gbp-node

GBP-layer group node for the Group Protocol Stack.

This is the IP-like substrate that the three sub-protocol crates (gtp-protocol, gap-protocol, gsp-protocol) build on. It owns the framing, AEAD, replay window, FSM and control plane.

What this crate provides

• GroupNode — the core node type. Call bootstrap_as_creator or bootstrap_as_joiner once after MLS welcome, then pipe every inbound wire frame through on_wire and route the resulting Events to sub-protocol clients.
• OutboundFrame — a wire-ready (to, wire) pair returned by every send helper.
• DeliveredPayload — decrypted plaintext + stream_type, stream_id, sequence_no, flags, and codec surfaced to sub-protocols via Event::PayloadReceived.
• Event — all events emitted by the node: StateChanged, PayloadReceived, Control, Error, EpochAdvanced, CoordinatorElectionNeeded, BecameCoordinator, CoordinatorClaim.

Example

use gbp_stack::{
    ControlOpcode, Event, GtpAccept, GtpClient, GroupNode, MlsContext,
    PayloadCodec, StreamType,
};

// After MLS two-party handshake (alice invites bob):
let gid = alice_mls.group_id_16();
let mut alice = GroupNode::new(1, gid);
let mut bob   = GroupNode::new(2, gid);
alice.bootstrap_as_creator(0);          // epoch 0
bob.bootstrap_as_joiner(0, 1);          // epoch 0, expect tid=1

// Apply epoch-1 transition.
let exec = alice.send_control(
    &mut alice_mls, 0, ControlOpcode::ExecuteTransition, 1, 7, vec![],
)?;
alice.apply_transition(1);
bob.on_wire(&mut bob_mls, &exec.wire)?;

// Send a text message via GTP.
let mut gtp_alice = GtpClient::new();
let mut gtp_bob   = GtpClient::new();

let frame = gtp_alice.send(
    &mut alice, &mut alice_mls, 2, 1, "hello", PayloadCodec::Cbor,
)?;

for event in bob.on_wire(&mut bob_mls, &frame.wire)? {
    if let Event::PayloadReceived(p) = event {
        if p.stream_type == StreamType::Text {
            match gtp_bob.accept(&p.plaintext, bob_mls.epoch(), p.codec)? {
                GtpAccept::New(msg)       => println!("{:?}", msg.text()),
                GtpAccept::Duplicate(msg) => println!("dup: {:?}", msg.text()),
            }
        }
    }
}

See crates/gbp/stack/examples/ for fully-runnable examples covering GTP, GAP and GSP.

License

Licensed under Apache License, Version 2.0.