kses.php

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<?php

// Added wp_ prefix to avoid conflicts with existing kses users
# kses 0.2.2 - HTML/XHTML filter that only allows some elements and attributes
# Copyright (C) 2002, 2003, 2005  Ulf Harnhammar
# *** CONTACT INFORMATION ***
#
# E-mail:      metaur at users dot sourceforge dot net
# Web page:    http://sourceforge.net/projects/kses
# Paper mail:  Ulf Harnhammar
#              Ymergatan 17 C
#              753 25  Uppsala
#              SWEDEN
#
# [kses strips evil scripts!]
if (!defined('CUSTOM_TAGS'))
	define('CUSTOM_TAGS', false);

// You can override this in your my-hacks.php file
if (!CUSTOM_TAGS) {
	$allowedposttags = array ('address' => array (), 'a' => array ('href' => array (), 'title' => array (), 'rel' => array (), 'rev' => array (), 'name' => array ()), 'abbr' => array ('title' => array ()), 'acronym' => array ('title' => array ()), 'b' => array (), 'big' => array (), 'blockquote' => array ('cite' => array ()), 'br' => array (), 'button' => array ('disabled' => array (), 'name' => array (), 'type' => array (), 'value' => array ()), 'caption' => array ('align' => array ()), 'code' => array (), 'col' => array ('align' => array (), 'char' => array (), 'charoff' => array (), 'span' => array (), 'valign' => array (), 'width' => array ()), 'del' => array ('datetime' => array ()), 'dd' => array (), 'div' => array ('align' => array ()), 'dl' => array (), 'dt' => array (), 'em' => array (), 'fieldset' => array (), 'font' => array ('color' => array (), 'face' => array (), 'size' => array ()), 'form' => array ('action' => array (), 'accept' => array (), 'accept-charset' => array (), 'enctype' => array (), 'method' => array (), 'name' => array (), 'target' => array ()), 'h1' => array ('align' => array ()), 'h2' => array ('align' => array ()), 'h3' => array ('align' => array ()), 'h4' => array ('align' => array ()), 'h5' => array ('align' => array ()), 'h6' => array ('align' => array ()), 'hr' => array ('align' => array (), 'noshade' => array (), 'size' => array (), 'width' => array ()), 'i' => array (), 'img' => array ('alt' => array (), 'align' => array (), 'border' => array (), 'height' => array (), 'hspace' => array (), 'longdesc' => array (), 'vspace' => array (), 'src' => array (), 'width' => array ()), 'ins' => array ('datetime' => array (), 'cite' => array ()), 'kbd' => array (), 'label' => array ('for' => array ()), 'legend' => array ('align' => array ()), 'li' => array (), 'p' => array ('align' => array ()), 'pre' => array ('width' => array ()), 'q' => array ('cite' => array ()), 's' => array (), 'strike' => array (), 'strong' => array (), 'sub' => array (), 'sup' => array (), 'table' => array ('align' => array (), 'bgcolor' => array (), 'border' => array (), 'cellpadding' => array (), 'cellspacing' => array (), 'rules' => array (), 'summary' => array (), 'width' => array ()), 'tbody' => array ('align' => array (), 'char' => array (), 'charoff' => array (), 'valign' => array ()), 'td' => array ('abbr' => array (), 'align' => array (), 'axis' => array (), 'bgcolor' => array (), 'char' => array (), 'charoff' => array (), 'colspan' => array (), 'headers' => array (), 'height' => array (), 'nowrap' => array (), 'rowspan' => array (), 'scope' => array (), 'valign' => array (), 'width' => array ()), 'textarea' => array ('cols' => array (), 'rows' => array (), 'disabled' => array (), 'name' => array (), 'readonly' => array ()), 'tfoot' => array ('align' => array (), 'char' => array (), 'charoff' => array (), 'valign' => array ()), 'th' => array ('abbr' => array (), 'align' => array (), 'axis' => array (), 'bgcolor' => array (), 'char' => array (), 'charoff' => array (), 'colspan' => array (), 'headers' => array (), 'height' => array (), 'nowrap' => array (), 'rowspan' => array (), 'scope' => array (), 'valign' => array (), 'width' => array ()), 'thead' => array ('align' => array (), 'char' => array (), 'charoff' => array (), 'valign' => array ()), 'title' => array (), 'tr' => array ('align' => array (), 'bgcolor' => array (), 'char' => array (), 'charoff' => array (), 'valign' => array ()), 'tt' => array (), 'u' => array (), 'ul' => array (), 'ol' => array (), 'var' => array () );
	$allowedtags = array ('a' => array ('href' => array (), 'title' => array ()), 'abbr' => array ('title' => array ()), 'acronym' => array ('title' => array ()), 'b' => array (), 'blockquote' => array ('cite' => array ()),
		//	'br' => array(),
	'code' => array (),
		//	'del' => array('datetime' => array()),
		//	'dd' => array(),
		//	'dl' => array(),
		//	'dt' => array(),
	'em' => array (), 'i' => array (),
		//	'ins' => array('datetime' => array(), 'cite' => array()),
		//	'li' => array(),
		//	'ol' => array(),
		//	'p' => array(),
		//	'q' => array(),
	'strike' => array (), 'strong' => array (),
		//	'sub' => array(),
		//	'sup' => array(),
		//	'u' => array(),
		//	'ul' => array(),
	);
}
function wp_kses($string, $allowed_html, $allowed_protocols = array ('http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'feed', 'gopher', 'mailto'))
	###############################################################################
		# This function makes sure that only the allowed HTML element names, attribute
		# names and attribute values plus only sane HTML entities will occur in
		# $string. You have to remove any slashes from PHP's magic quotes before you
		# call this function.
		###############################################################################
	{
	$string = wp_kses_no_null($string);
	$string = wp_kses_js_entities($string);
	$string = wp_kses_normalize_entities($string);
	$string = wp_kses_hook($string);
	$allowed_html_fixed = wp_kses_array_lc($allowed_html);
	return wp_kses_split($string, $allowed_html_fixed, $allowed_protocols);
} # function wp_kses

