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Diffstat (limited to 'assets/viz/2/goog/html/safestylesheet.js')
-rw-r--r-- | assets/viz/2/goog/html/safestylesheet.js | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/assets/viz/2/goog/html/safestylesheet.js b/assets/viz/2/goog/html/safestylesheet.js new file mode 100644 index 0000000..65a81b0 --- /dev/null +++ b/assets/viz/2/goog/html/safestylesheet.js @@ -0,0 +1,278 @@ +// Copyright 2014 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 SafeStyleSheet type and its builders. + * + * TODO(xtof): Link to document stating type contract. + */ + +goog.provide('goog.html.SafeStyleSheet'); + +goog.require('goog.array'); +goog.require('goog.asserts'); +goog.require('goog.string'); +goog.require('goog.string.Const'); +goog.require('goog.string.TypedString'); + + + +/** + * A string-like object which represents a CSS style sheet and that carries the + * security type contract that its value, as a string, will not cause untrusted + * script execution (XSS) when evaluated as CSS in a browser. + * + * Instances of this type must be created via the factory method + * {@code goog.html.SafeStyleSheet.fromConstant} 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. + * + * A SafeStyleSheet's string representation can safely be interpolated as the + * content of a style element within HTML. The SafeStyleSheet string should + * not be escaped before interpolation. + * + * Values of this type must be composable, i.e. for any two values + * {@code styleSheet1} and {@code styleSheet2} of this type, + * {@code goog.html.SafeStyleSheet.unwrap(styleSheet1) + + * goog.html.SafeStyleSheet.unwrap(styleSheet2)} must itself be a value that + * satisfies the SafeStyleSheet type constraint. This requirement implies that + * for any value {@code styleSheet} of this type, + * {@code goog.html.SafeStyleSheet.unwrap(styleSheet1)} must end in + * "beginning of rule" context. + + * A SafeStyleSheet can be constructed via security-reviewed unchecked + * conversions. In this case producers of SafeStyleSheet must ensure themselves + * that the SafeStyleSheet does not contain unsafe script. Note in particular + * that {@code <} is dangerous, even when inside CSS strings, and so should + * always be forbidden or CSS-escaped in user controlled input. For example, if + * {@code </style><script>evil</script>"} were interpolated + * inside a CSS string, it would break out of the context of the original + * style element and {@code evil} would execute. Also note that within an HTML + * style (raw text) element, HTML character references, such as + * {@code &lt;}, are not allowed. See + * + http://www.w3.org/TR/html5/scripting-1.html#restrictions-for-contents-of-script-elements + * (similar considerations apply to the style element). + * + * @see goog.html.SafeStyleSheet#fromConstant + * @constructor + * @final + * @struct + * @implements {goog.string.TypedString} + */ +goog.html.SafeStyleSheet = function() { + /** + * The contained value of this SafeStyleSheet. The field has a purposely + * ugly name to make (non-compiled) code that attempts to directly access this + * field stand out. + * @private {string} + */ + this.privateDoNotAccessOrElseSafeStyleSheetWrappedValue_ = ''; + + /** + * A type marker used to implement additional run-time type checking. + * @see goog.html.SafeStyleSheet#unwrap + * @const + * @private + */ + this.SAFE_STYLE_SHEET_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = + goog.html.SafeStyleSheet.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_; +}; + + +/** + * @override + * @const + */ +goog.html.SafeStyleSheet.prototype.implementsGoogStringTypedString = true; + + +/** + * Type marker for the SafeStyleSheet type, used to implement additional + * run-time type checking. + * @const {!Object} + * @private + */ +goog.html.SafeStyleSheet.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ = {}; + + +/** + * Creates a new SafeStyleSheet object by concatenating values. + * @param {...