MediaWiki 1.7.1 wiederhergestellt

1 files changed, 1184 insertions, 0 deletions

diff --git a/includes/Sanitizer.php b/includes/Sanitizer.php
new file mode 100644
index 00000000..f5a24dfa
--- /dev/null
+++ b/includes/Sanitizer.php
@@ -0,0 +1,1184 @@
+<?php
+/**
+ * XHTML sanitizer for MediaWiki
+ *
+ * Copyright (C) 2002-2005 Brion Vibber <brion@pobox.com> et al
+ * http://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @package MediaWiki
+ * @subpackage Parser
+ */
+
+/**
+ * Regular expression to match various types of character references in
+ * Sanitizer::normalizeCharReferences and Sanitizer::decodeCharReferences
+ */
+define( 'MW_CHAR_REFS_REGEX',
+	'/&([A-Za-z0-9]+);
+	 |&\#([0-9]+);
+	 |&\#x([0-9A-Za-z]+);
+	 |&\#X([0-9A-Za-z]+);
+	 |(&)/x' );
+
+/**
+ * Regular expression to match HTML/XML attribute pairs within a tag.
+ * Allows some... latitude.
+ * Used in Sanitizer::fixTagAttributes and Sanitizer::decodeTagAttributes
+ */
+$attrib = '[A-Za-z0-9]';
+$space = '[\x09\x0a\x0d\x20]';
+define( 'MW_ATTRIBS_REGEX',
+	"/(?:^|$space)($attrib+)
+	  ($space*=$space*
+		(?:
+		 # The attribute value: quoted or alone
+		  \"([^<\"]*)\"
+		 | '([^<']*)'
+		 |  ([a-zA-Z0-9!#$%&()*,\\-.\\/:;<>?@[\\]^_`{|}~]+)
+		 |  (\#[0-9a-fA-F]+) # Technically wrong, but lots of
+							 # colors are specified like this.
+							 # We'll be normalizing it.
+		)
+	   )?(?=$space|\$)/sx" );
+
+/**
+ * List of all named character entities defined in HTML 4.01
+ * http://www.w3.org/TR/html4/sgml/entities.html
+ * @private
+ */
+global $wgHtmlEntities;
+$wgHtmlEntities = array(
+	'Aacute'   => 193,
+	'aacute'   => 225,
+	'Acirc'    => 194,
+	'acirc'    => 226,
+	'acute'    => 180,
+	'AElig'    => 198,
+	'aelig'    => 230,
+	'Agrave'   => 192,
+	'agrave'   => 224,
+	'alefsym'  => 8501,
+	'Alpha'    => 913,
+	'alpha'    => 945,
+	'amp'      => 38,
+	'and'      => 8743,
+	'ang'      => 8736,
+	'Aring'    => 197,
+	'aring'    => 229,
+	'asymp'    => 8776,
+	'Atilde'   => 195,
+	'atilde'   => 227,
+	'Auml'     => 196,
+	'auml'     => 228,
+	'bdquo'    => 8222,
+	'Beta'     => 914,
+	'beta'     => 946,
+	'brvbar'   => 166,
+	'bull'     => 8226,
+	'cap'      => 8745,
+	'Ccedil'   => 199,
+	'ccedil'   => 231,
+	'cedil'    => 184,
+	'cent'     => 162,
+	'Chi'      => 935,
+	'chi'      => 967,
+	'circ'     => 710,
+	'clubs'    => 9827,
+	'cong'     => 8773,
+	'copy'     => 169,
+	'crarr'    => 8629,
+	'cup'      => 8746,
+	'curren'   => 164,
+	'dagger'   => 8224,
+	'Dagger'   => 8225,
+	'darr'     => 8595,
+	'dArr'     => 8659,
+	'deg'      => 176,
+	'Delta'    => 916,
+	'delta'    => 948,
+	'diams'    => 9830,
+	'divide'   => 247,
+	'Eacute'   => 201,
+	'eacute'   => 233,
+	'Ecirc'    => 202,
+	'ecirc'    => 234,
+	'Egrave'   => 200,
+	'egrave'   => 232,
+	'empty'    => 8709,
+	'emsp'     => 8195,
+	'ensp'     => 8194,
+	'Epsilon'  => 917,
+	'epsilon'  => 949,
+	'equiv'    => 8801,
+	'Eta'      => 919,
+	'eta'      => 951,
+	'ETH'      => 208,
+	'eth'      => 240,
+	'Euml'     => 203,
+	'euml'     => 235,
+	'euro'     => 8364,
+	'exist'    => 8707,
+	'fnof'     => 402,
+	'forall'   => 8704,
+	'frac12'   => 189,
+	'frac14'   => 188,
+	'frac34'   => 190,
+	'frasl'    => 8260,
+	'Gamma'    => 915,
+	'gamma'    => 947,
+	'ge'       => 8805,
+	'gt'       => 62,
+	'harr'     => 8596,
+	'hArr'     => 8660,
+	'hearts'   => 9829,
+	'hellip'   => 8230,
+	'Iacute'   => 205,
+	'iacute'   => 237,
+	'Icirc'    => 206,
+	'icirc'    => 238,
+	'iexcl'    => 161,
+	'Igrave'   => 204,
+	'igrave'   => 236,
+	'image'    => 8465,
+	'infin'    => 8734,
+	'int'      => 8747,
+	'Iota'     => 921,
+	'iota'     => 953,
+	'iquest'   => 191,
+	'isin'     => 8712,
+	'Iuml'     => 207,
+	'iuml'     => 239,
+	'Kappa'    => 922,
+	'kappa'    => 954,
+	'Lambda'   => 923,
+	'lambda'   => 955,
