Prepare SysV tooling in install-script test containers

The netbird package postinstall registers a SysV service when systemd is
not running. The trixie and fedora images ship without /etc/init.d and
the service tool, failing the postinstall before the UI gating under test.

.github/workflows/install-script-test.yml

@@ -7,6 +7,7 @@ on:
   pull_request:
     paths:
       - "release_files/install.sh"
+      - ".github/workflows/install-script-test.yml"
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}-${{ github.head_ref || github.actor_id }}
   cancel-in-progress: true
@@ -37,3 +38,64 @@ jobs:
 
       - name: check cli binary
         run: command -v netbird
+
+  test-install-script-distros:
+    name: UI gating on ${{ matrix.image }}${{ matrix.install_epel && ' (EPEL pre-confirmed)' || '' }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      max-parallel: 3
+      matrix:
+        include:
+          # GTK 4 below 4.10: desktop app must be skipped, CLI installed
+          - image: "ubuntu:22.04"
+            expect_ui: false
+          - image: "debian:12"
+            expect_ui: false
+          # GTK 4.10+ and WebKitGTK 6.0 available: desktop app installed
+          - image: "debian:13"
+            expect_ui: true
+          - image: "fedora:43"
+            expect_ui: true
+          # webkitgtk6.0 needs EPEL: skipped without confirmation,
+          # installed when NETBIRD_INSTALL_EPEL=true
+          - image: "almalinux:10"
+            expect_ui: false
+          - image: "almalinux:10"
+            expect_ui: true
+            install_epel: true
+    container:
+      image: ${{ matrix.image }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          persist-credentials: false
+
+      - name: prepare container
+        # The netbird package postinstall registers a SysV service when
+        # systemd is not running. The trixie and fedora images ship without
+        # the SysV directories and tools it needs, unlike the older images.
+        run: |
+          mkdir -p /etc/init.d
+          if command -v dnf >/dev/null 2>&1; then
+            dnf -y install initscripts-service || dnf -y install initscripts
+          fi
+
+      - name: run install script
+        env:
+          XDG_CURRENT_DESKTOP: GNOME
+          NETBIRD_INSTALL_EPEL: ${{ matrix.install_epel && 'true' || '' }}
+        run: sh -x release_files/install.sh
+
+      - name: check binaries
+        run: |
+          command -v netbird
+          if [ "${{ matrix.expect_ui }}" = "true" ]; then
+            command -v netbird-ui
+          else
+            if command -v netbird-ui; then
+              echo "netbird-ui should not have been installed on ${{ matrix.image }}"
+              exit 1
+            fi
+          fi

client/internal/engine.go

@@ -50,7 +50,6 @@ import (
 	icemaker "github.com/netbirdio/netbird/client/internal/peer/ice"
 	"github.com/netbirdio/netbird/client/internal/peerstore"
 	"github.com/netbirdio/netbird/client/internal/portforward"
-	"github.com/netbirdio/netbird/client/internal/pqkem"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/internal/relay"
 	"github.com/netbirdio/netbird/client/internal/rosenpass"
@@ -198,10 +197,6 @@ type Engine struct {
 	// rpManager is a Rosenpass manager
 	rpManager *rosenpass.Manager
 
-	// pqkemManager runs the ML-KEM post-quantum PSK exchange (gated by NB_ENABLE_PQ_MLKEM).
-	// It owns the data-path transport and peer endpoint routing.
-	pqkemManager *pqkem.Manager
-
 	// syncMsgMux is used to guarantee sequential Management Service message processing
 	syncMsgMux *sync.Mutex
 
@@ -656,19 +651,6 @@ func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL)
 		e.rpManager.SetInterface(e.wgInterface)
 	}
 
-	// Start the ML-KEM PQ manager after the interface is up so its dedicated UDP
-	// transport can bind on the WG overlay IP.
-	if pqkem.Enabled() {
-		tr, pqErr := newPQTransport(e.config.WgAddr.IP)
-		if pqErr != nil {
-			log.Errorf("pqkem: transport bind failed, exchange disabled: %v", pqErr)
-		} else {
-			e.pqkemManager = pqkem.NewManager(pqkem.LocalID(publicKey.String()), pqCallbackHandler{wg: e.wgInterface}, pqkem.NewLogger())
-			e.pqkemManager.Start(tr)
-			log.Infof("pqkem: enabled (udp port %d on overlay %s)", e.pqkemManager.LocalPort(), e.config.WgAddr.IP)
-		}
-	}
-
 	// if inbound conns are blocked there is no need to create the ACL manager
 	if e.firewall != nil && !e.config.BlockInbound {
 		e.acl = acl.NewDefaultManager(e.firewall)
@@ -932,10 +914,6 @@ func (e *Engine) removePeer(peerKey string) error {
 
 	e.connMgr.RemovePeerConn(peerKey)
 
