`/api/auth/sso/complete` only accepted cookie slots 0-4 and quietly
used slot 0 for anything higher. Since the account limit rose to
`MAX_ACCOUNT_SLOTS` (50) on HTTP/2, adding a sixth account through
server-side SSO wrote its refresh token over the first account's cookie,
while the new account was registered on slot 5 with no cookie behind it.
The route and the OAuth callback's pending-slot check now use the same
bound as every other auth route.
The mobile handoff returned the provider's token endpoint and the
webmail's client id as they were. With a confidential client the phone
could not renew (it has no secret), and a provider on another host was
refused by the app outright. The handoff now returns the same bundle a
paired phone gets: such grants renew through `/api/auth/pair/token` with
a sealed refresh token.
"Link Mobile App" only appeared for OAuth sessions, its step-up could
only go through the identity provider (which failed without an OAuth
client and bounced password+TOTP users to the provider's login page),
and it handed the phone the desktop's own refresh token. Revoking that
token on sign-out, or a rotating provider, signed the phone out too; a
confidential client stopped the phone at its first token expiry; and an
identity provider on another host was refused by the app.
The step-up now mints the phone's own grant:
- Password and password+TOTP accounts confirm the current password (and
code) in the dialog. The server uses it once to get an OAuth grant
from Stalwart's structured login for the app's own client, retries
with the webmail's client when the server insists on a registered one,
and falls back to an app password ("Bulwark mobile (paired <date>)")
or, on servers that offer neither, the verified password. Failed
attempts are limited per account so the webmail's address cannot be
banned by guessing through it.
- SSO accounts keep the provider round trip, now with `offline_access`
where offered; its fresh tokens become the phone's grant instead of
being thrown away, and must belong to the account being paired.
- The account and server always come from the slot's verified session
context, never from the request.
Grants live 5 minutes server-side, codes 2 minutes, both single use; the
store is pinned on `globalThis`. Redeem answers `invalid_code`,
`expired_code` or `used_code`, and the desktop polls a separate status
id to replace the QR with "Signed in on your phone". A phone whose
client is confidential, or whose provider is on another host, renews
through `/api/auth/pair/token` with a sealed refresh token, so current
app builds work unchanged. Signing out discards a pending grant but no
longer affects a paired phone.
The dialog shows for every account (not in Lite), with a copyable
sign-in link, a TOTP field when needed, and the app's own "Scan a
sign-in code" wording.
The step-up for linking a device sends the user to the identity
provider with `prompt=login`. The login route accepted that pending
state too, so a code from the re-auth could be spent there and sign this
browser in as whichever account answered the prompt. It now refuses a
re-auth state; only the pairing route completes one.
The callback page also handles its code once. React's development
double effect ran it twice: the second pass no longer saw the re-auth
flag and raced the pairing route for the single-use code.
Lets a per-brand authorize host front a single canonical issuer, so the
IdP token's `iss` stays constant for downstream validation while login
branding varies per domain. Discovery, token exchange and refresh keep
using OAUTH_ISSUER_URL.
The multi-account refresh-token cookie slot wiring was half-implemented:
every account's refresh token ended up on slot 0, so "+ Add Account"
silently clobbered the previous account's `jmap_rt` cookie. On page
refresh, only the most-recently-added account had a working refresh
token; the others bounced to login.
Three coordinated changes:
1. `app/[locale]/login/page.tsx` (handleOAuthLogin): write the next-free
cookie slot to `sessionStorage['oauth_cookie_slot']` before redirecting
to the IdP. `loginWithOAuth` already reads this key but it was never
written, so it always defaulted to 0.
2. `stores/auth-store.ts` (loginWithOAuth): distinguish "no value set"
(`rawSlot === null`) from "value is 0". Previously
`parseInt(getItem(...) || '0')` collapsed both cases, making the
`getNextCookieSlot()` fallback unreachable.
3. `stores/auth-store.ts` (loginWithServerSso) +
`app/api/auth/sso/complete/route.ts`: pass the slot through the body of
the POST and use it for `refreshTokenCookieName(slot)`. Same pattern as
the existing `/api/auth/token POST` that already accepts a slot. The
server defaults to 0 for back-compat with any caller that omits it.
After the fix, signing in with multiple accounts produces distinct
`jmap_rt`, `jmap_rt_1`, `jmap_rt_2`, ... cookies (matching the cookieSlot
field in account-store) and all accounts survive a page refresh.
Repro before the fix:
- Sign in with one account, refresh — works.
- Click "+ Add Account", sign in with a second account, refresh — second
account vanishes from the dropdown; switching to the first account in
the dropdown still shows the second account's identity in the From box.
Linus Rath
Linus Rath
Loïs Postula
Maxwell
Pascal Dietrich