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release(v4.0.0): Shade GA — V3.x consolidation + audit prep
V3.1 → V3.12 consolidated and tagged for the first GA release. Wire
format unchanged from 0.4.x — 4.0 peers interoperate with 0.4.x peers
byte-for-byte. The version bump is semantic: audit-cycle complete,
opt-in surface fully exposed, threat model refreshed for every new
surface.

Highlights:
- All 24 @shade/* packages bumped to 4.0.0 in lockstep.
- CHANGELOG 4.0.0 section is the canonical manifest of what landed.
- THREAT-MODEL extended (§10 fingerprint gates, §11 WebRTC P2P, §12
  Web-Worker boundary) + residual-risks table refreshed.
- OpenAPI now covers all 27 routes: prekey, transfer, KT, inbox,
  bridge, observer, /metrics, /healthz, /ready.
- MIGRATION 0.3.x → 4.0 documented + smoke-tested against
  shade migrate-storage on a real SQLite DB.
- docs/audit/REVIEW-BUNDLE.md + SCOPE.md ready for external reviewer.
- scripts/soak.ts harness for the GA-stable 2-week soak window.
- All V*.md plans archived under docs/archive/ with Status: Done.
- Voice/Video carved out into V5.0; 4.0 audit focuses on the frozen
  non-realtime stack.

Tests: TS 1000/1000 + Kotlin 11/11 cross-platform vectors green.
Docker: gt.zyon.no/stian/shade-prekey:4.0.0 builds and reports
  version 4.0.0 on /health.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-03 18:35:35 +02:00

2.7 KiB

shade-android

Kotlin implementation of the Shade E2EE protocol for Android apps. Byte-for-byte compatible with @shade/core (TypeScript), so messages encrypted on a TS backend can be decrypted on Android and vice versa.

Status

M-Cross 1 — keys + HKDF + X3DH + fingerprint. M-Cross 2 — full ratchet step (encrypt + decrypt roundtrip) + wire 0x02 (RatchetMessage and PreKeyMessage with/without OTPK). M-Cross 3 — streams 0x11 (KDF labels with embedded NULs, deterministic chunk nonce/AAD, wire 0x11 encode/decode). M-Cross 4 — backup-key HKDF + AES-GCM, group sender-key step (kdfChainKey + Ed25519 sign over aad ‖ ct), storage HKDF (storageKey/fieldKey/rowNonce). Pending: scrypt master-key, argon2id swap, Android KeystoreStorage (sibling module).

Cross-platform test vectors in /test-vectors/ are loaded by both the TS and Kotlin test suites; any byte-divergence fails CI within 60 s. See ROADMAP-ANDROID.md for the parity-checkpoint matrix and /docs/cross-platform.md for how to add a new vector.

Usage (target API)

import no.zyon.shade.ShadeSessionManager
import no.zyon.shade.crypto.TinkProvider
import no.zyon.shade.storage.KeystoreStorage

val crypto = TinkProvider()
val storage = KeystoreStorage(context)
val manager = ShadeSessionManager(crypto, storage)
manager.initialize()

// Establish a session with a peer
val bundle = fetchBundleFromServer("bob@example.com")
manager.initSessionFromBundle("bob@example.com", bundle)

// Encrypt
val envelope = manager.encrypt("bob@example.com", "hello")

// Decrypt
val plaintext = manager.decrypt("alice@example.com", incomingEnvelope)

Crypto primitives

Backed by Google Tink:

  • X25519 for Diffie-Hellman (via X25519.generatePrivateKey() / computeSharedSecret)
  • Ed25519 for signing (via Ed25519Sign / Ed25519Verify)
  • AES-256-GCM (via AesGcmJce)
  • HKDF-SHA256 (via Hkdf.computeHkdf)
  • HMAC-SHA256 (via MacFactory)

Building

Requires JDK 17. The module compiles as a pure-JVM Kotlin library so the parity gate runs without an Android SDK install. The Android-specific storage adapter (Keystore + EncryptedSharedPreferences) will land as a sibling Gradle module in M-Cross 4.

cd android
./gradlew :shade-android:test

The Gradle wrapper downloads Gradle 8.10.2 on first run.

Compatibility

The Kotlin implementation must produce byte-identical output to @shade/core for:

  • KDF chain derivations (root key ratchet, chain key ratchet)
  • X3DH shared secrets
  • Ratchet message keys and ciphertext (given the same keys)
  • Fingerprints (safety numbers)
  • Binary wire format (@shade/proto)

Shared test vectors in test-vectors/ are loaded by both the TS and Kotlin test suites. Any divergence fails the CI immediately.