* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
- * @package MediaWiki
- * @subpackage Parser
+ * @addtogroup Parser
*/
/**
* Sanitizer::normalizeCharReferences and Sanitizer::decodeCharReferences
*/
define( 'MW_CHAR_REFS_REGEX',
- '/&([A-Za-z0-9]+);
+ '/&([A-Za-z0-9\x80-\xff]+);
|&\#([0-9]+);
|&\#x([0-9A-Za-z]+);
|&\#X([0-9A-Za-z]+);
'zwj' => 8205,
'zwnj' => 8204 );
-/** @package MediaWiki */
+/**
+ * Character entity aliases accepted by MediaWiki
+ */
+global $wgHtmlEntityAliases;
+$wgHtmlEntityAliases = array(
+ 'רלמ' => 'rlm',
+ 'رلم' => 'rlm',
+);
+
+
+/**
+ * XHTML sanitizer for MediaWiki
+ * @addtogroup Parser
+ */
class Sanitizer {
/**
* Cleans up HTML, removes dangerous tags and attributes, and
* @param array $args for the processing callback
* @return string
*/
- function removeHTMLtags( $text, $processCallback = null, $args = array() ) {
- global $wgUseTidy, $wgUserHtml;
- $fname = 'Parser::removeHTMLtags';
- wfProfileIn( $fname );
+ static function removeHTMLtags( $text, $processCallback = null, $args = array() ) {
+ global $wgUseTidy;
+
+ static $htmlpairs, $htmlsingle, $htmlsingleonly, $htmlnest, $tabletags,
+ $htmllist, $listtags, $htmlsingleallowed, $htmlelements, $staticInitialised;
+
+ wfProfileIn( __METHOD__ );
+
+ if ( !$staticInitialised ) {
- 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',
'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
'dl', 'font', 'big', 'small', 'sub', 'sup', 'span'
);
- $tabletags = array( # Can only appear inside table
+ $tabletags = array( # Can only appear inside table, we will close them
'td', 'th', 'tr',
);
$htmllist = array( # Tags used by list
'li',
);
- } else {
- $htmlpairs = array();
- $htmlsingle = array();
- $htmlnest = array();
- $tabletags = array();
- }
+ $htmlsingleallowed = array_merge( $htmlsingle, $tabletags );
+ $htmlelements = array_merge( $htmlsingle, $htmlpairs, $htmlnest );
- $htmlsingleallowed = array_merge( $htmlsingle, $tabletags );
- $htmlelements = array_merge( $htmlsingle, $htmlpairs, $htmlnest );
+ # Convert them all to hashtables for faster lookup
+ $vars = array( 'htmlpairs', 'htmlsingle', 'htmlsingleonly', 'htmlnest', 'tabletags',
+ 'htmllist', 'listtags', 'htmlsingleallowed', 'htmlelements' );
+ foreach ( $vars as $var ) {
+ $$var = array_flip( $$var );
+ }
+ $staticInitialised = true;
+ }
# Remove HTML comments
$text = Sanitizer::removeHTMLcomments( $text );
$bits = explode( '<', $text );
- $text = array_shift( $bits );
+ $text = str_replace( '>', '>', array_shift( $bits ) );
if(!$wgUseTidy) {
- $tagstack = array(); $tablestack = array();
+ $tagstack = $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 );
+ $regs = array();
+ if( preg_match( '!^(/?)(\\w+)([^>]*?)(/{0,1}>)([^<]*)$!', $x, $regs ) ) {
+ list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
+ } else {
+ $slash = $t = $params = $brace = $rest = null;
+ }
$badtag = 0 ;
