PromucFlow_constructor/app/client/src/utils/validation/getIsSafeURL.ts

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2021-07-29 08:49:46 +00:00
/**
* REF: https://github.com/angular/angular/blob/master/packages/core/src/sanitization/url_sanitizer.ts
* A pattern that recognizes a commonly useful subset of URLs that are safe.
*
* 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 an allowed protocol (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:...".
*
* This regular expression was taken from the Closure sanitization library.
*/
const SAFE_URL_PATTERN = /^(?:(?:https?|mailto|ftp|tel|file|sms):|[^&:/?#]*(?:[/?#]|$))/gi;
/** A pattern that matches safe data URLs. Only matches image, video and audio types. */
const DATA_URL_PATTERN = /^data:(?:image\/(?:bmp|gif|jpeg|jpg|png|tiff|webp)|video\/(?:mpeg|mp4|ogg|webm)|audio\/(?:mp3|oga|ogg|opus));base64,[a-z0-9+\/]+=*$/i;
const getIsSafeURL = (value: string) =>
typeof value === "string" &&
(value.match(SAFE_URL_PATTERN) || value.match(DATA_URL_PATTERN));
export default getIsSafeURL;