vjrj
49b872b405
Throwaway research spike (spike/ branch, outside pub workspace, no prod deps touched). Validates the open Block 2 decisions before committing a funded round: 1. Deterministic one-way secp256k1 (Nostr) key derived from the Ğ1 root seed via HKDF — user still backs up ONE thing. Reproducible + signs (BIP340). 2. OfferTransport abstraction over Nostr NIP-99 (kind 30402); Offer stays inventory/location-agnostic, geohash coarsened on the wire (tested). 3. publish->discover-by-geohash proven end-to-end against an in-process hermetic mini-relay (~34ms round-trip). Findings + risks + recommendation in docs/design/spike-block2-findings.md. Block 1 suite untouched. 14 tests green, analyzer clean.
76 lines
3.2 KiB
Dart
76 lines
3.2 KiB
Dart
import 'dart:math';
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import 'dart:typed_data';
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import 'package:bip340/bip340.dart' as bip340;
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import 'package:block2_spike/block2_spike.dart';
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import 'package:commons_core/commons_core.dart';
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import 'package:test/test.dart';
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/// Q1 — Identity derivation: a deterministic, one-way secp256k1 (Nostr) key from
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/// the Duniter/Ğ1-style root seed, so the user still backs up ONE thing.
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void main() {
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group('NostrKey.deriveFromSeed', () {
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// A fixed seed so expectations are reproducible across runs/machines.
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final seed = Uint8List.fromList(List.generate(32, (i) => i));
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test('is reproducible: same seed → identical key', () {
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final a = NostrKey.deriveFromSeed(seed);
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final b = NostrKey.deriveFromSeed(seed);
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expect(a.privateKeyHex, b.privateKeyHex);
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expect(a.publicKeyHex, b.publicKeyHex);
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expect(a.npub, b.npub);
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});
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test('produces a well-formed x-only key and npub/nsec', () {
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final key = NostrKey.deriveFromSeed(seed);
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expect(key.privateKeyHex, matches(RegExp(r'^[0-9a-f]{64}$')));
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expect(key.publicKeyHex, matches(RegExp(r'^[0-9a-f]{64}$')));
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// Cross-check: bip340 derives the same pubkey from our private hex.
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expect(bip340.getPublicKey(key.privateKeyHex), key.publicKeyHex);
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expect(key.npub, startsWith('npub1'));
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expect(key.nsec, startsWith('nsec1'));
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});
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test('the derived key actually signs & verifies (BIP340)', () {
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final key = NostrKey.deriveFromSeed(seed);
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final message = 'a' * 64; // 32-byte hex message
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final sig = bip340.sign(key.privateKeyHex, message, 'b' * 64);
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expect(bip340.verify(key.publicKeyHex, message, sig), isTrue);
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});
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test('different seeds → different keys (avalanche on a 1-bit flip)', () {
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final flipped = Uint8List.fromList(seed)..[0] ^= 0x01;
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final a = NostrKey.deriveFromSeed(seed);
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final b = NostrKey.deriveFromSeed(flipped);
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expect(a.privateKeyHex, isNot(b.privateKeyHex));
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expect(a.publicKeyHex, isNot(b.publicKeyHex));
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});
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test('one-wayness: neither key contains the seed, and HKDF is not '
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'invertible', () {
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final key = NostrKey.deriveFromSeed(seed);
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final seedHex = seed
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.map((b) => b.toRadixString(16).padLeft(2, '0'))
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.join();
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// The seed does not appear verbatim in the derived material.
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expect(key.privateKeyHex, isNot(contains(seedHex)));
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expect(key.publicKeyHex, isNot(contains(seedHex)));
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// Structural argument (documented in findings §1): recovery of the seed
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// would require inverting HMAC-SHA256. We assert the property we CAN test:
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// two unrelated seeds never collide to the same key.
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final other = NostrKey.deriveFromSeed(
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Uint8List.fromList(List.generate(32, (i) => 255 - i)),
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);
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expect(key.privateKeyHex, isNot(other.privateKeyHex));
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});
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test('integrates with the real IdentityService seed length', () {
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final rootSeed = IdentityService(
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random: Random(42),
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).generateRootSeed();
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expect(rootSeed.length, IdentityService.rootSeedLengthBytes);
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final key = NostrKey.deriveFromSeed(rootSeed);
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expect(key.publicKeyHex, matches(RegExp(r'^[0-9a-f]{64}$')));
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});
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});
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}
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