dompurify
Version:
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. It's written in JavaScript and works in all modern browsers (Safari, Opera (15+), Internet Explorer (10+), Firefox and Chrome - as well as almost anything else usin
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text/typescript
/* eslint-disable @typescript-eslint/indent */
import type {
TrustedHTML,
TrustedTypesWindow,
} from 'trusted-types/lib/index.js';
import type { Config, UseProfilesConfig } from './config';
import * as TAGS from './tags.js';
import * as ATTRS from './attrs.js';
import * as EXPRESSIONS from './regexp.js';
import {
addToSet,
clone,
entries,
freeze,
arrayForEach,
arrayIsArray,
arrayLastIndexOf,
arrayPop,
arrayPush,
arraySplice,
stringMatch,
stringReplace,
stringToLowerCase,
stringToString,
stringIndexOf,
stringTrim,
regExpTest,
isRegex,
typeErrorCreate,
lookupGetter,
create,
objectHasOwnProperty,
stringifyValue,
} from './utils.js';
export type { Config } from './config';
declare const VERSION: string;
// https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
const NODE_TYPE = {
element: 1,
attribute: 2,
text: 3,
cdataSection: 4,
entityReference: 5, // Deprecated
entityNode: 6, // Deprecated
progressingInstruction: 7,
comment: 8,
document: 9,
documentType: 10,
documentFragment: 11,
notation: 12, // Deprecated
};
const getGlobal = function (): WindowLike {
return typeof window === 'undefined' ? null : window;
};
/**
* Creates a no-op policy for internal use only.
* Don't export this function outside this module!
* @param trustedTypes The policy factory.
* @param purifyHostElement The Script element used to load DOMPurify (to determine policy name suffix).
* @return The policy created (or null, if Trusted Types
* are not supported or creating the policy failed).
*/
const _createTrustedTypesPolicy = function (
trustedTypes: TrustedTypePolicyFactory,
purifyHostElement: HTMLScriptElement
) {
if (
typeof trustedTypes !== 'object' ||
typeof trustedTypes.createPolicy !== 'function'
) {
return null;
}
// Allow the callers to control the unique policy name
// by adding a data-tt-policy-suffix to the script element with the DOMPurify.
// Policy creation with duplicate names throws in Trusted Types.
let suffix = null;
const ATTR_NAME = 'data-tt-policy-suffix';
if (purifyHostElement && purifyHostElement.hasAttribute(ATTR_NAME)) {
suffix = purifyHostElement.getAttribute(ATTR_NAME);
}
const policyName = 'dompurify' + (suffix ? '#' + suffix : '');
try {
return trustedTypes.createPolicy(policyName, {
createHTML(html) {
return html;
},
createScriptURL(scriptUrl) {
return scriptUrl;
},
});
} catch (_) {
// Policy creation failed (most likely another DOMPurify script has
// already run). Skip creating the policy, as this will only cause errors
// if TT are enforced.
console.warn(
'TrustedTypes policy ' + policyName + ' could not be created.'
);
return null;
}
};
const _createHooksMap = function (): HooksMap {
return {
afterSanitizeAttributes: [],
afterSanitizeElements: [],
afterSanitizeShadowDOM: [],
beforeSanitizeAttributes: [],
beforeSanitizeElements: [],
beforeSanitizeShadowDOM: [],
uponSanitizeAttribute: [],
uponSanitizeElement: [],
uponSanitizeShadowNode: [],
};
};
function createDOMPurify(window: WindowLike = getGlobal()): DOMPurify {
const DOMPurify: DOMPurify = (root: WindowLike) => createDOMPurify(root);
DOMPurify.version = VERSION;
DOMPurify.removed = [];
if (
!window ||
!window.document ||
window.document.nodeType !== NODE_TYPE.document ||
!window.Element
) {
// Not running in a browser, provide a factory function
// so that you can pass your own Window
DOMPurify.isSupported = false;
return DOMPurify;
}
let { document } = window;
const originalDocument = document;
const currentScript: HTMLScriptElement =
originalDocument.currentScript as HTMLScriptElement;
const {
DocumentFragment,
HTMLTemplateElement,
Node,
Element,
NodeFilter,
NamedNodeMap = window.NamedNodeMap || (window as any).MozNamedAttrMap,
HTMLFormElement,
DOMParser,
trustedTypes,
} = window;
const ElementPrototype = Element.prototype;
const cloneNode = lookupGetter(ElementPrototype, 'cloneNode');
const remove = lookupGetter(ElementPrototype, 'remove');
const getNextSibling = lookupGetter(ElementPrototype, 'nextSibling');
const getChildNodes = lookupGetter(ElementPrototype, 'childNodes');
const getParentNode = lookupGetter(ElementPrototype, 'parentNode');
const getNodeType =
Node && Node.prototype ? lookupGetter(Node.prototype, 'nodeType') : null;
// As per issue #47, the web-components registry is inherited by a
// new document created via createHTMLDocument. As per the spec
// (http://w3c.github.io/webcomponents/spec/custom/#creating-and-passing-registries)
// a new empty registry is used when creating a template contents owner
// document, so we use that as our parent document to ensure nothing
// is inherited.
if (typeof HTMLTemplateElement === 'function') {
const template = document.createElement('template');
if (template.content && template.content.ownerDocument) {
document = template.content.ownerDocument;
}
}
let trustedTypesPolicy;
let emptyHTML = '';
const {
implementation,
createNodeIterator,
createDocumentFragment,
getElementsByTagName,
} = document;
const { importNode } = originalDocument;
let hooks = _createHooksMap();
/**
* Expose whether this browser supports running the full DOMPurify.
*/
DOMPurify.isSupported =
typeof entries === 'function' &&
typeof getParentNode === 'function' &&
implementation &&
implementation.createHTMLDocument !== undefined;
const {
MUSTACHE_EXPR,
ERB_EXPR,
TMPLIT_EXPR,
DATA_ATTR,
ARIA_ATTR,
IS_SCRIPT_OR_DATA,
ATTR_WHITESPACE,
CUSTOM_ELEMENT,
} = EXPRESSIONS;
let { IS_ALLOWED_URI } = EXPRESSIONS;
/**
* We consider the elements and attributes below to be safe. Ideally
* don't add any new ones but feel free to remove unwanted ones.
*/
/* allowed element names */
let ALLOWED_TAGS = null;
const DEFAULT_ALLOWED_TAGS = addToSet({}, [
...TAGS.html,
...TAGS.svg,
...TAGS.svgFilters,
...TAGS.mathMl,
...TAGS.text,
]);
/* Allowed attribute names */
let ALLOWED_ATTR = null;
const DEFAULT_ALLOWED_ATTR = addToSet({}, [
...ATTRS.html,
...ATTRS.svg,
...ATTRS.mathMl,
...ATTRS.xml,
]);
/*
* Configure how DOMPurify should handle custom elements and their attributes as well as customized built-in elements.
