Verified against the fips crate source: the mesh ULA is a pure function
of the PUBLIC key — fd || sha256(x-only pubkey)[0..15] — so the npub is
the durable address and needs no resolver. Android/tools/fipssh wraps
ssh for Termux: 'fipssh user@npub1…' derives the ULA (pure-python
bech32 + sha256, checksum-validated, typo protection) and execs ssh
over the companion's split tunnel; --resolve prints the ULA alone.
The derivation is pinned by a new Rust test
(npub_derives_the_same_mesh_ula_as_the_fips_identity, 3 seeds against
fips::Identity) and the helper's output was verified byte-identical
against a live fips identity pair. SSH-over-mesh handover updated with
an addendum: node docs/UI can advertise npub-based addressing, no
node-side DNS needed for this case.
Extends archy-fips-core with the two companion-release features' crypto
(#128, #139), same JNI-over-JSON contract as the mesh surface:
backup.rs — the ADR-005 encrypted-backup envelope, byte-compatible with
the node's backup code (Argon2id default params + ChaCha20-Poly1305,
blob = base64(salt||nonce||ct)); decrypt ignores extra envelope fields
so node backups read here too. Round-trip, tamper, wrong-passphrase and
cross-shape tests included.
nostr.rs — the phone-side remote-signer crypto: nsec/npub bech32 keys,
BIP340 schnorr event signing (NIP-01 id serialization), NIP-44 v2
payloads (HKDF-SHA256 + ChaCha20 + HMAC-SHA256, both padding prefixes),
NIP-04 fallback, nostrconnect:// parsing with repeated relay params.
Verified against the official NIP-44 vectors (conversation keys, message
keys, padded lengths, byte-exact encrypt vectors), the BIP-340 reference
sign vectors, and round-trip/tamper/failure tests. secp256k1 0.29 note:
Keypair::public_key() is the 33-byte compressed key — x-only pubkeys
must go through .x_only_public_key().0 (one real bug the vectors caught).
JNI glue adds com.archipelago.app.NativeCore: backupEncrypt/Decrypt,
nostrGenerateSecret/SecretFromAny/ParseConnectUri/SignEvent and the
NIP-44/NIP-04 cipher pairs. Android arm64 build verified via cargo-ndk
(7.2 MB .so, +0.4 MB for both modules). Host: cargo test 23/23, clippy clean.
Dorian