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author | Brian Picciano <mediocregopher@gmail.com> | 2018-11-12 16:18:45 -0500 |
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committer | Brian Picciano <mediocregopher@gmail.com> | 2018-11-12 16:18:45 -0500 |
commit | 5ed62d23b4bbbf7717de4adfa0eaf2af19365408 (patch) | |
tree | aa3285b40f9905e45b33f61b77afa06a0d33a790 /assets/viz/2/goog/html/safeurl.js | |
parent | 886684ec4c0a3d032a974ae8b8e29fb0e0632125 (diff) |
add viz 2 post
Diffstat (limited to 'assets/viz/2/goog/html/safeurl.js')
-rw-r--r-- | assets/viz/2/goog/html/safeurl.js | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/assets/viz/2/goog/html/safeurl.js b/assets/viz/2/goog/html/safeurl.js new file mode 100644 index 0000000..640a070 --- /dev/null +++ b/assets/viz/2/goog/html/safeurl.js @@ -0,0 +1,412 @@ +// 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 SafeUrl type and its builders. + * + * TODO(xtof): Link to document stating type contract. + */ + +goog.provide('goog.html.SafeUrl'); + +goog.require('goog.asserts'); +goog.require('goog.fs.url'); +goog.require('goog.i18n.bidi.Dir'); +goog.require('goog.i18n.bidi.DirectionalString'); +goog.require('goog.string'); +goog.require('goog.string.Const'); +goog.require('goog.string.TypedString'); + + + +/** + * A string that is safe to use in URL context in DOM APIs and HTML documents. + * + * A SafeUrl is a string-like object that carries the security type contract + * that its value as a string will not cause untrusted script execution + * when evaluated as a hyperlink URL in a browser. + * + * Values of this type are guaranteed to be safe to use in URL/hyperlink + * contexts, such as, assignment to URL-valued DOM properties, or + * interpolation into a HTML template in URL context (e.g., inside a href + * attribute), in the sense that the use will not result in a + * Cross-Site-Scripting vulnerability. + * + * Note that, as documented in {@code goog.html.SafeUrl.unwrap}, this type's + * contract does not guarantee that instances are safe to interpolate into HTML + * without appropriate escaping. + * + * Note also that this type's contract does not imply any guarantees regarding + * the resource the URL refers to. In particular, SafeUrls are <b>not</b> + * safe to use in a context where the referred-to resource is interpreted as + * trusted code, e.g., as the src of a script tag. + * + * Instances of this type must be created via the factory methods + * ({@code goog.html.SafeUrl.fromConstant}, {@code goog.html.SafeUrl.sanitize}), + * etc 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.SafeUrl#fromConstant + * @see goog.html.SafeUrl#from + * @see goog.html.SafeUrl#sanitize + * @constructor + * @final + * @struct + * @implements {goog.i18n.bidi.DirectionalString} + * @implements {goog.string.TypedString} + */ +goog.html.SafeUrl = function() { + /** + * The contained value of this SafeUrl. The field has a purposely ugly + * name to make (non-compiled) code that attempts to directly access this + * field stand out. + * @private {string} + */ + this.privateDoNotAccessOrElseSafeHtmlWrappedValue_ = ''; + + /** + * A type marker used to implement additional run-time type checking. + * @see goog.html.SafeUrl#unwrap + * @const + * @private + */ + this.SAFE_URL_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = + goog.html.SafeUrl.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_; +}; + + +/** + * The innocuous string generated by goog.html.SafeUrl.sanitize when passed + * an unsafe URL. + * + * about:invalid is registered in + * http://www.w3.org/TR/css3-values/#about-invalid. + * http://tools.ietf.org/html/rfc6694#section-2.2.1 permits about URLs to + * contain a fragment, which is not to be considered when determining if an + * about URL is well-known. + * + * Using about:invalid seems preferable to using a fixed data URL, since + * browsers might choose to not report CSP violations on it, as legitimate + * CSS function calls to attr() can result in this URL being produced. It is + * also a standard URL which matches exactly the semantics we need: + * "The about:invalid URI references a non-existent document with a generic + * error condition. It can be used when a URI is necessary, but the default + * value shouldn't be resolveable as any type of document". + * + * @const {string} + */ +goog.html.SafeUrl.INNOCUOUS_STRING = 'about:invalid#zClosurez'; + + +/** + * @override + * @const + */ +goog.html.SafeUrl.prototype.implementsGoogStringTypedString = true; + + +/** + * Returns this SafeUrl's value a string. + * + * IMPORTANT: In code where it is security relevant that an object's type is + * indeed {@code SafeUrl}, use {@code goog.html.SafeUrl.