* @property {RegExp|Function|null} tagNameCheck one of [null, regexPattern, predicate]. Default: `null` (disallow any custom elements)
* @property {RegExp|Function|null} attributeNameCheck one of [null, regexPattern, predicate]. Default: `null` (disallow any attributes not on the allow list)
* @property {boolean} allowCustomizedBuiltInElements allow custom elements derived from built-ins if they pass CUSTOM_ELEMENT_HANDLING.tagNameCheck. Default: `false`.
*/
let CUSTOM_ELEMENT_HANDLING = Object.seal(
create(null, {
tagNameCheck: {
writable: true,
configurable: false,
enumerable: true,
value: null,
},
attributeNameCheck: {
writable: true,
configurable: false,
enumerable: true,
value: null,
},
allowCustomizedBuiltInElements: {
writable: true,
configurable: false,
enumerable: true,
value: false,
},
})
);
/* Explicitly forbidden tags (overrides ALLOWED_TAGS/ADD_TAGS) */
let FORBID_TAGS = null;
/* Explicitly forbidden attributes (overrides ALLOWED_ATTR/ADD_ATTR) */
let FORBID_ATTR = null;
/* Config object to store ADD_TAGS/ADD_ATTR functions (when used as functions) */
const EXTRA_ELEMENT_HANDLING = Object.seal(
create(null, {
tagCheck: {
writable: true,
configurable: false,
enumerable: true,
value: null,
},
attributeCheck: {
writable: true,
configurable: false,
enumerable: true,
value: null,
},
})
);
/* Decide if ARIA attributes are okay */
let ALLOW_ARIA_ATTR = true;
/* Decide if custom data attributes are okay */
let ALLOW_DATA_ATTR = true;
/* Decide if unknown protocols are okay */
let ALLOW_UNKNOWN_PROTOCOLS = false;
/* Decide if self-closing tags in attributes are allowed.
* Usually removed due to a mXSS issue in jQuery 3.0 */
let ALLOW_SELF_CLOSE_IN_ATTR = true;
/* Output should be safe for common template engines.
* This means, DOMPurify removes data attributes, mustaches and ERB
*/
let SAFE_FOR_TEMPLATES = false;
/* Output should be safe even for XML used within HTML and alike.
* This means, DOMPurify removes comments when containing risky content.
*/
let SAFE_FOR_XML = true;
/* Decide if document with <html>... should be returned */
let WHOLE_DOCUMENT = false;
/* Track whether config is already set on this instance of DOMPurify. */
let SET_CONFIG = false;
/* Decide if all elements (e.g. style, script) must be children of
* document.body. By default, browsers might move them to document.head */
let FORCE_BODY = false;
/* Decide if a DOM `HTMLBodyElement` should be returned, instead of a html
* string (or a TrustedHTML object if Trusted Types are supported).
* If `WHOLE_DOCUMENT` is enabled a `HTMLHtmlElement` will be returned instead
*/
let RETURN_DOM = false;
/* Decide if a DOM `DocumentFragment` should be returned, instead of a html
* string (or a TrustedHTML object if Trusted Types are supported) */
let RETURN_DOM_FRAGMENT = false;
/* Try to return a Trusted Type object instead of a string, return a string in
* case Trusted Types are not supported */
let RETURN_TRUSTED_TYPE = false;
/* Output should be free from DOM clobbering attacks?
* This sanitizes markups named with colliding, clobberable built-in DOM APIs.
*/
let SANITIZE_DOM = true;
/* Achieve full DOM Clobbering protection by isolating the namespace of named
* properties and JS variables, mitigating attacks that abuse the HTML/DOM spec rules.
*
* HTML/DOM spec rules that enable DOM Clobbering:
* - Named Access on Window (§7.3.3)
* - DOM Tree Accessors (§3.1.5)
* - Form Element Parent-Child Relations (§4.10.3)
* - Iframe srcdoc / Nested WindowProxies (§4.8.5)
* - HTMLCollection (§4.2.10.2)
*
* Namespace isolation is implemented by prefixing `id` and `name` attributes
* with a constant string, i.e., `user-content-`
*/
let SANITIZE_NAMED_PROPS = false;
const SANITIZE_NAMED_PROPS_PREFIX = 'user-content-';
/* Keep element content when removing element? */
let KEEP_CONTENT = true;
/* If a `Node` is passed to sanitize(), then performs sanitization in-place instead
* of importing it into a new Document and returning a sanitized copy */
let IN_PLACE = false;
/* Allow usage of profiles like html, svg and mathMl */
let USE_PROFILES: UseProfilesConfig | false = {};
/* Tags to ignore content of when KEEP_CONTENT is true */
let FORBID_CONTENTS = null;
const DEFAULT_FORBID_CONTENTS = addToSet({}, [
'annotation-xml',
'audio',
'colgroup',
'desc',
'foreignobject',
'head',
'iframe',
'math',
'mi',
'mn',
'mo',
'ms',
'mtext',
'noembed',
'noframes',
'noscript',
'plaintext',
'script',
'style',
'svg',
'template',
'thead',
'title',
'video',
'xmp',
]);
/* Tags that are safe for data: URIs */
let DATA_URI_TAGS = null;
const DEFAULT_DATA_URI_TAGS = addToSet({}, [
'audio',
'video',
'img',
'source',
'image',
'track',
]);
/* Attributes safe for values like "javascript:" */
let URI_SAFE_ATTRIBUTES = null;
const DEFAULT_URI_SAFE_ATTRIBUTES = addToSet({}, [
'alt',
'class',
'for',
'id',
'label',
'name',
'pattern',
'placeholder',
'role',
'summary',
'title',
'value',
'style',
'xmlns',
]);
const MATHML_NAMESPACE = 'http://www.w3.org/1998/Math/MathML';
const SVG_NAMESPACE = 'http://www.w3.org/2000/svg';
const HTML_NAMESPACE = 'http://www.w3.org/1999/xhtml';
/* Document namespace */
let NAMESPACE = HTML_NAMESPACE;
let IS_EMPTY_INPUT = false;
/* Allowed XHTML+XML namespaces */
let ALLOWED_NAMESPACES = null;
const DEFAULT_ALLOWED_NAMESPACES = addToSet(
{},
[MATHML_NAMESPACE, SVG_NAMESPACE, HTML_NAMESPACE],
stringToString
);
let MATHML_TEXT_INTEGRATION_POINTS = addToSet({}, [
'mi',
'mo',
'mn',
'ms',
'mtext',
]);
let HTML_INTEGRATION_POINTS = addToSet({}, ['annotation-xml']);
// Certain elements are allowed in both SVG and HTML
// namespace. We need to specify them explicitly
// so that they don't get erroneously deleted from
// HTML namespace.
