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<?php namespace Phpcmf\Library;
/**
* {{www.xunruicms.com}}
* {{迅睿内容管理框架系统}}
* 本文件是框架系统文件，二次开发时不可以修改本文件，可以通过继承类方法来重写此文件
**/
/**
* 安全过滤
*/
class Security {
/**
* List of sanitize filename strings
*
* @var array
*/
public $filename_bad_chars = [
'../', '<!--', '-->', '<', '>',
"'", '"', '&', '$', '#',
'{', '}', '[', ']', '=',
';', '?', '%20', '%22',
'%3c', // <
'%253c', // <
'%3e', // >
'%0e', // >
'%28', // (
'%29', // )
'%2528', // (
'%26', // &
'%24', // $
'%3f', // ?
'%3b', // ;
'%3d' // =
];
protected $naughty_tags = [];
protected $evil_attributes = [];
/**
* Character set
*
* Will be overridden by the constructor.
*
* @var string
*/
public $charset = 'UTF-8';
/**
* XSS Hash
*
* Random Hash for protecting URLs.
*
* @var string
*/
protected $_xss_hash;
/**
* List of never allowed strings
*
* @var array
*/
protected $_never_allowed_str = [
'document.cookie' => '[xss_clean]',
'(document).cookie' => '[xss_clean]',
'document.write' => '[xss_clean]',
'(document).write' => '[xss_clean]',
'.parentNode' => '[xss_clean]',
'.innerHTML' => '[xss_clean]',
'-moz-binding' => '[xss_clean]',
'<!--' => '<!--',
'-->' => '-->',
'<![CDATA[' => '<![CDATA[',
'<comment>' => '<comment>',
'<%' => '<%'
];
// 替换前的处理
protected $_never_call_str = [
'"javascript:' => '"javascript_xunruicms:',
];
/**
* List of never allowed regex replacements
*
* @var array
*/
protected $_never_allowed_regex = [
'javascript\s*:',
'(\(?document\)?|\(?window\)?(\.document)?)\.(location|on\w*)',
'expression\s*(\(|&\#40;)', // CSS and IE
'vbscript\s*:', // IE, surprise!
'wscript\s*:', // IE
'jscript\s*:', // IE
'vbs\s*:', // IE
'Redirect\s+30\d',
"([\"'])+data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
];
// --------------------------------------------------------------------
/**
* XSS Clean
*
* Sanitizes data so that Cross Site Scripting Hacks can be
* prevented. This method does a fair amount of work but
* it is extremely thorough, designed to prevent even the
* most obscure XSS attempts. Nothing is ever 100% foolproof,
* of course, but I haven't been able to get anything passed
* the filter.
*
* Note: Should only be used to deal with data upon submission.
* It's not something that should be used for general
* runtime processing.
*
* @link http://channel.bitflux.ch/wiki/XSS_Prevention
* Based in part on some code and ideas from Bitflux.
*
* @link http://ha.ckers.org/xss.html
* 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.
*
* @param string|string[] $str Input data
* @param bool $is_image 严格的过滤
* @return string
*/
public function xss_clean($str, $is_image = FALSE)
{
if (is_numeric($str)) {
return $str;
} elseif (!$str) {
return '';
}
// Is the string an array?
if (is_array($str))
{
foreach ($str as $key => &$value)
{
$str[$key] = $this->xss_clean($value, $is_image);
}
return $str;
}
if (json_encode( $str) === false) {
return '[xss_clean]'; // 判断含有乱码直接过滤为空
}
$this->naughty_tags = [
'alert', 'area', 'prompt', 'confirm', 'applet', 'audio', 'basefont', 'base', 'behavior', 'bgsound',
'blink', 'body', 'expression', 'form', 'frameset', 'frame', 'head', 'html', 'ilayer',
'input', 'button', 'select', 'isindex', 'layer', 'link', 'meta', 'keygen', 'object',
'plaintext', 'script', 'textarea', 'title', 'math', 'svg', 'xml', 'xss',
//'iframe', 'video', 'embed', 'style' //排除过滤
];
$this->evil_attributes = [
'on\w+', 'xmlns', 'formaction', 'form', 'xlink:href', 'FSCommand', 'seekSegmentTime'
// ,'style' 排除过滤
];
if ($is_image) {
// 严格的过滤
$this->naughty_tags = array_merge($this->naughty_tags, array('iframe', 'video', 'embed', 'style'));
$this->evil_attributes = array_merge($this->evil_attributes, array('style'));
/*
* URL Decode
*
* Just in case stuff like this is submitted:
*
* <a href="http://%77%77%77%2E%67%6F%6F%67%6C%65%2E%63%6F%6D">Google</a>
*
* Note: Use rawurldecode() so it does not remove plus signs
* */
if (stripos($str, '%') !== false)
{
do
{
$oldstr = $str;
$str = rawurldecode($str);
$str = preg_replace_callback('#%(?:\s*[0-9a-f]){2,}#i', [$this, '_urldecodespaces'], $str);
}
while ($oldstr !== $str);
unset($oldstr);
}
/*
* 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.