+	'lang'     => 9001,
+	'laquo'    => 171,
+	'larr'     => 8592,
+	'lArr'     => 8656,
+	'lceil'    => 8968,
+	'ldquo'    => 8220,
+	'le'       => 8804,
+	'lfloor'   => 8970,
+	'lowast'   => 8727,
+	'loz'      => 9674,
+	'lrm'      => 8206,
+	'lsaquo'   => 8249,
+	'lsquo'    => 8216,
+	'lt'       => 60,
+	'macr'     => 175,
+	'mdash'    => 8212,
+	'micro'    => 181,
+	'middot'   => 183,
+	'minus'    => 8722,
+	'Mu'       => 924,
+	'mu'       => 956,
+	'nabla'    => 8711,
+	'nbsp'     => 160,
+	'ndash'    => 8211,
+	'ne'       => 8800,
+	'ni'       => 8715,
+	'not'      => 172,
+	'notin'    => 8713,
+	'nsub'     => 8836,
+	'Ntilde'   => 209,
+	'ntilde'   => 241,
+	'Nu'       => 925,
+	'nu'       => 957,
+	'Oacute'   => 211,
+	'oacute'   => 243,
+	'Ocirc'    => 212,
+	'ocirc'    => 244,
+	'OElig'    => 338,
+	'oelig'    => 339,
+	'Ograve'   => 210,
+	'ograve'   => 242,
+	'oline'    => 8254,
+	'Omega'    => 937,
+	'omega'    => 969,
+	'Omicron'  => 927,
+	'omicron'  => 959,
+	'oplus'    => 8853,
+	'or'       => 8744,
+	'ordf'     => 170,
+	'ordm'     => 186,
+	'Oslash'   => 216,
+	'oslash'   => 248,
+	'Otilde'   => 213,
+	'otilde'   => 245,
+	'otimes'   => 8855,
+	'Ouml'     => 214,
+	'ouml'     => 246,
+	'para'     => 182,
+	'part'     => 8706,
+	'permil'   => 8240,
+	'perp'     => 8869,
+	'Phi'      => 934,
+	'phi'      => 966,
+	'Pi'       => 928,
+	'pi'       => 960,
+	'piv'      => 982,
+	'plusmn'   => 177,
+	'pound'    => 163,
+	'prime'    => 8242,
+	'Prime'    => 8243,
+	'prod'     => 8719,
+	'prop'     => 8733,
+	'Psi'      => 936,
+	'psi'      => 968,
+	'quot'     => 34,
+	'radic'    => 8730,
+	'rang'     => 9002,
+	'raquo'    => 187,
+	'rarr'     => 8594,
+	'rArr'     => 8658,
+	'rceil'    => 8969,
+	'rdquo'    => 8221,
+	'real'     => 8476,
+	'reg'      => 174,
+	'rfloor'   => 8971,
+	'Rho'      => 929,
+	'rho'      => 961,
+	'rlm'      => 8207,
+	'rsaquo'   => 8250,
+	'rsquo'    => 8217,
+	'sbquo'    => 8218,
+	'Scaron'   => 352,
+	'scaron'   => 353,
+	'sdot'     => 8901,
+	'sect'     => 167,
+	'shy'      => 173,
+	'Sigma'    => 931,
+	'sigma'    => 963,
+	'sigmaf'   => 962,
+	'sim'      => 8764,
+	'spades'   => 9824,
+	'sub'      => 8834,
+	'sube'     => 8838,
+	'sum'      => 8721,
+	'sup'      => 8835,
+	'sup1'     => 185,
+	'sup2'     => 178,
+	'sup3'     => 179,
+	'supe'     => 8839,
+	'szlig'    => 223,
+	'Tau'      => 932,
+	'tau'      => 964,
+	'there4'   => 8756,
+	'Theta'    => 920,
+	'theta'    => 952,
+	'thetasym' => 977,
+	'thinsp'   => 8201,
+	'THORN'    => 222,
+	'thorn'    => 254,
+	'tilde'    => 732,
+	'times'    => 215,
+	'trade'    => 8482,
+	'Uacute'   => 218,
+	'uacute'   => 250,
+	'uarr'     => 8593,
+	'uArr'     => 8657,
+	'Ucirc'    => 219,
+	'ucirc'    => 251,
+	'Ugrave'   => 217,
+	'ugrave'   => 249,
+	'uml'      => 168,
+	'upsih'    => 978,
+	'Upsilon'  => 933,
+	'upsilon'  => 965,
+	'Uuml'     => 220,
+	'uuml'     => 252,
+	'weierp'   => 8472,
+	'Xi'       => 926,
+	'xi'       => 958,
+	'Yacute'   => 221,
+	'yacute'   => 253,
+	'yen'      => 165,
+	'Yuml'     => 376,
+	'yuml'     => 255,
+	'Zeta'     => 918,
+	'zeta'     => 950,
+	'zwj'      => 8205,
+	'zwnj'     => 8204 );
+
+/** @package MediaWiki */
+class Sanitizer {
+	/**
+	 * Cleans up HTML, removes dangerous tags and attributes, and
+	 * removes HTML comments
+	 * @private
+	 * @param string $text
+	 * @param callback $processCallback to do any variable or parameter replacements in HTML attribute values
+	 * @param array $args for the processing callback
+	 * @return string
+	 */
+	function removeHTMLtags( $text, $processCallback = null, $args = array() ) {
+		global $wgUseTidy, $wgUserHtml;
+		$fname = 'Parser::removeHTMLtags';
+		wfProfileIn( $fname );
+
+		if( $wgUserHtml ) {
+			$htmlpairs = array( # Tags that must be closed