-	if e.pqkemManager != nil {
-		e.pqkemManager.RemovePeer(pqkem.RemoteID(peerKey))
-	}
-
 	err := e.statusRecorder.RemovePeer(peerKey)
 	if err != nil {
 		log.Warnf("received error when removing peer %s from status recorder: %v", peerKey, err)
@@ -1922,9 +1900,6 @@ func (e *Engine) createPeerConn(pubKey string, allowedIPs []netip.Prefix, agentV
 		},
 		ICEConfig: e.createICEConfig(),
 	}
-	if e.pqkemManager != nil {
-		config.PQ = pqHandshaker{mgr: e.pqkemManager}
-	}
 
 	serviceDependencies := peer.ServiceDependencies{
 		StatusRecorder:     e.statusRecorder,
@@ -2108,10 +2083,6 @@ func (e *Engine) close() {
 		_ = e.rpManager.Close()
 	}
 
-	if e.pqkemManager != nil {
-		e.pqkemManager.Stop()
-	}
-
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 	if err := e.portForwardManager.GracefullyStop(ctx); err != nil {
@@ -2924,8 +2895,6 @@ func convertToOfferAnswer(msg *sProto.Message) (*peer.OfferAnswer, error) {
 		Version:         msg.GetBody().GetNetBirdVersion(),
 		RosenpassPubKey: rosenpassPubKey,
 		RosenpassAddr:   rosenpassAddr,
-		MlkemPayload:    msg.GetBody().GetMlkemPayload(),
-		MlkemPort:       int(msg.GetBody().GetMlkemPort()),
 		RelaySrvAddress: msg.GetBody().GetRelayServerAddress(),
 		RelaySrvIP:      relayIP,
 		SessionID:       sessionID,

client/internal/peer/conn.go

@@ -74,32 +74,6 @@ type RosenpassConfig struct {
 	PermissiveMode bool
 }
 
-// PQHandshaker attaches post-quantum ML-KEM material to signalling offers/answers and
-// feeds received material back. It is implemented by the engine over the pqkem
-// manager and is nil when the PQ exchange is disabled. remoteKey is the peer's
-// WireGuard public key.
-type PQHandshaker interface {
-	// OfferPayload returns the KEM offer to embed in an outgoing offer (nil if this
-	// peer is not the KEM initiator) and the local PQ data-path port to announce.
-	OfferPayload(remoteKey string) (payload []byte, port int)
-	// AnswerPayload processes a received KEM offer (nil if absent) and returns the KEM
-	// answer to embed in the outgoing answer (nil if none) and the local PQ port.
-	AnswerPayload(remoteKey string, recvOffer []byte) (payload []byte, port int)
-	// OnAnswer feeds a received KEM answer (nil if absent).
-	OnAnswer(remoteKey string, recvAnswer []byte)
-	// PSK returns the peer's latest derived post-quantum PSK to program at WG
-	// peer-config time (the pull path). ok is false until one has been derived.
-	PSK(remoteKey string) (wgtypes.Key, bool)
-	// SetRemoteAddr registers the peer's data-path endpoint learned from signalling:
-	// its WG overlay IP with the advertised pq UDP port.
-	SetRemoteAddr(remoteKey string, addr netip.AddrPort)
-	// OnDataPathRekeyed signals a fresh WireGuard handshake for the peer; it clocks the
-	// next chained PSK rotation pushed over the data path.
-	OnDataPathRekeyed(remoteKey string)
-	// OnDataPathDown signals the peer's tunnel went down.
-	OnDataPathDown(remoteKey string)
-}
-
 // ConnConfig is a peer Connection configuration
 type ConnConfig struct {
 	// Key is a public key of a remote peer
@@ -117,9 +91,6 @@ type ConnConfig struct {
 
 	RosenpassConfig RosenpassConfig
 
-	// PQ carries post-quantum ML-KEM material on offers/answers; nil when disabled.
-	PQ PQHandshaker
-
 	// ICEConfig ICE protocol configuration
 	ICEConfig icemaker.Config
 }
@@ -710,10 +681,6 @@ func (conn *Conn) onWGDisconnected(watcherCtx context.Context) {
 
 	conn.Log.Warnf("WireGuard handshake timeout detected, closing current connection")
 
-	if conn.config.PQ != nil {
-		conn.config.PQ.OnDataPathDown(conn.config.Key)
-	}
-
 	// Close the active connection based on current priority
 	switch conn.currentConnPriority {
 	case conntype.Relay:
@@ -979,11 +946,6 @@ func (conn *Conn) onWGCheckSuccess() {
 	conn.mu.Lock()
 	conn.wgTimeouts = 0
 	conn.mu.Unlock()
-
-	// A fresh WireGuard handshake is the clock for the post-quantum PSK rotation.
-	if conn.config.PQ != nil {
-		conn.config.PQ.OnDataPathRekeyed(conn.config.Key)
-	}
 }
 