*/
// 不进行二次编码的xss过滤
$str = preg_replace_callback("/[^a-z0-9>]+[a-z0-9]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str);
$str = preg_replace_callback('/<\w+.*/si', array($this, '_decode_entity'), $str);
}
// Remove Invisible Characters Again!
$str = remove_invisible_characters($str);
/*
* Convert all tabs to spaces
*
* This prevents strings like this: ja vascript
* 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.
*/
$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:
*
* <?xml
*
* But it doesn't seem to pose a problem.
*/
if ($is_image)
{
// Images have a tendency to have the 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', '<?\\1', $str);
}
else
{
$str = str_replace(['<?', '?'.'>'], ['<?', '?>'], $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.
*/
$words = [
'javascript', 'expression', 'vbscript', 'jscript', 'wscript',
'vbs', 'script', 'base64', 'applet', 'alert', 'document',
'write', 'cookie', 'window', 'confirm', 'prompt', 'eval'
];
foreach ($words as $word)
{
$word = implode('\s*', str_split($word)).'\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"
$str = preg_replace_callback('#('.substr($word, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
}
/*
* Remove disallowed Javascript in links or img tags
* We used to do some version comparisons and use of stripos(),
* but it is dog slow compared to these simplified non-capturing
* preg_match(), especially if the pattern exists in the string
*
* Note: It was reported that not only space characters, but all in
* the following pattern can be parsed as separators between a tag name
* and its attributes: [\d\s"\'`;,\/\=\(\x00\x0B\x09\x0C]
* ... however, remove_invisible_characters() above already strips the
* hex-encoded ones, so we'll skip them below.
*/
do
{
$original = $str;
if (preg_match('/<a/i', $str))
{
$str = preg_replace_callback('#<a(?:rea)?[^a-z0-9>]+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
}
if (preg_match('/<img/i', $str))
{
$str = preg_replace_callback('#<img[^a-z0-9]+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
}
if (preg_match('/script|xss/i', $str))
{
$str = preg_replace('#</*(?:script|xss).*?>#si', '[xss_clean]', $str);
}
}
while ($original !== $str);
unset($original);
/*
* 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: <blink>
* Becomes: <blink>
*/
$pattern = '#'
.'<((?<slash>/*\s*)((?<tagName>[a-z0-9]+)(?=[^a-z0-9]|$)|.+)' // tag start and name, followed by a non-tag character
.'[^\s\042\047a-z0-9>/=]*' // a valid attribute character immediately after the tag would count as a separator
// optional attributes
.'(?<attributes>(?:[\s\042\047/=]*' // non-attribute characters, excluding > (tag close) for obvious reasons
.'[^\s\042\047>/=]+' // attribute characters
// optional attribute-value
.'(?:\s*=' // attribute-value separator
.'(?:[^\s\042\047=><`]+|\s*\042[^\042]*\042|\s*\047[^\047]*\047|\s*(?U:[^\s\042\047=><`]*))' // single, double or non-quoted value
.')?' // end optional attribute-value group
.')*)' // end optional attributes group
.'[^>]*)(?<closeTag>\>)?#isS';
// Note: It would be nice to optimize this for speed, BUT
// only matching the naughty elements here results in
// false positives and in turn - vulnerabilities!
do
{
$old_str = $str;
$str = preg_replace_callback($pattern, array($this, '_sanitize_naughty_html'), $str);
}
while ($old_str !== $str);
unset($old_str);
/*
* Sanitize naughty scripting elements
*
* Similar to above, only instead of looking for
* tags it looks for PHP and JavaScript commands
* that are disallowed. Rather than removing the
* code, it simply converts the parenthesis to entities
* rendering the code un-executable.
*
* For example: eval('some code')
* Becomes: eval('some code')
*/
$str = preg_replace(
'#(alert|prompt|confirm|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',
'\\1\\2(\\3)',
$str
);
// Same thing, but for "tag functions" (e.g. eval`some code`)
// See https://github.com/bcit-ci/CodeIgniter/issues/5420
$str = preg_replace(
'#(alert|prompt|confirm|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)`(.*?)`#si',
'\\1\\2`\\3`',
$str
);
//最终清理
//
////这增加了一点额外的预防措施
//
////有东西通过了上面的过滤器
$str = $this->_do_never_allowed($str);
// now the only remaining whitespace attacks are \t, \n, and \r
$ra = ['onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload'];
foreach ($ra as $t) {
$str = str_replace(' '.$t.'="', ' '.$t.'=', $str);
}
return $str;
}
// --------------------------------------------------------------------
/**
* Do Never Allowed
*
* @used-by CI_Security::xss_clean()
* @param string
* @return string
*/
protected function _do_never_allowed($str)
{
$str = str_replace(array_keys($this->_never_call_str), $this->_never_call_str, $str);
$str = str_replace(array_keys($this->_never_allowed_str), $this->_never_allowed_str, $str);
foreach ($this->_never_allowed_regex as $regex)
{
$str = preg_replace('#'.$regex.'#is', '_\\0', $str);
}
$str = str_replace($this->_never_call_str, array_keys($this->_never_call_str), $str);
return $str;
}
}
|