+				'b', 'del', 'i', 'ins', 'u', 'font', 'big', 'small', 'sub', 'sup', 'h1',
+				'h2', 'h3', 'h4', 'h5', 'h6', 'cite', 'code', 'em', 's',
+				'strike', 'strong', 'tt', 'var', 'div', 'center',
+				'blockquote', 'ol', 'ul', 'dl', 'table', 'caption', 'pre',
+				'ruby', 'rt' , 'rb' , 'rp', 'p', 'span', 'u'
+			);
+			$htmlsingle = array(
+				'br', 'hr', 'li', 'dt', 'dd'
+			);
+			$htmlsingleonly = array( # Elements that cannot have close tags
+				'br', 'hr'
+			);
+			$htmlnest = array( # Tags that can be nested--??
+				'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
+				'dl', 'font', 'big', 'small', 'sub', 'sup', 'span'
+			);
+			$tabletags = array( # Can only appear inside table
+				'td', 'th', 'tr',
+			);
+			$htmllist = array( # Tags used by list
+				'ul','ol',
+			);
+			$listtags = array( # Tags that can appear in a list
+				'li',
+			);
+
+		} else {
+			$htmlpairs = array();
+			$htmlsingle = array();
+			$htmlnest = array();
+			$tabletags = array();
+		}
+
+		$htmlsingleallowed = array_merge( $htmlsingle, $tabletags );
+		$htmlelements = array_merge( $htmlsingle, $htmlpairs, $htmlnest );
+
+		# Remove HTML comments
+		$text = Sanitizer::removeHTMLcomments( $text );
+		$bits = explode( '<', $text );
+		$text = array_shift( $bits );
+		if(!$wgUseTidy) {
+			$tagstack = array(); $tablestack = array();
+			foreach ( $bits as $x ) {
+				$prev = error_reporting( E_ALL & ~( E_NOTICE | E_WARNING ) );
+				preg_match( '/^(\\/?)(\\w+)([^>]*?)(\\/{0,1}>)([^<]*)$/',
+				$x, $regs );
+				list( $qbar, $slash, $t, $params, $brace, $rest ) = $regs;
+				error_reporting( $prev );
+
+				$badtag = 0 ;
+				if ( in_array( $t = strtolower( $t ), $htmlelements ) ) {
+					# Check our stack
+					if ( $slash ) {
+						# Closing a tag...
+						if( in_array( $t, $htmlsingleonly ) ) {
+							$badtag = 1;
+						} elseif ( ( $ot = @array_pop( $tagstack ) ) != $t ) {
+							if ( in_array($ot, $htmlsingleallowed) ) {
+								# Pop all elements with an optional close tag
+								# and see if we find a match below them
+								$optstack = array();
+								array_push ($optstack, $ot);
+								while ( ( ( $ot = @array_pop( $tagstack ) ) != $t ) &&
+												in_array($ot, $htmlsingleallowed) ) {
+									array_push ($optstack, $ot);
+								}
+								if ( $t != $ot ) {
+									# No match. Push the optinal elements back again
+									$badtag = 1;
+									while ( $ot = @array_pop( $optstack ) ) {
+										array_push( $tagstack, $ot );
+									}
+								}
+							} else {
+								@array_push( $tagstack, $ot );
+								# <li> can be nested in <ul> or <ol>, skip those cases:
+								if(!(in_array($ot, $htmllist) && in_array($t, $listtags) )) {
+									$badtag = 1;
+								}
+							}
+						} else {
+							if ( $t == 'table' ) {
+								$tagstack = array_pop( $tablestack );
+							}
+						}
+						$newparams = '';
+					} else {
+						# Keep track for later
+						if ( in_array( $t, $tabletags ) &&
+						! in_array( 'table', $tagstack ) ) {
+							$badtag = 1;
+						} else if ( in_array( $t, $tagstack ) &&
+						! in_array ( $t , $htmlnest ) ) {
+							$badtag = 1 ;
+						# Is it a self closed htmlpair ? (bug 5487)
+						} else if( $brace == '/>' &&
+						in_array($t, $htmlpairs) ) {
+							$badtag = 1;
+						} elseif( in_array( $t, $htmlsingleonly ) ) {
+							# Hack to force empty tag for uncloseable elements
+							$brace = '/>';
+						} else if( in_array( $t, $htmlsingle ) ) {
+							# Hack to not close $htmlsingle tags
+							$brace = NULL;
+						} else {
+							if ( $t == 'table' ) {
+								array_push( $tablestack, $tagstack );
+								$tagstack = array();
+							}
+							array_push( $tagstack, $t );
+						}
+
+						# Replace any variables or template parameters with
+						# plaintext results.
