| // 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 The TrustedResourceUrl type and its builders. |
| * |
| * TODO(xtof): Link to document stating type contract. |
| */ |
| |
| goog.provide('goog.html.TrustedResourceUrl'); |
| |
| goog.require('goog.asserts'); |
| goog.require('goog.i18n.bidi.Dir'); |
| goog.require('goog.i18n.bidi.DirectionalString'); |
| goog.require('goog.string.Const'); |
| goog.require('goog.string.TypedString'); |
| |
| |
| |
| /** |
| * A URL which is under application control and from which script, CSS, and |
| * other resources that represent executable code, can be fetched. |
| * |
| * Given that the URL can only be constructed from strings under application |
| * control and is used to load resources, bugs resulting in a malformed URL |
| * should not have a security impact and are likely to be easily detectable |
| * during testing. Given the wide number of non-RFC compliant URLs in use, |
| * stricter validation could prevent some applications from being able to use |
| * this type. |
| * |
| * Instances of this type must be created via the factory method, |
| * ({@code fromConstant}, {@code fromConstants}, {@code format} or {@code |
| * formatWithParams}), and not by invoking its constructor. The constructor |
| * intentionally takes no parameters and the type is immutable; hence only a |
| * default instance corresponding to the empty string can be obtained via |
| * constructor invocation. |
| * |
| * @see goog.html.TrustedResourceUrl#fromConstant |
| * @constructor |
| * @final |
| * @struct |
| * @implements {goog.i18n.bidi.DirectionalString} |
| * @implements {goog.string.TypedString} |
| */ |
| goog.html.TrustedResourceUrl = function() { |
| /** |
| * The contained value of this TrustedResourceUrl. The field has a purposely |
| * ugly name to make (non-compiled) code that attempts to directly access this |
| * field stand out. |
| * @private {string} |
| */ |
| this.privateDoNotAccessOrElseTrustedResourceUrlWrappedValue_ = ''; |
| |
| /** |
| * A type marker used to implement additional run-time type checking. |
| * @see goog.html.TrustedResourceUrl#unwrap |
| * @const {!Object} |
| * @private |
| */ |
| this.TRUSTED_RESOURCE_URL_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = |
| goog.html.TrustedResourceUrl.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_; |
| }; |
| |
| |
| /** |
| * @override |
| * @const |
| */ |
| goog.html.TrustedResourceUrl.prototype.implementsGoogStringTypedString = true; |
| |
| |
| /** |
| * Returns this TrustedResourceUrl's value as a string. |
| * |
| * IMPORTANT: In code where it is security relevant that an object's type is |
| * indeed {@code TrustedResourceUrl}, use |
| * {@code goog.html.TrustedResourceUrl.unwrap} instead of this method. If in |
| * doubt, assume that it's security relevant. In particular, note that |
| * goog.html functions which return a goog.html type do not guarantee that |
| * the returned instance is of the right type. For example: |
| * |
| * <pre> |
| * var fakeSafeHtml = new String('fake'); |
| * fakeSafeHtml.__proto__ = goog.html.SafeHtml.prototype; |
| * var newSafeHtml = goog.html.SafeHtml.htmlEscape(fakeSafeHtml); |
| * // newSafeHtml is just an alias for fakeSafeHtml, it's passed through by |
| * // goog.html.SafeHtml.htmlEscape() as fakeSafeHtml instanceof |
| * // goog.html.SafeHtml. |
| * </pre> |
| * |
| * @see goog.html.TrustedResourceUrl#unwrap |
| * @override |
| */ |
| goog.html.TrustedResourceUrl.prototype.getTypedStringValue = function() { |
| return this.privateDoNotAccessOrElseTrustedResourceUrlWrappedValue_; |
| }; |
| |
| |
| /** |
| * @override |
| * @const |
| */ |
| goog.html.TrustedResourceUrl.prototype.implementsGoogI18nBidiDirectionalString = |
| true; |
| |
| |
| /** |
| * Returns this URLs directionality, which is always {@code LTR}. |
| * @override |