const COMMON_SVG_AND_HTML_ELEMENTS = addToSet({}, [
'title',
'style',
'font',
'a',
'script',
]);
/* Parsing of strict XHTML documents */
let PARSER_MEDIA_TYPE: null | DOMParserSupportedType = null;
const SUPPORTED_PARSER_MEDIA_TYPES = ['application/xhtml+xml', 'text/html'];
const DEFAULT_PARSER_MEDIA_TYPE = 'text/html';
let transformCaseFunc: null | Parameters<typeof addToSet>[2] = null;
/* Keep a reference to config to pass to hooks */
let CONFIG: Config | null = null;
/* Ideally, do not touch anything below this line */
/* ______________________________________________ */
const formElement = document.createElement('form');
const isRegexOrFunction = function (
testValue: unknown
): testValue is Function | RegExp {
return testValue instanceof RegExp || testValue instanceof Function;
};
/**
* _parseConfig
*
* @param cfg optional config literal
*/
// eslint-disable-next-line complexity
const _parseConfig = function (cfg: Config = {}): void {
if (CONFIG && CONFIG === cfg) {
return;
}
/* Shield configuration object from tampering */
if (!cfg || typeof cfg !== 'object') {
cfg = {};
}
/* Shield configuration object from prototype pollution */
cfg = clone(cfg);
PARSER_MEDIA_TYPE =
// eslint-disable-next-line unicorn/prefer-includes
SUPPORTED_PARSER_MEDIA_TYPES.indexOf(cfg.PARSER_MEDIA_TYPE) === -1
? DEFAULT_PARSER_MEDIA_TYPE
: cfg.PARSER_MEDIA_TYPE;
// HTML tags and attributes are not case-sensitive, converting to lowercase. Keeping XHTML as is.
transformCaseFunc =
PARSER_MEDIA_TYPE === 'application/xhtml+xml'
? stringToString
: stringToLowerCase;
/* Set configuration parameters */
ALLOWED_TAGS =
objectHasOwnProperty(cfg, 'ALLOWED_TAGS') &&
arrayIsArray(cfg.ALLOWED_TAGS)
? addToSet({}, cfg.ALLOWED_TAGS, transformCaseFunc)
: DEFAULT_ALLOWED_TAGS;
ALLOWED_ATTR =
objectHasOwnProperty(cfg, 'ALLOWED_ATTR') &&
arrayIsArray(cfg.ALLOWED_ATTR)
? addToSet({}, cfg.ALLOWED_ATTR, transformCaseFunc)
: DEFAULT_ALLOWED_ATTR;
ALLOWED_NAMESPACES =
objectHasOwnProperty(cfg, 'ALLOWED_NAMESPACES') &&
arrayIsArray(cfg.ALLOWED_NAMESPACES)
? addToSet({}, cfg.ALLOWED_NAMESPACES, stringToString)
: DEFAULT_ALLOWED_NAMESPACES;
URI_SAFE_ATTRIBUTES =
objectHasOwnProperty(cfg, 'ADD_URI_SAFE_ATTR') &&
arrayIsArray(cfg.ADD_URI_SAFE_ATTR)
? addToSet(
clone(DEFAULT_URI_SAFE_ATTRIBUTES),
cfg.ADD_URI_SAFE_ATTR,
transformCaseFunc
)
: DEFAULT_URI_SAFE_ATTRIBUTES;
DATA_URI_TAGS =
objectHasOwnProperty(cfg, 'ADD_DATA_URI_TAGS') &&
arrayIsArray(cfg.ADD_DATA_URI_TAGS)
? addToSet(
clone(DEFAULT_DATA_URI_TAGS),
cfg.ADD_DATA_URI_TAGS,
transformCaseFunc
)
: DEFAULT_DATA_URI_TAGS;
FORBID_CONTENTS =
objectHasOwnProperty(cfg, 'FORBID_CONTENTS') &&
arrayIsArray(cfg.FORBID_CONTENTS)
? addToSet({}, cfg.FORBID_CONTENTS, transformCaseFunc)
: DEFAULT_FORBID_CONTENTS;
FORBID_TAGS =
objectHasOwnProperty(cfg, 'FORBID_TAGS') && arrayIsArray(cfg.FORBID_TAGS)
? addToSet({}, cfg.FORBID_TAGS, transformCaseFunc)
: clone({});
FORBID_ATTR =
objectHasOwnProperty(cfg, 'FORBID_ATTR') && arrayIsArray(cfg.FORBID_ATTR)
? addToSet({}, cfg.FORBID_ATTR, transformCaseFunc)
: clone({});
USE_PROFILES = objectHasOwnProperty(cfg, 'USE_PROFILES')
? cfg.USE_PROFILES && typeof cfg.USE_PROFILES === 'object'
? clone(cfg.USE_PROFILES)
: cfg.USE_PROFILES
: false;
ALLOW_ARIA_ATTR = cfg.ALLOW_ARIA_ATTR !== false; // Default true
ALLOW_DATA_ATTR = cfg.ALLOW_DATA_ATTR !== false; // Default true
ALLOW_UNKNOWN_PROTOCOLS = cfg.ALLOW_UNKNOWN_PROTOCOLS || false; // Default false
ALLOW_SELF_CLOSE_IN_ATTR = cfg.ALLOW_SELF_CLOSE_IN_ATTR !== false; // Default true
SAFE_FOR_TEMPLATES = cfg.SAFE_FOR_TEMPLATES || false; // Default false
SAFE_FOR_XML = cfg.SAFE_FOR_XML !== false; // Default true
WHOLE_DOCUMENT = cfg.WHOLE_DOCUMENT || false; // Default false
RETURN_DOM = cfg.RETURN_DOM || false; // Default false
RETURN_DOM_FRAGMENT = cfg.RETURN_DOM_FRAGMENT || false; // Default false
RETURN_TRUSTED_TYPE = cfg.RETURN_TRUSTED_TYPE || false; // Default false
FORCE_BODY = cfg.FORCE_BODY || false; // Default false
SANITIZE_DOM = cfg.SANITIZE_DOM !== false; // Default true
SANITIZE_NAMED_PROPS = cfg.SANITIZE_NAMED_PROPS || false; // Default false
KEEP_CONTENT = cfg.KEEP_CONTENT !== false; // Default true
IN_PLACE = cfg.IN_PLACE || false; // Default false
IS_ALLOWED_URI = isRegex(cfg.ALLOWED_URI_REGEXP)
? cfg.ALLOWED_URI_REGEXP
: EXPRESSIONS.IS_ALLOWED_URI; // Default regexp
NAMESPACE =
typeof cfg.NAMESPACE === 'string' ? cfg.NAMESPACE : HTML_NAMESPACE; // Default HTML namespace
MATHML_TEXT_INTEGRATION_POINTS =
objectHasOwnProperty(cfg, 'MATHML_TEXT_INTEGRATION_POINTS') &&