+						if( is_callable( $processCallback ) ) {
+							call_user_func_array( $processCallback, array( &$params, $args ) );
+						}
+
+						# Strip non-approved attributes from the tag
+						$newparams = Sanitizer::fixTagAttributes( $params, $t );
+					}
+					if ( ! $badtag ) {
+						$rest = str_replace( '>', '&gt;', $rest );
+						$close = ( $brace == '/>' ) ? ' /' : '';
+						$text .= "<$slash$t$newparams$close>$rest";
+						continue;
+					}
+				}
+				$text .= '&lt;' . str_replace( '>', '&gt;', $x);
+			}
+			# Close off any remaining tags
+			while ( is_array( $tagstack ) && ($t = array_pop( $tagstack )) ) {
+				$text .= "</$t>\n";
+				if ( $t == 'table' ) { $tagstack = array_pop( $tablestack ); }
+			}
+		} else {
+			# this might be possible using tidy itself
+			foreach ( $bits as $x ) {
+				preg_match( '/^(\\/?)(\\w+)([^>]*?)(\\/{0,1}>)([^<]*)$/',
+				$x, $regs );
+				@list( $qbar, $slash, $t, $params, $brace, $rest ) = $regs;
+				if ( in_array( $t = strtolower( $t ), $htmlelements ) ) {
+					if( is_callable( $processCallback ) ) {
+						call_user_func_array( $processCallback, array( &$params, $args ) );
+					}
+					$newparams = Sanitizer::fixTagAttributes( $params, $t );
+					$rest = str_replace( '>', '&gt;', $rest );
+					$text .= "<$slash$t$newparams$brace$rest";
+				} else {
+					$text .= '&lt;' . str_replace( '>', '&gt;', $x);
+				}
+			}
+		}
+		wfProfileOut( $fname );
+		return $text;
+	}
+
+	/**
+	 * Remove '<!--', '-->', and everything between.
+	 * To avoid leaving blank lines, when a comment is both preceded
+	 * and followed by a newline (ignoring spaces), trim leading and
+	 * trailing spaces and one of the newlines.
+	 *
+	 * @private
+	 * @param string $text
+	 * @return string
+	 */
+	function removeHTMLcomments( $text ) {
+		$fname='Parser::removeHTMLcomments';
+		wfProfileIn( $fname );
+		while (($start = strpos($text, '<!--')) !== false) {
+			$end = strpos($text, '-->', $start + 4);
+			if ($end === false) {
+				# Unterminated comment; bail out
+				break;
+			}
+
+			$end += 3;
+
+			# Trim space and newline if the comment is both
+			# preceded and followed by a newline
+			$spaceStart = max($start - 1, 0);
+			$spaceLen = $end - $spaceStart;
+			while (substr($text, $spaceStart, 1) === ' ' && $spaceStart > 0) {
+				$spaceStart--;
+				$spaceLen++;
+			}
+			while (substr($text, $spaceStart + $spaceLen, 1) === ' ')
+				$spaceLen++;
+			if (substr($text, $spaceStart, 1) === "\n" and substr($text, $spaceStart + $spaceLen, 1) === "\n") {
+				# Remove the comment, leading and trailing
+				# spaces, and leave only one newline.
+				$text = substr_replace($text, "\n", $spaceStart, $spaceLen + 1);
+			}
+			else {
+				# Remove just the comment.
+				$text = substr_replace($text, '', $start, $end - $start);
+			}
+		}
+		wfProfileOut( $fname );
+		return $text;
+	}
+
+	/**
+	 * Take an array of attribute names and values and normalize or discard
+	 * illegal values for the given element type.
+	 *
+	 * - Discards attributes not on a whitelist for the given element
+	 * - Unsafe style attributes are discarded
+	 *
+	 * @param array $attribs
+	 * @param string $element
+	 * @return array
+	 *
+	 * @todo Check for legal values where the DTD limits things.
+	 * @todo Check for unique id attribute :P
+	 */
+	function validateTagAttributes( $attribs, $element ) {
+		$whitelist = array_flip( Sanitizer::attributeWhitelist( $element ) );
+		$out = array();
+		foreach( $attribs as $attribute => $value ) {
+			if( !isset( $whitelist[$attribute] ) ) {
+				continue;
+			}
+			# Strip javascript "expression" from stylesheets.
