Shortcodes: Improve the reliablity of shortcodes inside HTML tags.

Merge of [33359] to the 4.2 branch.

Props miqrogroove.

See #15694.


Built from https://develop.svn.wordpress.org/branches/4.2@33360


git-svn-id: http://core.svn.wordpress.org/branches/4.2@33332 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
Gary Pendergast 2015-07-22 05:44:27 +00:00
parent fe2d10ea5c
commit 4cd2612edc
8 changed files with 472 additions and 45 deletions

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@ -846,6 +846,7 @@ input[type="search"].categories-search,
border-bottom: 1px solid #e5e5e5;
font-size: 14px;
-webkit-appearance: none;
-moz-appearance: none;
appearance: none;
}

File diff suppressed because one or more lines are too long

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@ -846,6 +846,7 @@ input[type="search"].categories-search,
border-bottom: 1px solid #e5e5e5;
font-size: 14px;
-webkit-appearance: none;
-moz-appearance: none;
appearance: none;
}

File diff suppressed because one or more lines are too long

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@ -57,7 +57,7 @@ class WP_Embed {
add_shortcode( 'embed', array( $this, 'shortcode' ) );
// Do the shortcode (only the [embed] one is registered)
$content = do_shortcode( $content );
$content = do_shortcode( $content, true );
// Put the original shortcodes back
$shortcode_tags = $orig_shortcode_tags;
@ -312,6 +312,10 @@ class WP_Embed {
* @return string Potentially modified $content.
*/
public function autoembed( $content ) {
// Strip newlines from all elements.
$content = wp_replace_in_html_tags( $content, array( "\n" => " " ) );
// Find URLs that are on their own line.
return preg_replace_callback( '|^(\s*)(https?://[^\s"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
}

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@ -421,6 +421,9 @@ function wpautop($pee, $br = true) {
// Standardize newline characters to "\n".
$pee = str_replace(array("\r\n", "\r"), "\n", $pee);
// Strip newlines from all elements.
$pee = wp_replace_in_html_tags( $pee, array( "\n" => " " ) );
// Collapse line breaks before and after <option> elements so they don't get autop'd.
if ( strpos( $pee, '<option' ) !== false ) {
$pee = preg_replace( '|\s*<option|', '<option', $pee );
@ -509,6 +512,74 @@ function wpautop($pee, $br = true) {
return $pee;
}
/**
* Replace characters or phrases within HTML elements only.
*
* @since 4.2.3
*
* @param string $haystack The text which has to be formatted.
* @param array $replace_pairs In the form array('from' => 'to', ...).
* @return string The formatted text.
*/
function wp_replace_in_html_tags( $haystack, $replace_pairs ) {
// Find all elements.
$comments =
'!' // Start of comment, after the <.
. '(?:' // Unroll the loop: Consume everything until --> is found.
. '-(?!->)' // Dash not followed by end of comment.
. '[^\-]*+' // Consume non-dashes.
. ')*+' // Loop possessively.
. '(?:-->)?'; // End of comment. If not found, match all input.
$regex =
'/(' // Capture the entire match.
. '<' // Find start of element.
. '(?(?=!--)' // Is this a comment?
. $comments // Find end of comment.
. '|'
. '[^>]*>?' // Find end of element. If not found, match all input.
. ')'
. ')/s';
$textarr = preg_split( $regex, $haystack, -1, PREG_SPLIT_DELIM_CAPTURE );
$changed = false;
// Optimize when searching for one item.
if ( 1 === count( $replace_pairs ) ) {
// Extract $needle and $replace.
foreach ( $replace_pairs as $needle => $replace );
// Loop through delimeters (elements) only.
for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {
if ( false !== strpos( $textarr[$i], $needle ) ) {
$textarr[$i] = str_replace( $needle, $replace, $textarr[$i] );
$changed = true;
}
}
} else {
// Extract all $needles.
$needles = array_keys( $replace_pairs );
// Loop through delimeters (elements) only.
for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {
foreach ( $needles as $needle ) {
if ( false !== strpos( $textarr[$i], $needle ) ) {
$textarr[$i] = strtr( $textarr[$i], $replace_pairs );
$changed = true;
// After one strtr() break out of the foreach loop and look at next element.
break;
}
}
}
}
if ( $changed ) {
$haystack = implode( $textarr );
}
return $haystack;
}
/**
* Newline preservation help function for wpautop
*

