Files
dockhand-upstream/src/lib/server/registry-auth.ts
T

67 lines
3.1 KiB
TypeScript

/**
* Encode the AuthConfig JSON as base64url **with `=` padding** for the
* Docker X-Registry-Auth header. The Docker daemon decodes the header with
* Go's `base64.URLEncoding.DecodeString`, which is base64url with padding —
* unpadded base64url (Node's default 'base64url' Buffer encoding) is
* silently treated as malformed, causing the daemon to fall back to
* anonymous and trip the registry rate limit (#1105).
*
* Reference: moby/api/pkg/authconfig/authconfig.go uses
* `base64.URLEncoding.EncodeToString` / `DecodeString`.
*/
export function encodeRegistryAuth(authConfig: object): string {
const unpadded = Buffer.from(JSON.stringify(authConfig)).toString('base64url');
return unpadded + '='.repeat((4 - (unpadded.length % 4)) % 4);
}
/**
* Whether Basic credentials may be re-attached when a registry token request
* redirects. True only when the host is unchanged. A Harbor behind a
* TLS-terminating proxy advertises an `http://` realm that 301s to `https://`
* on the SAME host; undici strips Authorization across that origin change,
* turning a valid login into an anonymous 401. Re-attaching on a same-host
* scheme/port change matches docker/curl. A host CHANGE must never re-send
* creds (leak risk), so those are refused. (#1428)
*/
export function canReattachAuthOnRedirect(from: string, to: string): boolean {
try {
return new URL(from).hostname === new URL(to).hostname;
} catch {
return false;
}
}
/** Injectable fetch, so the redirect-follow loop is unit-testable without a network. */
export type FetchLike = (url: string, init?: { headers?: Record<string, string>; redirect?: 'manual' }) => Promise<Response>;
/**
* Fetch a registry token URL, manually following up to a few same-host redirects
* with the Authorization header re-attached. `authHeader` is the full header value
* (e.g. `Basic abc...`) or null for anonymous. Cross-host redirects drop the header
* (see canReattachAuthOnRedirect). Manual redirect handling is what fixes #1428:
* undici's automatic follow strips Authorization across an http->https origin change.
*/
export async function fetchRegistryToken(
tokenUrl: string,
authHeader: string | null,
fetchImpl: FetchLike = fetch as unknown as FetchLike
): Promise<Response> {
let url = tokenUrl;
for (let hop = 0; hop < 4; hop++) {
const headers: Record<string, string> = { 'User-Agent': 'Dockhand/1.0' };
if (authHeader) headers['Authorization'] = authHeader;
const res = await fetchImpl(url, { headers, redirect: 'manual' });
const location = res.status >= 300 && res.status < 400 ? res.headers.get('location') : null;
if (!location) return res;
await res.body?.cancel().catch(() => {});
const next = new URL(location, url).toString();
// Drop credentials if the redirect leaves the original host.
if (!canReattachAuthOnRedirect(url, next)) authHeader = null;
url = next;
}
// Too many hops: one final attempt so the caller sees a real status.
const headers: Record<string, string> = { 'User-Agent': 'Dockhand/1.0' };
if (authHeader) headers['Authorization'] = authHeader;
return fetchImpl(url, { headers });
}