<?php
/**
* @package s9e\TextFormatter
* @copyright Copyright (c) 2010-2021 The s9e authors
* @license http://www.opensource.org/licenses/mit-license.php The MIT License
*/
namespace s9e\TextFormatter\Configurator\TemplateChecks;
use DOMElement;
use DOMNode;
use DOMXPath;
use s9e\TextFormatter\Configurator\Exceptions\UnsafeTemplateException;
use s9e\TextFormatter\Configurator\Items\Tag;
use s9e\TextFormatter\Configurator\TemplateCheck;
/**
* NOTE: when this check is enabled, DisallowObjectParamsWithGeneratedName should be enabled too.
* Otherwise, <param/> elements with a dynamic 'name' attribute could be used to bypass this
* restriction. For the same reason, DisallowCopy, DisallowDisableOutputEscaping,
* DisallowDynamicAttributeNames, DisallowDynamicElementNames and DisallowUnsafeCopyOf should
* all be enabled too
*/
abstract class AbstractFlashRestriction extends TemplateCheck
{
/**
* @var string Name of the default setting
*/
public $defaultSetting;
/**
* @var string Name of the highest setting allowed
*/
public $maxSetting;
/**
* @var bool Whether this restriction applies only to elements using any kind of dynamic markup:
* XSL elements or attribute value templates
*/
public $onlyIfDynamic;
/**
* @var string Name of the restricted setting
*/
protected $settingName;
/**
* @var array Valid settings
*/
protected $settings;
/**
* @var DOMElement <xsl:template/> node
*/
protected $template;
/**
* Constructor
*
* @param string $maxSetting Max setting allowed
* @param bool $onlyIfDynamic Whether this restriction applies only to elements using any kind
* of dynamic markup: XSL elements or attribute value templates
*/
public function __construct($maxSetting, $onlyIfDynamic = false)
{
$this->maxSetting = $maxSetting;
$this->onlyIfDynamic = $onlyIfDynamic;
}
/**
* Test for the set Flash restriction
*
* @param DOMElement $template <xsl:template/> node
* @param Tag $tag Tag this template belongs to
* @return void
*/
public function check(DOMElement $template, Tag $tag)
{
$this->template = $template;
$this->checkEmbeds();
$this->checkObjects();
}
/**
* Test given element's attributes
*
* @param DOMElement $embed Context element
* @return void
*/
protected function checkAttributes(DOMElement $embed)
{
$settingName = strtolower($this->settingName);
$useDefault = true;
foreach ($embed->attributes as $attribute)
{
$attrName = strtolower($attribute->name);
if ($attrName === $settingName)
{
$this->checkSetting($attribute, $attribute->value);
$useDefault = false;
}
}
if ($useDefault)
{
$this->checkSetting($embed, $this->defaultSetting);
}
}
/**
* Test whether given element has dynamic attributes that match the setting's name
*
* @param DOMElement $embed Context element
* @return void
*/
protected function checkDynamicAttributes(DOMElement $embed)
{
$settingName = strtolower($this->settingName);
foreach ($embed->getElementsByTagNameNS(self::XMLNS_XSL, 'attribute') as $attribute)
{
$attrName = strtolower($attribute->getAttribute('name'));
if ($attrName === $settingName)
{
throw new UnsafeTemplateException('Cannot assess the safety of dynamic attributes', $attribute);
}
}
}
/**
* Test the presence of dynamic params in given object
*
* @param DOMElement $object Context element
* @return void
*/
protected function checkDynamicParams(DOMElement $object)
{
foreach ($this->getObjectParams($object) as $param)
{
foreach ($param->getElementsByTagNameNS(self::XMLNS_XSL, 'attribute') as $attribute)
{
// Test for a dynamic "value" attribute
if (strtolower($attribute->getAttribute('name')) === 'value')
{
throw new UnsafeTemplateException('Cannot assess the safety of dynamic attributes', $attribute);
}
}
}
}
/**
* Check embed elements in given template
*
* @return void
*/
protected function checkEmbeds()
{
foreach ($this->getElements('embed') as $embed)
{
// Test <xsl:attribute/> descendants
$this->checkDynamicAttributes($embed);
// Test the element's attributes
$this->checkAttributes($embed);
}
}
/**
* Check object elements in given template
*
* @return void
*/
protected function checkObjects()
{
foreach ($this->getElements('object') as $object)
{
// Make sure this object doesn't have dynamic params
$this->checkDynamicParams($object);
// Test the element's <param/> descendants
$params = $this->getObjectParams($object);
foreach ($params as $param)
{
$this->checkSetting($param, $param->getAttribute('value'));
}
if (empty($params))
{
$this->checkSetting($object, $this->defaultSetting);
}
}
}
/**
* Test whether given setting is allowed
*
* @param DOMNode $node Target node
* @param string $setting Setting
* @return void
*/
protected function checkSetting(DOMNode $node, $setting)
{
if (!isset($this->settings[strtolower($setting)]))
{
// Test whether the value contains an odd number of {
if (preg_match('/(?<!\\{)\\{(?:\\{\\{)*(?!\\{)/', $setting))
{
throw new UnsafeTemplateException('Cannot assess ' . $this->settingName . " setting '" . $setting . "'", $node);
}
throw new UnsafeTemplateException('Unknown ' . $this->settingName . " value '" . $setting . "'", $node);
}
$value = $this->settings[strtolower($setting)];
$maxValue = $this->settings[strtolower($this->maxSetting)];
if ($value > $maxValue)
{
throw new UnsafeTemplateException($this->settingName . " setting '" . $setting . "' exceeds restricted value '" . $this->maxSetting . "'", $node);
}
}
/**
* Test whether given node contains dynamic content (XSL elements or attribute value template)
*
* @param DOMElement $node Node
* @return bool
*/
protected function isDynamic(DOMElement $node)
{
if ($node->getElementsByTagNameNS(self::XMLNS_XSL, '*')->length)
{
return true;
}
// Look for any attributes containing "{" in this element or its descendants
$xpath = new DOMXPath($node->ownerDocument);
$query = './/@*[contains(., "{")]';
foreach ($xpath->query($query, $node) as $attribute)
{
// Test whether the value contains an odd number of {
if (preg_match('/(?<!\\{)\\{(?:\\{\\{)*(?!\\{)/', $attribute->value))
{
return true;
}
}
return false;
}
/**
* Get all elements the restriction applies to
*
* @param string $tagName Element's name
* @return DOMElement[]
*/
protected function getElements($tagName)
{
$nodes = [];
foreach ($this->template->ownerDocument->getElementsByTagName($tagName) as $node)
{
if (!$this->onlyIfDynamic || $this->isDynamic($node))
{
$nodes[] = $node;
}
}
return $nodes;
}
/**
* Get all param elements attached to given object
*
* @param DOMElement $object Context element
* @return DOMElement[]
*/
protected function getObjectParams(DOMElement $object)
{
$params = [];
$settingName = strtolower($this->settingName);
foreach ($object->getElementsByTagName('param') as $param)
{
$paramName = strtolower($param->getAttribute('name'));
if ($paramName === $settingName && $param->parentNode->isSameNode($object))
{
$params[] = $param;
}
}
return $params;
}
}