forked from extern/egroupware
8f797be836
- 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
172 lines
7.5 KiB
PHP
Executable File
172 lines
7.5 KiB
PHP
Executable File
<?php
|
|
|
|
/**
|
|
* Removes all unrecognized tags from the list of tokens.
|
|
*
|
|
* This strategy iterates through all the tokens and removes unrecognized
|
|
* tokens. If a token is not recognized but a TagTransform is defined for
|
|
* that element, the element will be transformed accordingly.
|
|
*/
|
|
|
|
class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
|
|
{
|
|
|
|
public function execute($tokens, $config, $context) {
|
|
$definition = $config->getHTMLDefinition();
|
|
$generator = new HTMLPurifier_Generator($config, $context);
|
|
$result = array();
|
|
|
|
$escape_invalid_tags = $config->get('Core', 'EscapeInvalidTags');
|
|
$remove_invalid_img = $config->get('Core', 'RemoveInvalidImg');
|
|
|
|
// currently only used to determine if comments should be kept
|
|
$trusted = $config->get('HTML', 'Trusted');
|
|
|
|
$remove_script_contents = $config->get('Core', 'RemoveScriptContents');
|
|
$hidden_elements = $config->get('Core', 'HiddenElements');
|
|
|
|
// remove script contents compatibility
|
|
if ($remove_script_contents === true) {
|
|
$hidden_elements['script'] = true;
|
|
} elseif ($remove_script_contents === false && isset($hidden_elements['script'])) {
|
|
unset($hidden_elements['script']);
|
|
}
|
|
|
|
$attr_validator = new HTMLPurifier_AttrValidator();
|
|
|
|
// removes tokens until it reaches a closing tag with its value
|
|
$remove_until = false;
|
|
|
|
// converts comments into text tokens when this is equal to a tag name
|
|
$textify_comments = false;
|
|
|
|
$token = false;
|
|
$context->register('CurrentToken', $token);
|
|
|
|
$e = false;
|
|
if ($config->get('Core', 'CollectErrors')) {
|
|
$e =& $context->get('ErrorCollector');
|
|
}
|
|
|
|
foreach($tokens as $token) {
|
|
if ($remove_until) {
|
|
if (empty($token->is_tag) || $token->name !== $remove_until) {
|
|
continue;
|
|
}
|
|
}
|
|
if (!empty( $token->is_tag )) {
|
|
// DEFINITION CALL
|
|
|
|
// before any processing, try to transform the element
|
|
if (
|
|
isset($definition->info_tag_transform[$token->name])
|
|
) {
|
|
$original_name = $token->name;
|
|
// there is a transformation for this tag
|
|
// DEFINITION CALL
|
|
$token = $definition->
|
|
info_tag_transform[$token->name]->
|
|
transform($token, $config, $context);
|
|
if ($e) $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Tag transform', $original_name);
|
|
}
|
|
|
|
if (isset($definition->info[$token->name])) {
|
|
|
|
// mostly everything's good, but
|
|
// we need to make sure required attributes are in order
|
|
if (
|
|
($token instanceof HTMLPurifier_Token_Start || $token instanceof HTMLPurifier_Token_Empty) &&
|
|
$definition->info[$token->name]->required_attr &&
|
|
($token->name != 'img' || $remove_invalid_img) // ensure config option still works
|
|
) {
|
|
$attr_validator->validateToken($token, $config, $context);
|
|
$ok = true;
|
|
foreach ($definition->info[$token->name]->required_attr as $name) {
|
|
if (!isset($token->attr[$name])) {
|
|
$ok = false;
|
|
break;
|
|
}
|
|
}
|
|
if (!$ok) {
|
|
if ($e) $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Missing required attribute', $name);
|
|
continue;
|
|
}
|
|
$token->armor['ValidateAttributes'] = true;
|
|
}
|
|
|
|
if (isset($hidden_elements[$token->name]) && $token instanceof HTMLPurifier_Token_Start) {
|
|
$textify_comments = $token->name;
|
|
} elseif ($token->name === $textify_comments && $token instanceof HTMLPurifier_Token_End) {
|
|
$textify_comments = false;
|
|
}
|
|
|
|
} elseif ($escape_invalid_tags) {
|
|
// invalid tag, generate HTML representation and insert in
|
|
if ($e) $e->send(E_WARNING, 'Strategy_RemoveForeignElements: Foreign element to text');
|
|
$token = new HTMLPurifier_Token_Text(
|
|
$generator->generateFromToken($token)
|
|
);
|
|
} else {
|
|
// check if we need to destroy all of the tag's children
|
|
// CAN BE GENERICIZED
|
|
if (isset($hidden_elements[$token->name])) {
|
|
if ($token instanceof HTMLPurifier_Token_Start) {
|
|
$remove_until = $token->name;
|
|
} elseif ($token instanceof HTMLPurifier_Token_Empty) {
|
|
// do nothing: we're still looking
|
|
} else {
|
|
$remove_until = false;
|
|
}
|
|
if ($e) $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Foreign meta element removed');
|
|
} else {
|
|
if ($e) $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Foreign element removed');
|
|
}
|
|
continue;
|
|
}
|
|
} elseif ($token instanceof HTMLPurifier_Token_Comment) {
|
|
// textify comments in script tags when they are allowed
|
|
if ($textify_comments !== false) {
|
|
$data = $token->data;
|
|
$token = new HTMLPurifier_Token_Text($data);
|
|
} elseif ($trusted) {
|
|
// keep, but perform comment cleaning
|
|
if ($e) {
|
|
// perform check whether or not there's a trailing hyphen
|
|
if (substr($token->data, -1) == '-') {
|
|
$e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Trailing hyphen in comment removed');
|
|
}
|
|
}
|
|
$token->data = rtrim($token->data, '-');
|
|
$found_double_hyphen = false;
|
|
while (strpos($token->data, '--') !== false) {
|
|
if ($e && !$found_double_hyphen) {
|
|
$e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Hyphens in comment collapsed');
|
|
}
|
|
$found_double_hyphen = true; // prevent double-erroring
|
|
$token->data = str_replace('--', '-', $token->data);
|
|
}
|
|
} else {
|
|
// strip comments
|
|
if ($e) $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Comment removed');
|
|
continue;
|
|
}
|
|
} elseif ($token instanceof HTMLPurifier_Token_Text) {
|
|
} else {
|
|
continue;
|
|
}
|
|
$result[] = $token;
|
|
}
|
|
if ($remove_until && $e) {
|
|
// we removed tokens until the end, throw error
|
|
$e->send(E_ERROR, 'Strategy_RemoveForeignElements: Token removed to end', $remove_until);
|
|
}
|
|
|
|
$context->destroy('CurrentToken');
|
|
|
|
return $result;
|
|
}
|
|
|
|
}
|
|
|
|
// vim: et sw=4 sts=4
|