[鸿蒙2025领航者闯关]实战前瞻：构建高可用、强一致的 Flutter + OpenHarmony 智慧金融移动银行平台（支持国密加密、生物认证与信创全栈合规）

// lib/services/gm_crypto.dart
class GmApiClient {
  Future<HttpResponse> post(String path, Map<String, dynamic> body) async {
    // 1. 序列化并 SM4 加密
    final plaintext = jsonEncode(body);
    final encrypted = await GmCrypto.sm4Encrypt(
      key: _getSessionKey(),
      data: utf8.encode(plaintext),
    );

    // 2. SM2 签名
    final signature = await GmCrypto.sm2Sign(
      data: encrypted,
      privateKey: await SecureStorage.get('user_sm2_key'),
    );

    // 3. 发送
    final response = await HttpClient.post(
      url: 'https://bank.example.com/api$path',
      headers: {
        'X-SM4-Encrypted': base64Encode(encrypted),
        'X-SM2-Signature': base64Encode(signature),
        'X-Cert-SN': await _getCertSerial(),
      },
    );

    return _decryptResponse(response);
  }
}

// lib/services/secure_transaction.dart
class SecureTransactionService {
  Future<bool> authorizeTransaction(Transaction tx) async {
    final riskLevel = _assessRisk(tx);

    if (riskLevel == RiskLevel.high) {
      // 启动 TEE 内双因子认证
      final authResult = await TEE.authenticate(
        factors: [BiometricFactor.face, BiometricFactor.fingerprint],
        timeout: Duration(seconds: 30),
      );

      if (!authResult.success) return false;
    }

    // 在 TEE 内签名
    final signedTx = await TEE.signWithSm2(
      data: tx.toJson(),
      keyAlias: 'banking_sign_key',
    );

    return await _submitToBackend(signedTx);
  }
}

Future<void> payWithDigitalRmb(Amount amount) async {
  // 1. 创建子钱包（绑定商户）
  final subWallet = await DigitalRmb.createSubWallet(
    merchantId: 'M123456',
    limit: amount,
  );

  // 2. 调起央行数字人民币 App（Deep Link）
  await FMLPlatform.launchUrl(
    Uri.parse('dcep://pay?subwallet=${subWallet.id}'),
  );
}

String generateOfflineQr(Transaction tx) {
  final signed = TEE.signOffline(tx); // 离线签名
  return QrEncoder.encode({
    'tx': tx.toJson(),
    'sig': base64Encode(signed.signature),
    'cert': _getUserCert(),
  });
}

# fml.config.yaml
build:
  targets:
    - ohos_arm64       # 鸿蒙手机/平板
    - uos_x86_64       # 统信 PC 版网银
    - kylin_loongarch  # 麒麟 + 龙芯 ATM 终端
  signing:
    algorithm: sm2
    certificate: ./certs/bank_gm_cert.p12
  optimization:
    disable_internet_fonts: true
    use_harmonyos_sans: true

if (Accessibility.isVoiceOverEnabled) {
  Semantics(
    label: '当前余额：${formatAmount(balance)}元',
    child: Text('¥ ${balance.toStringAsFixed(2)}'),
  );
}