Function makeSocks5Connection

src/cmap/connect.ts:488–538

(options: MakeConnectionOptions)

}

async function makeSocks5Connection(options: MakeConnectionOptions): Promise<Stream> {
  const hostAddress = HostAddress.fromHostPort(
    options.proxyHost ?? '', // proxyHost is guaranteed to set here
    options.proxyPort ?? 1080
  );

  // First, connect to the proxy server itself:
  const rawSocket = await makeSocket({
    ...options,
    hostAddress,
    tls: false,
    proxyHost: undefined
  });

  const destination = parseConnectOptions(options) as net.TcpNetConnectOpts;
  if (typeof destination.host !== 'string' || typeof destination.port !== 'number') {
    throw new MongoInvalidArgumentError('Can only make Socks5 connections to TCP hosts');
  }

  socks ??= loadSocks();

  let existingSocket: Stream;

  try {
    // Then, establish the Socks5 proxy connection:
    const connection = await socks.SocksClient.createConnection({
      existing_socket: rawSocket,
      timeout: options.connectTimeoutMS,
      command: 'connect',
      destination: {
        host: destination.host,
        port: destination.port
      },
      proxy: {
        // host and port are ignored because we pass existing_socket
        host: 'iLoveJavaScript',
        port: 0,
        type: 5,
        userId: options.proxyUsername || undefined,
        password: options.proxyPassword || undefined
      }
    });
    existingSocket = connection.socket;
  } catch (cause) {
    throw new MongoNetworkError(MongoError.buildErrorMessage(cause), { cause });
  }

  // Finally, now treat the resulting duplex stream as the
  // socket over which we send and receive wire protocol messages:
  return await makeSocket({ ...options, existingSocket, proxyHost: undefined });
}