The limiter covered only /api/v1/auth/login. Jellyfin's AuthenticateByName
and Subsonic's authenticate both called auth.Authenticate with no limiting,
so an attacker brute-forced through those instead: the same password, the
same argon2, no ceiling.
The limiter moves from auth.Handlers onto *Authenticator, which all three
surfaces already hold, so they share one budget and splitting guesses
across surfaces gains nothing. main.go builds one authenticator and hands
it to both compat layers, so the sharing is real rather than intended.
Subsonic needs care: it has no login step, authenticate runs on every
request, so a naive check would charge playback against the login budget
and lock a listener out mid-album. The limiter is consulted only when a
credential was actually supplied, and a success or an uncredentialed
request spends nothing.
Verified red-green on all three: removing the Jellyfin gate fails
TestAuthenticateByNameIsRateLimited with 401 instead of 429; removing the
Subsonic credential guard fails
TestSuccessAndUncredentialedDoNotConsumeTheBudget; neutering AllowLogin or
ResetLogin fails the auth tests.
Known gap, unchanged: the limiter is in-process, so it resets on restart
and does not span replicas. Fine for one binary against one SQLite file.
Vellum now speaks two foreign protocols, so the clients people already own can
use it. Both are translation layers over queries that already exist, and both go
through the same grant chokepoint as the web app — a token is a second way to be
a user, never a second set of permissions.
Shared foundation (coordinator, written before dispatch)
- migrations/0012_api_tokens.sql + internal/apitoken. Both protocols need a
credential that is not the session cookie, and letting two agents each invent
a token table would have produced two incompatible ones.
- The table stores two shapes for a real reason: a Jellyfin token is a bearer
value so only its hash is kept, while a Subsonic key must be recoverable
because verifying `t` means computing md5(key + salt) server-side. token_plain
is therefore the one column in the schema holding a usable credential. It is a
generated random secret, never a user password, and it is revocable.
Wave 9 - Jellyfin
- /System/Info/Public, /Users/AuthenticateByName, /Users/Me, /Users/{id},
/Items, /Users/{id}/Items, /Items/{id}, /Items/{id}/Images/Primary,
/Items/{id}/PlaybackInfo, /Videos/{id}/stream, /Audio/{id}/stream,
/Sessions/Playing{,/Progress,/Stopped}.
- Auth accepts X-Emby-Token, X-MediaBrowser-Token, ?api_key=, and
Authorization: MediaBrowser Token="...". The ?api_key= form is the one that
matters: <video> elements cannot set headers.
- Honest about the one thing Vellum cannot do. PlaybackInfo reports
SupportsDirectPlay/SupportsDirectStream true and SupportsTranscoding FALSE,
with a DirectStreamUrl carrying the api_key. A client that disables both
direct modes is demanding a transcode and is refused with ErrorCode
"NoCompatibleStream" — rather than handed a TranscodingUrl that would never
resolve, which is how a client hangs forever.
Wave 10 - Subsonic
- /rest/{method} dispatch with ping, getLicense, getMusicFolders, getIndexes,
getArtists/getArtist/getAlbum, getMusicDirectory, getSong, search3, stream,
getCoverArt, getAlbumList2, getRandomSongs, scrobble, getUser, getPlaylists,
plus GET /api/v1/subsonic/credentials to hand a user their key.
- Auth via t=md5(key+salt), p=key, constant-time comparison. A bad credential
returns HTTP 200 with the envelope status "failed" and error code 40 — NOT an
HTTP 401. Subsonic clients read the envelope, and getting this wrong is the
single most common integration failure in that protocol.
- stream supports format=raw and never invokes ffmpeg.
Coordinator wired both into main.go (the line agents were told to leave alone)
and verified against real requests.
Verified end to end, 18 packages pass, gofmt/vet clean, svelte-check 0/0:
- Jellyfin: discovery, AuthenticateByName minting a token, /Items reporting 18,
PlaybackInfo showing SupportsTranscoding=false, and a Range request to
/Videos/{id}/stream using ONLY ?api_key= returning 206 with Content-Range.
- Subsonic: ping as JSON and XML, md5(key+salt) auth succeeding, and a bad token
returning the failed envelope with code 40.
- Scoping, both protocols, with a genuinely non-admin user: 0 items, 404 on an
admin-only item, 404 on its stream, 0 music folders; admin still sees 18.
- The SPA is not shadowed by the root-mounted compat paths: /, /healthz and
/api/v1/version all still answer correctly.
Both agents failed with an HTTP 400 at the REPORT stage, not during the work;
their files were complete and compile, so the work was salvaged and verified
here rather than redone.
mithral