code: function ScryptPacket(passwd, salt, N, r, p, len) {
    Packet.call(this);
    this.passwd = passwd || null;
    this.salt = salt || null;
    this.N = N != null ? N : -1;
    this.r = r != null ? r : -1;
    this.p = p != null ? p : -1;
    this.len = len != null ? len : -1;
  }
docs: ScryptPacket
  @constructor