Every release build before this went out as CN=Flamenet Files. Not a decision —
app/build.gradle.kts read ~/.flamenet-android-signing.properties, a path with no
app in its name, so any Flamenet Android app built on that Mac inherited the
Files identity.
It matters because an Android signing key is permanent. Once a device installs a
build signed with one key it REFUSES every later build signed with another, so
the only remedies after the fact are a new package name — a different app,
orphaning every install — or Play App Signing, which has to be set up before
first publication. Sharing one key across products also means one compromised
keystore takes out both.
Now prefers ~/.flamenet-messenger-signing.properties and falls back to the
shared file, so a machine with only the old setup still produces a signed build
rather than failing in a confusing way.
Verified in the artifact:
Signer #1 certificate DN: CN=Flamenet Messenger, O=Extant 2000 LLC, C=US
RSA 4096, SHA-256 791fc826d572a70abfaf7db7fa7784dad0f86f204bb313f0d75ee676df8d3a1d
⚠️ The keystore and its password live outside the repo and there is NO recovery
for either. Losing them means the app can never be updated again.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Flamenet Messenger — Android
Nothing here is an app yet. This is the engine, and it is deliberately first.
An Android client needs the protocol implemented a third time. That third
implementation is the one that finds the places where the specification says
less than the two existing engines quietly agreed on — but only if it is
written against the spec and the published vectors rather than against a
reading of our own Swift and JavaScript. So the engine comes first, it is a
plain Kotlin/JVM library with no Android in it at all, and it is held to
engine/test/vectors/protocol-v1.json — the same file the other two engines
are checked against, read from that one location rather than copied here.
./gradlew :engine:test
No Android SDK, no emulator, no device. It runs anywhere a JVM does, which is also what lets it run in CI on Linux.
What the engine covers today
| Area | Spec | State |
|---|---|---|
| Safety numbers | §7 | Done — fingerprints and conversation ordering match the published vectors |
| Key transparency verification | §19 | Done — RFC 6962 leaf/node hashing, unbalanced split, bottom-up audit paths |
| Byte helpers | — | Unsigned comparison, constant-time equality |
What it does not cover
Listed rather than left to be discovered, because a table of green ticks with the hard parts quietly missing is worse than no table:
| Area | Spec | State |
|---|---|---|
| X25519 / Ed25519 | §3 | Not started — needs a provider that works on both JVM and Android |
| X3DH key agreement | §4 | Not started |
| Double Ratchet | §6 | Not started |
| Sealed sender | §12 | Not started |
| ML-KEM-768 hybrid | §11 | Not started |
| ML-DSA-65 identities | §20 | Not started |
| Relay client | §8 | Not started |
| The app itself | — | Not started |
Until those exist, Android is honestly marked "not started" on the website, and a conversation gets the protocol's guarantees only when both ends are iOS.
Why the vectors matter more than the code
Two implementations that agree may both be wrong in the same way, especially when one was written while reading the other. The audit-path ordering in §19 is the worked example: a top-down reading of a bottom-up path produces the correct root for every left-spine index, so it passes any test that only checks index 0. The vector file pins a right-descending index for that reason, and the Kotlin tests assert both that the published path verifies and that the same path reversed does not.
If this engine ever disagrees with the file, the interesting question is which of the three is wrong — not this one by default.