 // recordConnectionMetrics records connection stage timestamps as metrics
@@ -1025,15 +987,6 @@ func (conn *Conn) AgentVersionString() string {
 }
 
 func (conn *Conn) presharedKey(remoteRosenpassKey []byte) *wgtypes.Key {
-	// Post-quantum: once the ML-KEM exchange has derived a PSK for this peer, program
-	// it here so the peer's next WireGuard handshake adopts it. Applied at peer-config
-	// time (bootstrap / reconnect); steady-state rotation is pushed separately.
-	if conn.config.PQ != nil {
-		if psk, ok := conn.config.PQ.PSK(conn.config.Key); ok {
-			return &psk
-		}
-	}
-
 	if conn.config.RosenpassConfig.PubKey == nil {
 		return conn.config.WgConfig.PreSharedKey
 	}

client/internal/peer/handshaker.go

@@ -39,16 +39,6 @@ type OfferAnswer struct {
 	// This value is the local Rosenpass server address when sending the message
 	RosenpassAddr string
 
-	// MlkemPayload carries the post-quantum X25519MLKEM768 handshake message
-	// (pqkem-framed offer on an OFFER, answer on an ANSWER) that seeds the
-	// WireGuard PSK. Opaque here — the pqkem library frames and parses it. Nil
-	// when the peer does not run the ML-KEM PQ exchange.
-	MlkemPayload []byte
-
-	// MlkemPort is the peer's ML-KEM PQ service UDP port (bound on its WG overlay
-	// IP) where data-path rekey messages are sent. Zero when not running the exchange.
-	MlkemPort int
-
 	// relay server address
 	RelaySrvAddress string
 	// RelaySrvIP is the IP the remote peer is connected to on its
@@ -130,8 +120,6 @@ func (h *Handshaker) Listen(ctx context.Context) {
 
 			h.updateRemoteICEState(&remoteOfferAnswer)
 
-			h.pqRegisterEndpoint(remoteOfferAnswer.MlkemPort)
-
 			if h.relayListener != nil {
 				h.relayListener.Notify(&remoteOfferAnswer)
 			}
@@ -140,7 +128,7 @@ func (h *Handshaker) Listen(ctx context.Context) {
 				h.iceListener(&remoteOfferAnswer)
 			}
 
-			if err := h.sendAnswer(&remoteOfferAnswer); err != nil {
+			if err := h.sendAnswer(); err != nil {
 				h.log.Errorf("failed to send remote offer confirmation: %s", err)
 				continue
 			}
@@ -154,8 +142,6 @@ func (h *Handshaker) Listen(ctx context.Context) {
 
 			h.updateRemoteICEState(&remoteOfferAnswer)
 
-			h.pqRegisterEndpoint(remoteOfferAnswer.MlkemPort)
-
 			if h.relayListener != nil {
 				h.relayListener.Notify(&remoteOfferAnswer)
 			}
@@ -163,10 +149,6 @@ func (h *Handshaker) Listen(ctx context.Context) {
 			if h.iceListener != nil && h.RemoteICESupported() {
 				h.iceListener(&remoteOfferAnswer)
 			}
-
-			if h.config.PQ != nil {
-				h.config.PQ.OnAnswer(h.config.Key, remoteOfferAnswer.MlkemPayload)
-			}
 		case <-ctx.Done():
 			h.log.Infof("stop listening for remote offers and answers")
 			return
@@ -174,16 +156,6 @@ func (h *Handshaker) Listen(ctx context.Context) {
 	}
 }
 
-// pqRegisterEndpoint feeds the post-quantum handshaker the peer's data-path endpoint
-// (its WG overlay IP plus the advertised pq UDP port) learned from a remote offer/answer.
-func (h *Handshaker) pqRegisterEndpoint(remotePort int) {
-	if h.config.PQ == nil || remotePort <= 0 || remotePort > 65535 || len(h.config.WgConfig.AllowedIps) == 0 {
-		return
-	}
-	addr := netip.AddrPortFrom(h.config.WgConfig.AllowedIps[0].Addr(), uint16(remotePort))
-	h.config.PQ.SetRemoteAddr(h.config.Key, addr)
-}
-
 func (h *Handshaker) SendOffer() error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
@@ -223,23 +195,13 @@ func (h *Handshaker) sendOffer() error {
 	}
 
 	offer := h.buildOfferAnswer()
-	if h.config.PQ != nil {
-		offer.MlkemPayload, offer.MlkemPort = h.config.PQ.OfferPayload(h.config.Key)
-	}
 	h.log.Debugf("sending offer with serial: %s", offer.SessionIDString())
 
 	return h.signaler.SignalOffer(offer, h.config.Key)
 }
 
-func (h *Handshaker) sendAnswer(remoteOffer *OfferAnswer) error {
+func (h *Handshaker) sendAnswer() error {
 	answer := h.buildOfferAnswer()
-	if h.config.PQ != nil {
-		var recvOffer []byte
-		if remoteOffer != nil {
-			recvOffer = remoteOffer.MlkemPayload
-		}
-		answer.MlkemPayload, answer.MlkemPort = h.config.PQ.AnswerPayload(h.config.Key, recvOffer)
-	}
 	h.log.Debugf("sending answer with serial: %s", answer.SessionIDString())
 