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@ -528,6 +528,82 @@ function wp_kses( $string, $allowed_html, $allowed_protocols = array() ) {
return wp_kses_split($string, $allowed_html, $allowed_protocols);
}
/**
* Filters one attribute only and ensures its value is allowed.
*
* This function has the advantage of being more secure than esc_attr() and can
* escape data in some situations where wp_kses() must strip the whole attribute.
*
* @since 4.2.3
*
* @param string $string The 'whole' attribute, including name and value.
* @param string $element The element name to which the attribute belongs.
* @return string Filtered attribute.
*/
function wp_kses_one_attr( $string, $element ) {
$uris = array('xmlns', 'profile', 'href', 'src', 'cite', 'classid', 'codebase', 'data', 'usemap', 'longdesc', 'action');
$allowed_html = wp_kses_allowed_html( 'post' );
$allowed_protocols = wp_allowed_protocols();
$string = wp_kses_no_null( $string, array( 'slash_zero' => 'keep' ) );
$string = wp_kses_js_entities( $string );
$string = wp_kses_normalize_entities( $string );
// Preserve leading and trailing whitespace.
$matches = array();
preg_match('/^\s*/', $string, $matches);
$lead = $matches[0];
preg_match('/\s*$/', $string, $matches);
$trail = $matches[0];
if ( empty( $trail ) ) {
$string = substr( $string, strlen( $lead ) );
} else {
$string = substr( $string, strlen( $lead ), -strlen( $trail ) );
}
// Parse attribute name and value from input.
$split = preg_split( '/\s*=\s*/', $string, 2 );
$name = $split[0];
if ( count( $split ) == 2 ) {
$value = $split[1];
// Remove quotes surrounding $value.
// Also guarantee correct quoting in $string for this one attribute.
if ( '' == $value ) {
$quote = '';
} else {
$quote = $value[0];
}
if ( '"' == $quote || "'" == $quote ) {
if ( substr( $value, -1 ) != $quote ) {
return '';
}
$value = substr( $value, 1, -1 );
} else {
$quote = '"';
}
// Sanitize quotes and angle braces.
$value = htmlspecialchars( $value, ENT_QUOTES, null, false );
// Sanitize URI values.
if ( in_array( strtolower( $name ), $uris ) ) {
$value = wp_kses_bad_protocol( $value, $allowed_protocols );
}
$string = "$name=$quote$value$quote";
$vless = 'n';
} else {
$value = '';
$vless = 'y';
}
// Sanitize attribute by name.
wp_kses_attr_check( $name, $value, $string, $vless, $element, $allowed_html );
// Restore whitespace.
return $lead . $string . $trail;
}
/**
* Return a list of allowed tags and attributes for a given context.
*
@ -748,45 +824,11 @@ function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
// Go through $attrarr, and save the allowed attributes for this element
// in $attr2
$attr2 = '';
$allowed_attr = $allowed_html[strtolower($element)];
foreach ($attrarr as $arreach) {
if ( ! isset( $allowed_attr[strtolower($arreach['name'])] ) )
continue; // the attribute is not allowed
$current = $allowed_attr[strtolower($arreach['name'])];
if ( $current == '' )
continue; // the attribute is not allowed
if ( strtolower( $arreach['name'] ) == 'style' ) {
$orig_value = $arreach['value'];
$value = safecss_filter_attr( $orig_value );
if ( empty( $value ) )
continue;
$arreach['value'] = $value;
$arreach['whole'] = str_replace( $orig_value, $value, $arreach['whole'] );
}
if ( ! is_array($current) ) {
foreach ( $attrarr as $arreach ) {
if ( wp_kses_attr_check( $arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html ) ) {
$attr2 .= ' '.$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('/[<>]/', '', $attr2);
@ -794,6 +836,53 @@ function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
return "<$element$attr2$xhtml_slash>";
}
/**
* Determine whether an attribute is allowed.
*
* @since 4.2.3
*
* @param string $name The attribute name. Returns empty string when not allowed.
* @param string $value The attribute value. Returns a filtered value.
* @param string $whole The name=value input. Returns filtered input.