| */ |
| goog.html.TrustedResourceUrl.prototype.getDirection = function() { |
| return goog.i18n.bidi.Dir.LTR; |
| }; |
| |
| |
| if (goog.DEBUG) { |
| /** |
| * Returns a debug string-representation of this value. |
| * |
| * To obtain the actual string value wrapped in a TrustedResourceUrl, use |
| * {@code goog.html.TrustedResourceUrl.unwrap}. |
| * |
| * @see goog.html.TrustedResourceUrl#unwrap |
| * @override |
| */ |
| goog.html.TrustedResourceUrl.prototype.toString = function() { |
| return 'TrustedResourceUrl{' + |
| this.privateDoNotAccessOrElseTrustedResourceUrlWrappedValue_ + '}'; |
| }; |
| } |
| |
| |
| /** |
| * Performs a runtime check that the provided object is indeed a |
| * TrustedResourceUrl object, and returns its value. |
| * |
| * @param {!goog.html.TrustedResourceUrl} trustedResourceUrl The object to |
| * extract from. |
| * @return {string} The trustedResourceUrl object's contained string, unless |
| * the run-time type check fails. In that case, {@code unwrap} returns an |
| * innocuous string, or, if assertions are enabled, throws |
| * {@code goog.asserts.AssertionError}. |
| */ |
| goog.html.TrustedResourceUrl.unwrap = function(trustedResourceUrl) { |
| // Perform additional Run-time type-checking to ensure that |
| // trustedResourceUrl is indeed an instance of the expected type. This |
| // provides some additional protection against security bugs due to |
| // application code that disables type checks. |
| // Specifically, the following checks are performed: |
| // 1. The object is an instance of the expected type. |
| // 2. The object is not an instance of a subclass. |
| // 3. The object carries a type marker for the expected type. "Faking" an |
| // object requires a reference to the type marker, which has names intended |
| // to stand out in code reviews. |
| if (trustedResourceUrl instanceof goog.html.TrustedResourceUrl && |
| trustedResourceUrl.constructor === goog.html.TrustedResourceUrl && |
| trustedResourceUrl |
| .TRUSTED_RESOURCE_URL_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ === |
| goog.html.TrustedResourceUrl |
| .TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_) { |
| return trustedResourceUrl |
| .privateDoNotAccessOrElseTrustedResourceUrlWrappedValue_; |
| } else { |
| goog.asserts.fail('expected object of type TrustedResourceUrl, got \'' + |
| trustedResourceUrl + '\' of type ' + goog.typeOf(trustedResourceUrl)); |
| return 'type_error:TrustedResourceUrl'; |
| } |
| }; |
| |
| |
| /** |
| * Creates a TrustedResourceUrl from a format string and arguments. |
| * |
| * The arguments for interpolation into the format string map labels to values. |
| * Values of type `goog.string.Const` are interpolated without modifcation. |
| * Values of other types are cast to string and encoded with |
| * encodeURIComponent. |
| * |
| * `%{<label>}` markers are used in the format string to indicate locations |
| * to be interpolated with the valued mapped to the given label. `<label>` |
| * must contain only alphanumeric and `_` characters. |
| * |
| * The format string must start with one of the following: |
| * - `https://<origin>/` |
| * - `//<origin>/` |
| * - `/<pathStart>` |
| * - `about:blank` |
| * |
| * `<origin>` must contain only alphanumeric or any of the following: `-.:[]`. |
| * `<pathStart>` is any character except `/` and `\`. |
| * |
| * Example usage: |
| * |
| * var url = goog.html.TrustedResourceUrl.format(goog.string.Const.from( |
| * 'https://www.google.com/search?q=%{query}), {'query': searchTerm}); |
| * |
| * var url = goog.html.TrustedResourceUrl.format(goog.string.Const.from( |
| * '//www.youtube.com/v/%{videoId}?hl=en&fs=1%{autoplay}'), { |
| * 'videoId': videoId, |
| * 'autoplay': opt_autoplay ? |
| * goog.string.Const.EMPTY : goog.string.Const.from('&autoplay=1') |
| * }); |
| * |