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> + * + * IMPORTANT: The guarantees of the SafeUrl type contract only extend to the + * behavior of browsers when interpreting URLs. Values of SafeUrl objects MUST + * be appropriately escaped before embedding in a HTML document. Note that the + * required escaping is context-sensitive (e.g. a different escaping is + * required for embedding a URL in a style property within a style + * attribute, as opposed to embedding in a href attribute). + * + * @see goog.html.SafeUrl#unwrap + * @override + */ +goog.html.SafeUrl.prototype.getTypedStringValue = function() { + return this.privateDoNotAccessOrElseSafeHtmlWrappedValue_; +}; + + +/** + * @override + * @const + */ +goog.html.SafeUrl.prototype.implementsGoogI18nBidiDirectionalString = true; + + +/** + * Returns this URLs directionality, which is always {@code LTR}. + * @override + */ +goog.html.SafeUrl.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 SafeUrl, use + * {@code goog.html.SafeUrl.unwrap}. + * + * @see goog.html.SafeUrl#unwrap + * @override + */ + goog.html.SafeUrl.prototype.toString = function() { + return 'SafeUrl{' + this.privateDoNotAccessOrElseSafeHtmlWrappedValue_ + + '}'; + }; +} + + +/** + * Performs a runtime check that the provided object is indeed a SafeUrl + * object, and returns its value. + * + * IMPORTANT: The guarantees of the SafeUrl type contract only extend to the + * behavior of browsers when interpreting URLs. Values of SafeUrl objects MUST + * be appropriately escaped before embedding in a HTML document. Note that the + * required escaping is context-sensitive (e.g. a different escaping is + * required for embedding a URL in a style property within a style + * attribute, as opposed to embedding in a href attribute). + * + * @param {!goog.html.SafeUrl} safeUrl The object to extract from. + * @return {string} The SafeUrl 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.SafeUrl.unwrap = function(safeUrl) { + // Perform additional Run-time type-checking to ensure that safeUrl 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 (safeUrl instanceof goog.html.SafeUrl && + safeUrl.constructor === goog.html.SafeUrl && + safeUrl.SAFE_URL_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ === + goog.html.SafeUrl.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_) { + return safeUrl.privateDoNotAccessOrElseSafeHtmlWrappedValue_; + } else { + goog.asserts.fail('expected object of type SafeUrl, got \'' + + safeUrl + '\' of type ' + goog.typeOf(safeUrl)); + return 'type_error:SafeUrl'; + } +}; + + +/** + * Creates a SafeUrl 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 SafeUrl. + * @return {!goog.html.SafeUrl} A SafeUrl object initialized to {@code url}. + */ +goog.html.SafeUrl.fromConstant = function(url) { + return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse( + goog.string.Const.unwrap(url)); +}; + + +/** + * A pattern that matches Blob or data types that can have SafeUrls created + * from URL.createObjectURL(blob) or via a data: URI. Only matches image and + * video types, currently. + * @const + * @private + */ +goog.html.SAFE_MIME_TYPE_PATTERN_ = + /^(?:image\/(?:bmp|gif|jpeg|jpg|png|tiff|webp)|video\/(?:mpeg|mp4|ogg|webm))$/i; + + +/** + * Creates a SafeUrl wrapping a blob URL for the given {@code blob}. + * + * The blob URL is created with {@code URL.createObjectURL}. If the MIME type + * for {@code blob} is not of a known safe image or video MIME type, then the + * SafeUrl will wrap {@link #INNOCUOUS_STRING}. + * + * @see http://www.w3.org/TR/FileAPI/#url + * @param {!Blob} blob + * @return {!goog.html.SafeUrl} The blob URL, or an innocuous string wrapped + * as a SafeUrl. + */ +goog.html.SafeUrl.fromBlob = function(blob) { + var url = goog.html.SAFE_MIME_TYPE_PATTERN_.test(blob.type) ? + goog.fs.url.createObjectUrl(blob) : + goog.html.SafeUrl.INNOCUOUS_STRING; + return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse(url); +}; + + +/** + * Matches a base-64 data URL, with the first match group being the MIME type. + * @const + * @private + */ +goog.html.DATA_URL_PATTERN_ = /^data:([^;,]*);base64,[a-z0-9+\/]+=*$/i; + + +/** + * Creates a SafeUrl wrapping a data: URL, after validating it matches a + * known-safe image or video MIME type. + * + * @param {string} dataUrl A valid base64 data URL with one of the whitelisted + * image or video MIME types. + * @return {!goog.html.SafeUrl} A matching safe URL, or {@link INNOCUOUS_STRING} + * wrapped as a SafeUrl if it does not pass. + */ +goog.html.SafeUrl.fromDataUrl = function(dataUrl) { + // There's