mirror of
https://github.com/ezyang/htmlpurifier.git
synced 2024-12-22 08:21:52 +00:00
286 lines
9.8 KiB
PHP
286 lines
9.8 KiB
PHP
<?php
|
|
|
|
// if want to implement error collecting here, we'll need to use some sort
|
|
// of global data (probably trigger_error) because it's impossible to pass
|
|
// $config or $context to the callback functions.
|
|
|
|
/**
|
|
* Handles referencing and derefencing character entities
|
|
*/
|
|
class HTMLPurifier_EntityParser
|
|
{
|
|
|
|
/**
|
|
* Reference to entity lookup table.
|
|
* @type HTMLPurifier_EntityLookup
|
|
*/
|
|
protected $_entity_lookup;
|
|
|
|
/**
|
|
* Callback regex string for entities in text.
|
|
* @type string
|
|
*/
|
|
protected $_textEntitiesRegex;
|
|
|
|
/**
|
|
* Callback regex string for entities in attributes.
|
|
* @type string
|
|
*/
|
|
protected $_attrEntitiesRegex;
|
|
|
|
/**
|
|
* Tests if the beginning of a string is a semi-optional regex
|
|
*/
|
|
protected $_semiOptionalPrefixRegex;
|
|
|
|
public function __construct() {
|
|
// From
|
|
// http://stackoverflow.com/questions/15532252/why-is-reg-being-rendered-as-without-the-bounding-semicolon
|
|
$semi_optional = "quot|QUOT|lt|LT|gt|GT|amp|AMP|AElig|Aacute|Acirc|Agrave|Aring|Atilde|Auml|COPY|Ccedil|ETH|Eacute|Ecirc|Egrave|Euml|Iacute|Icirc|Igrave|Iuml|Ntilde|Oacute|Ocirc|Ograve|Oslash|Otilde|Ouml|REG|THORN|Uacute|Ucirc|Ugrave|Uuml|Yacute|aacute|acirc|acute|aelig|agrave|aring|atilde|auml|brvbar|ccedil|cedil|cent|copy|curren|deg|divide|eacute|ecirc|egrave|eth|euml|frac12|frac14|frac34|iacute|icirc|iexcl|igrave|iquest|iuml|laquo|macr|micro|middot|nbsp|not|ntilde|oacute|ocirc|ograve|ordf|ordm|oslash|otilde|ouml|para|plusmn|pound|raquo|reg|sect|shy|sup1|sup2|sup3|szlig|thorn|times|uacute|ucirc|ugrave|uml|uuml|yacute|yen|yuml";
|
|
|
|
// NB: three empty captures to put the fourth match in the right
|
|
// place
|
|
$this->_semiOptionalPrefixRegex = "/&()()()($semi_optional)/";
|
|
|
|
$this->_textEntitiesRegex =
|
|
'/&(?:'.
|
|
// hex
|
|
'[#]x([a-fA-F0-9]+);?|'.
|
|
// dec
|
|
'[#]0*(\d+);?|'.
|
|
// string (mandatory semicolon)
|
|
// NB: order matters: match semicolon preferentially
|
|
'([A-Za-z_:][A-Za-z0-9.\-_:]*);|'.
|
|
// string (optional semicolon)
|
|
"($semi_optional)".
|
|
')/';
|
|
|
|
$this->_attrEntitiesRegex =
|
|
'/&(?:'.
|
|
// hex
|
|
'[#]x([a-fA-F0-9]+);?|'.
|
|
// dec
|
|
'[#]0*(\d+);?|'.
|
|
// string (mandatory semicolon)
|
|
// NB: order matters: match semicolon preferentially
|
|
'([A-Za-z_:][A-Za-z0-9.\-_:]*);|'.
|
|
// string (optional semicolon)
|
|
// don't match if trailing is equals or alphanumeric (URL
|
|
// like)
|
|
"($semi_optional)(?![=;A-Za-z0-9])".