cfg.MATHML_TEXT_INTEGRATION_POINTS &&
typeof cfg.MATHML_TEXT_INTEGRATION_POINTS === 'object'
? clone(cfg.MATHML_TEXT_INTEGRATION_POINTS)
: addToSet({}, ['mi', 'mo', 'mn', 'ms', 'mtext']); // Default built-in map
HTML_INTEGRATION_POINTS =
objectHasOwnProperty(cfg, 'HTML_INTEGRATION_POINTS') &&
cfg.HTML_INTEGRATION_POINTS &&
typeof cfg.HTML_INTEGRATION_POINTS === 'object'
? clone(cfg.HTML_INTEGRATION_POINTS)
: addToSet({}, ['annotation-xml']); // Default built-in map
const customElementHandling =
objectHasOwnProperty(cfg, 'CUSTOM_ELEMENT_HANDLING') &&
cfg.CUSTOM_ELEMENT_HANDLING &&
typeof cfg.CUSTOM_ELEMENT_HANDLING === 'object'
? clone(cfg.CUSTOM_ELEMENT_HANDLING)
: create(null);
CUSTOM_ELEMENT_HANDLING = create(null);
if (
objectHasOwnProperty(customElementHandling, 'tagNameCheck') &&
isRegexOrFunction(customElementHandling.tagNameCheck)
) {
CUSTOM_ELEMENT_HANDLING.tagNameCheck = customElementHandling.tagNameCheck; // Default undefined
}
if (
objectHasOwnProperty(customElementHandling, 'attributeNameCheck') &&
isRegexOrFunction(customElementHandling.attributeNameCheck)
) {
CUSTOM_ELEMENT_HANDLING.attributeNameCheck =
customElementHandling.attributeNameCheck; // Default undefined
}
if (
objectHasOwnProperty(
customElementHandling,
'allowCustomizedBuiltInElements'
) &&
typeof customElementHandling.allowCustomizedBuiltInElements === 'boolean'
) {
CUSTOM_ELEMENT_HANDLING.allowCustomizedBuiltInElements =
customElementHandling.allowCustomizedBuiltInElements; // Default undefined
}
if (SAFE_FOR_TEMPLATES) {
ALLOW_DATA_ATTR = false;
}
if (RETURN_DOM_FRAGMENT) {
RETURN_DOM = true;
}
/* Parse profile info */
if (USE_PROFILES) {
ALLOWED_TAGS = addToSet({}, TAGS.text);
ALLOWED_ATTR = create(null);
if (USE_PROFILES.html === true) {
addToSet(ALLOWED_TAGS, TAGS.html);
addToSet(ALLOWED_ATTR, ATTRS.html);
}
if (USE_PROFILES.svg === true) {
addToSet(ALLOWED_TAGS, TAGS.svg);
addToSet(ALLOWED_ATTR, ATTRS.svg);
addToSet(ALLOWED_ATTR, ATTRS.xml);
}
if (USE_PROFILES.svgFilters === true) {
addToSet(ALLOWED_TAGS, TAGS.svgFilters);
addToSet(ALLOWED_ATTR, ATTRS.svg);
addToSet(ALLOWED_ATTR, ATTRS.xml);
}
if (USE_PROFILES.mathMl === true) {
addToSet(ALLOWED_TAGS, TAGS.mathMl);
addToSet(ALLOWED_ATTR, ATTRS.mathMl);
addToSet(ALLOWED_ATTR, ATTRS.xml);
}
}
/* Always reset function-based ADD_TAGS / ADD_ATTR checks to prevent
* leaking across calls when switching from function to array config */
EXTRA_ELEMENT_HANDLING.tagCheck = null;
EXTRA_ELEMENT_HANDLING.attributeCheck = null;
/* Merge configuration parameters */
if (objectHasOwnProperty(cfg, 'ADD_TAGS')) {
if (typeof cfg.ADD_TAGS === 'function') {
EXTRA_ELEMENT_HANDLING.tagCheck = cfg.ADD_TAGS;
} else if (arrayIsArray(cfg.ADD_TAGS)) {
if (ALLOWED_TAGS === DEFAULT_ALLOWED_TAGS) {
ALLOWED_TAGS = clone(ALLOWED_TAGS);
}
addToSet(ALLOWED_TAGS, cfg.ADD_TAGS, transformCaseFunc);
}
}
if (objectHasOwnProperty(cfg, 'ADD_ATTR')) {
if (typeof cfg.ADD_ATTR === 'function') {
EXTRA_ELEMENT_HANDLING.attributeCheck = cfg.ADD_ATTR;
} else if (arrayIsArray(cfg.ADD_ATTR)) {
if (ALLOWED_ATTR === DEFAULT_ALLOWED_ATTR) {
ALLOWED_ATTR = clone(ALLOWED_ATTR);
}
addToSet(ALLOWED_ATTR, cfg.ADD_ATTR, transformCaseFunc);
}
}
if (
objectHasOwnProperty(cfg, 'ADD_URI_SAFE_ATTR') &&
arrayIsArray(cfg.ADD_URI_SAFE_ATTR)
) {
addToSet(URI_SAFE_ATTRIBUTES, cfg.ADD_URI_SAFE_ATTR, transformCaseFunc);
}
if (
objectHasOwnProperty(cfg, 'FORBID_CONTENTS') &&
arrayIsArray(cfg.FORBID_CONTENTS)
) {
if (FORBID_CONTENTS === DEFAULT_FORBID_CONTENTS) {
FORBID_CONTENTS = clone(FORBID_CONTENTS);
}
addToSet(FORBID_CONTENTS, cfg.FORBID_CONTENTS, transformCaseFunc);
}
if (
objectHasOwnProperty(cfg, 'ADD_FORBID_CONTENTS') &&
arrayIsArray(cfg.ADD_FORBID_CONTENTS)
) {
if (FORBID_CONTENTS === DEFAULT_FORBID_CONTENTS) {
FORBID_CONTENTS = clone(FORBID_CONTENTS);
}
addToSet(FORBID_CONTENTS, cfg.ADD_FORBID_CONTENTS, transformCaseFunc);
}
/* Add #text in case KEEP_CONTENT is set to true */
if (KEEP_CONTENT) {
ALLOWED_TAGS['#text'] = true;
}
/* Add html, head and body to ALLOWED_TAGS in case WHOLE_DOCUMENT is true */
if (WHOLE_DOCUMENT) {
addToSet(ALLOWED_TAGS, ['html', 'head', 'body']);
}
/* Add tbody to ALLOWED_TAGS in case tables are permitted, see #286, #365 */
if (ALLOWED_TAGS.table) {
addToSet(ALLOWED_TAGS, ['tbody']);
delete FORBID_TAGS.tbody;
}
if (cfg.TRUSTED_TYPES_POLICY) {
if (typeof cfg.TRUSTED_TYPES_POLICY.createHTML !== 'function') {
throw typeErrorCreate(
'TRUSTED_TYPES_POLICY configuration option must provide a "createHTML" hook.'
