF token verified');
return $this;
}
// --------------------------------
/**
* Set Cross Site Request Forgery Protection Cookie
* 设置伪造cookie保护跨站请求
* @return object
*/
public function csrf_set_cookie()
{
$expire = time() + $this->_csrf_expire;
$secure_cookie = (config_item('cookie_secure') === TRUE) ? 1 : 0;
// 当存在https时设置cookie
if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off'))
{
return FALSE;
}
// 设置cookie
setcookie($this->_csrf_cookie_name, $this->_csrf_hash, $expire, config_item('cookie_path'), config_item('cookie_domain'), $secure_cookie);
log_message('debug', "CRSF cookie Set");
return $this;
}
// --------------------------------
/**
* Show CSRF Error
* 显示CSRF错误
* @return void
*/
public function csrf_show_error()
{
show_error('The action you have requested is not allowed.');
}
// --------------------------------
/**
* Get CSRF Hash
* 获取CSRF hash
* Getter Method
*
* @return string self::_csrf_hash
*/
public function get_csrf_hash()
{
return $this->_csrf_hash;
}
// --------------------------------
/**
* Get CSRF Token Name
* 获取CSRF 令排名
* Getter Method
*
* @return string self::csrf_token_name
*/
public function get_csrf_token_name()
{
return $this->_csrf_token_name;
}
// --------------------------------
/**
* XSS Clean
*
* Sanitizes 清理 data so that Cross Site Scripting Hacks can be
* prevented.阻止 This function does a fair amount of work but
* it is extremely thorough, designed to prevent even the
* most obscure XSS attempts 企图. Nothing is ever 100% foolproof,
* of course, but I haven't been able to get anything passed
* the filter.
* 对数据进行过滤，从而可以防止跨站脚本攻击。这个函数做了一些工作，但是它是非常彻底的，
* 甚至可以防止大多数模糊的XSS企图。当然，没有什么是100%安全的，
* 但是我们在这个过滤器中已经做了所欲我们所能做想到的了。
*
* Note: This function should only be used to deal with data
* upon submission. It's not something that should
* be used for general runtime processing.
* 注意：这个函数只能用来处理已经提交的数据。
* 在通常的运行过程中，不应该使用该函数。
*
* This function was based in part on some code and ideas I
* got from Bitflux: http://channel.bitflux.ch/wiki/XSS_Prevention
*
* To help develop this script I used this great list of
* vulnerabilities along with a few other hacks I've
* harvested from examining vulnerabilities in other programs:
* http://ha.ckers.org/xss.html
*
* @param mixed string or array
* @param bool
* @return string
*/
public function xss_clean($str, $is_image = FALSE)
{
/*
* Is the string an array?
* 需要过滤的字符串是数组吗？
*
*/
if (is_array($str))
{
while (list($key) = each($str))
{
$str[$key] = $this->xss_clean($str[$key]);
}
return $str;
}
/*
* Remove Invisible Characters
* 移除不可见字符
*/
$str = remove_invisible_characters($str);
// Validate Entities in URLs
// 验证在URL中的字符实体
$str = $this->_validate_entities($str);
/*
* URL Decode
* URL解码
* Just in case stuff like this is submitted:
* 防止下面这样的东西提交
* Google
*
* Note: Use rawurldecode() so it does not remove plus signs
* rawurldecode() 不会把加号（'+'）解码为空格，而 urldecode() 可以。
*
*/
$str = rawurldecode($str);
/*
* Convert character entities to ASCII
* 把实体字符转换成ASCII码
* 这使得我们下面的测试是可靠的，我们仅仅转换实体内的标签，因为这些是会造成安全问题的实体
* This permits our tests below to work reliably.
* We only convert entities that are within tags since
* these are the ones that will pose security problems.
*
*/
$str = preg_replace_callback("/[a-z]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str);
$str = preg_replace_callback("/<\w+.*?(?=>|<|$)/si", array($this, '_decode_entity'), $str);
/*
* Remove Invisible Characters Again!
* 再次删除不可见字符
*/
$str = remove_invisible_characters($str);
/*
* Convert all tabs to spaces
* 转换所有制表符为空格
* This prevents strings like this: ja vascript
* 这用来防止字符串类似于ja vascript
* NOTE: we deal with spaces between characters later.
* 注意： 我们将在后面处理字符之间的空格
* NOTE: preg_replace was found to be amazingly slow here on
* large blocks of data, so we use str_replace.
* 注意：preg_replace在这里是极其缓慢的对于大块的数据，所以使用str_replace
*
*/
if (strpos($str, "\t") !== FALSE)
{
$str = str_replace("\t", ' ', $str);
}
/*
* Capture 捕获 converted string for later comparison
* 为以后的比较捕获转换的字符串
*/
$converted_string = $str;
// Remove Strings that are never allowed
// 删除绝不容许的字符串
$str = $this->_do_never_allowed($str);
/*
* Makes PHP tags safe
* 使PHP标签安全
* Note: XML tags are inadvertently replaced too:
* 注意： XML标签也会被无意的替换
* '), array(''), $str);
}
/*
* Compact any exploded words
* 压缩所有分解了的单词
* This corrects words like: j a v a s c r i p t
* These words are compacted back to their correct state.
*/
$words = array(
'javascript', 'expression', 'vbscript', 'script', 'base64',
'applet', 'alert', 'document', 'write', 'cookie', 'window'
);
foreach ($words as $word)
{
$temp = '';
for ($i = 0, $wordlen = strlen($word); $i < $wordlen; $i++)
{
$temp .= substr($word, $i, 1)."\s*";
}
// We only want to do this when it is followed by a non-word character
// That way valid stuff like "dealer to" does not become "dealerto"
$str = preg_replace_callback('#('.substr($temp, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
}
/*
* Remove disallowed Javascript in links or img tags
* 移除在链接和图片标签中不允许的javascript代码
* We used to do some version comparisons and use of stripos for PHP5,
* 我们通常在PHP5中使用stripos做一些版本的比较，
* but it is dog slow compared to these simplified non-capturing
* 但是特别是当模式在字符串中存在的时候，它要比非捕获的preg_match()慢很多
* preg_match(), especially if the pattern exists in the string
*/
do
{
$original = $str;
if (preg_match("/]*?)(>|$)#si", array($this, '_js_link_removal'), $str);
}
if (preg_match("/![]()
]*?)(\s?/?>|$)#si", array($this, '_js_img_removal'), $str);
}
if (preg_match("/script/i", $str) OR preg_match("/xss/i", $str))
{
$str = preg_replace("#<(/*)(script|xss)(.*?)\>#si", '[removed]', $str);
}
}
while($original != $str);
unset($original);
// Remove evil attributes such as style, onclick and xmlns
// 移除有害的属性，比如style ， onclick ， xmlns
$str = $this->_remove_evil_attributes($str, $is_image);
/*
* Sanitize naughty HTML elements
* 清理不适当的HTML元素
* If a tag containing any of the words in the list
* below is found, the tag gets converted to entities.
* 如果一个标签包含任何一个下面列表中的单词，这个标签转换为一个字符实体
* So this:
