DALib.Networking

DALib.Networking is a typed packet library for the DOOMVAS v1 network protocol — the protocol spoken by Dark Ages and related games — written in C# and targeting .NET 9 and .NET 10.

It has no dependencies beyond the base class library. No image stack, no native assets: a server, client, or proxy can speak the protocol without pulling in DALib's asset and rendering layers.

Install

dotnet add package DALib.Networking

What it does

Wire framing and codec

PacketCodec encodes typed packets into wire bytes and parses wire bytes back into typed packets, in both directions. One codec is built per process; it is stateless and shared. PacketSession pairs it with a single connection's crypto state so callers don't thread that state through every call.

Cryptography

CRC-16-CCITT, per-connection CryptoState (ordinals, key table, encryption seed), and the dialog obfuscation layer that wraps opcodes 0x39 and 0x3A. The encryption method is derived from the opcode — packets do not declare it, and the codec routes each one for you.

The opcode surface

Every client-to-server and server-to-client packet is modeled as a record with named fields, each documented against the retail client's own behavior. Discriminated bodies (dialogs, merchant menus, boards, exchanges, player shops) are modeled as an abstract base plus sealed per-form variants.

Extension points

Consumers register their own packet types by attribute and hand their assembly to the codec, which discovers them alongside the built-in ones:

var codec = new PacketCodec([typeof(IPacket).Assembly, typeof(MyPacket).Assembly]);

Usage

using DALib.Networking.Crypto;
using DALib.Networking.Packets.Client;
using DALib.Networking.Wire;

// One codec per process; one session per connection.
var codec = new PacketCodec();
var session = new PacketSession(codec, new CryptoState());

ReadOnlyMemory<byte> wire = session.EncodeClient(
    new ClientExitPacket { Signal = ExitSignal.Request });

IServerPacket packet = session.ParseServerPacket(received);

Relationship to DALib

DALib is the sibling library for the game's data formats — .dat archives, maps, palettes, sprites, and rendering. The two packages are independent: neither depends on the other, and they version separately. Networking lived inside DALib through its beta line and moved here at 1.0.0.

License

MIT, matching DALib. See LICENSE and CONTRIBUTORS.md.

(C) 2026 ERISCO, LLC.