);
}
if (typeof cfg.TRUSTED_TYPES_POLICY.createScriptURL !== 'function') {
throw typeErrorCreate(
'TRUSTED_TYPES_POLICY configuration option must provide a "createScriptURL" hook.'
);
}
// Overwrite existing TrustedTypes policy.
trustedTypesPolicy = cfg.TRUSTED_TYPES_POLICY;
// Sign local variables required by `sanitize`.
emptyHTML = trustedTypesPolicy.createHTML('');
} else {
// Uninitialized policy, attempt to initialize the internal dompurify policy.
if (trustedTypesPolicy === undefined) {
trustedTypesPolicy = _createTrustedTypesPolicy(
trustedTypes,
currentScript
);
}
// If creating the internal policy succeeded sign internal variables.
if (trustedTypesPolicy !== null && typeof emptyHTML === 'string') {
emptyHTML = trustedTypesPolicy.createHTML('');
}
}
// Prevent further manipulation of configuration.
// Not available in IE8, Safari 5, etc.
if (freeze) {
freeze(cfg);
}
CONFIG = cfg;
};
/* Keep track of all possible SVG and MathML tags
* so that we can perform the namespace checks
* correctly. */
const ALL_SVG_TAGS = addToSet({}, [
...TAGS.svg,
...TAGS.svgFilters,
...TAGS.svgDisallowed,
]);
const ALL_MATHML_TAGS = addToSet({}, [
...TAGS.mathMl,
...TAGS.mathMlDisallowed,
]);
/**
* @param element a DOM element whose namespace is being checked
* @returns Return false if the element has a
* namespace that a spec-compliant parser would never
* return. Return true otherwise.
*/
const _checkValidNamespace = function (element: Element): boolean {
let parent = getParentNode(element);
// In JSDOM, if we're inside shadow DOM, then parentNode
// can be null. We just simulate parent in this case.
if (!parent || !parent.tagName) {
parent = {
namespaceURI: NAMESPACE,
tagName: 'template',
};
}
const tagName = stringToLowerCase(element.tagName);
const parentTagName = stringToLowerCase(parent.tagName);
if (!ALLOWED_NAMESPACES[element.namespaceURI]) {
return false;
}
if (element.namespaceURI === SVG_NAMESPACE) {
// The only way to switch from HTML namespace to SVG
// is via <svg>. If it happens via any other tag, then
// it should be killed.
if (parent.namespaceURI === HTML_NAMESPACE) {
return tagName === 'svg';
}
// The only way to switch from MathML to SVG is via`
// svg if parent is either <annotation-xml> or MathML
// text integration points.
if (parent.namespaceURI === MATHML_NAMESPACE) {
return (
tagName === 'svg' &&
(parentTagName === 'annotation-xml' ||
MATHML_TEXT_INTEGRATION_POINTS[parentTagName])
);
}
// We only allow elements that are defined in SVG
// spec. All others are disallowed in SVG namespace.
return Boolean(ALL_SVG_TAGS[tagName]);
}
if (element.namespaceURI === MATHML_NAMESPACE) {
// The only way to switch from HTML namespace to MathML
// is via <math>. If it happens via any other tag, then
// it should be killed.
if (parent.namespaceURI === HTML_NAMESPACE) {
return tagName === 'math';
}
// The only way to switch from SVG to MathML is via
// <math> and HTML integration points
if (parent.namespaceURI === SVG_NAMESPACE) {
return tagName === 'math' && HTML_INTEGRATION_POINTS[parentTagName];
}
// We only allow elements that are defined in MathML
// spec. All others are disallowed in MathML namespace.
return Boolean(ALL_MATHML_TAGS[tagName]);
}
if (element.namespaceURI === HTML_NAMESPACE) {
// The only way to switch from SVG to HTML is via
// HTML integration points, and from MathML to HTML
// is via MathML text integration points
if (
parent.namespaceURI === SVG_NAMESPACE &&
!HTML_INTEGRATION_POINTS[parentTagName]
) {
return false;
}
if (
parent.namespaceURI === MATHML_NAMESPACE &&
!MATHML_TEXT_INTEGRATION_POINTS[parentTagName]
) {
return false;
}
// We disallow tags that are specific for MathML
// or SVG and should never appear in HTML namespace
return (
!ALL_MATHML_TAGS[tagName] &&
(COMMON_SVG_AND_HTML_ELEMENTS[tagName] || !ALL_SVG_TAGS[tagName])
);
}
// For XHTML and XML documents that support custom namespaces
if (
PARSER_MEDIA_TYPE === 'application/xhtml+xml' &&
ALLOWED_NAMESPACES[element.namespaceURI]
) {
return true;
}
// The code should never reach this place (this means
// that the element somehow got namespace that is not
// HTML, SVG, MathML or allowed via ALLOWED_NAMESPACES).
// Return false just in case.
return false;
};
/**
* _forceRemove
*
* @param node a DOM node
*/
const _forceRemove = function (node: Node): void {
arrayPush(DOMPurify.removed, { element: node });
try {
// eslint-disable-next-line unicorn/prefer-dom-node-remove
getParentNode(node).removeChild(node);
} catch (_) {
remove(node);
}
};
/**
* _removeAttribute
*
* @param name an Attribute name
* @param element a DOM node
*/
const _removeAttribute = function (name: string, element: Element): void {
try {
arrayPush(DOMPurify.removed, {
attribute: element.getAttributeNode(name),
from: element,
});
} catch (_) {
arrayPush(DOMPurify.removed, {
attribute: null,
from: element,
});
}
element.removeAttribute(name);
// We void attribute values for unremovable "is" attributes
if (name === 'is') {
if (RETURN_DOM || RETURN_DOM_FRAGMENT) {
try {
_forceRemove(element);
} catch (_) {}
} else {
try {
element.setAttribute(name, '');
} catch (_) {}
}
}
};
/**
* _initDocument
*
* @param dirty - a string of dirty markup
* @return a DOM, filled with the dirty markup
*/
const _initDocument = function (dirty: string): Document {
/* Create a HTML document */
let doc = null;
let leadingWhitespace = null;
if (FORCE_BODY) {
dirty = '<remove></remove>' + dirty;
} else {
/* If FORCE_BODY isn't used, leading whitespace needs to be preserved manually */
const matches = stringMatch(dirty, /^[\r\n\t ]+/);
leadingWhitespace = matches && matches[0];
}
if (
PARSER_MEDIA_TYPE === 'application/xhtml+xml' &&
NAMESPACE === HTML_NAMESPACE
) {
// Root of XHTML doc must contain xmlns declaration (see https://www.w3.org/TR/xhtml1/normative.html#strict)
dirty =
'<html xmlns="http://www.w3.org/1999/xhtml"><head></head><body>' +
dirty +
'</body></html>';
}
const dirtyPayload = trustedTypesPolicy
? trustedTypesPolicy.createHTML(dirty)
: dirty;
/*
* Use the DOMParser API by default, fallback later if needs be
* DOMParser not work for svg when has multiple root element.
*/
if (NAMESPACE === HTML_NAMESPACE) {
try {
doc = new DOMParser().parseFromString(dirtyPayload, PARSER_MEDIA_TYPE);
} catch (_) {}
}
/* Use createHTMLDocument in case DOMParser is not available */
if (!doc || !doc.documentElement) {
doc = implementation.createDocument(NAMESPACE, 'template', null);
try {
doc.documentElement.innerHTML = IS_EMPTY_INPUT
? emptyHTML
: dirtyPayload;
} catch (_) {
// Syntax error if dirtyPayload is invalid xml
}
}
const body = doc.body || doc.documentElement;
if (dirty && leadingWhitespace) {
body.insertBefore(
document.createTextNode(leadingWhitespace),
body.childNodes[0] || null
);
}
/* Work on whole document or just its body */
if (NAMESPACE === HTML_NAMESPACE) {
return getElementsByTagName.call(
doc,
WHOLE_DOCUMENT ? 'html' : 'body'
)[0];
}
return WHOLE_DOCUMENT ? doc.documentElement : body;
};
/**
* Creates a NodeIterator object that you can use to traverse filtered lists of nodes or elements in a document.
*
* @param root The root element or node to start traversing on.
* @return The created NodeIterator
*/
const _createNodeIterator = function (root: Node): NodeIterator {
return createNodeIterator.call(
root.ownerDocument || root,
root,
// eslint-disable-next-line no-bitwise
NodeFilter.SHOW_ELEMENT |
NodeFilter.SHOW_COMMENT |
NodeFilter.SHOW_TEXT |
NodeFilter.SHOW_PROCESSING_INSTRUCTION |
NodeFilter.SHOW_CDATA_SECTION,
null
);
};
/**
* Strip template-engine expressions ({{...}}, ${...}, <%...%>) from the
* character data of an element subtree. Used as the final safety net for
* SAFE_FOR_TEMPLATES on every DOM-returning code path so that expressions
* which only form after text-node normalization (e.g. fragments split across
* stripped elements) cannot survive into a template-evaluating framework.
*
* Walks text/comment/CDATA/processing-instruction nodes and mutates `.data`
* in place rather than round-tripping through innerHTML. This preserves
* descendant node references (important for IN_PLACE callers), avoids a
* serialize/reparse cycle, and reads literal character data — which means
* `<%...%>` in text content matches the ERB regex against its real bytes
* instead of the HTML-entity-escaped form innerHTML would produce.
*
* Attribute values are not visited here; SAFE_FOR_TEMPLATES handling for
* attributes is performed during the per-node `_sanitizeAttributes` pass.
*
* @param node The root element whose character data should be scrubbed.
*/
const _scrubTemplateExpressions = function (node: Element): void {
node.normalize();
const walker = createNodeIterator.call(
node.ownerDocument || node,
node,
// eslint-disable-next-line no-bitwise
NodeFilter.SHOW_TEXT |
NodeFilter.SHOW_COMMENT |
NodeFilter.SHOW_CDATA_SECTION |
NodeFilter.SHOW_PROCESSING_INSTRUCTION,
null
);
let currentNode = walker.nextNode() as CharacterData | null;
while (currentNode) {
let data = currentNode.data;
arrayForEach([MUSTACHE_EXPR, ERB_EXPR, TMPLIT_EXPR], (expr: RegExp) => {
data = stringReplace(data, expr, ' ');
});
currentNode.data = data;
currentNode = walker.nextNode() as CharacterData | null;
}
};
/**
* _isClobbered
*
* @param element element to check for clobbering attacks
* @return true if clobbered, false if safe
*/
const _isClobbered = function (element: Element): boolean {
return (
element instanceof HTMLFormElement &&
(typeof element.nodeName !== 'string' ||
typeof element.textContent !== 'string' ||
typeof element.removeChild !== 'function' ||
!(element.attributes instanceof NamedNodeMap) ||
typeof element.removeAttribute !== 'function' ||
typeof element.setAttribute !== 'function' ||
typeof element.namespaceURI !== 'string' ||
typeof element.insertBefore !== 'function' ||
typeof element.hasChildNodes !== 'function')
);
};
/**
* Checks whether the given object is a DOM node, including nodes that
* originate from a different window/realm (e.g. an iframe's
* contentDocument). The previous `value instanceof Node` check was
* realm-bound: nodes from a different window failed it, causing
* sanitize() to silently stringify them and reset IN_PLACE to false,
* returning the original node unsanitized. See GHSA-4w3q-35jp-p934.
*
* Implementation: call the cached `nodeType` getter from Node.prototype
* directly on the value. This bypasses any clobbered instance property
* (e.g. a child element named "nodeType") and works across realms
* because the WebIDL `nodeType` getter reads an internal slot that
* every real Node has, regardless of which window minted it.
