GBPStack 1.2.2

GBPStack — .NET bindings for the Group Protocol Stack

Managed (.NET) bindings for the Group Protocol Stack: a layered, end-to-end encrypted group-messaging protocol family built on top of MLS (RFC 9420).

This NuGet package bundles the managed wrapper plus the native runtime library gbp_stack for every supported runtime identifier: win-x64, win-arm64, linux-x64, linux-arm64, osx-x64, osx-arm64. .NET picks the right binary at runtime — no extra setup is required.

Layers

┌── application ──────────────────────────────────────────────────────┐
│   GtpClient · GapClient · GspClient   (TCP/UDP/SCTP-like)           │
├─────────────────────────────────────────────────────────────────────┤
│   GroupNode (GBP — IP-like base)                                    │
├─────────────────────────────────────────────────────────────────────┤
│   MlsContext (RFC 9420)                                             │
└─────────────────────────────────────────────────────────────────────┘

Sub-protocol toolkits

Beyond the protocol clients, the package ships ready-made helpers:

• MessageHistory + Watermark — bounded GTP message log + per-sender high-water mark for serving and consuming resync requests.
• JitterBuffer — bounded GAP reorder window keyed by MediaSourceId, with Push, PopInOrder, PopForce and late-frame detection.
• RoleRegistry + Permissions — bind numeric role ids to permission bit-masks and check them with Require / Has.
• CapabilitiesNegotiator — track per-member advertisements and query the Intersection, Union, GroupSupports and Missing views.
• SFrameSession + SFrameEncryptor — SFrame (draft-ietf-sframe-enc) E2EE for GAP audio frames; per-sender AES-GCM keys derived from MLS exporter, 1024-entry sliding-window replay protection.

Install

dotnet add package GBPStack --version 1.2.2

Quick start

using GBPStack;

using var aliceMls = MlsContext.Create("alice");
using var bobMls   = MlsContext.Create("bob");

var bobKp   = bobMls.ExportKeyPackage();
var welcome = aliceMls.Invite(bobKp);
bobMls.AcceptWelcome(welcome);

var groupId = aliceMls.GroupId;
using var alice = GroupNode.Create(memberId: 1, groupId);
using var bob   = GroupNode.Create(memberId: 2, groupId);
alice.BootstrapAsCreator(aliceMls.Epoch);
bob.BootstrapAsJoiner(bobMls.Epoch);

using var aliceGtp = GtpClient.Create();
using var bobGtp   = GtpClient.Create();

var frame = aliceGtp.Send(alice, aliceMls, target: 2, messageId: 0xCAFE_F00D, "hello");
foreach (var ev in bob.OnWire(bobMls, frame.Wire))
    if (ev.Kind == "payload_received" && ev.StreamType == StreamType.Text)
        Console.WriteLine(bobGtp.Accept(ev.Plaintext!).Text);

License

Licensed under Apache License, Version 2.0.