@aikidosec/firewall
Version:
Zen by Aikido is an embedded Application Firewall that autonomously protects Node.js apps against common and critical attacks, provides rate limiting, detects malicious traffic (including bots), and more.
32 lines (31 loc) • 1.36 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.getRedirectOrigin = getRedirectOrigin;
/**
* This function checks if the given URL is part of a redirect chain that is passed in the redirects parameter.
* It returns the origin of a redirect chain if the URL is the result of a redirect.
* The origin is the first URL in the chain, so the initial URL that was requested and redirected to the given URL
* or in case of multiple redirects the URL that was redirected to the given URL.
*
* Example:
* Redirect chain: A -> B -> C: getRedirectOrigin([A -> B, B -> C], C) => A
* : getRedirectOrigin([A -> B, B -> C], B) => A
* : getRedirectOrigin([A -> B, B -> C], D) => undefined
*/
function getRedirectOrigin(redirects, url) {
if (!Array.isArray(redirects)) {
return undefined;
}
let currentUrl = url;
// Follow the redirect chain until we reach the origin or don't find a redirect
while (true) {
const redirect = redirects.find(
// url.href contains the full URL so we can use it for comparison
(r) => r.destination.href === currentUrl.href);
if (!redirect) {
break;
}
currentUrl = redirect.source;
}
return currentUrl.href === url.href ? undefined : currentUrl;
}