halkyon/packages/halkyon_keys/test/safety_code_test.dart

import 'package:halkyon_keys/halkyon_keys.dart';
import 'package:sodium/sodium_sumo.dart';
import 'package:test/test.dart';

Future<void> main() async {
  final sodium = await SodiumSumoInit.init();

  PublicKeys keysOf(AccountKeys account) => (
    encryption: account.encryptionPublicKey,
    signing: account.signingPublicKey,
  );

  group('safety codes (ADR 0044, D18)', () {
    final alice = AccountKeys.generate(sodium);
    final bob = AccountKeys.generate(sodium);

    test('both people see the same 60 digits, in twelve groups of five', () {
      final code = safetyCode(sodium, keysOf(alice), keysOf(bob));
      expect(code, safetyCode(sodium, keysOf(bob), keysOf(alice)));
      expect(code, matches(RegExp(r'^\d{5}( \d{5}){11}$')));
    });

    test('another key on either side, of either kind, gives another '
        'code', () {
      final code = safetyCode(sodium, keysOf(alice), keysOf(bob));
      final mallory = AccountKeys.generate(sodium);
      expect(safetyCode(sodium, keysOf(alice), keysOf(mallory)), isNot(code));
      expect(
        safetyCode(sodium, keysOf(alice), (
          encryption: mallory.encryptionPublicKey,
          signing: bob.signingPublicKey,
        )),
        isNot(code),
      );
      expect(
        safetyCode(sodium, keysOf(alice), (
          encryption: bob.encryptionPublicKey,
          signing: mallory.signingPublicKey,
        )),
        isNot(code),
      );
    });

    test("half of the code is each person's own, whoever they compare "
        'with', () {
      final carol = AccountKeys.generate(sodium);
      final withBob = safetyCode(
        sodium,
        keysOf(alice),
        keysOf(bob),
      ).replaceAll(' ', '');
      final withCarol = safetyCode(
        sodium,
        keysOf(alice),
        keysOf(carol),
      ).replaceAll(' ', '');
      final halves = {
        withBob.substring(0, 30),
        withBob.substring(30),
      }.intersection({withCarol.substring(0, 30), withCarol.substring(30)});
      expect(halves, hasLength(1));
    });
  });
}