 	return h.signaler.SignalAnswer(answer, h.config.Key)

client/internal/peer/signaler.go

@@ -63,8 +63,6 @@ func (s *Signaler) signalOfferAnswer(offerAnswer OfferAnswer, remoteKey string,
 		},
 		RosenpassPubKey: offerAnswer.RosenpassPubKey,
 		RosenpassAddr:   offerAnswer.RosenpassAddr,
-		MlkemPayload:    offerAnswer.MlkemPayload,
-		MlkemPort:       offerAnswer.MlkemPort,
 		RelaySrvAddress: offerAnswer.RelaySrvAddress,
 		RelaySrvIP:      offerAnswer.RelaySrvIP,
 		SessionID:       sessionIDBytes,

client/internal/pqkem/bench_test.go

@@ -1,59 +0,0 @@
-package pqkem
-
-import (
-	"crypto/ecdh"
-	"crypto/mlkem"
-	"crypto/rand"
-	"testing"
-)
-
-func BenchmarkX25519Keygen(b *testing.B) {
-	c := ecdh.X25519()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		if _, err := c.GenerateKey(rand.Reader); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
-
-func BenchmarkX25519ECDH(b *testing.B) {
-	c := ecdh.X25519()
-	a, _ := c.GenerateKey(rand.Reader)
-	p, _ := c.GenerateKey(rand.Reader)
-	pub := p.PublicKey()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		if _, err := a.ECDH(pub); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
-
-func BenchmarkMLKEMKeygen(b *testing.B) {
-	for i := 0; i < b.N; i++ {
-		if _, err := mlkem.GenerateKey768(); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
-
-func BenchmarkMLKEMEncaps(b *testing.B) {
-	dk, _ := mlkem.GenerateKey768()
-	ek := dk.EncapsulationKey()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		_, _ = ek.Encapsulate()
-	}
-}
-
-func BenchmarkMLKEMDecaps(b *testing.B) {
-	dk, _ := mlkem.GenerateKey768()
-	_, ct := dk.EncapsulationKey().Encapsulate()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		if _, err := dk.Decapsulate(ct); err != nil {
-			b.Fatal(err)
-		}
-	}
-}

client/internal/pqkem/callbacks.go

@@ -1,18 +0,0 @@
-package pqkem
-
-// CallbackHandler is implemented by the host and invoked by the library. The
-// library only reports events; the host owns the reaction. Keeping this an
-// interface — rather than touching the transport or keying directly — is what lets
-// the KEM code be extracted as a standalone library.
-type CallbackHandler interface {
-	// OnNewPSKReady fires when a fresh post-quantum PSK has been derived for a peer
-	// and must be programmed into the consumer's secure channel. It is invoked at
-	// the commit point of each side: the initiator on receiving the answer, the
-	// responder on receiving the confirm.
-	OnNewPSKReady(remoteID RemoteID, psk PSK) error
-
-	// OnRekeyFailed fires when an exchange fails to converge within the allotted
-	// time. The host should tear the peer connection down so it re-establishes, and
-	// log a WARN. The library reports the event; it does not dictate the reaction.
-	OnRekeyFailed(remoteID RemoteID) error
-}

