* Regular expression to match various types of character references in
* Sanitizer::normalizeCharReferences and Sanitizer::decodeCharReferences
*/
- const CHAR_REFS_REGEX =
+ const CHAR_REFS_REGEX =
'/&([A-Za-z0-9\x80-\xff]+);
|&\#([0-9]+);
|&\#[xX]([0-9A-Fa-f]+);
|(&)/x';
+ /**
+ * Blacklist for evil uris like javascript:
+ * WARNING: DO NOT use this in any place that actually requires blacklisting
+ * for security reasons. There are NUMEROUS[1] ways to bypass blacklisting, the
+ * only way to be secure from javascript: uri based xss vectors is to whitelist
+ * things that you know are safe and deny everything else.
+ * [1]: http://ha.ckers.org/xss.html
+ */
const EVIL_URI_PATTERN = '!(^|\s|\*/\s*)(javascript|vbscript)([^\w]|$)!i';
const XMLNS_ATTRIBUTE_PATTERN = "/^xmlns:[:A-Z_a-z-.0-9]+$/";
/**
* List of all named character entities defined in HTML 4.01
* http://www.w3.org/TR/html4/sgml/entities.html
+ * As well as ' which is only defined starting in XHTML1.
* @private
*/
static $htmlEntities = array(
'amp' => 38,
'and' => 8743,
'ang' => 8736,
+ 'apos' => 39, // New in XHTML & HTML 5; avoid in output for compatibility with IE.
'Aring' => 197,
'aring' => 229,
'asymp' => 8776,
$attribFirst = '[:A-Z_a-z0-9]';
$attrib = '[:A-Z_a-z-.0-9]';
$space = '[\x09\x0a\x0d\x20]';
- self::$attribsRegex =
+ self::$attribsRegex =
"/(?:^|$space)({$attribFirst}{$attrib}*)
($space*=$space*
(?:
# and see if we find a match below them
$optstack = array();
array_push( $optstack, $ot );
- $ot = @array_pop( $tagstack );
+ wfSuppressWarnings();
+ $ot = array_pop( $tagstack );
+ wfRestoreWarnings();
while ( $ot != $t && isset( $htmlsingleallowed[$ot] ) ) {
array_push( $optstack, $ot );
- $ot = @array_pop( $tagstack );
+ wfSuppressWarnings();
+ $ot = array_pop( $tagstack );
+ wfRestoreWarnings();
}
if ( $t != $ot ) {
# No match. Push the optional elements back again
$badtag = true;
- while ( $ot = @array_pop( $optstack ) ) {
+ wfSuppressWarnings();
+ $ot = array_pop( $optstack );
+ wfRestoreWarnings();
+ while ( $ot ) {
array_push( $tagstack, $ot );
+ wfSuppressWarnings();
+ $ot = array_pop( $optstack );
+ wfRestoreWarnings();
}
}
} else {
return $text;
}
+ /**
+ * Take an array of attribute names and values and fix some deprecated values
+ * for the given element type.
+ * This does not validate properties, so you should ensure that you call
+ * validateTagAttributes AFTER this to ensure that the resulting style rule
+ * this may add is safe.
+ *
+ * - Converts most presentational attributes like align into inline css
+ *
+ * @param $attribs Array
+ * @param $element String
+ * @return Array
+ */
+ static function fixDeprecatedAttributes( $attribs, $element ) {
+ global $wgHtml5, $wgCleanupPresentationalAttributes;
+
+ // presentational attributes were removed from html5, we can leave them
+ // in when html5 is turned off
+ if ( !$wgHtml5 || !$wgCleanupPresentationalAttributes ) {
+ return $attribs;
+ }
+
+ $table = array( 'table' );
+ $cells = array( 'td', 'th' );
+ $colls = array( 'col', 'colgroup' );
+ $tblocks = array( 'tbody', 'tfoot', 'thead' );
+ $h = array( 'h1', 'h2', 'h3', 'h4', 'h5', 'h6' );
+
+ $presentationalAttribs = array(
+ 'align' => array( 'text-align', array_merge( array( 'caption', 'hr', 'div', 'p', 'tr' ), $table, $cells, $colls, $tblocks, $h ) ),
+ 'clear' => array( 'clear', array( 'br' ) ),
+ 'height' => array( 'height', $cells ),
+ 'nowrap' => array( 'white-space', $cells ),
+ 'size' => array( 'height', array( 'hr' ) ),
+ 'type' => array( 'list-style-type', array( 'li', 'ol', 'ul' ) ),
+ 'valign' => array( 'vertical-align', array_merge( $cells, $colls, $tblocks ) ),
+ 'width' => array( 'width', array_merge( array( 'hr', 'pre' ), $table, $cells, $colls ) ),
+ );
+
+ // Ensure that any upper case or mixed case attributes are converted to lowercase
+ foreach ( $attribs as $attribute => $value ) {
+ if ( $attribute !== strtolower( $attribute ) && array_key_exists( strtolower( $attribute ), $presentationalAttribs ) ) {
+ $attribs[strtolower( $attribute )] = $value;
+ unset( $attribs[$attribute] );
+ }
+ }
+
+ $style = "";
+ foreach ( $presentationalAttribs as $attribute => $info ) {
+ list( $property, $elements ) = $info;
+
+ // Skip if this attribute is not relevant to this element
+ if ( !in_array( $element, $elements ) ) {
+ continue;
+ }
+
+ // Skip if the attribute is not used