- if ( in_array( $t = strtolower( $t ), $htmlelements ) ) {
+ if ( isset( $htmlelements[$t = strtolower( $t )] ) ) {
# Check our stack
if ( $slash ) {
# Closing a tag...
- if( in_array( $t, $htmlsingleonly ) ) {
+ if( isset( $htmlsingleonly[$t] ) ) {
$badtag = 1;
} elseif ( ( $ot = @array_pop( $tagstack ) ) != $t ) {
- if ( in_array($ot, $htmlsingleallowed) ) {
+ if ( isset( $htmlsingleallowed[$ot] ) ) {
# 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) ) {
+ isset( $htmlsingleallowed[$ot] ) )
+ {
array_push ($optstack, $ot);
}
if ( $t != $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) )) {
+ if(!(isset( $htmllist[$ot] ) && isset( $listtags[$t] ) )) {
$badtag = 1;
}
}
$newparams = '';
} else {
# Keep track for later
- if ( in_array( $t, $tabletags ) &&
+ if ( isset( $tabletags[$t] ) &&
! in_array( 'table', $tagstack ) ) {
$badtag = 1;
} else if ( in_array( $t, $tagstack ) &&
- ! in_array ( $t , $htmlnest ) ) {
+ ! isset( $htmlnest [$t ] ) ) {
$badtag = 1 ;
# Is it a self closed htmlpair ? (bug 5487)
} else if( $brace == '/>' &&
- in_array($t, $htmlpairs) ) {
+ isset( $htmlpairs[$t] ) ) {
$badtag = 1;
- } elseif( in_array( $t, $htmlsingleonly ) ) {
+ } elseif( isset( $htmlsingleonly[$t] ) ) {
# Hack to force empty tag for uncloseable elements
$brace = '/>';
- } else if( in_array( $t, $htmlsingle ) ) {
+ } else if( isset( $htmlsingle[$t] ) ) {
# Hack to not close $htmlsingle tags
$brace = NULL;
+ } else if( isset( $tabletags[$t] )
+ && in_array($t ,$tagstack) ) {
+ // New table tag but forgot to close the previous one
+ $text .= "</$t>";
} else {
if ( $t == 'table' ) {
array_push( $tablestack, $tagstack );
}
if ( ! $badtag ) {
$rest = str_replace( '>', '>', $rest );
- $close = ( $brace == '/>' ) ? ' /' : '';
+ $close = ( $brace == '/>' && !$slash ) ? ' /' : '';
$text .= "<$slash$t$newparams$close>$rest";
continue;
}
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 ) ) {
+ @list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
+ if ( isset( $htmlelements[$t = strtolower( $t )] ) ) {
if( is_callable( $processCallback ) ) {
call_user_func_array( $processCallback, array( &$params, $args ) );
}
}
}
}
- wfProfileOut( $fname );
+ wfProfileOut( __METHOD__ );
return $text;
}
* @param string $text
* @return string
*/
- function removeHTMLcomments( $text ) {
- $fname='Parser::removeHTMLcomments';
- wfProfileIn( $fname );
+ static function removeHTMLcomments( $text ) {
+ wfProfileIn( __METHOD__ );
while (($start = strpos($text, '<!--')) !== false) {
$end = strpos($text, '-->', $start + 4);
if ($end === false) {
$text = substr_replace($text, '', $start, $end - $start);
}
}
- wfProfileOut( $fname );
+ wfProfileOut( __METHOD__ );
return $text;
}
* @todo Check for legal values where the DTD limits things.
* @todo Check for unique id attribute :P
*/
- function validateTagAttributes( $attribs, $element ) {
+ static function validateTagAttributes( $attribs, $element ) {
$whitelist = array_flip( Sanitizer::attributeWhitelist( $element ) );
$out = array();
foreach( $attribs as $attribute => $value ) {
# Strip javascript "expression" from stylesheets.
# http://msdn.microsoft.com/workshop/author/dhtml/overview/recalc.asp
if( $attribute == 'style' ) {
- $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 ) ) {
+ $value = Sanitizer::checkCss( $value );
+ if( $value === false ) {
# haxx0r
continue;
}
}
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 = StringUtils::delimiterReplace( '/*', '*/', ' ', $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
* @param string $element
* @return string
*/
- function fixTagAttributes( $text, $element ) {
+ static 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 ) : '';
* @param $text
* @return HTML-encoded text fragment
*/
- function encodeAttribute( $text ) {
+ static 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.
"\r" => ' ',
"\t" => '	',
) );
-
+
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 ) {
+ static 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(
* 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
+ * @see 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
+ * @see http://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with the id attribute
*
* @static
*
* @param string $id
* @return string
*/
- function escapeId( $id ) {
+ static function escapeId( $id ) {
static $replace = array(
'%3A' => ':',
'%' => '.'
return str_replace( array_keys( $replace ), array_values( $replace ), $id );
}
+ /**
+ * Given a value, escape it so that it can be used as a CSS class and
+ * return it.
+ *
+ * @todo For extra validity, input should be validated UTF-8.
+ *
+ * @see http://www.w3.org/TR/CSS21/syndata.html Valid characters/format
+ *
+ * @param string $class
+ * @return string
+ */
+ static function escapeClass( $class ) {
+ // Convert ugly stuff to underscores and kill underscores in ugly places
+ return rtrim(preg_replace(
+ array('/(^[0-9\\-])|[\\x00-\\x20!"#$%&\'()*+,.\\/:;<=>?@[\\]^`{|}~]|\\xC2\\xA0/','/_+/'),
+ '_',
+ $class ), '_');
+ }
+
/**
* Regex replace callback for armoring links against further processing.
