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Feature #19600 » 0009778_v3.patch

Administrator Admin, 2008-11-12 12:57

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typo3/contrib/RemoveXSS/RemoveXSS.php (Arbeitskopie)
* Used with permission by the author.
* URL: http://quickwired.com/smallprojects/php_xss_filter_function.php
*
* Check XSS attacks on http://ha.ckers.org/xss.html
*
* License:
* This code is public domain, you are free to do whatever you want with it,
* including adding it to your own project which can be under any license.
......
* $Id$
*
* @author Travis Puderbaugh <kallahar@quickwired.com>
* @package RemoveXSS
* @author Jigal van Hemert <jigal@xs4all.nl>
* @package RemoveXSS
*/
class RemoveXSS {
final class RemoveXSS {
/**
* Removes potential XSS code from an input string.
* Wrapper for RemoveXSS::process().
*
* Using an external class by Travis Puderbaugh <kallahar@quickwired.com>
*
* @param string Input string
* @param string replaceString for inserting in keywords (which destroyes the tags)
* @return string Input string with potential XSS code removed
* @deprecated since TYPO3 4.3, use static call RemoveXSS::process() instead
*/
public function RemoveXSS($val, $replaceString = '<x>') {
return self::process($val, $replaceString);
}
/**
* Wrapper for the RemoveXSS function.
* Removes potential XSS code from an input string.
*
* Using an external class by Travis Puderbaugh <kallahar@quickwired.com>
*
* @param string Input string
* @param string replaceString for inserting in keywords (which destroyes the tags)
* @return string Input string with potential XSS code removed
*/
function RemoveXSS($val) {
public static function process($val, $replaceString = '<x>') {
// don't use empty $replaceString because then no XSS-remove will be done
if ($replaceString == '') {
$replaceString = '<x>';
}
// remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed
// this prevents some character re-spacing such as <java\0script>
// note that you have to handle splits with \n, \r, and \t later since they *are* allowed in some inputs
$val = preg_replace('/([\x00-\x08][\x0b-\x0c][\x0e-\x20])/', '', $val);
$val = preg_replace('/([\x00-\x08][\x0b-\x0c][\x0e-\x19])/', '', $val);
// straight replacements, the user should never need these since they're normal characters
// this prevents like <IMG SRC=&#X40&#X61&#X76&#X61&#X73&#X63&#X72&#X69&#X70&#X74&#X3A&#X61&#X6C&#X65&#X72&#X74&#X28&#X27&#X58&#X53&#X53&#X27&#X29>
$search = 'abcdefghijklmnopqrstuvwxyz';
$search.= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$search.= '1234567890!@#$%^&*()';
$search.= '~`";:?+/={}[]-_|\'\\';
$search = '/&#[xX]0{0,8}(21|22|23|24|25|26|27|28|29|2a|2b|2d|2f|30|31|32|33|34|35|36|37|38|39|3a|3b|3d|3f|40|41|42|43|44|45|46|47|48|49|4a|4b|4c|4d|4e|4f|50|51|52|53|54|55|56|57|58|59|5a|5b|5c|5d|5e|5f|60|61|62|63|64|65|66|67|68|69|6a|6b|6c|6d|6e|6f|70|71|72|73|74|75|76|77|78|79|7a|7b|7c|7d|7e);?/ie';
$val = preg_replace($search, "chr(hexdec('\\1'))", $val);
$search = '/&#0{0,8}(33|34|35|36|37|38|39|40|41|42|43|45|47|48|49|50|51|52|53|54|55|56|57|58|59|61|63|64|65|66|67|68|69|70|71|72|73|74|75|76|77|78|79|80|81|82|83|84|85|86|87|88|89|90|91|92|93|94|95|96|97|98|99|100|101|102|103|104|105|106|107|108|109|110|111|112|113|114|115|116|117|118|119|120|121|122|123|124|125|126);?/ie';
$val = preg_replace($search, "chr('\\1')", $val);
for ($i = 0; $i < strlen($search); $i++) {
// ;? matches the ;, which is optional
// 0{0,7} matches any padded zeros, which are optional and go up to 8 chars
// now the only remaining whitespace attacks are \t, \n, and \r