function wp_kses_hook($string)
###############################################################################
# You add any kses hooks here.
###############################################################################
{
	return $string;
} # function wp_kses_hook

function wp_kses_version()
###############################################################################
# This function returns kses' version number.
###############################################################################
{
	return '0.2.2';
} # function wp_kses_version

function wp_kses_split($string, $allowed_html, $allowed_protocols)
###############################################################################
# This function searches for HTML tags, no matter how malformed. It also
# matches stray ">" characters.
###############################################################################
{
	return preg_replace('%((<!--.*?(-->|$))|(<[^>]*(>|$)|>))%e',
	"wp_kses_split2('\\1', \$allowed_html, ".'$allowed_protocols)', $string);
} # function wp_kses_split

function wp_kses_split2($string, $allowed_html, $allowed_protocols)
###############################################################################
# This function does a lot of work. It rejects some very malformed things
# like <:::>. It returns an empty string, if the element isn't allowed (look
# ma, no strip_tags()!). Otherwise it splits the tag into an element and an
# attribute list.
###############################################################################
{
	$string = wp_kses_stripslashes($string);

	if (substr($string, 0, 1) != '<')
		return '&gt;';
	# It matched a ">" character

	if (preg_match('%^<!--(.*?)(-->)?$%', $string, $matches)) {
		$string = str_replace(array('<!--', '-->'), '', $matches[1]);
		while ( $string != $newstring = wp_kses($string, $allowed_html, $allowed_protocols) )
			$string = $newstring;
		if ( $string == '' )
			return '';
		return "<!--{$string}-->";
	}
	# Allow HTML comments

	if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
		return '';
	# It's seriously malformed

	$slash = trim($matches[1]);
	$elem = $matches[2];
	$attrlist = $matches[3];

	if (!@isset($allowed_html[strtolower($elem)]))
		return '';
	# They are using a not allowed HTML element

	if ($slash != '')
		return "<$slash$elem>";
	# No attributes are allowed for closing elements

	return wp_kses_attr("$slash$elem", $attrlist, $allowed_html, $allowed_protocols);
} # function wp_kses_split2

function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols)
###############################################################################
# This function removes all attributes, if none are allowed for this element.
# If some are allowed it calls wp_kses_hair() to split them further, and then it
# builds up new HTML code from the data that kses_hair() returns. It also
# removes "<" and ">" characters, if there are any left. One more thing it
# does is to check if the tag has a closing XHTML slash, and if it does,
# it puts one in the returned code as well.
###############################################################################
{
	# Is there a closing XHTML slash at the end of the attributes?

