Class SocksConnection

packages/utils/socksProxy.ts:74–280

}

class SocksConnection {
  private _buffer = Buffer.from([]);
  private _offset = 0;
  private _fence = 0;
  private _fenceCallback: (() => void) | undefined;
  private _socket: net.Socket;
  private _boundOnData: (buffer: Buffer) => void;
  private _uid: string;
  private _client: SocksConnectionClient;

  constructor(uid: string, socket: net.Socket, client: SocksConnectionClient) {
    this._uid = uid;
    this._socket = socket;
    this._client = client;
    this._boundOnData = this._onData.bind(this);
    socket.on('data', this._boundOnData);
    socket.on('close', () => this._onClose());
    socket.on('end', () => this._onClose());
    socket.on('error', () => this._onClose());
    this._run().catch(() => this._socket.end());
  }

  async _run() {
    assert(await this._authenticate());
    const { command, host, port } = await this._parseRequest();
    if (command !== SocksCommand.CONNECT) {
      this._writeBytes(Buffer.from([
        0x05,
        SocksReply.CommandNotSupported,
        0x00, // RSV
        0x01, // IPv4
        0x00, 0x00, 0x00, 0x00, // Address
        0x00, 0x00 // Port
      ]));
      return;
    }

    this._socket.off('data', this._boundOnData);
    this._client.onSocketRequested({ uid: this._uid, host, port });
  }

  async _authenticate(): Promise<boolean> {
    // Request:
    // +----+----------+----------+
    // |VER | NMETHODS | METHODS  |
    // +----+----------+----------+
    // | 1  |    1     | 1 to 255 |
    // +----+----------+----------+

    // Response:
    // +----+--------+
    // |VER | METHOD |
    // +----+--------+
    // | 1  |   1    |
    // +----+--------+

    const version = await this._readByte();
    assert(version === 0x05, 'The VER field must be set to x05 for this version of the protocol, was ' + version);