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/**
* --------------------------------------------------------------------------
* Bootstrap util/sanitizer.js
* Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
* --------------------------------------------------------------------------
*/
// js-docs-start allow-list
const ARIA_ATTRIBUTE_PATTERN = /^aria-[\w-]*$/i
export const DefaultAllowlist = {
// Global attributes allowed on any supplied element below.
'*': ['class', 'dir', 'id', 'lang', 'role', ARIA_ATTRIBUTE_PATTERN],
a: ['target', 'href', 'title', 'rel'],
area: [],
b: [],
br: [],
col: [],
code: [],
dd: [],
div: [],
dl: [],
dt: [],
em: [],
hr: [],
h1: [],
h2: [],
h3: [],
h4: [],
h5: [],
h6: [],
i: [],
img: ['src', 'srcset', 'alt', 'title', 'width', 'height'],
li: [],
ol: [],
p: [],
pre: [],
s: [],
small: [],
span: [],
sub: [],
sup: [],
strong: [],
u: [],
ul: []
}
// js-docs-end allow-list
const uriAttributes = new Set([
'background',
'cite',
'href',
'itemtype',
'longdesc',
'poster',
'src',
'xlink:href'
])
/**
* A pattern that recognizes URLs that are safe wrt. XSS in URL navigation
* contexts.
*
* Shout-out to Angular https://github.com/angular/angular/blob/15.2.8/packages/core/src/sanitization/url_sanitizer.ts#L38
*/
// eslint-disable-next-line unicorn/better-regex
const SAFE_URL_PATTERN = /^(?!javascript:)(?:[a-z0-9+.-]+:|[^&:/?#]*(?:[/?#]|$))/i
const allowedAttribute = (attribute, allowedAttributeList) => {
const attributeName = attribute.nodeName.toLowerCase()
if (allowedAttributeList.includes(attributeName)) {
if (uriAttributes.has(attributeName)) {
return Boolean(SAFE_URL_PATTERN.test(attribute.nodeValue))
}
return true
}
// Check if a regular expression validates the attribute.
return allowedAttributeList.filter(attributeRegex => attributeRegex instanceof RegExp)
.some(regex => regex.test(attributeName))
}
export function sanitizeHtml(unsafeHtml, allowList, sanitizeFunction) {
if (!unsafeHtml.length) {
return unsafeHtml
}
if (sanitizeFunction && typeof sanitizeFunction === 'function') {
return sanitizeFunction(unsafeHtml)
}
const domParser = new window.DOMParser()
const createdDocument = domParser.parseFromString(unsafeHtml, 'text/html')
const elements = [].concat(...createdDocument.body.querySelectorAll('*'))
for (const element of elements) {
const elementName = element.nodeName.toLowerCase()
if (!Object.keys(allowList).includes(elementName)) {
element.remove()
continue
}
const attributeList = [].concat(...element.attributes)
const allowedAttributes = [].concat(allowList['*'] || [], allowList[elementName] || [])
for (const attribute of attributeList) {
if (!allowedAttribute(attribute, allowedAttributes)) {
element.removeAttribute(attribute.nodeName)
}
}
}
return createdDocument.body.innerHTML
}
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