client/internal/pqkem/convergence.go

@@ -1,224 +0,0 @@
-package pqkem
-
-import (
-	"context"
-	"time"
-)
-
-// startExchange creates a fresh initiator exchange (acknowledging ackID, zero for a
-// bootstrap) and returns the framed offer for the caller to send — pushed over the
-// data path for a chained rekey, or handed to the host for signalling when viaSignal
-// is set. Any previous in-flight exchange for the peer is cancelled.
-func (m *Manager) startExchange(remoteID RemoteID, viaSignal bool, ackID ExchangeID) ([]byte, error) {
-	init, err := NewInitiator()
-	if err != nil {
-		return nil, err
-	}
-	id, err := newExchangeID()
-	if err != nil {
-		return nil, err
-	}
-	raw, err := (&OfferMsg{ExchangeID: id, AckID: ackID, KEMOffer: init.Offer()}).Encode()
-	if err != nil {
-		return nil, err
-	}
-
-	ctx, cancel := context.WithCancel(m.rootCtx)
-	m.mu.Lock()
-	if old := m.exchanges[remoteID]; old != nil && old.cancel != nil {
-		old.cancel()
-	}
-	m.exchanges[remoteID] = &exchangeCtl{
-		id:        id,
-		state:     stateAwaitingAnswer,
-		startedAt: time.Now(),
-		cancel:    cancel,
-		lastSent:  raw,
-		initiator: init,
-		viaSignal: viaSignal,
-	}
-	m.mu.Unlock()
-
-	m.wait.Add(1)
-	go m.initiatorLoop(ctx, remoteID, id)
-	return raw, nil
-}
-
-// processOffer (responder) first acknowledges the previous exchange the offer names
-// (that offer riding the data path under the freshly adopted key proves it worked),
-// then derives the PSK for the new offer, commits it optimistically, and returns the
-// framed answer. A duplicate offer returns the cached answer without re-deriving.
-func (m *Manager) processOffer(remoteID RemoteID, o *OfferMsg) ([]byte, error) {
-	if o.AckID != (ExchangeID{}) {
-		m.ackConverged(remoteID, o.AckID)
-	}
-
-	m.mu.Lock()
-	if ex := m.exchanges[remoteID]; ex != nil && ex.id == o.ExchangeID {
-		state, last := ex.state, ex.lastSent
-		m.mu.Unlock()
-		if state == stateReserved {
-			return nil, nil
-		}
-		return last, nil
-	}
-	// Reserve the slot so a concurrent duplicate offer bails.
-	m.exchanges[remoteID] = &exchangeCtl{id: o.ExchangeID, state: stateReserved, startedAt: time.Now()}
-	m.mu.Unlock()
-
-	answerBytes, psk, err := Respond(o.KEMOffer, m.binding(remoteID))
-	if err != nil {
-		return nil, err
-	}
-	raw, err := (&AnswerMsg{ExchangeID: o.ExchangeID, KEMAnswer: answerBytes}).Encode()
-	if err != nil {
-		return nil, err
-	}
-
-	m.mu.Lock()
-	ex := m.exchanges[remoteID]
-	if ex == nil || ex.id != o.ExchangeID {
-		m.mu.Unlock()
-		return nil, nil
-	}
-	ex.state = stateAwaitingAck
-	ex.lastSent = raw
-	ex.pendingPSK = psk
-	m.psks[remoteID] = psk
-	m.mu.Unlock()
-
-	// Commit optimistically so our data path can rekey to the new PSK.
-	if err := m.cbHandler.OnNewPSKReady(remoteID, psk); err != nil {
-		return nil, err
-	}
-	return raw, nil
-}
-
-// processAnswer (initiator) derives and commits the PSK and parks in
-// stateAwaitingRekey; the next offer (chained from OnDataPathRekeyed) will acknowledge
-// this exchange. Only valid in stateAwaitingAnswer; advancing the state under the
-// lock makes a concurrent/duplicate answer bail.
-func (m *Manager) processAnswer(remoteID RemoteID, a *AnswerMsg) error {
-	m.mu.Lock()
-	ex := m.exchanges[remoteID]
-	if ex == nil || ex.id != a.ExchangeID || ex.state != stateAwaitingAnswer {
-		m.mu.Unlock()
-		return nil
-	}
-	ex.state = stateAwaitingRekey
-	init := ex.initiator
-	ex.initiator = nil
-	m.mu.Unlock()
-
-	psk, err := init.Finish(a.KEMAnswer, m.binding(remoteID))
-	if err != nil {
-		return err
-	}
-
-	// The initiator has converged: the responder must have derived the key to answer.
-	m.mu.Lock()
-	m.established[remoteID] = true
-	m.failures[remoteID] = 0
-	m.psks[remoteID] = psk
-	m.mu.Unlock()
-
-	return m.cbHandler.OnNewPSKReady(remoteID, psk)
-}
-
-// ackConverged (responder) records convergence of the exchange named by ackID: a
-// later offer acknowledging it proves both sides operate on that exchange's key. Only
-// acts on a matching stateAwaitingAck exchange; anything else is ignored.
-func (m *Manager) ackConverged(remoteID RemoteID, ackID ExchangeID) {
-	m.mu.Lock()
-	ex := m.exchanges[remoteID]
-	if ex == nil || ex.id != ackID || ex.state != stateAwaitingAck {
-		m.mu.Unlock()
-		return
-	}
-	delete(m.exchanges, remoteID)
-	m.established[remoteID] = true
-	m.failures[remoteID] = 0
-	_ = time.Since(ex.startedAt) // convergence latency (metrics hook, later step)
-	m.mu.Unlock()
-}
-
-// initiatorLoop enforces the offer->answer convergence deadline and retransmits the
-// initiator's outstanding data-path offer while awaiting the answer (a
-// signalling-bootstrapped offer is retransmitted by the host, so it is not resent
-// here). Exhausting the deadline before the answer arrives is a failure. Once the
-// answer is in (state past awaitingAnswer) the loop exits: the next rotation is driven
-// by OnDataPathRekeyed, and the idle wait for it has no deadline.
-func (m *Manager) initiatorLoop(ctx context.Context, remoteID RemoteID, id ExchangeID) {
-	defer m.wait.Done()
-	t := time.NewTicker(m.retryInterval)
-	defer t.Stop()
-
-	attempts := 0
-	for {
-		select {
-		case <-ctx.Done():
-			return
-		case <-t.C:
-			m.mu.Lock()
-			ex := m.exchanges[remoteID]
-			if ex == nil || ex.id != id {
-				m.mu.Unlock()
-				return
-			}
-
-			switch ex.state {
-			case stateAwaitingAnswer:
-				if attempts >= m.maxRetries {
-					delete(m.exchanges, remoteID)
-					fail := m.registerFailureLocked(remoteID)
-					m.mu.Unlock()
-					m.raiseFailure(remoteID, fail)
-					return
-				}
-				viaSignal := ex.viaSignal
-				msg := ex.lastSent
-				attempts++
-				m.mu.Unlock()
-				if !viaSignal {
-					if err := m.pushDataPath(remoteID, msg); err != nil {
-						m.logger.Warn("pqkem: offer retransmit failed", "peer", remoteID, "err", err)
-					}
-				}
-
-			default:
-				// Past awaiting the answer (converged) or superseded: the loop's job
-				// is done. The next rotation is driven externally by OnDataPathRekeyed,
-				// so there is no deadline while idle-waiting for it (that wait can be
-				// as long as the transport's natural rekey interval).
-				m.mu.Unlock()
-				return
-			}
-		}
-	}
-}
-
-// registerFailureLocked applies policy B and reports whether OnRekeyFailed is due:
-// an initial exchange (peer never established) fails immediately; a rekey tolerates
-// up to maxRekeyFailures consecutive misses (we stay on the still-valid previous
-// PSK) before failing. Assumes m.mu is held.
-func (m *Manager) registerFailureLocked(remoteID RemoteID) bool {
-	if !m.established[remoteID] {
-		return true
-	}
-	m.failures[remoteID]++
-	if m.failures[remoteID] >= m.maxRekeyFailures {
-		m.failures[remoteID] = 0
-		return true
-	}
-	return false
-}
-
-func (m *Manager) raiseFailure(remoteID RemoteID, fail bool) {
-	if !fail {
-		m.logger.Warn("pqkem: rekey attempt timed out, will retry next cycle", "peer", remoteID)
-		return
-	}
-	if err := m.cbHandler.OnRekeyFailed(remoteID); err != nil {
-		m.logger.Error("pqkem: OnRekeyFailed handler error", "peer", remoteID, "err", err)
-	}
-}

