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+/* 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_