Messages arrived late or not at all, for two independent reasons.
Dead connections: neither side sent a ping, and after AUTH the server
waited for a frame without a timeout. Mobile NAT drops idle TCP silently,
so the client wrote into a void while the relay still held the device in
its online map — and therefore never sent a push wake-up either. The ping
is a protocol-level one rather than v1::Ping, because dart:io answers
those on its own; the fix works with clients already in the wild.
Poisoned queue: a client decrypts an envelope (ratchet advances), stores
it and acknowledges it. If that ACK is lost, a second decryption attempt
can only fail, so the envelope is never acknowledged — and was redelivered
on every connect until its 30-day TTL, without ever reaching the recipient.
attempt_count existed from the first migration but was never counted; it
now bounds redelivery.
Receipts reported DELIVERED_ONLINE whenever a write into the bounded mpsc
channel succeeded, which it does even for a long-dead socket. Online is now
claimed only for devices that recently sent something.
Push send failures were logged at debug while the relay runs at info, so a
rejected wake-up looked exactly like a working one.
Rate limiting and the per-IP WebSocket cap trusted X-Forwarded-For and
X-Real-Ip unconditionally. Onion traffic bypasses the reverse proxy, so a
client could set the header itself and slip past every limit. Forwarded
headers are now honoured only from peers inside SEPOT_TRUSTED_PROXIES;
everyone else is keyed by peer address, and onion clients share one bucket.
The queue flush also read the whole backlog into memory at once, and the
certificate authority kept the trust-root private key in the database even
though it is only ever needed offline.
Fixes reported by testers and found in an app review:
- First message right after install no longer fails. Before the app
finished registering with the relay, the outgoing message could crash on
a null delivery address. The profile field is now optional and the send
path throws a clear "still connecting, try again shortly" error while
registration completes in the background.
- The QR code and share link now appear only once the delivery address is
ready. Previously a link generated before the first connection lacked
routing, so the other side could not send the first message. The screen
now shows a connecting state and reactively swaps in the QR when ready.
- Incomplete contact links are rejected on import instead of failing at
first send, with a clear prompt to ask for a fresh link.
- Auto-lock no longer silences the app: after locking and unlocking,
messaging is restarted (it previously stayed dead until app restart).
- Group messages are marked failed on a non-per-member send error instead
of hanging in the "sending" state forever.
- Hardened the relay client against a rare duplicate connection when
toggling Tor or locking mid-connect, and fromShareString now rejects a
delivery address of the wrong length.
- Pin unifiedpush below 6.2.0 to drop the webcrypto dependency (its native
framework lacks LC_ENCRYPTION_INFO and blocked the iOS upload).
- Skip Android release lint (network dependency check hangs on the build
host and adds no value for a Flutter app).
Settings crashed with a TypeError: the profile card passed a
SepotFingerprint object where the localized string formatter expects
a String (hidden behind a `dynamic` parameter). Also fixes RangeError
in avatar initials (empty names, double spaces) and switches initials
to grapheme clusters so emoji don't get split.
New photo preview screen: a captured or picked photo no longer sends
immediately — it opens in a preview with freehand drawing (7 colours,
undo), draggable text overlay, 90° rotation and a caption field.
Nothing leaves the device until Send is tapped.
Incoming-content hardening: decryption and content processing are now
separated in the delivery path. Once an envelope is decrypted the
ratchet has advanced, so redelivery can never help — permanently
malformed content (FormatException/TypeError) is acked and dropped
instead of poisoning the queue on every reconnect. Attachment metadata
now validates base64 of the crypto fields up front, and a corrupt
inline thumbnail no longer breaks bubble rendering.
PNG without real transparency (screenshots, edited photos) is now
re-encoded as JPEG — several times smaller on the wire.
Tests: 116 (new widget tests for Settings and the photo preview,
AttachmentMeta wire validation).
Initial public release. Anonymous on-device identity (no phone number,
e-mail, or password), Signal-protocol cryptography (X3DH + PQXDH, Double
Ratchet, sealed sender) via libsignal, a metadata-minimizing relay,
group chats, disappearing messages, encrypted local storage, optional
Tor transport, and a UI localized into Czech, English, German, Russian,
and Italian.
Monorepo: Flutter client (app/), Rust relay + wire types (rust/),
protobuf definitions (proto/), self-host deploy (deploy/).
Licensed under AGPL-3.0 with an app-store distribution exception (§7).
Julius Joska