client/internal/pqkem/convergence_test.go

@@ -1,74 +0,0 @@
-package pqkem
-
-import (
-	"net/netip"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/require"
-)
-
-// dropTransport is a pqkem.Transport that silently discards everything.
-type dropTransport struct{}
-
-func (dropTransport) Send(netip.AddrPort, []byte) error { return nil }
-func (dropTransport) LocalPort() int                    { return 0 }
-func (dropTransport) Run(func(netip.AddrPort, []byte))  {}
-func (dropTransport) Close() error                      { return nil }
-
-func failedCount(f *fakeWG) int {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	return len(f.failed)
-}
-
-func TestManager_InitialTimeoutFailsImmediately(t *testing.T) {
-	wg := newFakeWG()
-	d := NewManager("bbbb", wg, nil) // bbbb > aaaa -> initiator
-	d.Start(dropTransport{})
-	d.retryInterval = 5 * time.Millisecond
-	d.maxRetries = 3
-	defer d.Stop()
-
-	// Bootstrap offer is produced for signalling; no answer ever comes back -> the
-	// initial exchange fails fast.
-	offer, err := d.SignalOffer("aaaa")
-	require.NoError(t, err)
-	require.NotNil(t, offer)
-
-	require.Eventually(t, func() bool { return failedCount(wg) == 1 }, time.Second, 5*time.Millisecond)
-}
-
-func TestManager_RekeyToleratesKFailures(t *testing.T) {
-	dA, dB, _, wgB, lbB := pair(t)
-	defer dA.Stop()
-	defer dB.Stop()
-
-	// Tighten B's timings before any exchange loop spawns (the loop reads these
-	// fields, so writing them after a loop is running would race).
-	dB.retryInterval = 5 * time.Millisecond
-	dB.maxRetries = 2
-
-	// Establish: bootstrap + data-path-rekeyed so B becomes established and its data
-	// path is usable.
-	bootstrap(t, dA, dB)
-	dA.OnDataPathRekeyed("bbbb")
-	dB.OnDataPathRekeyed("aaaa")
-	require.NotEqual(t, PSK{}, wgB.psk("aaaa"))
-
-	// Drop B's outbound so rekeys can no longer converge.
-	lbB.drop.Store(true)
-
-	// K-1 data-path rekeys must NOT raise OnRekeyFailed.
-	for i := 0; i < DefaultMaxRekeyFailures-1; i++ {
-		_, err := dB.startExchange("aaaa", false, ExchangeID{})
-		require.NoError(t, err)
-		time.Sleep(50 * time.Millisecond)
-	}
-	require.Equal(t, 0, failedCount(wgB), "no failure before K attempts")
-
-	// The K-th failure raises it once.
-	_, err := dB.startExchange("aaaa", false, ExchangeID{})
-	require.NoError(t, err)
-	require.Eventually(t, func() bool { return failedCount(wgB) == 1 }, time.Second, 5*time.Millisecond)
-}