| * While this function can be used to create a TrustedResourceUrl from only |
| * constants, fromConstant() and fromConstants() are generally preferable for |
| * that purpose. |
| * |
| * @param {!goog.string.Const} format The format string. |
| * @param {!Object<string, (string|number|!goog.string.Const)>} args Mapping |
| * of labels to values to be interpolated into the format string. |
| * goog.string.Const values are interpolated without encoding. |
| * @return {!goog.html.TrustedResourceUrl} |
| * @throws {!Error} On an invalid format string or if a label used in the |
| * the format string is not present in args. |
| */ |
| goog.html.TrustedResourceUrl.format = function(format, args) { |
| var result = goog.html.TrustedResourceUrl.format_(format, args); |
| return goog.html.TrustedResourceUrl |
| .createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse(result); |
| }; |
| |
| |
| /** |
| * String version of TrustedResourceUrl.format. |
| * @param {!goog.string.Const} format |
| * @param {!Object<string, (string|number|!goog.string.Const)>} args |
| * @return {string} |
| * @throws {!Error} |
| * @private |
| */ |
| goog.html.TrustedResourceUrl.format_ = function(format, args) { |
| var formatStr = goog.string.Const.unwrap(format); |
| if (!goog.html.TrustedResourceUrl.BASE_URL_.test(formatStr)) { |
| throw new Error('Invalid TrustedResourceUrl format: ' + formatStr); |
| } |
| return formatStr.replace( |
| goog.html.TrustedResourceUrl.FORMAT_MARKER_, function(match, id) { |
| if (!Object.prototype.hasOwnProperty.call(args, id)) { |
| throw new Error( |
| 'Found marker, "' + id + '", in format string, "' + formatStr + |
| '", but no valid label mapping found ' + |
| 'in args: ' + JSON.stringify(args)); |
| } |
| var arg = args[id]; |
| if (arg instanceof goog.string.Const) { |
| return goog.string.Const.unwrap(arg); |
| } else { |
| return encodeURIComponent(String(arg)); |
| } |
| }); |
| }; |
| |
| |
| /** |
| * @private @const {!RegExp} |
| */ |
| goog.html.TrustedResourceUrl.FORMAT_MARKER_ = /%{(\w+)}/g; |
| |
| |
| /** |
| * The URL must be absolute, scheme-relative or path-absolute. So it must |
| * start with: |
| * - https:// followed by allowed origin characters. |
| * - // followed by allowed origin characters. |
| * - / not followed by / or \. There will only be an absolute path. |
| * |
| * Based on |
| * https://url.spec.whatwg.org/commit-snapshots/56b74ce7cca8883eab62e9a12666e2fac665d03d/#url-parsing |
| * an initial / which is not followed by another / or \ will end up in the "path |
| * state" and from there it can only go to "fragment state" and "query state". |
| * |
| * We don't enforce a well-formed domain name. So '.' or '1.2' are valid. |
| * That's ok because the origin comes from a compile-time constant. |
| * |
| * A regular expression is used instead of goog.uri for several reasons: |
| * - Strictness. E.g. we don't want any userinfo component and we don't |
| * want '/./, nor \' in the first path component. |
| * - Small trusted base. goog.uri is generic and might need to change, |
| * reasoning about all the ways it can parse a URL now and in the future |
| * is error-prone. |
| * - Code size. We expect many calls to .format(), many of which might |
| * not be using goog.uri. |
| * - Simplicity. Using goog.uri would likely not result in simpler nor shorter |
| * code. |
| * @private @const {!RegExp} |
| */ |
| goog.html.TrustedResourceUrl.BASE_URL_ = |
| /^(?:https:)?\/\/[0-9a-z.:[\]-]+\/|^\/[^\/\\]|^about:blank(#|$)/i; |
| |
| |
| /** |
| * Formats the URL same as TrustedResourceUrl.format and then adds extra URL |
| * parameters. |
| * |
| * Example usage: |
| * |
| * // Creates '//www.youtube.com/v/abc?autoplay=1' for videoId='abc' and |
| * // opt_autoplay=1. Creates '//www.youtube.com/v/abc' for videoId='abc' |
| * // and opt_autoplay=undefined. |