+			# http://msdn.microsoft.com/workshop/author/dhtml/overview/recalc.asp
+			if( $attribute == 'style' ) {
+				$value = Sanitizer::checkCss( $value );
+				if( $value === false ) {
+					# haxx0r
+					continue;
+				}
+			}
+
+			if ( $attribute === 'id' )
+				$value = Sanitizer::escapeId( $value );
+
+			// If this attribute was previously set, override it.
+			// Output should only have one attribute of each name.
+			$out[$attribute] = $value;
+		}
+		return $out;
+	}
+	
+	/**
+	 * Pick apart some CSS and check it for forbidden or unsafe structures.
+	 * Returns a sanitized string, or false if it was just too evil.
+	 *
+	 * Currently URL references, 'expression', 'tps' are forbidden.
+	 *
+	 * @param string $value
+	 * @return mixed
+	 */
+	static function checkCss( $value ) {
+		$stripped = Sanitizer::decodeCharReferences( $value );
+
+		// Remove any comments; IE gets token splitting wrong
+		$stripped = preg_replace( '!/\\*.*?\\*/!S', ' ', $stripped );
+		$value = $stripped;
+
+		// ... and continue checks
+		$stripped = preg_replace( '!\\\\([0-9A-Fa-f]{1,6})[ \\n\\r\\t\\f]?!e',
+			'codepointToUtf8(hexdec("$1"))', $stripped );
+		$stripped = str_replace( '\\', '', $stripped );
+		if( preg_match( '/(expression|tps*:\/\/|url\\s*\().*/is',
+				$stripped ) ) {
+			# haxx0r
+			return false;
+		}
+		
+		return $value;
+	}
+
+	/**
+	 * Take a tag soup fragment listing an HTML element's attributes
+	 * and normalize it to well-formed XML, discarding unwanted attributes.
+	 * Output is safe for further wikitext processing, with escaping of
+	 * values that could trigger problems.
+	 *
+	 * - Normalizes attribute names to lowercase
+	 * - Discards attributes not on a whitelist for the given element
+	 * - Turns broken or invalid entities into plaintext
+	 * - Double-quotes all attribute values
+	 * - Attributes without values are given the name as attribute
+	 * - Double attributes are discarded
+	 * - Unsafe style attributes are discarded
+	 * - Prepends space if there are attributes.
+	 *
+	 * @param string $text
+	 * @param string $element
+	 * @return string
+	 */
+	function fixTagAttributes( $text, $element ) {
+		if( trim( $text ) == '' ) {
+			return '';
+		}
+		
+		$stripped = Sanitizer::validateTagAttributes(
+			Sanitizer::decodeTagAttributes( $text ), $element );
+		
+		$attribs = array();
+		foreach( $stripped as $attribute => $value ) {
+			$encAttribute = htmlspecialchars( $attribute );
+			$encValue = Sanitizer::safeEncodeAttribute( $value );
+			
+			$attribs[] = "$encAttribute=\"$encValue\"";
+		}
+		return count( $attribs ) ? ' ' . implode( ' ', $attribs ) : '';
+	}
+
+	/**
+	 * Encode an attribute value for HTML output.
+	 * @param $text
+	 * @return HTML-encoded text fragment
+	 */
+	function encodeAttribute( $text ) {
+		$encValue = htmlspecialchars( $text );
+		
+		// Whitespace is normalized during attribute decoding,
+		// so if we've been passed non-spaces we must encode them
+		// ahead of time or they won't be preserved.
+		$encValue = strtr( $encValue, array(
+			"\n" => '&#10;',
+			"\r" => '&#13;',
+			"\t" => '&#9;',
+		) );
+		
+		return $encValue;
+	}
+	
+	/**
+	 * Encode an attribute value for HTML tags, with extra armoring
+	 * against further wiki processing.
+	 * @param $text
+	 * @return HTML-encoded text fragment
+	 */
+	function safeEncodeAttribute( $text ) {
+		$encValue = Sanitizer::encodeAttribute( $text );
+		
+		# Templates and links may be expanded in later parsing,
+		# creating invalid or dangerous output. Suppress this.
+		$encValue = strtr( $encValue, array(
+			'<'    => '&lt;',   // This should never happen,
+			'>'    => '&gt;',   // we've received invalid input
+			'"'    => '&quot;', // which should have been escaped.
+			'{'    => '&#123;',
+			'['    => '&#91;',
+			"''"   => '&#39;&#39;',
+			'ISBN' => '&#73;SBN',
+			'RFC'  => '&#82;FC',
+			'PMID' => '&#80;MID',
+			'|'    => '&#124;',
+			'__'   => '&#95;_',
+		) );
+
+		# Stupid hack
+		$encValue = preg_replace_callback(
+			'/(' . wfUrlProtocols() . ')/',
+			array( 'Sanitizer', 'armorLinksCallback' ),
+			$encValue );
+		return $encValue;
+	}
+
+	/**
+	 * Given a value escape it so that it can be used in an id attribute and
+	 * return it, this does not validate the value however (see first link)
+	 *
+	 * @link http://www.w3.org/TR/html401/types.html#type-name Valid characters
+	 *                                                          in the id and
+	 *                                                          name attributes
+	 * @link http://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with the id attribute
+	 *
+	 * @bug 4461
+	 *
+	 * @static
+	 *
+	 * @param string $id
+	 * @return string
+	 */
+	function escapeId( $id ) {
+		static $replace = array(
+			'%3A' => ':',
+			'%' => '.'
