## Summary
After a pairing QR scan, the app shows connection progress until code
entry or a connection error. A WebSocket handshake that remains pending
stops after ten seconds. Cancel is available until storage starts. It
resets pairing and restores the entry form. Pasted codes remain
available after an error or cancellation. Back navigation stays blocked
during identity transfer and storage. Cancel on Send identity to desktop
returns to Settings, so another attempt starts through the authorization
step.
### Related issue
Related to [#9001](https://github.com/block/buzz/pull/9001), which
covers organization sign-in after identity transfer. This change covers
the earlier connection stage.
### Testing
A simulator build with PR #9001 completes identity transfer and saves
the community. The community chooser still blocks organization sign-in.
[PR #9028](https://github.com/block/buzz/pull/9028) covers that step.
Physical iPhone testing and successful real-relay checks in light and
dark mode remain pending. On a build with this change, scan a desktop
pairing QR code. Check that progress appears, Cancel returns to the
entry form, and a fresh attempt reaches code entry. Paste a pairing
code, cancel during connection, and check that the form keeps the code.
Test a failed connection and retry. In Settings, open Send identity to
desktop, start a recovery connection, and cancel. Check that Settings
appears and another attempt asks for authorization. Camera recognition
speed and the reported intermittent phone network failure remain
unverified.
Generated with Codex
---------
Signed-off-by: Daniel Rouleau <drouleau@squareup.com>
Co-authored-by: Sol <c35e7cc95f6fdbfb7e861dccc02bdca567b6d6b20f16b5115c3c6ae082bbeede@buzz.block.builderlab.xyz>
Mobile signs every Nostr event (sends, relay AUTH, media auth headers,
preference writes) in pure Dart on the UI isolate. On an iPhone SE (2nd
gen, Profile build) one BIP-340 signature costs about 10.7 ms and
deriving the public key another 5.6 ms, so a burst of signed writes
drops frames.
This adds `mobile/packages/buzz_secp256k1`, a small FFI package that
builds vendored bitcoin-core/libsecp256k1 v0.8.0 (ecdh, extrakeys,
schnorrsig modules) through a Dart build hook, so the same C and the
same Dart API ship on iOS and Android with no platform bridge code. All
13 `nostr.Event.from` signing sites now go through `signNostrEvent`,
which keeps the `nostr` package's event-id serialization and moves only
key derivation and signing to native code. Calls stay synchronous.
The package also exposes `schnorrVerify` and `ecdhX`; follow-up PRs move
verification and the NIP-44 conversation key over. Incoming relay events
are still not verified, unchanged by this PR.
Safety: the signing context is randomized once per isolate, secret keys
and keypairs are wiped from the native scratch buffer after each call,
aux randomness comes from `Random.secure()`, and the static verify
context runs libsecp256k1's self test before first use.
### Validation
- Added tests: BIP-340 official vectors and native-vs-pure-Dart
differential tests in the package; `event_signing_test.dart` signs with
64 random keys and checks pubkey, event id and signature against the
existing `nostr` builder and verifier, plus malformed-key rejection.
- Full mobile analyze and test suite pass locally.
- Builds: iOS release (framework ~1.3 MB) and Android debug APK with the
library for arm64-v8a, armeabi-v7a and x86_64 (~1.2–1.3 MB each).
- On-device (iPhone SE 2nd gen, Profile, median per op): sign 10,736 µs
→ 41 µs, derive pubkey 5,580 µs → 16.5 µs, full signed event 10,744 µs →
65 µs. Event-id JSON and SHA-256 are 23 µs, so they stay in Dart.
- Device, iOS (iPhone SE 2nd gen, Profile): `buzz_secp256k1.framework`
embedded; the signed-in app authenticated to a real community relay,
loaded channels and history, and paged older messages. No native-asset
or secp256k1 errors in the console.
- Device, Android (emulator, debug): APK contains `libbuzz_secp256k1.so`
and loads it. Against a local mock relay that verifies with the
pure-Dart `nostr` package, the app's NIP-42 AUTH, NIP-98 `POST /query`
headers, and kind 20001/30078 events all verified.
- Blossom GET auth, iOS: the dev relay returns 401 for unauthenticated
`/media/` GETs. From inside the running app, the production
`MediaGetAuthService.headersFor()` header for a nonexistent hash got 404
(accepted, file missing), compared with 401 without it. The community
has no relay-hosted image, so none was rendered.
buzz-review-completed (agent review, Codex and security review clean;
device validation above; human app test not applicable under the mobile
testing exception)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
Co-authored-by: george <973be878edd6d4f79692a3827f20a6f7fe0ed0362f269ff6b6ba8867033d7d8e@sprout-oss.stage.blox.sqprod.co>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Age-check errors previously blocked Buzz startup. Normal app startup now
proceeds immediately; only a valid under-18 response from the current
launch request can restrict access.
Age check enforcement remains disabled at compile time by default.
Builds can opt in with `--dart-define=BUZZ_AGE_GATING_ENABLED=true`.
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
