Commit Graph

4 Commits

Author SHA1 Message Date
Kgothatso Ngako
bcdfd2ec94 Merge branch 'mantra' into claude/marmot-direct-message-type-7a0473
Twenty-two commits had landed on mantra since this branch left it, several
of them in the same files. Merged this way round so mantra stayed untouched
until the result compiled and its tests passed.

The migration had to be renumbered, and this is the conflict that mattered.
mantra is at database version 7 and already has its own 5.json -- for
MarmotInnerEvent.payloadEventId, nothing to do with direct messages. This
branch had also written a 5.json, for a different schema. Resolved by
restoring mantra's 5.json untouched and moving the direct message columns
to an AutoMigration(7, 8) with a regenerated 8.json. Taking either 5.json
over the other would have left every device validating a migration chain
against a schema it was never built from; keeping version = 5 would have
made a v7 install refuse to open at all.

The regenerated 8.json is two ADD COLUMNs and nothing else, same as before.

fromGroupEventResult was restructured on mantra: the kind switch moved into
applyInnerEvent, and a SubmissionEvent envelope now wraps nip30303 payloads.
Took that structure and re-applied the direct message branch ahead of it
rather than inside it -- a gift wrap is not a nip30303 payload to apply, and
what happens to it depends only on whether this device's key opens it, so it
does not belong in a function about applying submissions.

The isUserMessage fix was re-applied to the eight call sites mantra's
version has, up from the six it had here.

ChatMessageListViewModel and ChatRoomMessagingScreen took mantra's versions
with the composer state, the two renderings and the reply action layered
back on.

docs/README.md keeps both new rows and mantra's closing note about the
skipped-keys document.

108 tests pass, up from 50 here and 83 on mantra.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-05 23:45:08 +02:00
Kgothatso Ngako
d110737f9a fix: keep a room's MlsGroup alive so a late message can still be read
Two events published in the same second reliably lose one of them. The
receiver stores the kind:445 and produces nothing from it -- no inner
event, no chat line, no error anybody sees, because MarmotGroupEvent is
written before the message is decrypted and so survives while everything
downstream silently does not.

Observed as a FROST signing session that never started on the receiver:
proposeSigning publishes the proposal and then the proposer's own nonce,
the relay handed them back in the other order, and the proposal was
dropped. The nonce is still sitting there filed against a session that
will never exist. The same bug ate a dialect earlier, which then took out
the artifact referencing it via a foreign key.

MLS is specified to tolerate this. RFC 9420 says a receiver that gets
generation N+1 before N keeps the intermediate keys so the older message
can still be read, and quartz's SecretTree does exactly that, in a
private skippedKeys map. What it does not do is persist it:
exportSenderStates() returns the ratchet positions only, so saveState()
drops the cache. NostrDao rebuilt the group from stored state for every
inbound event, so the cache was empty every single time, and generation N
arriving after N+1 failed `require(generation >= applicationGeneration)`
and was swallowed. Terminal -- the key is derived from a ratchet that has
moved past it, and nothing asks the sender to resend.

This keeps the instance alive instead. MlsGroupCache holds one MlsGroup
per room, and the inbound path goes through it, so skippedKeys survives
from one message to the next. That covers the case that actually bites --
a burst arriving in one sync, decrypted one after another against the
same tree -- which is what every bursty flow needs: proposeRitual sends
two, addArtifact sends two, and addChapter sends one per paragraph plus
one, of which only the ones arriving in ascending generation order
survived.

Reuse is conditional on the stored state still being exactly what the
cache last wrote. Sending a message advances the sender ratchet and saves;
so does adding a member. When that happens the cache rebuilds rather than
carrying on from a group that has been overtaken -- which is what keeps
this from being worse than no cache at all: the fallback is always the old
behaviour, never a diverged ratchet.

One lock per room, not one overall, because the group is mutable and
decryption advances it: two events for the same room decrypted at once
would corrupt the tree, and a busy room should not hold up a quiet one.

**This is a mitigation, not the fix.** It does not survive a restart, and
it does not survive another writer, so a long enough reorder still loses
the message. The fix belongs in quartz -- carry skippedKeys through
saveState/restore -- and quartz is a mavenCentral binary, not a fork, so
it cannot be made here. docs/mls-skipped-keys.md has the analysis, the
patch, the migration constraint on the persisted state format, and the
three ways to actually land it.