+		);
+
+		$id = urlencode( Sanitizer::decodeCharReferences( strtr( $id, ' ', '_' ) ) );
+
+		return str_replace( array_keys( $replace ), array_values( $replace ), $id );
+	}
+
+	/**
+	 * Regex replace callback for armoring links against further processing.
+	 * @param array $matches
+	 * @return string
+	 * @private
+	 */
+	function armorLinksCallback( $matches ) {
+		return str_replace( ':', '&#58;', $matches[1] );
+	}
+
+	/**
+	 * Return an associative array of attribute names and values from
+	 * a partial tag string. Attribute names are forces to lowercase,
+	 * character references are decoded to UTF-8 text.
+	 *
+	 * @param string
+	 * @return array
+	 */
+	function decodeTagAttributes( $text ) {
+		$attribs = array();
+
+		if( trim( $text ) == '' ) {
+			return $attribs;
+		}
+
+		$pairs = array();
+		if( !preg_match_all(
+			MW_ATTRIBS_REGEX,
+			$text,
+			$pairs,
+			PREG_SET_ORDER ) ) {
+			return $attribs;
+		}
+
+		foreach( $pairs as $set ) {
+			$attribute = strtolower( $set[1] );
+			$value = Sanitizer::getTagAttributeCallback( $set );
+			
+			// Normalize whitespace
+			$value = preg_replace( '/[\t\r\n ]+/', ' ', $value );
+			$value = trim( $value );
+			
+			// Decode character references
+			$attribs[$attribute] = Sanitizer::decodeCharReferences( $value );
+		}
+		return $attribs;
+	}
+
+	/**
+	 * Pick the appropriate attribute value from a match set from the
+	 * MW_ATTRIBS_REGEX matches.
+	 *
+	 * @param array $set
+	 * @return string
+	 * @private
+	 */
+	function getTagAttributeCallback( $set ) {
+		if( isset( $set[6] ) ) {
+			# Illegal #XXXXXX color with no quotes.
+			return $set[6];
+		} elseif( isset( $set[5] ) ) {
+			# No quotes.
+			return $set[5];
+		} elseif( isset( $set[4] ) ) {
+			# Single-quoted
+			return $set[4];
+		} elseif( isset( $set[3] ) ) {
+			# Double-quoted
+			return $set[3];
+		} elseif( !isset( $set[2] ) ) {
+			# In XHTML, attributes must have a value.
+			# For 'reduced' form, return explicitly the attribute name here.
+			return $set[1];
+		} else {
+			throw new MWException( "Tag conditions not met. This should never happen and is a bug." );
+		}
+	}
+
+	/**
+	 * Normalize whitespace and character references in an XML source-
+	 * encoded text for an attribute value.
+	 *
+	 * See http://www.w3.org/TR/REC-xml/#AVNormalize for background,
+	 * but note that we're not returning the value, but are returning
+	 * XML source fragments that will be slapped into output.
+	 *
+	 * @param string $text
+	 * @return string
+	 * @private
+	 */
+	function normalizeAttributeValue( $text ) {
+		return str_replace( '"', '&quot;',
+			preg_replace(
+				'/\r\n|[\x20\x0d\x0a\x09]/',
+				' ',
+				Sanitizer::normalizeCharReferences( $text ) ) );
+	}
+
+	/**
+	 * Ensure that any entities and character references are legal
+	 * for XML and XHTML specifically. Any stray bits will be
+	 * &amp;-escaped to result in a valid text fragment.
+	 *
+	 * a. any named char refs must be known in XHTML
+	 * b. any numeric char refs must be legal chars, not invalid or forbidden
+	 * c. use &#x, not &#X
+	 * d. fix or reject non-valid attributes
+	 *
+	 * @param string $text
+	 * @return string
+	 * @private
+	 */
+	function normalizeCharReferences( $text ) {
+		return preg_replace_callback(
+			MW_CHAR_REFS_REGEX,
+			array( 'Sanitizer', 'normalizeCharReferencesCallback' ),
+			$text );
+	}
+	/**
+	 * @param string $matches
+	 * @return string
+	 */
+	function normalizeCharReferencesCallback( $matches ) {
+		$ret = null;
+		if( $matches[1] != '' ) {
+			$ret = Sanitizer::normalizeEntity( $matches[1] );
+		} elseif( $matches[2] != '' ) {
+			$ret = Sanitizer::decCharReference( $matches[2] );
+		} elseif( $matches[3] != ''  ) {
+			$ret = Sanitizer::hexCharReference( $matches[3] );
+		} elseif( $matches[4] != '' ) {
+			$ret = Sanitizer::hexCharReference( $matches[4] );
+		}
+		if( is_null( $ret ) ) {
+			return htmlspecialchars( $matches[0] );
+		} else {
+			return $ret;
+		}
+	}
+
+	/**
+	 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
+	 * return the named entity reference as is. Otherwise, returns
+	 * HTML-escaped text of pseudo-entity source (eg &amp;foo;)
+	 *
+	 * @param string $name
+	 * @return string
+	 */
+	function normalizeEntity( $name ) {
+		global $wgHtmlEntities;
+		if( isset( $wgHtmlEntities[$name] ) ) {
+			return "&$name;";
+		} else {
+			return "&amp;$name;";
+		}
+	}
+
+	function decCharReference( $codepoint ) {
+		$point = intval( $codepoint );
+		if( Sanitizer::validateCodepoint( $point ) ) {
+			return sprintf( '&#%d;', $point );
+		} else {
+			return null;
+		}
+	}
+
+	function hexCharReference( $codepoint ) {
+		$point = hexdec( $codepoint );
+		if( Sanitizer::validateCodepoint( $point ) ) {
+			return sprintf( '&#x%x;', $point );
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Returns true if a given Unicode codepoint is a valid character in XML.
