Files
SRCmail/lib/iframe-bridge.ts

64 lines
1.9 KiB
TypeScript

function normalizeOrigin(value: string): string | null {
if (!value) return null;
try {
const u = new URL(value);
if (u.protocol !== 'https:' && u.protocol !== 'http:') return null;
return u.origin;
} catch {
return null;
}
}
const PARENT_ORIGIN = typeof window !== 'undefined'
? normalizeOrigin(document.querySelector('meta[name="parent-origin"]')?.getAttribute('content') || '')
: null;
export function isEmbedded(): boolean {
try {
return window.self !== window.top;
} catch {
return true;
}
}
export function notifyParent(type: string, payload: Record<string, unknown> = {}) {
if (!isEmbedded()) return;
// Refuse to broadcast when the parent origin is unknown. A wildcard
// targetOrigin would leak the payload (e.g. username) to any frame
// the parent has open.
if (!PARENT_ORIGIN) return;
try {
window.parent.postMessage({ source: 'bulwark', type, ...payload }, PARENT_ORIGIN);
} catch {
// Cross-origin postMessage may fail in restricted contexts
}
}
export function listenFromParent(
handler: (msg: { type: string; [k: string]: unknown }) => void,
allowedOrigin: string,
): () => void {
// Reject installation entirely when the caller cannot pin an origin.
// Without this gate any cross-origin frame could forge
// { source: 'portal', type: 'sso:trigger-logout' } and ride the session.
const normalized = normalizeOrigin(allowedOrigin);
if (!normalized) {
if (typeof console !== 'undefined') {
console.error('[iframe-bridge] listenFromParent requires a valid http(s) allowedOrigin; listener not installed');
}
return () => {};
}
const listener = (event: MessageEvent) => {
if (event.origin !== normalized) return;
if (event.source !== window.parent) return;
if (!event.data || event.data.source !== 'portal') return;
handler(event.data);
};
window.addEventListener('message', listener);
return () => window.removeEventListener('message', listener);
}