* @param array $matches
* @return string
* @private
*/
- function armorLinksCallback( $matches ) {
+ private static function armorLinksCallback( $matches ) {
return str_replace( ':', ':', $matches[1] );
}
* @param string
* @return array
*/
- function decodeTagAttributes( $text ) {
+ static function decodeTagAttributes( $text ) {
$attribs = array();
if( trim( $text ) == '' ) {
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 string
* @private
*/
- function getTagAttributeCallback( $set ) {
+ private static function getTagAttributeCallback( $set ) {
if( isset( $set[6] ) ) {
# Illegal #XXXXXX color with no quotes.
return $set[6];
* @return string
* @private
*/
- function normalizeAttributeValue( $text ) {
+ private static function normalizeAttributeValue( $text ) {
return str_replace( '"', '"',
- preg_replace(
- '/\r\n|[\x20\x0d\x0a\x09]/',
- ' ',
+ self::normalizeWhitespace(
Sanitizer::normalizeCharReferences( $text ) ) );
}
+
+ private static function normalizeWhitespace( $text ) {
+ return preg_replace(
+ '/\r\n|[\x20\x0d\x0a\x09]/',
+ ' ',
+ $text );
+ }
/**
* Ensure that any entities and character references are legal
* @return string
* @private
*/
- function normalizeCharReferences( $text ) {
+ static function normalizeCharReferences( $text ) {
return preg_replace_callback(
MW_CHAR_REFS_REGEX,
array( 'Sanitizer', 'normalizeCharReferencesCallback' ),
* @param string $matches
* @return string
*/
- function normalizeCharReferencesCallback( $matches ) {
+ static function normalizeCharReferencesCallback( $matches ) {
$ret = null;
if( $matches[1] != '' ) {
$ret = Sanitizer::normalizeEntity( $matches[1] );
/**
* 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 &foo;)
+ * return the named entity reference as is. If the entity is a
+ * MediaWiki-specific alias, returns the HTML equivalent. Otherwise,
+ * returns HTML-escaped text of pseudo-entity source (eg &foo;)
*
* @param string $name
* @return string
+ * @static
*/
- function normalizeEntity( $name ) {
- global $wgHtmlEntities;
- if( isset( $wgHtmlEntities[$name] ) ) {
+ static function normalizeEntity( $name ) {
+ global $wgHtmlEntities, $wgHtmlEntityAliases;
+ if ( isset( $wgHtmlEntityAliases[$name] ) ) {
+ return "&{$wgHtmlEntityAliases[$name]};";
+ } elseif( isset( $wgHtmlEntities[$name] ) ) {
return "&$name;";
} else {
return "&$name;";
}
}
- function decCharReference( $codepoint ) {
+ static function decCharReference( $codepoint ) {
$point = intval( $codepoint );
if( Sanitizer::validateCodepoint( $point ) ) {
return sprintf( '&#%d;', $point );
}
}
- function hexCharReference( $codepoint ) {
+ static function hexCharReference( $codepoint ) {
$point = hexdec( $codepoint );
if( Sanitizer::validateCodepoint( $point ) ) {
return sprintf( '&#x%x;', $point );
* @param int $codepoint
* @return bool
*/
- function validateCodepoint( $codepoint ) {
+ private static function validateCodepoint( $codepoint ) {
return ($codepoint == 0x09)
|| ($codepoint == 0x0a)
|| ($codepoint == 0x0d)
* @param string $text
* @return string
* @public
+ * @static
*/
- function decodeCharReferences( $text ) {
+ public static function decodeCharReferences( $text ) {
return preg_replace_callback(
MW_CHAR_REFS_REGEX,
array( 'Sanitizer', 'decodeCharReferencesCallback' ),
* @param string $matches
* @return string
*/
- function decodeCharReferencesCallback( $matches ) {
+ static function decodeCharReferencesCallback( $matches ) {
if( $matches[1] != '' ) {
return Sanitizer::decodeEntity( $matches[1] );
} elseif( $matches[2] != '' ) {
* @return string
* @private
*/
- function decodeChar( $codepoint ) {
+ static function decodeChar( $codepoint ) {
if( Sanitizer::validateCodepoint( $codepoint ) ) {
return codepointToUtf8( $codepoint );
} else {
* @param string $name
