nsTreeSanitizer.h
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsTreeSanitizer_h_
#define nsTreeSanitizer_h_
#include "mozilla/css/StyleRule.h"
#include "nsIPrincipal.h"
#include "mozilla/dom/Element.h"
class nsIContent;
/**
* See the documentation of nsIParserUtils::sanitize for documentation
* about the default behavior and the configuration options of this sanitizer.
*/
class MOZ_STACK_CLASS nsTreeSanitizer {
public:
/**
* The constructor.
*
* @param aFlags Flags from nsIParserUtils
*/
explicit nsTreeSanitizer(uint32_t aFlags = 0);
static void InitializeStatics();
static void ReleaseStatics();
/**
* Sanitizes a disconnected DOM fragment freshly obtained from a parser.
* The argument must be of type nsINode::eDOCUMENT_FRAGMENT and,
* consequently, must not be in the document. Furthermore, the fragment
* must have just come from a parser so that it can't have mutation
* event listeners set on it.
*/
void Sanitize(nsIContent* aFragment);
/**
* Sanitizes a disconnected (not in a docshell) document freshly obtained
* from a parser. The document must not be embedded in a docshell and must
* not have had a chance to get mutation event listeners attached to it.
* The root element must be <html>.
*/
void Sanitize(nsIDocument* aDocument);
private:
/**
* Whether <style> and style="" are allowed.
*/
bool mAllowStyles;
/**
* Whether comment nodes are allowed.
*/
bool mAllowComments;
/**
* Whether HTML <font>, <center>, bgcolor="", etc., are dropped.
*/
bool mDropNonCSSPresentation;
/**
* Whether to remove forms and form controls (excluding fieldset/legend).
*/
bool mDropForms;
/**
* Whether only cid: embeds are allowed.
*/
bool mCidEmbedsOnly;
/**
* Whether to drop <img>, <video>, <audio> and <svg>.
*/
bool mDropMedia;
/**
* Whether we are sanitizing a full document (as opposed to a fragment).
*/
bool mFullDocument;
void SanitizeChildren(nsINode* aRoot);
/**
* Queries if an element must be replaced with its children.
* @param aNamespace the namespace of the element the question is about
* @param aLocal the local name of the element the question is about
* @return true if the element must be replaced with its children and
* false if the element is to be kept
*/
bool MustFlatten(int32_t aNamespace, nsIAtom* aLocal);
/**
* Queries if an element including its children must be removed.
* @param aNamespace the namespace of the element the question is about
* @param aLocal the local name of the element the question is about
* @param aElement the element node itself for inspecting attributes
* @return true if the element and its children must be removed and
* false if the element is to be kept
*/
bool MustPrune(int32_t aNamespace,
nsIAtom* aLocal,
mozilla::dom::Element* aElement);
/**
* Checks if a given local name (for an attribute) is on the given list
* of URL attribute names.
* @param aURLs the list of URL attribute names
* @param aLocalName the name to search on the list
* @return true if aLocalName is on the aURLs list and false otherwise
*/
bool IsURL(nsIAtom*** aURLs, nsIAtom* aLocalName);
/**
* Removes dangerous attributes from the element. If the style attribute
* is allowed, its value is sanitized. The values of URL attributes are
* sanitized, except src isn't sanitized when it is allowed to remain
* potentially dangerous.
*
* @param aElement the element whose attributes should be sanitized
* @param aAllowed the whitelist of permitted local names to use
* @param aURLs the local names of URL-valued attributes
* @param aAllowXLink whether XLink attributes are allowed
* @param aAllowStyle whether the style attribute is allowed
* @param aAllowDangerousSrc whether to leave the value of the src
* attribute unsanitized
*/
void SanitizeAttributes(mozilla::dom::Element* aElement,
nsTHashtable<nsISupportsHashKey>* aAllowed,
nsIAtom*** aURLs,
bool aAllowXLink,
bool aAllowStyle,
bool aAllowDangerousSrc);
/**
* Remove the named URL attribute from the element if the URL fails a
* security check.
*
* @param aElement the element whose attribute to possibly modify
* @param aNamespace the namespace of the URL attribute
* @param aLocalName the local name of the URL attribute
* @return true if the attribute was removed and false otherwise
*/
bool SanitizeURL(mozilla::dom::Element* aElement,
int32_t aNamespace,
nsIAtom* aLocalName);
/**
* Checks a style rule for the presence of the 'binding' CSS property and
* removes that property from the rule and reserializes in case the
* property was found.
*
* @param aDeclaration The style declaration to check
* @param aRuleText the serialized mutated rule if the method returns true
* @return true if the rule was modified and false otherwise
*/
bool SanitizeStyleDeclaration(mozilla::css::Declaration* aDeclaration,
nsAutoString& aRuleText);
/**
* Parses a style sheet and reserializes it with the 'binding' property
* removed if it was present.
*
* @param aOrigin the original style sheet source
* @param aSanitized the reserialization without 'binding'; only valid if
* this method return true
* @param aDocument the document the style sheet belongs to
* @param aBaseURI the base URI to use
* @return true if the 'binding' property was encountered and false
* otherwise
*/
bool SanitizeStyleSheet(const nsAString& aOriginal,
nsAString& aSanitized,
nsIDocument* aDocument,
nsIURI* aBaseURI);
/**
* Removes all attributes from an element node.
*/
void RemoveAllAttributes(nsIContent* aElement);
/**
* The whitelist of HTML elements.
*/
static nsTHashtable<nsISupportsHashKey>* sElementsHTML;
/**
* The whitelist of non-presentational HTML attributes.
*/
static nsTHashtable<nsISupportsHashKey>* sAttributesHTML;
/**
* The whitelist of presentational HTML attributes.
*/
static nsTHashtable<nsISupportsHashKey>* sPresAttributesHTML;
/**
* The whitelist of SVG elements.
*/
static nsTHashtable<nsISupportsHashKey>* sElementsSVG;
/**
* The whitelist of SVG attributes.
*/
static nsTHashtable<nsISupportsHashKey>* sAttributesSVG;
/**
* The whitelist of SVG elements.
*/
static nsTHashtable<nsISupportsHashKey>* sElementsMathML;
/**
* The whitelist of MathML attributes.
*/
static nsTHashtable<nsISupportsHashKey>* sAttributesMathML;
/**
* Reusable null principal for URL checks.
*/
static nsIPrincipal* sNullPrincipal;
};
#endif // nsTreeSanitizer_h_