| * var url = goog.html.TrustedResourceUrl.formatWithParams( |
| * goog.string.Const.from('//www.youtube.com/v/%{videoId}'), |
| * {'videoId': videoId}, |
| * {'autoplay': opt_autoplay}); |
| * |
| * @param {!goog.string.Const} format The format string. |
| * @param {!Object<string, (string|number|!goog.string.Const)>} args Mapping |
| * of labels to values to be interpolated into the format string. |
| * goog.string.Const values are interpolated without encoding. |
| * @param {!Object<string, *>} params Parameters to add to URL. Parameters with |
| * value {@code null} or {@code undefined} are skipped. Both keys and values |
| * are encoded. Note that JavaScript doesn't guarantee the order of values |
| * in an object which might result in non-deterministic order of the |
| * parameters. However, browsers currently preserve the order. |
| * @return {!goog.html.TrustedResourceUrl} |
| * @throws {!Error} On an invalid format string or if a label used in the |
| * the format string is not present in args. |
| */ |
| goog.html.TrustedResourceUrl.formatWithParams = function(format, args, params) { |
| var url = goog.html.TrustedResourceUrl.format_(format, args); |
| var separator = /\?/.test(url) ? '&' : '?'; |
| for (var key in params) { |
| if (params[key] == null) { |
| continue; |
| } |
| url += separator + encodeURIComponent(key) + '=' + |
| encodeURIComponent(String(params[key])); |
| separator = '&'; |
| } |
| return goog.html.TrustedResourceUrl |
| .createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse(url); |
| }; |
| |
| |
| /** |
| * Creates a TrustedResourceUrl object from a compile-time constant string. |
| * |
| * Compile-time constant strings are inherently program-controlled and hence |
| * trusted. |
| * |
| * @param {!goog.string.Const} url A compile-time-constant string from which to |
| * create a TrustedResourceUrl. |
| * @return {!goog.html.TrustedResourceUrl} A TrustedResourceUrl object |
| * initialized to {@code url}. |
| */ |
| goog.html.TrustedResourceUrl.fromConstant = function(url) { |
| return goog.html.TrustedResourceUrl |
| .createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse( |
| goog.string.Const.unwrap(url)); |
| }; |
| |
| |
| /** |
| * Creates a TrustedResourceUrl object from a compile-time constant strings. |
| * |
| * Compile-time constant strings are inherently program-controlled and hence |
| * trusted. |
| * |
| * @param {!Array<!goog.string.Const>} parts Compile-time-constant strings from |
| * which to create a TrustedResourceUrl. |
| * @return {!goog.html.TrustedResourceUrl} A TrustedResourceUrl object |
| * initialized to concatenation of {@code parts}. |
| */ |
| goog.html.TrustedResourceUrl.fromConstants = function(parts) { |
| var unwrapped = ''; |
| for (var i = 0; i < parts.length; i++) { |
| unwrapped += goog.string.Const.unwrap(parts[i]); |
| } |
| return goog.html.TrustedResourceUrl |
| .createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse(unwrapped); |
| }; |
| |
| |
| /** |
| * Type marker for the TrustedResourceUrl type, used to implement additional |
| * run-time type checking. |
| * @const {!Object} |
| * @private |
| */ |
| goog.html.TrustedResourceUrl.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = {}; |
| |
| |
| /** |
| * Package-internal utility method to create TrustedResourceUrl instances. |
| * |
| * @param {string} url The string to initialize the TrustedResourceUrl object |
| * with. |
| * @return {!goog.html.TrustedResourceUrl} The initialized TrustedResourceUrl |
| * object. |
| * @package |
| */ |
| goog.html.TrustedResourceUrl |
| .createTrustedResourceUrlSecurityPrivateDoNotAccessOrElse = function(url) { |
| var trustedResourceUrl = new goog.html.TrustedResourceUrl(); |
| trustedResourceUrl.privateDoNotAccessOrElseTrustedResourceUrlWrappedValue_ = |
| url; |
| return trustedResourceUrl; |
| }; |