Not verified end to end: the proposal that exposed this cannot be
recovered, since its generation is already past, so confirming the fix
needs a fresh burst.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-05 23:09:53 +02:00
Kgothatso Ngako
635cef9311 docs: write down how a direct message travels, and what it costs
The reasoning behind this is not recoverable from the code, which is the
bar docs/README.md sets for having a document at all. Three things in
particular would otherwise have to be rediscovered by whoever changes this
next, and two of them are traps.

Why the wrap uses a throwaway key rather than the sender's own -- and what
that does not buy. It does not hide the sender from the group: MLS
authenticates every application message to a leaf, so the identity is
there regardless. What it costs is a carve-out in MIP-03's pubkey check
and the sender's ability to ever read their own messages back.

Why the check that carve-out removes is not a hole. The authorship claim
moves from the wrap's plaintext pubkey to the seal's verified signature,
bound to the MLS leaf that sent it -- strictly harder to forge than what
it replaced.

The one query that would broadcast one of these. What this builds is a
genuine, correctly signed NIP-59 gift wrap, indistinguishable from what
the NIP-17 path would be right to publish, and the only thing keeping it
off a relay is that it never becomes a GiftWrapPayload.

Written against what shipped rather than what was planned, so it records
two deviations. senderIdentity is resolved in NostrDao rather than added
to GroupEventResult.ApplicationMessage, because quartz is a binary
dependency here and the local checkout is a reference copy, not a build
input. And a failed validation drops the message and logs rather than
throwing, because the caller is inside storeNostrEvent's transaction.

The unbuilt parts are listed as absences rather than left implied: there
is no member picker, so a private message can only be a reply to one
somebody already sent, and nothing in the UI yet tells a user in words
that the group can see who they messaged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-05 19:10:22 +02:00
Kgothatso Ngako
b99cb8fcd5 docs: write down the shared-key subsystem and how Marmot membership fails
First docs in the repo -- README.md is still the stock KMP template. Three
documents plus an index, covering the parts whose behaviour is not recoverable by
reading the code: where the reasoning lives in a protocol, where a failure mode is
silent, or where a decision looked arbitrary and was not.

marmot-membership.md is the one that earns its place. Everything about adding a
member compiles, the invite reports success, and a member simply never appears --
and the reason is never in the invite code. It records that
inviteMemberToChatRoom hardcodes isOneMemberInitialGroupCreation = false and that
ChatRepository does not expose it, so every group invite takes the deferred-welcome
path including the first, when the group is still just its creator and the commit
has no audience at all. Then why that is silent rather than noisy:
MarmotInboundManager refuses future-epoch messages outright, on both wire formats,
with no queue and no replay, so a commit arriving before its recipient's welcome
is dropped and that member never advances. EPOCH_RETENTION_WINDOW retains past
epochs and does nothing for messages from ahead. Three options are set out with the
per-invite correctness table, including the honest limit that the recommended one
narrows the race without closing it.

shared-key-derivation.md argues why the paths are not BIP32 -- no chain code
exists, hardened derivation is impossible rather than unimplemented, and a FROST
tweak takes the scalar as input so the chain code leaves the problem entirely. It
records the x-only serialisation trap avoided by choosing the scalar directly, and
states the rule that must not be broken: never reconstruct a derived key in the
clear, because k = k' - t hands over the group key rather than one derived key.

shared-key-ceremony.md covers the seven kinds, the three approval gates and why
the coordinator's aggregations are deliberately not among them, faults as values
rather than exceptions, and the transcript's idempotency-by-construction. It also
writes down the invariant that produces no error when broken: pendingApproval must
mirror the gates in advance, or the screen offers an approval that does nothing --
or none while the ritual sits still.

Every factual claim was checked against the source rather than recalled, which
turned up one correction worth having: there are two future-epoch refusals, for
PrivateMessage and for Commit, so the drop covers both wire formats and not just
one.

Each document leads with the failure mode rather than the architecture, on the
grounds that a failure is what sends somebody to docs in the first place, and each
lists its known gaps -- including that none of this has run on a physical device.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-05 14:39:19 +02:00