	$xhtml_slash = '';
	if (preg_match('%\s/\s*$%', $attr))
		$xhtml_slash = ' /';

	# Are any attributes allowed at all for this element?

	if (@ count($allowed_html[strtolower($element)]) == 0)
		return "<$element$xhtml_slash>";

	# Split it

	$attrarr = wp_kses_hair($attr, $allowed_protocols);

	# Go through $attrarr, and save the allowed attributes for this element
	# in $attr2

	$attr2 = '';

	foreach ($attrarr as $arreach) {
		if (!@ isset ($allowed_html[strtolower($element)][strtolower($arreach['name'])]))
			continue; # the attribute is not allowed

		$current = $allowed_html[strtolower($element)][strtolower($arreach['name'])];
		if ($current == '')
			continue; # the attribute is not allowed

		if (!is_array($current))
			$attr2 .= ' '.$arreach['whole'];
		# there are no checks

		else {
			# there are some checks
			$ok = true;
			foreach ($current as $currkey => $currval)
				if (!wp_kses_check_attr_val($arreach['value'], $arreach['vless'], $currkey, $currval)) {
					$ok = false;
					break;
				}

			if ($ok)
				$attr2 .= ' '.$arreach['whole']; # it passed them
		} # if !is_array($current)
	} # foreach

	# Remove any "<" or ">" characters

	$attr2 = preg_replace('/[<>]/', '', $attr2);

	return "<$element$attr2$xhtml_slash>";
} # function wp_kses_attr

function wp_kses_hair($attr, $allowed_protocols)
###############################################################################
# This function does a lot of work. It parses an attribute list into an array
# with attribute data, and tries to do the right thing even if it gets weird
# input. It will add quotes around attribute values that don't have any quotes
# or apostrophes around them, to make it easier to produce HTML code that will
# conform to W3C's HTML specification. It will also remove bad URL protocols
# from attribute values.
###############################################################################
{
	$attrarr = array ();
	$mode = 0;
	$attrname = '';

	# Loop through the whole attribute list

	while (strlen($attr) != 0) {
		$working = 0; # Was the last operation successful?

		switch ($mode) {
			case 0 : # attribute name, href for instance

				if (preg_match('/^([-a-zA-Z]+)/', $attr, $match)) {
					$attrname = $match[1];
					$working = $mode = 1;
					$attr = preg_replace('/^[-a-zA-Z]+/', '', $attr);
				}

				break;

			case 1 : # equals sign or valueless ("selected")

				if (preg_match('/^\s*=\s*/', $attr)) # equals sign
					{
					$working = 1;
					$mode = 2;
					$attr = preg_replace('/^\s*=\s*/', '', $attr);
					break;
				}

				if (preg_match('/^\s+/', $attr)) # valueless
					{
					$working = 1;
					$mode = 0;
					$attrarr[] = array ('name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y');
					$attr = preg_replace('/^\s+/', '', $attr);
				}

				break;

			case 2 : # attribute value, a URL after href= for instance

				if (preg_match('/^"([^"]*)"(\s+|$)/', $attr, $match))
					# "value"
					{
					$thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);

					$attrarr[] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
					$working = 1;
					$mode = 0;
					$attr = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr);
					break;
				}

				if (preg_match("/^'([^']*)'(\s+|$)/", $attr, $match))
					# 'value'
					{
					$thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);

					$attrarr[] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname='$thisval'", 'vless' => 'n');
					$working = 1;
					$mode = 0;
					$attr = preg_replace("/^'[^']*'(\s+|$)/", '', $attr);
					break;
				}

				if (preg_match("%^([^\s\"']+)(\s+|$)%", $attr, $match))
					# value
					{
					$thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);

					$attrarr[] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
					# We add quotes to conform to W3C's HTML spec.
					$working = 1;