* @param string $vless 'y' when attribute like "enabled", otherwise 'n'.
* @param string $element The name of the element to which this attribute belongs.
* @param array $allowed_html The full list of allowed elements and attributes.
* @return bool Is the attribute allowed?
*/
function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowed_html ) {
$allowed_attr = $allowed_html[strtolower( $element )];
$name_low = strtolower( $name );
if ( ! isset( $allowed_attr[$name_low] ) || '' == $allowed_attr[$name_low] ) {
$name = $value = $whole = '';
return false;
}
if ( 'style' == $name_low ) {
$new_value = safecss_filter_attr( $value );
if ( empty( $new_value ) ) {
$name = $value = $whole = '';
return false;
}
$whole = str_replace( $value, $new_value, $whole );
$value = $new_value;
}
if ( is_array( $allowed_attr[$name_low] ) ) {
// there are some checks
foreach ( $allowed_attr[$name_low] as $currkey => $currval ) {
if ( ! wp_kses_check_attr_val( $value, $vless, $currkey, $currval ) ) {
$name = $value = $whole = '';
return false;
}
}
}
return true;
}
/**
* Builds an attribute list from string containing attributes.
*
@ -923,6 +1012,109 @@ function wp_kses_hair($attr, $allowed_protocols) {
return $attrarr;
}
/**
* Finds all attributes of an HTML element.
*
* Does not modify input. May return "evil" output.
*
* Based on wp_kses_split2() and wp_kses_attr()
*
* @since 4.2.3
*
* @param string $element HTML element/tag
* @return array|bool List of attributes found in $element. Returns false on failure.
*/
function wp_kses_attr_parse( $element ) {
$valid = preg_match('%^(<\s*)(/\s*)?([a-zA-Z0-9]+\s*)([^>]*)(>?)$%', $element, $matches);
if ( 1 !== $valid ) {
return false;
}
$begin = $matches[1];
$slash = $matches[2];
$elname = $matches[3];
$attr = $matches[4];
$end = $matches[5];
if ( '' !== $slash ) {
// Closing elements do not get parsed.
return false;
}
// Is there a closing XHTML slash at the end of the attributes?
if ( 1 === preg_match( '%\s*/\s*$%', $attr, $matches ) ) {
$xhtml_slash = $matches[0];
$attr = substr( $attr, 0, -strlen( $xhtml_slash ) );
} else {
$xhtml_slash = '';
}
// Split it
$attrarr = wp_kses_hair_parse( $attr );
if ( false === $attrarr ) {
return false;
}
// Make sure all input is returned by adding front and back matter.
array_unshift( $attrarr, $begin . $slash . $elname );
array_push( $attrarr, $xhtml_slash . $end );
return $attrarr;
}
/**
* Builds an attribute list from string containing attributes.
*
* Does not modify input. May return "evil" output.
* In case of unexpected input, returns false instead of stripping things.
*
* Based on wp_kses_hair() but does not return a multi-dimensional array.
*
* @since 4.2.3
*
* @param string $attr Attribute list from HTML element to closing HTML element tag
* @return array|bool List of attributes found in $attr. Returns false on failure.
*/
function wp_kses_hair_parse( $attr ) {
if ( '' === $attr ) {
return array();
}
$regex =
'(?:'
. '[-a-zA-Z:]+' // Attribute name.
. '|'
. '\[\[?[^\[\]]+\]\]?' // Shortcode in the name position implies unfiltered_html.
. ')'
. '(?:' // Attribute value.
. '\s*=\s*' // All values begin with '='
. '(?:'
. '"[^"]*"' // Double-quoted
. '|'
. "'[^']*'" // Single-quoted
. '|'
. '[^\s"\']+' // Non-quoted
. '(?:\s|$)' // Must have a space
. ')'
. '|'
. '(?:\s|$)' // If attribute has no value, space is required.
. ')'
. '\s*'; // Trailing space is optional except as mentioned above.
// Although it is possible to reduce this procedure to a single regexp,
// we must run that regexp twice to get exactly the expected result.
$validation = "%^($regex)+$%";
$extraction = "%$regex%";
if ( 1 === preg_match( $validation, $attr ) ) {
preg_match_all( $extraction, $attr, $attrarr );
return $attrarr[0];
} else {
return false;
}
}
/**
* Performs different checks for attribute values.
*