+ if ( !array_key_exists( $attribute, $attribs ) ) {
+ continue;
+ }
+
+ $value = $attribs[$attribute];
+
+ // For nowrap the value should be nowrap instead of whatever text is in the value
+ if ( $attribute === 'nowrap' ) {
+ $value = 'nowrap';
+ }
+
+ // clear="all" is clear: both; in css
+ if ( $attribute === 'clear' && strtolower( $value ) === 'all' ) {
+ $value = 'both';
+ }
+
+ // Size based properties should have px applied to them if they have no unit
+ if ( in_array( $attribute, array( 'height', 'width', 'size' ) ) ) {
+ if ( preg_match( '/^[\d.]+$/', $value ) ) {
+ $value = "{$value}px";
+ }
+ }
+
+ $style .= " $property: $value;";
+
+ unset( $attribs[$attribute] );
+ }
+
+ if ( $style ) {
+ // Prepend our style rules so that they can be overridden by user css
+ if ( isset($attribs['style']) ) {
+ $style .= " " . $attribs['style'];
+ }
+ $attribs['style'] = trim($style);
+ }
+
+ return $attribs;
+ }
+
/**
* Take an array of attribute names and values and normalize or discard
* illegal values for the given element type.
}
//RDFa and microdata properties allow URLs, URIs and/or CURIs. check them for sanity
- if ( $attribute === 'rel' || $attribute === 'rev' ||
+ if ( $attribute === 'rel' || $attribute === 'rev' ||
$attribute === 'about' || $attribute === 'property' || $attribute === 'resource' || #RDFa
$attribute === 'datatype' || $attribute === 'typeof' || #RDFa
$attribute === 'itemid' || $attribute === 'itemprop' || $attribute === 'itemref' || #HTML5 microdata
//Paranoia. Allow "simple" values but suppress javascript
if ( preg_match( self::EVIL_URI_PATTERN, $value ) ) {
- continue;
+ continue;
}
}
/**
* Pick apart some CSS and check it for forbidden or unsafe structures.
- * Returns a sanitized string, or false if it was just too evil.
+ * Returns a sanitized string. This sanitized string will have
+ * character references and escape sequences decoded, and comments
+ * stripped. If the input is just too evil, only a comment complaining
+ * about evilness will be returned.
*
* Currently URL references, 'expression', 'tps' are forbidden.
*
+ * NOTE: Despite the fact that character references are decoded, the
+ * returned string may contain character references given certain
+ * clever input strings. These character references must
+ * be escaped before the return value is embedded in HTML.
+ *
* @param $value String
- * @return Mixed
+ * @return String
*/
static function checkCss( $value ) {
+ // Decode character references like {
$value = Sanitizer::decodeCharReferences( $value );
- // Remove any comments; IE gets token splitting wrong
- $value = StringUtils::delimiterReplace( '/*', '*/', ' ', $value );
-
- // Remove anything after a comment-start token, to guard against
- // incorrect client implementations.
- $commentPos = strpos( $value, '/*' );
- if ( $commentPos !== false ) {
- $value = substr( $value, 0, $commentPos );
- }
-
// Decode escape sequences and line continuation
// See the grammar in the CSS 2 spec, appendix D.
+ // This has to be done AFTER decoding character references.
+ // This means it isn't possible for this function to return
+ // unsanitized escape sequences. It is possible to manufacture
+ // input that contains character references that decode to
+ // escape sequences that decode to character references, but
+ // it's OK for the return value to contain character references
+ // because the caller is supposed to escape those anyway.
static $decodeRegex;
if ( !$decodeRegex ) {
$space = '[\\x20\\t\\r\\n\\f]';
$nl = '(?:\\n|\\r\\n|\\r|\\f)';
$backslash = '\\\\';
- $decodeRegex = "/ $backslash
+ $decodeRegex = "/ $backslash
(?:
($nl) | # 1. Line continuation
([0-9A-Fa-f]{1,6})$space? | # 2. character number
$value = preg_replace_callback( $decodeRegex,
array( __CLASS__, 'cssDecodeCallback' ), $value );
+ // Remove any comments; IE gets token splitting wrong
+ // This must be done AFTER decoding character references and
+ // escape sequences, because those steps can introduce comments
+ // This step cannot introduce character references or escape
+ // sequences, because it replaces comments with spaces rather
+ // than removing them completely.
+ $value = StringUtils::delimiterReplace( '/*', '*/', ' ', $value );
+
+ // Remove anything after a comment-start token, to guard against
+ // incorrect client implementations.