|
|
')/';
|
|
|
|
}
|
|
|
|
/**
|
|
* Substitute entities with the parsed equivalents. Use this on
|
|
* textual data in an HTML document (as opposed to attributes.)
|
|
*
|
|
* @param string $string String to have entities parsed.
|
|
* @return string Parsed string.
|
|
*/
|
|
public function substituteTextEntities($string)
|
|
{
|
|
return preg_replace_callback(
|
|
$this->_textEntitiesRegex,
|
|
array($this, 'entityCallback'),
|
|
$string
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Substitute entities with the parsed equivalents. Use this on
|
|
* attribute contents in documents.
|
|
*
|
|
* @param string $string String to have entities parsed.
|
|
* @return string Parsed string.
|
|
*/
|
|
public function substituteAttrEntities($string)
|
|
{
|
|
return preg_replace_callback(
|
|
$this->_attrEntitiesRegex,
|
|
array($this, 'entityCallback'),
|
|
$string
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Callback function for substituteNonSpecialEntities() that does the work.
|
|
*
|
|
* @param array $matches PCRE matches array, with 0 the entire match, and
|
|
* either index 1, 2 or 3 set with a hex value, dec value,
|
|
* or string (respectively).
|
|
* @return string Replacement string.
|
|
*/
|
|
|
|
protected function entityCallback($matches)
|
|
{
|
|
$entity = $matches[0];
|
|
$hex_part = isset($matches[1]) ? $matches[1] : null;
|
|
$dec_part = isset($matches[2]) ? $matches[2] : null;
|
|
$named_part = empty($matches[3]) ? (empty($matches[4]) ? "" : $matches[4]) : $matches[3];
|
|
if ($hex_part !== NULL && $hex_part !== "") {
|
|
return HTMLPurifier_Encoder::unichr(hexdec($hex_part));
|
|
} elseif ($dec_part !== NULL && $dec_part !== "") {
|
|
return HTMLPurifier_Encoder::unichr((int) $dec_part);
|
|
} else {
|
|
if (!$this->_entity_lookup) {
|
|
$this->_entity_lookup = HTMLPurifier_EntityLookup::instance();
|
|
}
|
|
if (isset($this->_entity_lookup->table[$named_part])) {
|
|
return $this->_entity_lookup->table[$named_part];
|
|
} else {
|
|
// exact match didn't match anything, so test if
|
|
// any of the semicolon optional match the prefix.
|
|
// Test that this is an EXACT match is important to
|
|
// prevent infinite loop
|
|
if (!empty($matches[3])) {
|
|
return preg_replace_callback(
|
|
$this->_semiOptionalPrefixRegex,
|
|
array($this, 'entityCallback'),
|
|
$entity
|
|
);
|
|
}
|
|
return $entity;
|
|
}
|
|
}
|
|
}
|
|
|
|
// LEGACY CODE BELOW
|
|
|
|
/**
|
|
* Callback regex string for parsing entities.
|
|
* @type string
|
|
*/
|
|
protected $_substituteEntitiesRegex =
|
|
'/&(?:[#]x([a-fA-F0-9]+)|[#]0*(\d+)|([A-Za-z_:][A-Za-z0-9.\-_:]*));?/';
|
|
// 1. hex 2. dec 3. string (XML style)
|
|
|
|
/**
|
|
* Decimal to parsed string conversion table for special entities.
|
|
* @type array
|
|
*/
|
|
protected $_special_dec2str =
|
|
array(
|
|
34 => '"',
|
|
38 => '&',
|
|
39 => "'",
|
|
60 => '<',
|
|
62 => '>'
|
|
);
|
|
|
|
/**
|
|
* Stripped entity names to decimal conversion table for special entities.