*
* @param value object to check whether it's a DOM node
* @return true if value is a DOM node from any realm
*/
const _isNode = function (value: unknown): value is Node {
if (!getNodeType || typeof value !== 'object' || value === null) {
return false;
}
try {
return typeof getNodeType(value) === 'number';
} catch (_) {
return false;
}
};
function _executeHooks<T extends HookFunction>(
hooks: HookFunction[],
currentNode: Parameters<T>[0],
data: Parameters<T>[1]
): void {
arrayForEach(hooks, (hook: T) => {
hook.call(DOMPurify, currentNode, data, CONFIG);
});
}
/**
* _sanitizeElements
*
* @protect nodeName
* @protect textContent
* @protect removeChild
* @param currentNode to check for permission to exist
* @return true if node was killed, false if left alive
*/
const _sanitizeElements = function (currentNode: any): boolean {
let content = null;
/* Execute a hook if present */
_executeHooks(hooks.beforeSanitizeElements, currentNode, null);
/* Check if element is clobbered or can clobber */
if (_isClobbered(currentNode)) {
_forceRemove(currentNode);
return true;
}
/* Now let's check the element's type and name */
const tagName = transformCaseFunc(currentNode.nodeName);
/* Execute a hook if present */
_executeHooks(hooks.uponSanitizeElement, currentNode, {
tagName,
allowedTags: ALLOWED_TAGS,
});
/* Detect mXSS attempts abusing namespace confusion */
if (
SAFE_FOR_XML &&
currentNode.hasChildNodes() &&
!_isNode(currentNode.firstElementChild) &&
regExpTest(/<[/\w!]/g, currentNode.innerHTML) &&
regExpTest(/<[/\w!]/g, currentNode.textContent)
) {
_forceRemove(currentNode);
return true;
}
/* Remove risky CSS construction leading to mXSS */
if (
SAFE_FOR_XML &&
currentNode.namespaceURI === HTML_NAMESPACE &&
tagName === 'style' &&
_isNode(currentNode.firstElementChild)
) {
_forceRemove(currentNode);
return true;
}
/* Remove any occurrence of processing instructions */
if (currentNode.nodeType === NODE_TYPE.progressingInstruction) {
_forceRemove(currentNode);
return true;
}
/* Remove any kind of possibly harmful comments */
if (
SAFE_FOR_XML &&
currentNode.nodeType === NODE_TYPE.comment &&
regExpTest(/<[/\w]/g, currentNode.data)
) {
_forceRemove(currentNode);
return true;
}
/* Remove element if anything forbids its presence */
if (
FORBID_TAGS[tagName] ||
(!(
EXTRA_ELEMENT_HANDLING.tagCheck instanceof Function &&
EXTRA_ELEMENT_HANDLING.tagCheck(tagName)
) &&
!ALLOWED_TAGS[tagName])
) {
/* Check if we have a custom element to handle */
if (!FORBID_TAGS[tagName] && _isBasicCustomElement(tagName)) {
if (
CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof RegExp &&
regExpTest(CUSTOM_ELEMENT_HANDLING.tagNameCheck, tagName)
) {
return false;
}
if (
CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof Function &&
CUSTOM_ELEMENT_HANDLING.tagNameCheck(tagName)
) {
return false;
}
}
/* Keep content except for bad-listed elements */
if (KEEP_CONTENT && !FORBID_CONTENTS[tagName]) {
const parentNode = getParentNode(currentNode) || currentNode.parentNode;
const childNodes = getChildNodes(currentNode) || currentNode.childNodes;
if (childNodes && parentNode) {
const childCount = childNodes.length;
for (let i = childCount - 1; i >= 0; --i) {
const childClone = cloneNode(childNodes[i], true);
parentNode.insertBefore(childClone, getNextSibling(currentNode));
}
}
}
_forceRemove(currentNode);
return true;
}
/* Check whether element has a valid namespace */
if (currentNode instanceof Element && !_checkValidNamespace(currentNode)) {
_forceRemove(currentNode);
return true;
}
/* Make sure that older browsers don't get fallback-tag mXSS */
if (
(tagName === 'noscript' ||
tagName === 'noembed' ||
tagName === 'noframes') &&
regExpTest(/<\/no(script|embed|frames)/i, currentNode.innerHTML)
) {
_forceRemove(currentNode);
return true;
}
/* Sanitize element content to be template-safe */
if (SAFE_FOR_TEMPLATES && currentNode.nodeType === NODE_TYPE.text) {
/* Get the element's text content */
content = currentNode.textContent;
arrayForEach([MUSTACHE_EXPR, ERB_EXPR, TMPLIT_EXPR], (expr: RegExp) => {
content = stringReplace(content, expr, ' ');
});
if (currentNode.textContent !== content) {
arrayPush(DOMPurify.removed, { element: currentNode.cloneNode() });
currentNode.textContent = content;
}
}
/* Execute a hook if present */
_executeHooks(hooks.afterSanitizeElements, currentNode, null);
return false;
};
/**
* _isValidAttribute
*
* @param lcTag Lowercase tag name of containing element.
* @param lcName Lowercase attribute name.
* @param value Attribute value.
* @return Returns true if `value` is valid, otherwise false.
*/
// eslint-disable-next-line complexity
const _isValidAttribute = function (
lcTag: string,
lcName: string,
value: string
): boolean {
/* FORBID_ATTR must always win, even if ADD_ATTR predicate would allow it */
if (FORBID_ATTR[lcName]) {
return false;
}
/* Make sure attribute cannot clobber */
if (
SANITIZE_DOM &&
(lcName === 'id' || lcName === 'name') &&
(value in document || value in formElement)
) {
return false;
}
const nameIsPermitted =
ALLOWED_ATTR[lcName] ||
(EXTRA_ELEMENT_HANDLING.attributeCheck instanceof Function &&
EXTRA_ELEMENT_HANDLING.attributeCheck(lcName, lcTag));
/* Allow valid data-* attributes: At least one character after "-"
(https://html.spec.whatwg.org/multipage/dom.html#embedding-custom-non-visible-data-with-the-data-*-attributes)
XML-compatible (https://html.spec.whatwg.org/multipage/infrastructure.html#xml-compatible and http://www.w3.org/TR/xml/#d0e804)
We don't need to check the value; it's always URI safe. */
if (
ALLOW_DATA_ATTR &&
!FORBID_ATTR[lcName] &&
regExpTest(DATA_ATTR, lcName)
) {
// This attribute is safe
} else if (ALLOW_ARIA_ATTR && regExpTest(ARIA_ATTR, lcName)) {
// This attribute is safe
/* Otherwise, check the name is permitted */
} else if (!nameIsPermitted || FORBID_ATTR[lcName]) {
if (
// First condition does a very basic check if a) it's basically a valid custom element tagname AND
// b) if the tagName passes whatever the user has configured for CUSTOM_ELEMENT_HANDLING.tagNameCheck
// and c) if the attribute name passes whatever the user has configured for CUSTOM_ELEMENT_HANDLING.attributeNameCheck
(_isBasicCustomElement(lcTag) &&
((CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof RegExp &&
regExpTest(CUSTOM_ELEMENT_HANDLING.tagNameCheck, lcTag)) ||
(CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof Function &&
CUSTOM_ELEMENT_HANDLING.tagNameCheck(lcTag))) &&
((CUSTOM_ELEMENT_HANDLING.attributeNameCheck instanceof RegExp &&
regExpTest(CUSTOM_ELEMENT_HANDLING.attributeNameCheck, lcName)) ||
(CUSTOM_ELEMENT_HANDLING.attributeNameCheck instanceof Function &&
CUSTOM_ELEMENT_HANDLING.attributeNameCheck(lcName, lcTag)))) ||
// Alternative, second condition checks if it's an `is`-attribute, AND
// the value passes whatever the user has configured for CUSTOM_ELEMENT_HANDLING.tagNameCheck
(lcName === 'is' &&
CUSTOM_ELEMENT_HANDLING.allowCustomizedBuiltInElements &&
((CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof RegExp &&
regExpTest(CUSTOM_ELEMENT_HANDLING.tagNameCheck, value)) ||
(CUSTOM_ELEMENT_HANDLING.tagNameCheck instanceof Function &&
CUSTOM_ELEMENT_HANDLING.tagNameCheck(value))))
) {
// If user has supplied a regexp or function in CUSTOM_ELEMENT_HANDLING.tagNameCheck, we need to also allow derived custom elements using the same tagName test.