+	 * @param int $codepoint
+	 * @return bool
+	 */
+	function validateCodepoint( $codepoint ) {
+		return ($codepoint ==    0x09)
+			|| ($codepoint ==    0x0a)
+			|| ($codepoint ==    0x0d)
+			|| ($codepoint >=    0x20 && $codepoint <=   0xd7ff)
+			|| ($codepoint >=  0xe000 && $codepoint <=   0xfffd)
+			|| ($codepoint >= 0x10000 && $codepoint <= 0x10ffff);
+	}
+
+	/**
+	 * Decode any character references, numeric or named entities,
+	 * in the text and return a UTF-8 string.
+	 *
+	 * @param string $text
+	 * @return string
+	 * @public
+	 */
+	function decodeCharReferences( $text ) {
+		return preg_replace_callback(
+			MW_CHAR_REFS_REGEX,
+			array( 'Sanitizer', 'decodeCharReferencesCallback' ),
+			$text );
+	}
+
+	/**
+	 * @param string $matches
+	 * @return string
+	 */
+	function decodeCharReferencesCallback( $matches ) {
+		if( $matches[1] != '' ) {
+			return Sanitizer::decodeEntity( $matches[1] );
+		} elseif( $matches[2] != '' ) {
+			return  Sanitizer::decodeChar( intval( $matches[2] ) );
+		} elseif( $matches[3] != ''  ) {
+			return  Sanitizer::decodeChar( hexdec( $matches[3] ) );
+		} elseif( $matches[4] != '' ) {
+			return  Sanitizer::decodeChar( hexdec( $matches[4] ) );
+		}
+		# Last case should be an ampersand by itself
+		return $matches[0];
+	}
+
+	/**
+	 * Return UTF-8 string for a codepoint if that is a valid
+	 * character reference, otherwise U+FFFD REPLACEMENT CHARACTER.
+	 * @param int $codepoint
+	 * @return string
+	 * @private
+	 */
+	function decodeChar( $codepoint ) {
+		if( Sanitizer::validateCodepoint( $codepoint ) ) {
+			return codepointToUtf8( $codepoint );
+		} else {
+			return UTF8_REPLACEMENT;
+		}
+	}
+
+	/**
+	 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
+	 * return the UTF-8 encoding of that character. Otherwise, returns
+	 * pseudo-entity source (eg &foo;)
+	 *
+	 * @param string $name
+	 * @return string
+	 */
+	function decodeEntity( $name ) {
+		global $wgHtmlEntities;
+		if( isset( $wgHtmlEntities[$name] ) ) {
+			return codepointToUtf8( $wgHtmlEntities[$name] );
+		} else {
+			return "&$name;";
+		}
+	}
+
+	/**
+	 * Fetch the whitelist of acceptable attributes for a given
+	 * element name.
+	 *
+	 * @param string $element
+	 * @return array
+	 */
+	function attributeWhitelist( $element ) {
+		static $list;
+		if( !isset( $list ) ) {
+			$list = Sanitizer::setupAttributeWhitelist();
+		}
+		return isset( $list[$element] )
+			? $list[$element]
+			: array();
+	}
+
+	/**
+	 * @return array
+	 */
+	function setupAttributeWhitelist() {
+		$common = array( 'id', 'class', 'lang', 'dir', 'title', 'style' );
+		$block = array_merge( $common, array( 'align' ) );
+		$tablealign = array( 'align', 'char', 'charoff', 'valign' );
+		$tablecell = array( 'abbr',
+		                    'axis',
+		                    'headers',
+		                    'scope',
+		                    'rowspan',
+		                    'colspan',
+		                    'nowrap', # deprecated
+		                    'width',  # deprecated
+		                    'height', # deprecated
+		                    'bgcolor' # deprecated
+		                    );
+
+		# Numbers refer to sections in HTML 4.01 standard describing the element.
+		# See: http://www.w3.org/TR/html4/
+		$whitelist = array (
+			# 7.5.4
+			'div'        => $block,
+			'center'     => $common, # deprecated
+			'span'       => $block, # ??