+ $commentPos = strpos( $value, '/*' );
+ if ( $commentPos !== false ) {
+ $value = substr( $value, 0, $commentPos );
+ }
+
// Reject problematic keywords and control characters
if ( preg_match( '/[\000-\010\016-\037\177]/', $value ) ) {
return '/* invalid control char */';
return $value;
}
+ /**
+ * @param $matches array
+ * @return String
+ */
static function cssDecodeCallback( $matches ) {
if ( $matches[1] !== '' ) {
// Line continuation
return '';
}
- $stripped = Sanitizer::validateTagAttributes(
- Sanitizer::decodeTagAttributes( $text ), $element );
+ $decoded = Sanitizer::decodeTagAttributes( $text );
+ $decoded = Sanitizer::fixDeprecatedAttributes( $decoded, $element );
+ $stripped = Sanitizer::validateTagAttributes( $decoded, $element );
$attribs = array();
foreach( $stripped as $attribute => $value ) {
Sanitizer::normalizeCharReferences( $text ) ) );
}
+ /**
+ * @param $text string
+ * @return mixed
+ */
private static function normalizeWhitespace( $text ) {
return preg_replace(
'/\r\n|[\x20\x0d\x0a\x09]/',
}
}
+ /**
+ * @param $codepoint
+ * @return null|string
+ */
static function decCharReference( $codepoint ) {
$point = intval( $codepoint );
if( Sanitizer::validateCodepoint( $point ) ) {
}
}
+ /**
+ * @param $codepoint
+ * @return null|string
+ */
static function hexCharReference( $codepoint ) {
$point = hexdec( $codepoint );
if( Sanitizer::validateCodepoint( $point ) ) {
* return the UTF-8 encoding of that character. Otherwise, returns
* pseudo-entity source (eg &foo;)
*
- * @param $name Strings
+ * @param $name String
* @return String
*/
static function decodeEntity( $name ) {
if ( $wgAllowRdfaAttributes ) {
#RDFa attributes as specified in section 9 of http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014
$common = array_merge( $common, array(
- 'about', 'property', 'resource', 'datatype', 'typeof',
+ 'about', 'property', 'resource', 'datatype', 'typeof',
) );
}
'th' => array_merge( $common, $tablecell, $tablealign ),
# 12.2 # NOTE: <a> is not allowed directly, but the attrib whitelist is used from the Parser object
- 'a' => array_merge( $common, array( 'href', 'rel', 'rev' ) ), # rel/rev esp. for RDFa
+ 'a' => array_merge( $common, array( 'href', 'rel', 'rev' ) ), # rel/rev esp. for RDFa
# 13.2
# Not usually allowed, but may be used for extension-style hooks
return $out;
}
+ /**
+ * @param $url string
+ * @return mixed|string
+ */
static function cleanUrl( $url ) {
# 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_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
+ $url = preg_replace_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
array( __CLASS__, 'cleanUrlCallback' ), $url );
# Validate hostname portion
\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
+ [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe0f VARIATION SELECTOR-1-16
/xuD";
$host = preg_replace( $strip, '', $host );
- // @todo Fixme: validate hostnames here
+ // @todo FIXME: Validate hostnames here
return $protocol . $host . $rest;
} else {
}
}
+ /**
+ * @param $matches array
+ * @return string
+ */
static function cleanUrlCallback( $matches ) {
return urlencode( $matches[0] );
}
+
+ /**
+ * Does a string look like an e-mail address?
+ *
+ * This validates an email address using an HTML5 specification found at:
+ * http://www.whatwg.org/specs/web-apps/current-work/multipage/states-of-the-type-attribute.html#valid-e-mail-address
+ * Which as of 2011-01-24 says:
+ *
+ * A valid e-mail address is a string that matches the ABNF production
+ * 1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
+ * in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
+ * 3.5.
+ *
+ * This function is an implementation of the specification as requested in
+ * bug 22449.
+ *
+ * Client-side forms will use the same standard validation rules via JS or
+ * HTML 5 validation; additional restrictions can be enforced server-side
+ * by extensions via the 'isValidEmailAddr' hook.
+ *
+ * Note that this validation doesn't 100% match RFC 2822, but is believed
+ * to be liberal enough for wide use. Some invalid addresses will still
+ * pass validation here.
+ *
+ * @since 1.18
+ *
+ * @param $addr String E-mail address
+ * @return Bool
+ */
+ public static function validateEmail( $addr ) {
+ $result = null;
+ if( !wfRunHooks( 'isValidEmailAddr', array( $addr, &$result ) ) ) {
+ return $result;
+ }
+
+ // Please note strings below are enclosed in brackets [], this make the
+ // hyphen "-" a range indicator. Hence it is double backslashed below.
+ // See bug 26948
+ $rfc5322_atext = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~" ;
+ $rfc1034_ldh_str = "a-z0-9\\-" ;
+
+ $HTML5_email_regexp = "/
+ ^ # start of string
+ [$rfc5322_atext\\.]+ # user part which is liberal :p
+ @ # 'apostrophe'
+ [$rfc1034_ldh_str]+ # First domain part
+ (\\.[$rfc1034_ldh_str]+)* # Following part prefixed with a dot
+ $ # End of string
+ /ix" ; // case Insensitive, eXtended
+
+ return (bool) preg_match( $HTML5_email_regexp, $addr );
+ }
}