client/internal/pqkem/env.go

@@ -1,59 +0,0 @@
-package pqkem
-
-import (
-	"log/slog"
-	"os"
-	"strconv"
-	"strings"
-
-	log "github.com/sirupsen/logrus"
-)
-
-// EnvEnabled is the environment variable that turns the ML-KEM post-quantum
-// exchange on for this client. Accepts on/off aliases plus anything
-// strconv.ParseBool understands (true/false/1/0).
-const EnvEnabled = "NB_ENABLE_PQ_MLKEM"
-
-// Enabled reports whether the ML-KEM PQ exchange is enabled via the environment.
-// An empty or unrecognized value is treated as disabled.
-func Enabled() bool {
-	raw := strings.ToLower(strings.TrimSpace(os.Getenv(EnvEnabled)))
-	switch raw {
-	case "":
-		return false
-	case "on":
-		return true
-	case "off":
-		return false
-	}
-	enabled, err := strconv.ParseBool(raw)
-	if err != nil {
-		log.Warnf("failed to parse %s value %q: %v", EnvEnabled, raw, err)
-		return false
-	}
-	return enabled
-}
-
-// EnvLogLevel overrides the ML-KEM manager's slog level (debug/info/warn/error).
-// Defaults to info.
-const EnvLogLevel = "NB_PQ_MLKEM_LOG_LEVEL"
-
-// NewLogger builds the slog logger for the ML-KEM manager: a text handler to stdout
-// at the level from EnvLogLevel. Mirrors the Rosenpass manager's logger setup so PQ
-// components log consistently.
-func NewLogger() *slog.Logger {
-	return slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: logLevel()}))
-}
-
-func logLevel() slog.Level {
-	switch strings.ToLower(strings.TrimSpace(os.Getenv(EnvLogLevel))) {
-	case "debug":
-		return slog.LevelDebug
-	case "warn":
-		return slog.LevelWarn
-	case "error":
-		return slog.LevelError
-	default:
-		return slog.LevelInfo
-	}
-}