+
+			# 7.5.5
+			'h1'         => $block,
+			'h2'         => $block,
+			'h3'         => $block,
+			'h4'         => $block,
+			'h5'         => $block,
+			'h6'         => $block,
+
+			# 7.5.6
+			# address
+
+			# 8.2.4
+			# bdo
+
+			# 9.2.1
+			'em'         => $common,
+			'strong'     => $common,
+			'cite'       => $common,
+			# dfn
+			'code'       => $common,
+			# samp
+			# kbd
+			'var'        => $common,
+			# abbr
+			# acronym
+
+			# 9.2.2
+			'blockquote' => array_merge( $common, array( 'cite' ) ),
+			# q
+
+			# 9.2.3
+			'sub'        => $common,
+			'sup'        => $common,
+
+			# 9.3.1
+			'p'          => $block,
+
+			# 9.3.2
+			'br'         => array( 'id', 'class', 'title', 'style', 'clear' ),
+
+			# 9.3.4
+			'pre'        => array_merge( $common, array( 'width' ) ),
+
+			# 9.4
+			'ins'        => array_merge( $common, array( 'cite', 'datetime' ) ),
+			'del'        => array_merge( $common, array( 'cite', 'datetime' ) ),
+
+			# 10.2
+			'ul'         => array_merge( $common, array( 'type' ) ),
+			'ol'         => array_merge( $common, array( 'type', 'start' ) ),
+			'li'         => array_merge( $common, array( 'type', 'value' ) ),
+
+			# 10.3
+			'dl'         => $common,
+			'dd'         => $common,
+			'dt'         => $common,
+
+			# 11.2.1
+			'table'      => array_merge( $common,
+								array( 'summary', 'width', 'border', 'frame',
+											 'rules', 'cellspacing', 'cellpadding',
+											 'align', 'bgcolor', 'frame', 'rules',
+											 'border' ) ),
+
+			# 11.2.2
+			'caption'    => array_merge( $common, array( 'align' ) ),
+
+			# 11.2.3
+			'thead'      => array_merge( $common, $tablealign ),
+			'tfoot'      => array_merge( $common, $tablealign ),
+			'tbody'      => array_merge( $common, $tablealign ),
+
+			# 11.2.4
+			'colgroup'   => array_merge( $common, array( 'span', 'width' ), $tablealign ),
+			'col'        => array_merge( $common, array( 'span', 'width' ), $tablealign ),
+
+			# 11.2.5
+			'tr'         => array_merge( $common, array( 'bgcolor' ), $tablealign ),
+
+			# 11.2.6
+			'td'         => array_merge( $common, $tablecell, $tablealign ),
+			'th'         => array_merge( $common, $tablecell, $tablealign ),
+
+			# 15.2.1
+			'tt'         => $common,
+			'b'          => $common,
+			'i'          => $common,
+			'big'        => $common,
+			'small'      => $common,
+			'strike'     => $common,
+			's'          => $common,
+			'u'          => $common,
+
+			# 15.2.2
+			'font'       => array_merge( $common, array( 'size', 'color', 'face' ) ),
+			# basefont
+
+			# 15.3
+			'hr'         => array_merge( $common, array( 'noshade', 'size', 'width' ) ),
+
+			# XHTML Ruby annotation text module, simple ruby only.
+			# http://www.w3c.org/TR/ruby/
+			'ruby'       => $common,
+			# rbc
+			# rtc
+			'rb'         => $common,
+			'rt'         => $common, #array_merge( $common, array( 'rbspan' ) ),
+			'rp'         => $common,
+			);
+		return $whitelist;
+	}
+
+	/**
+	 * Take a fragment of (potentially invalid) HTML and return
+	 * a version with any tags removed, encoded suitably for literal
+	 * inclusion in an attribute value.
+	 *
+	 * @param string $text HTML fragment
+	 * @return string
+	 */
+	function stripAllTags( $text ) {
+		# Actual <tags>
+		$text = preg_replace( '/ < .*? > /x', '', $text );
+
+		# Normalize &entities and whitespace
+		$text = Sanitizer::normalizeAttributeValue( $text );
+
+		# Will be placed into "double-quoted" attributes,
+		# make sure remaining bits are safe.
+		$text = str_replace(
+			array('<', '>', '"'),
+			array('&lt;', '&gt;', '&quot;'),
+			$text );
+
+		return $text;
+	}
+
+	/**
+	 * Hack up a private DOCTYPE with HTML's standard entity declarations.
+	 * PHP 4 seemed to know these if you gave it an HTML doctype, but
+	 * PHP 5.1 doesn't.
+	 *
+	 * Use for passing XHTML fragments to PHP's XML parsing functions
+	 *
+	 * @return string
+	 * @static
+	 */
+	function hackDocType() {
+		global $wgHtmlEntities;
+		$out = "<!DOCTYPE html [\n";
+		foreach( $wgHtmlEntities as $entity => $codepoint ) {
+			$out .= "<!ENTITY $entity \"&#$codepoint;\">";
+		}
+		$out .= "]>\n";
+		return $out;
+	}
+
+}
+
+?>