* @return string
*/
- function decodeEntity( $name ) {
- global $wgHtmlEntities;
+ static function decodeEntity( $name ) {
+ global $wgHtmlEntities, $wgHtmlEntityAliases;
+ if ( isset( $wgHtmlEntityAliases[$name] ) ) {
+ $name = $wgHtmlEntityAliases[$name];
+ }
if( isset( $wgHtmlEntities[$name] ) ) {
return codepointToUtf8( $wgHtmlEntities[$name] );
} else {
* @param string $element
* @return array
*/
- function attributeWhitelist( $element ) {
+ static function attributeWhitelist( $element ) {
static $list;
if( !isset( $list ) ) {
$list = Sanitizer::setupAttributeWhitelist();
}
/**
+ * @todo Document it a bit
* @return array
*/
- function setupAttributeWhitelist() {
+ static function setupAttributeWhitelist() {
$common = array( 'id', 'class', 'lang', 'dir', 'title', 'style' );
$block = array_merge( $common, array( 'align' ) );
$tablealign = array( 'align', 'char', 'charoff', 'valign' );
# 11.2.1
'table' => array_merge( $common,
array( 'summary', 'width', 'border', 'frame',
- 'rules', 'cellspacing', 'cellpadding',
- 'align', 'bgcolor', 'frame', 'rules',
- 'border' ) ),
+ 'rules', 'cellspacing', 'cellpadding',
+ 'align', 'bgcolor',
+ ) ),
# 11.2.2
'caption' => array_merge( $common, array( 'align' ) ),
/**
* Take a fragment of (potentially invalid) HTML and return
- * a version with any tags removed, encoded suitably for literal
- * inclusion in an attribute value.
+ * a version with any tags removed, encoded as plain text.
+ *
+ * Warning: this return value must be further escaped for literal
+ * inclusion in HTML output as of 1.10!
*
* @param string $text HTML fragment
* @return string
*/
- function stripAllTags( $text ) {
+ static function stripAllTags( $text ) {
# Actual <tags>
- $text = preg_replace( '/ < .*? > /x', '', $text );
+ $text = StringUtils::delimiterReplace( '<', '>', '', $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('<', '>', '"'),
- $text );
+ $text = self::decodeCharReferences( $text );
+ $text = self::normalizeWhitespace( $text );
return $text;
}
* @return string
* @static
*/
- function hackDocType() {
+ static function hackDocType() {
global $wgHtmlEntities;
$out = "<!DOCTYPE html [\n";
foreach( $wgHtmlEntities as $entity => $codepoint ) {
return $out;
}
+ static function cleanUrl( $url, $hostname=true ) {
+ # Normalize any HTML entities in input. They will be
+ # re-escaped by makeExternalLink().
+ $url = Sanitizer::decodeCharReferences( $url );
+
+ # Escape any control characters introduced by the above step
+ $url = preg_replace( '/[\][<>"\\x00-\\x20\\x7F]/e', "urlencode('\\0')", $url );
+
+ # Validate hostname portion
+ $matches = array();
+ if( preg_match( '!^([^:]+:)(//[^/]+)?(.*)$!iD', $url, $matches ) ) {
+ list( /* $whole */, $protocol, $host, $rest ) = $matches;
+
+ // Characters that will be ignored in IDNs.
+ // http://tools.ietf.org/html/3454#section-3.1
+ // Strip them before further processing so blacklists and such work.
+ $strip = "/
+ \\s| # general whitespace
+ \xc2\xad| # 00ad SOFT HYPHEN
+ \xe1\xa0\x86| # 1806 MONGOLIAN TODO SOFT HYPHEN
+ \xe2\x80\x8b| # 200b ZERO WIDTH SPACE
+ \xe2\x81\xa0| # 2060 WORD JOINER
+ \xef\xbb\xbf| # feff ZERO WIDTH NO-BREAK SPACE
+ \xcd\x8f| # 034f COMBINING GRAPHEME JOINER
+ \xe1\xa0\x8b| # 180b MONGOLIAN FREE VARIATION SELECTOR ONE
+ \xe1\xa0\x8c| # 180c MONGOLIAN FREE VARIATION SELECTOR TWO
+ \xe1\xa0\x8d| # 180d MONGOLIAN FREE VARIATION SELECTOR THREE
+ \xe2\x80\x8c| # 200c ZERO WIDTH NON-JOINER
+ \xe2\x80\x8d| # 200d ZERO WIDTH JOINER
+ [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe00f VARIATION SELECTOR-1-16
+ /xuD";
+
+ $host = preg_replace( $strip, '', $host );
+
+ // @fixme: validate hostnames here
+
+ return $protocol . $host . $rest;
+ } else {
+ return $url;
+ }
+ }
+
}
?>