Customize the WebSocket client

Overview

The CloudClient class is a protocol-aware WebSocket client designed specifically for MPC (Multi-Party Computation) operations. It serves as a thin wrapper around the WebSocketClient which implements WebSocketClientInterface from silent-shard-sdk.

1. CloudClient

• Role: Protocol-aware MPC client
• Responsibility:
  • MPC-specific URL construction
  • Operation routing (keygen/sign/refresh)
• Customization Use Cases:
  • Add authentication headers

2. WebSocketClient implements WebSocketClientInterface

• Role: Low-level WebSocket implementation
• Responsibility:
  • Raw WebSocket connection management
  • Message queueing and asynchronous I/O
  • Binary/text data transmission
• Customization Use Cases:
  • Replace WebSocket library (e.g., Socket.IO, different WebSocket impl)
  • Modify low-level message queueing logic

Example adding authentication headers to WebSocket connection

main.dart

import 'package:silent_shard_sdk/silent_shard_sdk.dart' as sdk;

// To add custom header with each connection
class CloudSocketClient extends sdk.CloudClient {
  final String userToken;

  CloudSocketClient(
      {required super.baseUri,
      required this.userToken,
      required super.isSecure,
      super.webSocketClient})
      : super();

  @override
  Future<void> connect(String uri, [String protocol = 'duo-instance']) {
    return webSocketClient.connect(uri: uri, protocol: protocol, headers: {
      'Authorization': 'Bearer $userToken',
    });
  }
}

Future<void> setup() async {
  final customCloudClient = CloudSocketClient(
    baseUri: 'wss://cloud.silent-shard.com',
    isSecure: true,
    userToken: 'your-token',
  );

  final session = await sdk.createDuoEcdsaSession(
    cloudClient: customCloudClient,
    cloudVerifyingKeyHex: 'SERVER_PUBLIC_KEY_HEX',
    storageClient: sdk.SimpleStorageClient(),
  );

  final keyshare = await session.keygen();
  print('Keyshare: $keyshare');
}