a slight risk here that a browser sniffs the content type if it + // doesn't know the MIME type and executes HTML within the data: URL. For this + // to cause XSS it would also have to execute the HTML in the same origin + // of the page with the link. It seems unlikely that both of these will + // happen, particularly in not really old IEs. + var match = dataUrl.match(goog.html.DATA_URL_PATTERN_); + var valid = match && goog.html.SAFE_MIME_TYPE_PATTERN_.test(match[1]); + return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse( + valid ? dataUrl : goog.html.SafeUrl.INNOCUOUS_STRING); +}; + + +/** + * Creates a SafeUrl wrapping a tel: URL. + * + * @param {string} telUrl A tel URL. + * @return {!goog.html.SafeUrl} A matching safe URL, or {@link INNOCUOUS_STRING} + * wrapped as a SafeUrl if it does not pass. + */ +goog.html.SafeUrl.fromTelUrl = function(telUrl) { + // There's a risk that a tel: URL could immediately place a call once + // clicked, without requiring user confirmation. For that reason it is + // handled in this separate function. + if (!goog.string.caseInsensitiveStartsWith(telUrl, 'tel:')) { + telUrl = goog.html.SafeUrl.INNOCUOUS_STRING; + } + return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse( + telUrl); +}; + + +/** + * A pattern that recognizes a commonly useful subset of URLs that satisfy + * the SafeUrl contract. + * + * This regular expression matches a subset of URLs that will not cause script + * execution if used in URL context within a HTML document. Specifically, this + * regular expression matches if (comment from here on and regex copied from + * Soy's EscapingConventions): + * (1) Either a protocol in a whitelist (http, https, mailto or ftp). + * (2) or no protocol. A protocol must be followed by a colon. The below + * allows that by allowing colons only after one of the characters [/?#]. + * A colon after a hash (#) must be in the fragment. + * Otherwise, a colon after a (?) must be in a query. + * Otherwise, a colon after a single solidus (/) must be in a path. + * Otherwise, a colon after a double solidus (//) must be in the authority + * (before port). + * + * The pattern disallows &, used in HTML entity declarations before + * one of the characters in [/?#]. This disallows HTML entities used in the + * protocol name, which should never happen, e.g. "http" for "http". + * It also disallows HTML entities in the first path part of a relative path, + * e.g. "foo<bar/baz". Our existing escaping functions should not produce + * that. More importantly, it disallows masking of a colon, + * e.g. "javascript:...". + * + * @private + * @const {!RegExp} + */ +goog.html.SAFE_URL_PATTERN_ = + /^(?:(?:https?|mailto|ftp):|[^&:/?#]*(?:[/?#]|$))/i; + + +/** + * Creates a SafeUrl object from {@code url}. If {@code url} is a + * goog.html.SafeUrl then it is simply returned. Otherwise the input string is + * validated to match a pattern of commonly used safe URLs. + * + * {@code url} may be a URL with the http, https, mailto or ftp scheme, + * or a relative URL (i.e., a URL without a scheme; specifically, a + * scheme-relative, absolute-path-relative, or path-relative URL). + * + * @see http://url.spec.whatwg.org/#concept-relative-url + * @param {string|!goog.string.TypedString} url The URL to validate. + * @return {!goog.html.SafeUrl} The validated URL, wrapped as a SafeUrl. + */ +goog.html.SafeUrl.sanitize = function(url) { + if (url instanceof goog.html.SafeUrl) { + return url; + } else if (url.implementsGoogStringTypedString) { + url = url.getTypedStringValue(); + } else { + url = String(url); + } + if (!goog.html.SAFE_URL_PATTERN_.test(url)) { + url = goog.html.SafeUrl.INNOCUOUS_STRING; + } + return goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse(url); +}; + + +/** + * Type marker for the SafeUrl type, used to implement additional run-time + * type checking. + * @const {!Object} + * @private + */ +goog.html.SafeUrl.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = {}; + + +/** + * Package-internal utility method to create SafeUrl instances. + * + * @param {string} url The string to initialize the SafeUrl object with. + * @return {!goog.html.SafeUrl} The initialized SafeUrl object. + * @package + */ +goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse = function( + url) { + var safeUrl = new goog.html.SafeUrl(); + safeUrl.privateDoNotAccessOrElseSafeHtmlWrappedValue_ = url; + return safeUrl; +}; + + +/** + * A SafeUrl corresponding to the special about:blank url. + * @const {!goog.html.SafeUrl} + */ +goog.html.SafeUrl.ABOUT_BLANK = + goog.html.SafeUrl.createSafeUrlSecurityPrivateDoNotAccessOrElse( + 'about:blank'); |