// Additionally, we need to allow attributes passing the CUSTOM_ELEMENT_HANDLING.attributeNameCheck user has configured, as custom elements can define these at their own discretion.
} else {
return false;
}
/* Check value is safe. First, is attr inert? If so, is safe */
} else if (URI_SAFE_ATTRIBUTES[lcName]) {
// This attribute is safe
/* Check no script, data or unknown possibly unsafe URI
unless we know URI values are safe for that attribute */
} else if (
regExpTest(IS_ALLOWED_URI, stringReplace(value, ATTR_WHITESPACE, ''))
) {
// This attribute is safe
/* Keep image data URIs alive if src/xlink:href is allowed */
/* Further prevent gadget XSS for dynamically built script tags */
} else if (
(lcName === 'src' || lcName === 'xlink:href' || lcName === 'href') &&
lcTag !== 'script' &&
stringIndexOf(value, 'data:') === 0 &&
DATA_URI_TAGS[lcTag]
) {
// This attribute is safe
/* Allow unknown protocols: This provides support for links that
are handled by protocol handlers which may be unknown ahead of
time, e.g. fb:, spotify: */
} else if (
ALLOW_UNKNOWN_PROTOCOLS &&
!regExpTest(IS_SCRIPT_OR_DATA, stringReplace(value, ATTR_WHITESPACE, ''))
) {
// This attribute is safe
/* Check for binary attributes */
} else if (value) {
return false;
} else {
// Binary attributes are safe at this point
/* Anything else, presume unsafe, do not add it back */
}
return true;
};
/* Names the HTML spec reserves from valid-custom-element-name; these must
* never be treated as basic custom elements even when a permissive
* CUSTOM_ELEMENT_HANDLING.tagNameCheck is configured. */
const RESERVED_CUSTOM_ELEMENT_NAMES = addToSet({}, [
'annotation-xml',
'color-profile',
'font-face',
'font-face-format',
'font-face-name',
'font-face-src',
'font-face-uri',
'missing-glyph',
]);
/**
* _isBasicCustomElement
* checks if at least one dash is included in tagName, and it's not the first char
* for more sophisticated checking see https://github.com/sindresorhus/validate-element-name
*
* @param tagName name of the tag of the node to sanitize
* @returns Returns true if the tag name meets the basic criteria for a custom element, otherwise false.
*/
const _isBasicCustomElement = function (tagName: string): boolean {
return (
!RESERVED_CUSTOM_ELEMENT_NAMES[stringToLowerCase(tagName)] &&
regExpTest(CUSTOM_ELEMENT, tagName)
);
};
/**
* _sanitizeAttributes
*
* @protect attributes
* @protect nodeName
* @protect removeAttribute
* @protect setAttribute
*
* @param currentNode to sanitize
*/
const _sanitizeAttributes = function (currentNode: Element): void {
/* Execute a hook if present */
_executeHooks(hooks.beforeSanitizeAttributes, currentNode, null);
const { attributes } = currentNode;
/* Check if we have attributes; if not we might have a text node */
if (!attributes || _isClobbered(currentNode)) {
return;
}
const hookEvent = {
attrName: '',
attrValue: '',
keepAttr: true,
allowedAttributes: ALLOWED_ATTR,
forceKeepAttr: undefined,
};
let l = attributes.length;
/* Go backwards over all attributes; safely remove bad ones */
while (l--) {
const attr = attributes[l];
const { name, namespaceURI, value: attrValue } = attr;
const lcName = transformCaseFunc(name);
const initValue = attrValue;
let value = name === 'value' ? initValue : stringTrim(initValue);
/* Execute a hook if present */
hookEvent.attrName = lcName;
hookEvent.attrValue = value;
hookEvent.keepAttr = true;
hookEvent.forceKeepAttr = undefined; // Allows developers to see this is a property they can set
_executeHooks(hooks.uponSanitizeAttribute, currentNode, hookEvent);
value = hookEvent.attrValue;
/* Full DOM Clobbering protection via namespace isolation,
* Prefix id and name attributes with `user-content-`
*/
if (
SANITIZE_NAMED_PROPS &&
(lcName === 'id' || lcName === 'name') &&
stringIndexOf(value, SANITIZE_NAMED_PROPS_PREFIX) !== 0
) {
// Remove the attribute with this value
_removeAttribute(name, currentNode);
// Prefix the value and later re-create the attribute with the sanitized value
value = SANITIZE_NAMED_PROPS_PREFIX + value;
}
// Else: already prefixed, leave the attribute alone — the prefix is
// itself the clobbering protection, and re-applying it is incorrect.
/* Work around a security issue with comments inside attributes */
if (
SAFE_FOR_XML &&
regExpTest(
/((--!?|])>)|<\/(style|script|title|xmp|textarea|noscript|iframe|noembed|noframes)/i,
value
)
) {
_removeAttribute(name, currentNode);
continue;
}
/* Make sure we cannot easily use animated hrefs, even if animations are allowed */
if (lcName === 'attributename' && stringMatch(value, 'href')) {
_removeAttribute(name, currentNode);
continue;
}
/* Did the hooks approve of the attribute? */
if (hookEvent.forceKeepAttr) {
continue;
}
/* Did the hooks approve of the attribute? */
if (!hookEvent.keepAttr) {
_removeAttribute(name, currentNode);
con