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// Copyright 2013 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Transitional utilities to unsafely trust random strings as
* goog.html types. Intended for temporary use when upgrading a library that
* used to accept plain strings to use safe types, but where it's not
* practical to transitively update callers.
*
* IMPORTANT: No new code should use the conversion functions in this file,
* they are intended for refactoring old code to use goog.html types. New code
* should construct goog.html types via their APIs, template systems or
* sanitizers. If that’s not possible it should use
* goog.html.uncheckedconversions and undergo security review.
*
* The semantics of the conversions in goog.html.legacyconversions are very
* different from the ones provided by goog.html.uncheckedconversions. The
* latter are for use in code where it has been established through manual
* security review that the value produced by a piece of code will always
* satisfy the SafeHtml contract (e.g., the output of a secure HTML sanitizer).
* In uses of goog.html.legacyconversions, this guarantee is not given -- the
* value in question originates in unreviewed legacy code and there is no
* guarantee that it satisfies the SafeHtml contract.
*
* There are only three valid uses of legacyconversions:
*
* 1. Introducing a goog.html version of a function which currently consumes
* string and passes that string to a DOM API which can execute script - and
* hence cause XSS - like innerHTML. For example, Dialog might expose a
* setContent method which takes a string and sets the innerHTML property of
* an element with it. In this case a setSafeHtmlContent function could be
* added, consuming goog.html.SafeHtml instead of string, and using
* goog.dom.safe.setInnerHtml instead of directly setting innerHTML.
* setContent could then internally use legacyconversions to create a SafeHtml
* from string and pass the SafeHtml to setSafeHtmlContent. In this scenario
* remember to document the use of legacyconversions in the modified setContent
* and consider deprecating it as well.
*
* 2. Automated refactoring of application code which handles HTML as string
* but needs to call a function which only takes goog.html types. For example,
* in the Dialog scenario from (1) an alternative option would be to refactor
* setContent to accept goog.html.SafeHtml instead of string and then refactor
* all current callers to use legacyconversions to pass SafeHtml. This is
* generally preferable to (1) because it keeps the library clean of
* legacyconversions, and makes code sites in application code that are
* potentially vulnerable to XSS more apparent.
*
* 3. Old code which needs to call APIs which consume goog.html types and for
* which it is prohibitively expensive to refactor to use goog.html types.
* Generally, this is code where safety from XSS is either hopeless or
* unimportant.
*
* @visibility {//closure/goog/html:approved_for_legacy_conversion}
* @visibility {//closure/goog/bin/sizetests:__pkg__}
*/
goog.provide('goog.html.legacyconversions');
goog.require('goog.html.SafeHtml');
goog.require('goog.html.SafeScript');
goog.require('goog.html.SafeStyle');
goog.require('goog.html.SafeStyleSheet');
goog.require('goog.html.SafeUrl');
goog.require('goog.html.TrustedResourceUrl');
/**
* Performs an "unchecked conversion" from string to SafeHtml for legacy API
* purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} html A string to be converted to SafeHtml.
* @return {!goog.html.SafeHtml} The value of html, wrapped in a SafeHtml
* object.
*/
goog.html.legacyconversions.safeHtmlFromString = function(html) {
goog.html.legacyconversions.reportCallback_();
return goog.html.SafeHtml.createSafeHtmlSecurityPrivateDoNotAccessOrElse(
html, null /* dir */);
};
/**
* Performs an "unchecked conversion" from string to SafeScript for legacy API
* purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} script A string to be converted to SafeScript.
* @return {!goog.html.SafeScript} The value of script, wrapped in a SafeScript
* object.
*/
goog.html.legacyconversions.safeScriptFromString = function(script) {
goog.html.legacyconversions.reportCallback_();
return goog.html.SafeScript.createSafeScriptSecurityPrivateDoNotAccessOrElse(
script);
};
/**
* Performs an "unchecked conversion" from string to SafeStyle for legacy API
* purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} style A string to be converted to SafeStyle.
* @return {!goog.html.SafeStyle} The value of style, wrapped in a SafeStyle
* object.
*/
goog.html.legacyconversions.safeStyleFromString = function(style) {
goog.html.legacyconversions.reportCallback_();
return goog.html.SafeStyle.createSafeStyleSecurityPrivateDoNotAccessOrElse(
style);
};
/**
* Performs an "unchecked conversion" from string to SafeStyleSheet for legacy
* API purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} styleSheet A string to be converted to SafeStyleSheet.
* @return {!goog.html.SafeStyleSheet} The value of style sheet, wrapped in
* a SafeStyleSheet object.
*/
goog.html.legacyconversions.safeStyleSheetFromString = function(styleSheet) {
goog.html.legacyconversions.reportCallback_();
return goog.html.SafeStyleSheet
.createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(styleSheet);
};
/**
* Performs an "unchecked conversion" from string to SafeUrl for legacy API
* purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} url A string to be converted to SafeUrl.
* @return {!goog.html.SafeUrl} The value of url, wrapped in a SafeUrl
* object.
*/
goog.html.legacyconversions.safeUrlFromString = function(url) {
goog.html.legacyconversions.reportCallback_();
return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse(url);
};
/**
* Performs an "unchecked conversion" from string to TrustedResourceUrl for
* legacy API purposes.
*
* Please read fileoverview documentation before using.
*
* @param {string} url A string to be converted to TrustedResourceUrl.
* @return {!goog.html.TrustedResourceUrl} The value of url, wrapped in a
* TrustedResourceUrl object.
*/
goog.html.legacyconversions.trustedResourceUrlFromString = function(url) {
goog.html.legacyconversions.reportCallback_();
return goog.html.TrustedResourceUrl
.createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse(url);
};
/**
* @private {function(): undefined}
*/
goog.html.legacyconversions.reportCallback_ = goog.nullFunction;
/**
* Sets a function that will be called every time a legacy conversion is
* performed. The function is called with no parameters but it can use
* goog.debug.getStacktrace to get a stacktrace.
*
* @param {function(): undefined} callback Error callback as defined above.
*/
goog.html.legacyconversions.setReportCallback = function(callback) {
goog.html.legacyconversions.reportCallback_ = callback;
};