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@ -184,9 +184,10 @@ function has_shortcode( $content, $tag ) {
* @global array $shortcode_tags List of shortcode tags and their callback hooks.
*
* @param string $content Content to search for shortcodes.
* @param bool $ignore_html When true, shortcodes inside HTML elements will be skipped.
* @return string Content with shortcodes filtered out.
*/
function do_shortcode($content) {
function do_shortcode( $content, $ignore_html = false ) {
global $shortcode_tags;
if ( false === strpos( $content, '[' ) ) {
@ -196,8 +197,24 @@ function do_shortcode($content) {
if (empty($shortcode_tags) || !is_array($shortcode_tags))
return $content;
$tagnames = array_keys($shortcode_tags);
$tagregexp = join( '|', array_map('preg_quote', $tagnames) );
$pattern = "/\\[($tagregexp)/s";
if ( 1 !== preg_match( $pattern, $content ) ) {
// Avoids parsing HTML when there are no shortcodes or embeds anyway.
return $content;
}
$content = do_shortcodes_in_html_tags( $content, $ignore_html );
$pattern = get_shortcode_regex();
return preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
$content = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
// Always restore square braces so we don't break things like <!--[if IE ]>
$content = unescape_invalid_shortcodes( $content );
return $content;
}
/**
@ -290,6 +307,141 @@ function do_shortcode_tag( $m ) {
}
}
/**
* Search only inside HTML elements for shortcodes and process them.
*
* Any [ or ] characters remaining inside elements will be HTML encoded
* to prevent interference with shortcodes that are outside the elements.
* Assumes $content processed by KSES already. Users with unfiltered_html
* capability may get unexpected output if angle braces are nested in tags.
*
* @since 4.2.3
*
* @param string $content Content to search for shortcodes
* @param bool $ignore_html When true, all square braces inside elements will be encoded.
* @return string Content with shortcodes filtered out.
*/
function do_shortcodes_in_html_tags( $content, $ignore_html ) {
// Normalize entities in unfiltered HTML before adding placeholders.
$trans = array( '&#91;' => '&#091;', '&#93;' => '&#093;' );
$content = strtr( $content, $trans );
$trans = array( '[' => '&#91;', ']' => '&#93;' );
$pattern = get_shortcode_regex();
$comment_regex =
'!' // Start of comment, after the <.
. '(?:' // Unroll the loop: Consume everything until --> is found.
. '-(?!->)' // Dash not followed by end of comment.
. '[^\-]*+' // Consume non-dashes.
. ')*+' // Loop possessively.
. '(?:-->)?'; // End of comment. If not found, match all input.
$regex =
'/(' // Capture the entire match.
. '<' // Find start of element.
. '(?(?=!--)' // Is this a comment?
. $comment_regex // Find end of comment.
. '|'
. '[^>]*>?' // Find end of element. If not found, match all input.
. ')'
. ')/s';
$textarr = preg_split( $regex, $content, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
foreach ( $textarr as &$element ) {
if ( '<' !== $element[0] ) {
continue;
}
$noopen = false === strpos( $element, '[' );
$noclose = false === strpos( $element, ']' );
if ( $noopen || $noclose ) {
// This element does not contain shortcodes.
if ( $noopen xor $noclose ) {
// Need to encode stray [ or ] chars.
$element = strtr( $element, $trans );
}
continue;
}
if ( $ignore_html || '<!--' === substr( $element, 0, 4 ) ) {
// Encode all [ and ] chars.
$element = strtr( $element, $trans );
continue;
}
$attributes = wp_kses_attr_parse( $element );
if ( false === $attributes ) {
// Looks like we found some crazy unfiltered HTML. Skipping it for sanity.
$element = strtr( $element, $trans );
continue;
}
// Get element name
$front = array_shift( $attributes );
$back = array_pop( $attributes );
$matches = array();
preg_match('%[a-zA-Z0-9]+%', $front, $matches);
$elname = $matches[0];
// Look for shortcodes in each attribute separately.
foreach ( $attributes as &$attr ) {
$open = strpos( $attr, '[' );
$close = strpos( $attr, ']' );
if ( false === $open || false === $close ) {
continue; // Go to next attribute. Square braces will be escaped at end of loop.
}
$double = strpos( $attr, '"' );
$single = strpos( $attr, "'" );
if ( ( false === $single || $open < $single ) && ( false === $double || $open < $double ) ) {
// $attr like '[shortcode]' or 'name = [shortcode]' implies unfiltered_html.
// In this specific situation we assume KSES did not run because the input
// was written by an administrator, so we should avoid changing the output
// and we do not need to run KSES here.
$attr = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $attr );
} else {
// $attr like 'name = "[shortcode]"' or "name = '[shortcode]'"
// We do not know if $content was unfiltered. Assume KSES ran before shortcodes.
$count = 0;
$new_attr = preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $attr, -1, $count );
if ( $count > 0 ) {
// Sanitize the shortcode output using KSES.
$new_attr = wp_kses_one_attr( $new_attr, $elname );
if ( '' !== $new_attr ) {
// The shortcode is safe to use now.
$attr = $new_attr;
}
}
}
}
$element = $front . implode( '', $attributes ) . $back;
// Now encode any remaining [ or ] chars.
$element = strtr( $element, $trans );
}
$content = implode( '', $textarr );
return $content;
}
/**
* Remove placeholders added by do_shortcodes_in_html_tags().
*
* @since 4.2.3
*
* @param string $content Content to search for placeholders.
* @return string Content with placeholders removed.
*/
function unescape_invalid_shortcodes( $content ) {
// Clean up entire string, avoids re-parsing HTML.
$trans = array( '&#91;' => '[', '&#93;' => ']' );
$content = strtr( $content, $trans );
return $content;
}
/**
* Retrieve all attributes from the shortcodes tag.
*
@ -389,9 +541,15 @@ function strip_shortcodes( $content ) {
if (empty($shortcode_tags) || !is_array($shortcode_tags))
return $content;
$pattern = get_shortcode_regex();
$content = do_shortcodes_in_html_tags( $content, true );
return preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
$pattern = get_shortcode_regex();
$content = preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
// Always restore square braces so we don't break things like <!--[if IE ]>
$content = unescape_invalid_shortcodes( $content );
return $content;
}
function strip_shortcode_tag( $m ) {