|
|
* @type array
|
|
*/
|
|
protected $_special_ent2dec =
|
|
array(
|
|
'quot' => 34,
|
|
'amp' => 38,
|
|
'lt' => 60,
|
|
'gt' => 62
|
|
);
|
|
|
|
/**
|
|
* Substitutes non-special entities with their parsed equivalents. Since
|
|
* running this whenever you have parsed character is t3h 5uck, we run
|
|
* it before everything else.
|
|
*
|
|
* @param string $string String to have non-special entities parsed.
|
|
* @return string Parsed string.
|
|
*/
|
|
public function substituteNonSpecialEntities($string)
|
|
{
|
|
// it will try to detect missing semicolons, but don't rely on it
|
|
return preg_replace_callback(
|
|
$this->_substituteEntitiesRegex,
|
|
array($this, 'nonSpecialEntityCallback'),
|
|
$string
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Callback function for substituteNonSpecialEntities() that does the work.
|
|
*
|
|
* @param array $matches PCRE matches array, with 0 the entire match, and
|
|
* either index 1, 2 or 3 set with a hex value, dec value,
|
|
* or string (respectively).
|
|
* @return string Replacement string.
|
|
*/
|
|
|
|
protected function nonSpecialEntityCallback($matches)
|
|
{
|
|
// replaces all but big five
|
|
$entity = $matches[0];
|
|
$is_num = (@$matches[0][1] === '#');
|
|
if ($is_num) {
|
|
$is_hex = (@$entity[2] === 'x');
|
|
$code = $is_hex ? hexdec($matches[1]) : (int) $matches[2];
|
|
// abort for special characters
|
|
if (isset($this->_special_dec2str[$code])) {
|
|
return $entity;
|
|
}
|
|
return HTMLPurifier_Encoder::unichr($code);
|
|
} else {
|
|
if (isset($this->_special_ent2dec[$matches[3]])) {
|
|
return $entity;
|
|
}
|
|
if (!$this->_entity_lookup) {
|
|
$this->_entity_lookup = HTMLPurifier_EntityLookup::instance();
|
|
}
|
|
if (isset($this->_entity_lookup->table[$matches[3]])) {
|
|
return $this->_entity_lookup->table[$matches[3]];
|
|
} else {
|
|
return $entity;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Substitutes only special entities with their parsed equivalents.
|
|
*
|
|
* @notice We try to avoid calling this function because otherwise, it
|
|
* would have to be called a lot (for every parsed section).
|
|
*
|
|
* @param string $string String to have non-special entities parsed.
|
|
* @return string Parsed string.
|
|
*/
|
|
public function substituteSpecialEntities($string)
|
|
{
|
|
return preg_replace_callback(
|
|
$this->_substituteEntitiesRegex,
|
|
array($this, 'specialEntityCallback'),
|
|
$string
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Callback function for substituteSpecialEntities() that does the work.
|
|
*
|
|
* This callback has same syntax as nonSpecialEntityCallback().
|
|
*
|
|
* @param array $matches PCRE-style matches array, with 0 the entire match, and
|
|
* either index 1, 2 or 3 set with a hex value, dec value,
|
|
* or string (respectively).
|
|
* @return string Replacement string.
|
|
*/
|
|
protected function specialEntityCallback($matches)
|
|
{
|
|
$entity = $matches[0];
|
|
$is_num = (@$matches[0][1] === '#');
|
|
if ($is_num) {
|
|
$is_hex = (@$entity[2] === 'x');
|
|
$int = $is_hex ? hexdec($matches[1]) : (int) $matches[2];
|
|
return isset($this->_special_dec2str[$int]) ?
|
|
$this->_special_dec2str[$int] :
|
|
$entity;
|
|
} else {
|
|
return isset($this->_special_ent2dec[$matches[3]]) ?
|
|
$this->_special_dec2str[$this->_special_ent2dec[$matches[3]]] :
|
|
$entity;
|
|
}
|
|
}
|
|
}
|
|
|
|
// vim: et sw=4 sts=4
|