(!goog.html.SafeStyleSheet|!Array<!goog.html.SafeStyleSheet>)} + * var_args Values to concatenate. + * @return {!goog.html.SafeStyleSheet} + */ +goog.html.SafeStyleSheet.concat = function(var_args) { + var result = ''; + + /** + * @param {!goog.html.SafeStyleSheet|!Array<!goog.html.SafeStyleSheet>} + * argument + */ + var addArgument = function(argument) { + if (goog.isArray(argument)) { + goog.array.forEach(argument, addArgument); + } else { + result += goog.html.SafeStyleSheet.unwrap(argument); + } + }; + + goog.array.forEach(arguments, addArgument); + return goog.html.SafeStyleSheet + .createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(result); +}; + + +/** + * Creates a SafeStyleSheet object from a compile-time constant string. + * + * {@code styleSheet} must not have any < characters in it, so that + * the syntactic structure of the surrounding HTML is not affected. + * + * @param {!goog.string.Const} styleSheet A compile-time-constant string from + * which to create a SafeStyleSheet. + * @return {!goog.html.SafeStyleSheet} A SafeStyleSheet object initialized to + * {@code styleSheet}. + */ +goog.html.SafeStyleSheet.fromConstant = function(styleSheet) { + var styleSheetString = goog.string.Const.unwrap(styleSheet); + if (styleSheetString.length === 0) { + return goog.html.SafeStyleSheet.EMPTY; + } + // > is a valid character in CSS selectors and there's no strict need to + // block it if we already block <. + goog.asserts.assert( + !goog.string.contains(styleSheetString, '<'), + "Forbidden '<' character in style sheet string: " + styleSheetString); + return goog.html.SafeStyleSheet + .createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(styleSheetString); +}; + + +/** + * Returns this SafeStyleSheet's value as a string. + * + * IMPORTANT: In code where it is security relevant that an object's type is + * indeed {@code SafeStyleSheet}, use {@code goog.html.SafeStyleSheet.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 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.SafeStyleSheet#unwrap + * @override + */ +goog.html.SafeStyleSheet.prototype.getTypedStringValue = function() { + return this.privateDoNotAccessOrElseSafeStyleSheetWrappedValue_; +}; + + +if (goog.DEBUG) { + /** + * Returns a debug string-representation of this value. + * + * To obtain the actual string value wrapped in a SafeStyleSheet, use + * {@code goog.html.SafeStyleSheet.unwrap}. + * + * @see goog.html.SafeStyleSheet#unwrap + * @override + */ + goog.html.SafeStyleSheet.prototype.toString = function() { + return 'SafeStyleSheet{' + + this.privateDoNotAccessOrElseSafeStyleSheetWrappedValue_ + '}'; + }; +} + + +/** + * Performs a runtime check that the provided object is indeed a + * SafeStyleSheet object, and returns its value. + * + * @param {!goog.html.SafeStyleSheet} safeStyleSheet The object to extract from. + * @return {string} The safeStyleSheet 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.SafeStyleSheet.unwrap = function(safeStyleSheet) { + // Perform additional Run-time type-checking to ensure that + // safeStyleSheet 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 (safeStyleSheet instanceof goog.html.SafeStyleSheet && + safeStyleSheet.constructor === goog.html.SafeStyleSheet && + safeStyleSheet + .SAFE_STYLE_SHEET_TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_ === + goog.html.SafeStyleSheet.TYPE_MARKER_GOOG_HTML_SECURITY_PRIVATE_) { + return safeStyleSheet.privateDoNotAccessOrElseSafeStyleSheetWrappedValue_; + } else { + goog.asserts.fail('expected object of type SafeStyleSheet, got \'' + + safeStyleSheet + '\' of type ' + goog.typeOf(safeStyleSheet)); + return 'type_error:SafeStyleSheet'; + } +}; + + +/** + * Package-internal utility method to create SafeStyleSheet instances. + * + * @param {string} styleSheet The string to initialize the SafeStyleSheet + * object with. + * @return {!goog.html.SafeStyleSheet} The initialized SafeStyleSheet object. + * @package + */ +goog.html.SafeStyleSheet.createSafeStyleSheetSecurityPrivateDoNotAccessOrElse = + function(styleSheet) { + return new goog.html.SafeStyleSheet().initSecurityPrivateDoNotAccessOrElse_( + styleSheet); +}; + + +/** + * Called from createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(). This + * method exists only so that the compiler can dead code eliminate static + * fields (like EMPTY) when they're not accessed. + * @param {string} styleSheet + * @return {!goog.html.SafeStyleSheet} + * @private + */ +goog.html.SafeStyleSheet.prototype.initSecurityPrivateDoNotAccessOrElse_ = + function(styleSheet) { + this.privateDoNotAccessOrElseSafeStyleSheetWrappedValue_ = styleSheet; + return this; +}; + + +/** + * A SafeStyleSheet instance corresponding to the empty string. + * @const {!goog.html.SafeStyleSheet} + */ +goog.html.SafeStyleSheet.EMPTY = + goog.html.SafeStyleSheet + .createSafeStyleSheetSecurityPrivateDoNotAccessOrElse(''); |