Files
immich-folio/lib/admin/auth.ts
Ralksta 37f7f62157 security: fix pre-auth bypasses and restore Immich 3.x compatibility (#378)
Seven security issues from an audit, plus album pages and the map coming
up empty against Immich 3.x. Verified against a real Immich 3.0.3
instance in a production build.

Security:
- Admin session forgery via a hardcoded 'dev-fallback-secret' signing key
  that bypassed the production AUTH_SECRET guard
- /api/map ignored album passwords and returned working asset tokens;
  rewriting ?size=thumbnail to ?size=original downloaded full-resolution
  originals from protected albums
- Admin login had no rate limit, and the client IP came from a spoofable
  header, so rotating it bypassed every limit in the app
- Raw Immich asset UUIDs were serialized into the RSC payload
- Album tokens never expired server-side; a captured token replayed forever
- Path traversal into the Immich API via an unvalidated album id
- /admin ran with no enforced CSP (only Report-Only reached it)

TRUSTED_PROXIES is replaced by TRUSTED_PROXY_HOPS. The old variable
matched proxy IPs against the socket peer address, which self-hosted
Next.js never exposes, so the check could never pass: unset, the limiter
read a spoofable header; set, every request shared one bucket and a single
client could rate-limit the whole site. Migrates automatically.

Immich 3.x: GET /albums/:id no longer embeds assets. Assets now come from
POST /search/metadata with withExif: true — without that flag EXIF is
omitted and grid aspect ratios, the lightbox panel and map markers stay
empty. Drops support for Immich below 3.0, which now logs a warning.

Upgrade: requires Immich 3.0+; set TRUSTED_PROXY_HOPS (nginx = 1);
visitors of protected areas and admin sessions must log in once more.

91 unit tests (25 new); the new admin-auth and rate-limit cases were
confirmed to fail against the pre-fix code.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-20 18:57:57 +02:00

95 lines
3.0 KiB
TypeScript

/**
* Admin authentication utilities.
* Uses HMAC-signed session tokens stored in HttpOnly cookies.
*/
import crypto from 'crypto';
import { env } from '../env';
import { resolveAuthSecret } from '../secret';
import { cookies } from 'next/headers';
const COOKIE_NAME = 'folio_admin_session';
const SESSION_DURATION_MS = 24 * 60 * 60 * 1000; // 24 hours
function getSigningKey(): Buffer {
// Bind the key to ADMIN_PASSWORD as well, so rotating the password
// immediately invalidates every outstanding session token.
const secret = resolveAuthSecret();
return crypto
.createHash('sha256')
.update(`admin:${secret}:${env.ADMIN_PASSWORD ?? ''}`)
.digest();
}
/** Create a signed session token. */
export function createAdminToken(): string {
const payload = {
role: 'admin',
iat: Date.now(),
exp: Date.now() + SESSION_DURATION_MS,
};
const data = Buffer.from(JSON.stringify(payload)).toString('base64url');
const key = getSigningKey();
const sig = crypto.createHmac('sha256', key).update(data).digest('base64url');
return `${data}.${sig}`;
}
/** Verify a session token. Returns true if valid. */
export function verifyAdminToken(token: string): boolean {
const parts = token.split('.');
if (parts.length !== 2) return false;
const [data, sig] = parts;
const key = getSigningKey();
const expectedSig = crypto.createHmac('sha256', key).update(data).digest('base64url');
// timingSafeEqual throws on length mismatch — guard first so a malformed
// cookie yields a clean 401 instead of an unhandled RangeError (500).
const sigBuf = Buffer.from(sig);
const expectedBuf = Buffer.from(expectedSig);
if (sigBuf.length !== expectedBuf.length) return false;
if (!crypto.timingSafeEqual(sigBuf, expectedBuf)) {
return false;
}
try {
const payload = JSON.parse(Buffer.from(data, 'base64url').toString());
if (payload.role !== 'admin') return false;
if (typeof payload.exp !== 'number' || payload.exp < Date.now()) return false;
return true;
} catch {
return false;
}
}
/** Verify admin password. */
export function verifyAdminPassword(password: string): boolean {
const adminPw = env.ADMIN_PASSWORD;
if (!adminPw) return false;
// Constant-time comparison
const pwBuf = Buffer.from(password);
const expectedBuf = Buffer.from(adminPw);
if (pwBuf.length !== expectedBuf.length) {
// Still do a comparison to prevent timing attacks on length
crypto.timingSafeEqual(pwBuf, Buffer.alloc(pwBuf.length));
return false;
}
return crypto.timingSafeEqual(pwBuf, expectedBuf);
}
/** Check if the current request has a valid admin session. */
export async function isAdminAuthenticated(): Promise<boolean> {
const cookieStore = await cookies();
const token = cookieStore.get(COOKIE_NAME)?.value;
if (!token) return false;
return verifyAdminToken(token);
}
/** Check if admin panel is enabled (password is set). */
export function isAdminEnabled(): boolean {
return !!env.ADMIN_PASSWORD;
}
export { COOKIE_NAME, SESSION_DURATION_MS };