$ra1 = array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base', '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');
$ra_tag = array('applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra_attribute = array('style', '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');
$ra_protocol = array('javascript', 'vbscript', 'expression');
// &#x0040 @ search for the hex values
$val = preg_replace('/(&#[x|X]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
// &#00064 @ 0{0,7} matches '0' zero to seven times
$val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
}
//remove the potential &#xxx; stuff for testing
$val2 = preg_replace('/(&#[xX]?0{0,8}(9|10|13|a|b);)*\s*/i', '', $val);
$ra = array();
// now the only remaining whitespace attacks are \t, \n, and \r
$ra1 = array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra2 = array('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');
$ra = array_merge($ra1, $ra2);
$found = true; // keep replacing as long as the previous round replaced something
while ($found == true) {
$val_before = $val;
for ($i = 0; $i < sizeof($ra); $i++) {
$pattern = '/';
for ($j = 0; $j < strlen($ra[$i]); $j++) {
if ($j > 0) {
$pattern .= '(';
$pattern .= '(&#[x|X]0{0,8}([9][a][b]);?)?';
$pattern .= '|(&#0{0,8}([9][10][13]);?)?';
$pattern .= ')?';
}
$pattern .= $ra[$i][$j];
foreach ($ra1 as $ra1word) {
//stripos is faster than the regular expressions used later
//and because the words we're looking for only have chars < 0x80
//we can use the non-multibyte safe version
if (stripos($val2, $ra1word ) !== false ) {
//keep list of potential words that were found
if (in_array($ra1word, $ra_protocol)) {
$ra[] = array($ra1word, 'ra_protocol');
}
$pattern .= '/i';
$replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2); // add in <> to nerf the tag
$val = preg_replace($pattern, $replacement, $val); // filter out the hex tags
if ($val_before == $val) {
// no replacements were made, so exit the loop
$found = false;
if (in_array($ra1word, $ra_tag)) {
$ra[] = array($ra1word, 'ra_tag');
}
if (in_array($ra1word, $ra_attribute)) {
$ra[] = array($ra1word, 'ra_attribute');
}
//some keywords appear in more than one array
//these get multiple entries in $ra, each with the appropriate type
}
}
//only process potential words
if (count($ra) > 0) {
// keep replacing as long as the previous round replaced something
$found = true;
while ($found == true) {
$val_before = $val;
for ($i = 0; $i < sizeof($ra); $i++) {
$pattern = '';
for ($j = 0; $j < strlen($ra[$i][0]); $j++) {
if ($j > 0) {
$pattern .= '((&#[xX]0{0,8}([9ab]);)|(&#0{0,8}(9|10|13);)|\s)*';
}
$pattern .= $ra[$i][0][$j];
}
//handle each type a little different (extra conditions to prevent false positives a bit better)
switch ($ra[$i][1]) {
case 'ra_protocol':
//these take the form of e.g. 'javascript:'
$pattern .= '((&#[xX]0{0,8}([9ab]);)|(&#0{0,8}(9|10|13);)|\s)*(?=:)';
break;
case 'ra_tag':
//these take the form of e.g. '<SCRIPT[^\da-z] ....';
$pattern = '(?<=<)' . $pattern . '((&#[xX]0{0,8}([9ab]);)|(&#0{0,8}(9|10|13);)|\s)*(?=[^\da-z])';
break;
case 'ra_attribute':
//these take the form of e.g. 'onload=' Beware that a lot of characters are allowed
//between the attribute and the equal sign!
$pattern .= '[\s\!\#\$\%\&\(\)\*\~\+\-\_\.\,\:\;\?\@\[\/\|\\\\\]\^\`]*(?==)';
break;
}
$pattern = '/' . $pattern . '/i';
// add in <x> to nerf the tag
$replacement = substr_replace($ra[$i][0], $replaceString, 2, 0);
// filter out the hex tags
$val = preg_replace($pattern, $replacement, $val);
if ($val_before == $val) {
// no replacements were made, so exit the loop
$found = false;
}
}
}
}
return $val;
}
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