CI安全类提供了全局防御CSRF攻击和XSS攻击策略，只需要在配置文件开启即可：
代码如下:
并提供了实用方法：
代码如下:
CI也提供了安全函数：
xss_clean()//xss过滤 sanitize_filename()//净化文件名 do_hash()//md5或sha加密 strip_image_tags() //删除图片标签的不必要字符 encode_PHP_tags()//把PHP脚本标签强制转成实体对象
代码如下:
'[removed]',
'document.write'=> '[removed]',
'.parentNode'=> '[removed]',
'.innerHTML'=> '[removed]',
'window.location'=> '[removed]',
'-moz-binding'=> '[removed]',
''=> '-->',
' ''=> ''
);
//不允许出现的正则表达式数组
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?"
);
//构造函数
public function __construct()
{
// CSRF保护是否开启
if (config_item('csrf_protection') === TRUE)
{
// CSRF配置
foreach (array('csrf_expire','csrf_token_name','csrf_cookie_name') as $key)
{
if (FALSE !== ($val = config_item($key)))
{
$this->{'_'.$key} = $val;
}
}
// _csrf_cookie_name加上cookie前缀
if (config_item('cookie_prefix'))
{
$this->_csrf_cookie_name = config_item('cookie_prefix').$this->_csrf_cookie_name;
}
// 设置csrf的hash值
$this->_csrf_set_hash();
}
log_message('debug',"Security Class Initialized");
}
// --------------------------------------------------------------------
/**
* Verify Cross Site Request Forgery Protection
*
* @returnobject
*/
public function csrf_verify()
{
// 如果不是post请求，则设置csrf的cookie值
if (strtoupper($_SERVER['REQUEST_METHOD']) !== 'POST')
{
return $this->csrf_set_cookie();
}
// Do the tokens exist in both the _POST and _COOKIE arrays?
if ( ! isset($_POST[$this->_csrf_token_name],$_COOKIE[$this->_csrf_cookie_name]))
{
$this->csrf_show_error();
}
// token匹配吗
if ($_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name])
{
$this->csrf_show_error();
}
// We kill this since we're done and we don't want to
// polute the _POST array
unset($_POST[$this->_csrf_token_name]);
// Nothing should last forever
unset($_COOKIE[$this->_csrf_cookie_name]);
$this->_csrf_set_hash();
$this->csrf_set_cookie();
log_message('debug','CSRF token verified');
return $this;
}
// --------------------------------------------------------------------
/**
* 设置csrf的cookie值
*/
public function csrf_set_cookie()
{
$expire = time() + $this->_csrf_expire;
$secure_cookie = (config_item('cookie_secure') === TRUE) ? 1 : 0;
if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off'))
{
return FALSE;
}
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;
}
//csrf保存
public function csrf_show_error()
{
show_error('The action you have requested is not allowed.');
}
//获取csrf的hash值
public function get_csrf_hash()
{
return $this->_csrf_hash;
}
//获取csrf的token值
public function get_csrf_token_name()
{
return $this->_csrf_token_name;
}
/**
* XSS 过滤
*/
public function xss_clean($str,$is_image = FALSE)
{
//是否是数组
if (is_array($str))
{
while (list($key) = each($str))
{
$str[$key] = $this->xss_clean($str[$key]);
}
return $str;
}
//去掉可见字符串
$str = remove_invisible_characters($str);
// 验证实体url
$str = $this->_validate_entities($str);
/*
* URL 解码
*
* Just in case stuff like this is submitted:
*
* Google>
*
* Note: Use rawurldecode() so it does not remove plus signs
*
*/
$str = rawurldecode($str);
/*
* Convert character entities to ASCII
*
* 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",'_decode_entity'),$str);
/*
* Remove Invisible Characters Again!
*/
$str = remove_invisible_characters($str);
/*
* Convert all tabs to spaces
*
* This prevents strings like this: javascript
* NOTE: we deal with spaces between characters later.
* NOTE: preg_replace was found to be amazingly slow here on
* large blocks of data,so we use str_replace.
*/
if (strpos($str,"\t") !== FALSE)
{
$str = str_replace("\t",' ',$str);
}
/*
* Capture converted string for later comparison
*/
$converted_string = $str;
// Remove Strings that are never allowed
$str = $this->_do_never_allowed($str);
/*
* Makes PHP tags safe
*
* Note: XML tags are inadvertently replaced too:
*
* PHP short opening and
// closing tags every so often so we skip those and only
// do the long opening tags.
$str = preg_replace('/<\?(PHP)/i',"'),array(''),$str);
}
/*
* Compact any exploded words
*
* 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,-3).')(\W)#is','_compact_exploded_words'),$str);
}
/*
* Remove disallowed Javascript in links or img tags
* We used to do some version comparisons and use of stripos for PHP5,
* but it is dog slow compared to these simplified non-capturing
* preg_match(),especially if the pattern exists in the string
*/
do
{
$original = $str;
if (preg_match("/]*?)(>|$)#si",'_js_link_removal'),$str);
}
if (preg_match("/![]()
]*?)(\s?/?>|$)#si",'_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
$str = $this->_remove_evil_attributes($str,$is_image);
/*
* Sanitize naughty HTML elements
*
* If a tag containing any of the words in the list
* below is found,the tag gets converted to entities.
*
* So this:
