egroupware/phpgwapi/inc/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
Ralf Becker 8f797be836 Added HTMLPurifier (http://htmlpurifier.org/) Version 3.3.0
- can be used via html class like: 

        $clean_html = html::purify($html);

- using it now in eTemplate to remove malicious code from html:
  a) when displaying "formatted text"
  b) when "formatted text" get's input by the user
2009-05-19 17:32:06 +00:00

421 lines
15 KiB
PHP
Executable File

<?php
/**
* Definition of the purified HTML that describes allowed children,
* attributes, and many other things.
*
* Conventions:
*
* All member variables that are prefixed with info
* (including the main $info array) are used by HTML Purifier internals
* and should not be directly edited when customizing the HTMLDefinition.
* They can usually be set via configuration directives or custom
* modules.
*
* On the other hand, member variables without the info prefix are used
* internally by the HTMLDefinition and MUST NOT be used by other HTML
* Purifier internals. Many of them, however, are public, and may be
* edited by userspace code to tweak the behavior of HTMLDefinition.
*
* @note This class is inspected by Printer_HTMLDefinition; please
* update that class if things here change.
*
* @warning Directives that change this object's structure must be in
* the HTML or Attr namespace!
*/
class HTMLPurifier_HTMLDefinition extends HTMLPurifier_Definition
{
// FULLY-PUBLIC VARIABLES ---------------------------------------------
/**
* Associative array of element names to HTMLPurifier_ElementDef
*/
public $info = array();
/**
* Associative array of global attribute name to attribute definition.
*/
public $info_global_attr = array();
/**
* String name of parent element HTML will be going into.
*/
public $info_parent = 'div';
/**
* Definition for parent element, allows parent element to be a
* tag that's not allowed inside the HTML fragment.
*/
public $info_parent_def;
/**
* String name of element used to wrap inline elements in block context
* @note This is rarely used except for BLOCKQUOTEs in strict mode
*/
public $info_block_wrapper = 'p';
/**
* Associative array of deprecated tag name to HTMLPurifier_TagTransform
*/
public $info_tag_transform = array();
/**
* Indexed list of HTMLPurifier_AttrTransform to be performed before validation.
*/
public $info_attr_transform_pre = array();
/**
* Indexed list of HTMLPurifier_AttrTransform to be performed after validation.
*/
public $info_attr_transform_post = array();
/**
* Nested lookup array of content set name (Block, Inline) to
* element name to whether or not it belongs in that content set.
*/
public $info_content_sets = array();
/**
* Indexed list of HTMLPurifier_Injector to be used.
*/
public $info_injector = array();
/**
* Doctype object
*/
public $doctype;
// RAW CUSTOMIZATION STUFF --------------------------------------------
/**
* Adds a custom attribute to a pre-existing element
* @note This is strictly convenience, and does not have a corresponding
* method in HTMLPurifier_HTMLModule
* @param $element_name String element name to add attribute to
* @param $attr_name String name of attribute
* @param $def Attribute definition, can be string or object, see
* HTMLPurifier_AttrTypes for details
*/
public function addAttribute($element_name, $attr_name, $def) {
$module = $this->getAnonymousModule();
if (!isset($module->info[$element_name])) {
$element = $module->addBlankElement($element_name);
} else {
$element = $module->info[$element_name];
}
$element->attr[$attr_name] = $def;
}
/**
* Adds a custom element to your HTML definition
* @note See HTMLPurifier_HTMLModule::addElement for detailed
* parameter and return value descriptions.
*/
public function addElement($element_name, $type, $contents, $attr_collections, $attributes) {
$module = $this->getAnonymousModule();
// assume that if the user is calling this, the element
// is safe. This may not be a good idea
$element = $module->addElement($element_name, $type, $contents, $attr_collections, $attributes);
return $element;
}
/**
* Adds a blank element to your HTML definition, for overriding
* existing behavior
* @note See HTMLPurifier_HTMLModule::addBlankElement for detailed
* parameter and return value descriptions.
*/
public function addBlankElement($element_name) {
$module = $this->getAnonymousModule();
$element = $module->addBlankElement($element_name);
return $element;
}
/**
* Retrieves a reference to the anonymous module, so you can
* bust out advanced features without having to make your own
* module.
*/
public function getAnonymousModule() {
if (!$this->_anonModule) {
$this->_anonModule = new HTMLPurifier_HTMLModule();
$this->_anonModule->name = 'Anonymous';
}
return $this->_anonModule;
}
private $_anonModule;
// PUBLIC BUT INTERNAL VARIABLES --------------------------------------
public $type = 'HTML';
public $manager; /**< Instance of HTMLPurifier_HTMLModuleManager */
/**
* Performs low-cost, preliminary initialization.
*/
public function __construct() {
$this->manager = new HTMLPurifier_HTMLModuleManager();
}
protected function doSetup($config) {
$this->processModules($config);
$this->setupConfigStuff($config);
unset($this->manager);
// cleanup some of the element definitions
foreach ($this->info as $k => $v) {
unset($this->info[$k]->content_model);
unset($this->info[$k]->content_model_type);
}
}
/**
* Extract out the information from the manager
*/
protected function processModules($config) {
if ($this->_anonModule) {
// for user specific changes
// this is late-loaded so we don't have to deal with PHP4
// reference wonky-ness
$this->manager->addModule($this->_anonModule);
unset($this->_anonModule);
}
$this->manager->setup($config);
$this->doctype = $this->manager->doctype;
foreach ($this->manager->modules as $module) {
foreach($module->info_tag_transform as $k => $v) {
if ($v === false) unset($this->info_tag_transform[$k]);
else $this->info_tag_transform[$k] = $v;
}
foreach($module->info_attr_transform_pre as $k => $v) {
if ($v === false) unset($this->info_attr_transform_pre[$k]);
else $this->info_attr_transform_pre[$k] = $v;
}
foreach($module->info_attr_transform_post as $k => $v) {
if ($v === false) unset($this->info_attr_transform_post[$k]);
else $this->info_attr_transform_post[$k] = $v;
}
foreach ($module->info_injector as $k => $v) {
if ($v === false) unset($this->info_injector[$k]);
else $this->info_injector[$k] = $v;
}
}
$this->info = $this->manager->getElements();
$this->info_content_sets = $this->manager->contentSets->lookup;
}
/**
* Sets up stuff based on config. We need a better way of doing this.
*/
protected function setupConfigStuff($config) {
$block_wrapper = $config->get('HTML', 'BlockWrapper');
if (isset($this->info_content_sets['Block'][$block_wrapper])) {
$this->info_block_wrapper = $block_wrapper;
} else {
trigger_error('Cannot use non-block element as block wrapper',
E_USER_ERROR);
}
$parent = $config->get('HTML', 'Parent');
$def = $this->manager->getElement($parent, true);
if ($def) {
$this->info_parent = $parent;
$this->info_parent_def = $def;
} else {
trigger_error('Cannot use unrecognized element as parent',
E_USER_ERROR);
$this->info_parent_def = $this->manager->getElement($this->info_parent, true);
}
// support template text
$support = "(for information on implementing this, see the ".
"support forums) ";
// setup allowed elements -----------------------------------------
$allowed_elements = $config->get('HTML', 'AllowedElements');
$allowed_attributes = $config->get('HTML', 'AllowedAttributes'); // retrieve early
if (!is_array($allowed_elements) && !is_array($allowed_attributes)) {
$allowed = $config->get('HTML', 'Allowed');
if (is_string($allowed)) {
list($allowed_elements, $allowed_attributes) = $this->parseTinyMCEAllowedList($allowed);
}
}
if (is_array($allowed_elements)) {
foreach ($this->info as $name => $d) {
if(!isset($allowed_elements[$name])) unset($this->info[$name]);
unset($allowed_elements[$name]);
}
// emit errors
foreach ($allowed_elements as $element => $d) {
$element = htmlspecialchars($element); // PHP doesn't escape errors, be careful!
trigger_error("Element '$element' is not supported $support", E_USER_WARNING);
}
}
// setup allowed attributes ---------------------------------------
$allowed_attributes_mutable = $allowed_attributes; // by copy!
if (is_array($allowed_attributes)) {
// This actually doesn't do anything, since we went away from
// global attributes. It's possible that userland code uses
// it, but HTMLModuleManager doesn't!
foreach ($this->info_global_attr as $attr => $x) {
$keys = array($attr, "*@$attr", "*.$attr");
$delete = true;
foreach ($keys as $key) {
if ($delete && isset($allowed_attributes[$key])) {
$delete = false;
}
if (isset($allowed_attributes_mutable[$key])) {
unset($allowed_attributes_mutable[$key]);
}
}
if ($delete) unset($this->info_global_attr[$attr]);
}
foreach ($this->info as $tag => $info) {
foreach ($info->attr as $attr => $x) {
$keys = array("$tag@$attr", $attr, "*@$attr", "$tag.$attr", "*.$attr");
$delete = true;
foreach ($keys as $key) {
if ($delete && isset($allowed_attributes[$key])) {
$delete = false;
}
if (isset($allowed_attributes_mutable[$key])) {
unset($allowed_attributes_mutable[$key]);
}
}
if ($delete) unset($this->info[$tag]->attr[$attr]);
}
}
// emit errors
foreach ($allowed_attributes_mutable as $elattr => $d) {
$bits = preg_split('/[.@]/', $elattr, 2);
$c = count($bits);
switch ($c) {
case 2:
if ($bits[0] !== '*') {
$element = htmlspecialchars($bits[0]);
$attribute = htmlspecialchars($bits[1]);
if (!isset($this->info[$element])) {
trigger_error("Cannot allow attribute '$attribute' if element '$element' is not allowed/supported $support");
} else {
trigger_error("Attribute '$attribute' in element '$element' not supported $support",
E_USER_WARNING);
}
break;
}
// otherwise fall through
case 1:
$attribute = htmlspecialchars($bits[0]);
trigger_error("Global attribute '$attribute' is not ".
"supported in any elements $support",
E_USER_WARNING);
break;
}
}
}
// setup forbidden elements ---------------------------------------
$forbidden_elements = $config->get('HTML', 'ForbiddenElements');
$forbidden_attributes = $config->get('HTML', 'ForbiddenAttributes');
foreach ($this->info as $tag => $info) {
if (isset($forbidden_elements[$tag])) {
unset($this->info[$tag]);
continue;
}
foreach ($info->attr as $attr => $x) {
if (
isset($forbidden_attributes["$tag@$attr"]) ||
isset($forbidden_attributes["*@$attr"]) ||
isset($forbidden_attributes[$attr])
) {
unset($this->info[$tag]->attr[$attr]);
continue;
} // this segment might get removed eventually
elseif (isset($forbidden_attributes["$tag.$attr"])) {
// $tag.$attr are not user supplied, so no worries!
trigger_error("Error with $tag.$attr: tag.attr syntax not supported for HTML.ForbiddenAttributes; use tag@attr instead", E_USER_WARNING);
}
}
}
foreach ($forbidden_attributes as $key => $v) {
if (strlen($key) < 2) continue;
if ($key[0] != '*') continue;
if ($key[1] == '.') {
trigger_error("Error with $key: *.attr syntax not supported for HTML.ForbiddenAttributes; use attr instead", E_USER_WARNING);
}
}
// setup injectors -----------------------------------------------------
foreach ($this->info_injector as $i => $injector) {
if ($injector->checkNeeded($config) !== false) {
// remove injector that does not have it's required
// elements/attributes present, and is thus not needed.
unset($this->info_injector[$i]);
}
}
}
/**
* Parses a TinyMCE-flavored Allowed Elements and Attributes list into
* separate lists for processing. Format is element[attr1|attr2],element2...
* @warning Although it's largely drawn from TinyMCE's implementation,
* it is different, and you'll probably have to modify your lists
* @param $list String list to parse
* @param array($allowed_elements, $allowed_attributes)
* @todo Give this its own class, probably static interface
*/
public function parseTinyMCEAllowedList($list) {
$list = str_replace(array(' ', "\t"), '', $list);
$elements = array();
$attributes = array();
$chunks = preg_split('/(,|[\n\r]+)/', $list);
foreach ($chunks as $chunk) {
if (empty($chunk)) continue;
// remove TinyMCE element control characters
if (!strpos($chunk, '[')) {
$element = $chunk;
$attr = false;
} else {
list($element, $attr) = explode('[', $chunk);
}
if ($element !== '*') $elements[$element] = true;
if (!$attr) continue;
$attr = substr($attr, 0, strlen($attr) - 1); // remove trailing ]
$attr = explode('|', $attr);
foreach ($attr as $key) {
$attributes["$element.$key"] = true;
}
}
return array($elements, $attributes);
}
}
// vim: et sw=4 sts=4