client/internal/pqkem/kem.go

@@ -1,167 +0,0 @@
-// Package pqkem is a spike (NET-1406) for a post-quantum pre-shared-key exchange
-// that could replace Rosenpass. It performs an X25519MLKEM768 hybrid key
-// encapsulation and derives a 32-byte pre-shared key (PSK).
-//
-// The exchange is a single round trip designed to ride the (already
-// authenticated) Signal offer/answer channel:
-//
-//	initiator --Offer(1216B)--> responder
-//	initiator <--Answer(1120B)-- responder
-//
-// Both sides then hold the same PSK, which is bound to the two peers' identities
-// (their peer identity keys) so the derived key cannot be transplanted
-// to a different peer pair even if the transport authentication were bypassed.
-//
-// Combiner note: this follows draft-ietf-tls-ecdhe-mlkem for X25519MLKEM768 — on
-// the wire ML-KEM ‖ X25519 (the draft deliberately reversed the share order for
-// this group), and ML-KEM_ss ‖ X25519_ss fed into the KDF. The spike uses SHA-256
-// (also binding the transcript and peer identities); a production version should
-// use HKDF — see TODO below.
-package pqkem
-
-import (
-	"crypto/ecdh"
-	"crypto/mlkem"
-	"crypto/rand"
-	"crypto/sha256"
-	"fmt"
-)
-
-const (
-	// OfferSize is the initiator message: ML-KEM-768 encapsulation key ‖ X25519 public key
-	// (share order per draft-ietf-tls-ecdhe-mlkem for X25519MLKEM768).
-	OfferSize = mlkem.EncapsulationKeySize768 + 32 // 1216
-	// AnswerSize is the responder message: ML-KEM-768 ciphertext ‖ X25519 public key.
-	AnswerSize = mlkem.CiphertextSize768 + 32 // 1120
-
-	pskLabel = "netbird-pq-psk-v1"
-)
-
-// PSK is the 32-byte derived pre-shared key handed to the consumer to key its channel.
-type PSK [32]byte
-
-// Binding identifies the peer pair the PSK is derived for. Callers set both
-// peer identity keys; the order does not matter (it is canonicalised).
-type Binding struct {
-	LocalID  []byte
-	RemoteID []byte
-}
-
-// Initiator holds the ephemeral secrets between Offer and Finish.
-type Initiator struct {
-	x25519  *ecdh.PrivateKey
-	mlkemDK *mlkem.DecapsulationKey768
-	offer   []byte
-}
-
-// NewInitiator generates the ephemeral X25519 + ML-KEM-768 keypairs.
-func NewInitiator() (*Initiator, error) {
-	x, err := ecdh.X25519().GenerateKey(rand.Reader)
-	if err != nil {
-		return nil, fmt.Errorf("x25519 keygen: %w", err)
-	}
-	dk, err := mlkem.GenerateKey768()
-	if err != nil {
-		return nil, fmt.Errorf("ml-kem keygen: %w", err)
-	}
-
-	offer := make([]byte, 0, OfferSize)
-	offer = append(offer, dk.EncapsulationKey().Bytes()...)
-	offer = append(offer, x.PublicKey().Bytes()...)
-
-	return &Initiator{x25519: x, mlkemDK: dk, offer: offer}, nil
-}
-
-// Offer returns the initiator message to send over Signal.
-func (i *Initiator) Offer() []byte {
-	return i.offer
-}
-
-// Finish consumes the responder's answer and derives the PSK.
-func (i *Initiator) Finish(answer []byte, b Binding) (PSK, error) {
-	if len(answer) != AnswerSize {
-		return PSK{}, fmt.Errorf("answer: got %d bytes, want %d", len(answer), AnswerSize)
-	}
-	ct := answer[:mlkem.CiphertextSize768]
-	peerX := answer[mlkem.CiphertextSize768:]
-
-	ssMLKEM, err := i.mlkemDK.Decapsulate(ct)
-	if err != nil {
-		return PSK{}, fmt.Errorf("ml-kem decapsulate: %w", err)
-	}
-	pub, err := ecdh.X25519().NewPublicKey(peerX)
-	if err != nil {
-		return PSK{}, fmt.Errorf("parse peer x25519: %w", err)
-	}
-	ssX, err := i.x25519.ECDH(pub)
-	if err != nil {
-		return PSK{}, fmt.Errorf("x25519 ecdh: %w", err)
-	}
-
-	return derivePSK(ssMLKEM, ssX, i.offer, answer, b), nil
-}
-
-// Respond consumes an initiator offer, produces the answer, and derives the PSK.
-func Respond(offer []byte, b Binding) (answer []byte, psk PSK, err error) {
-	if len(offer) != OfferSize {
-		return nil, PSK{}, fmt.Errorf("offer: got %d bytes, want %d", len(offer), OfferSize)
-	}
-	peerEK := offer[:mlkem.EncapsulationKeySize768]
-	peerX := offer[mlkem.EncapsulationKeySize768:]
-
-	ek, err := mlkem.NewEncapsulationKey768(peerEK)
-	if err != nil {
-		return nil, PSK{}, fmt.Errorf("parse peer ml-kem key: %w", err)
-	}
-	ssMLKEM, ct := ek.Encapsulate()
-
-	x, err := ecdh.X25519().GenerateKey(rand.Reader)
-	if err != nil {
-		return nil, PSK{}, fmt.Errorf("x25519 keygen: %w", err)
-	}
-	pub, err := ecdh.X25519().NewPublicKey(peerX)
-	if err != nil {
-		return nil, PSK{}, fmt.Errorf("parse peer x25519: %w", err)
-	}
-	ssX, err := x.ECDH(pub)
-	if err != nil {
-		return nil, PSK{}, fmt.Errorf("x25519 ecdh: %w", err)
-	}
-
-	answer = make([]byte, 0, AnswerSize)
-	answer = append(answer, ct...)
-	answer = append(answer, x.PublicKey().Bytes()...)
-
-	// derivePSK uses the same argument order on both sides; the responder's local
-	// binding is the mirror of the initiator's, canonicalised inside derivePSK.
-	return answer, derivePSK(ssMLKEM, ssX, offer, answer, b), nil
-}
-
-// derivePSK combines the two shared secrets and binds the result to the full
-// transcript (offer ‖ answer) and the canonicalised peer identities.
-//
-// TODO(NET-1406): replace the SHA-256 concat with the RFC HKDF combiner
-// (crypto/hkdf, Go 1.24+) and proper labels before this leaves spike status.
-func derivePSK(ssMLKEM, ssX, offer, answer []byte, b Binding) PSK {
-	lo, hi := canonicalPair(b.LocalID, b.RemoteID)
-
-	h := sha256.New()
-	h.Write([]byte(pskLabel))
-	h.Write(ssMLKEM)
-	h.Write(ssX)
-	h.Write(offer)
-	h.Write(answer)
-	h.Write(lo)
-	h.Write(hi)
-
-	var psk PSK
-	copy(psk[:], h.Sum(nil))
-	return psk
-}
-
-func canonicalPair(a, b []byte) (lo, hi []byte) {
-	if string(a) <= string(b) {
-		return a, b
-	}
-	return b, a
-}

client/internal/pqkem/kem_test.go

@@ -1,89 +0,0 @@
-package pqkem
-
-import (
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/require"
-)
-
-var (
-	wgA = []byte("peer-A-wireguard-pubkey-32bytes!")
-	wgB = []byte("peer-B-wireguard-pubkey-32bytes!")
-)
-
-func TestExchange_DerivesMatchingPSK(t *testing.T) {
-	init, err := NewInitiator()
-	require.NoError(t, err)
-
-	require.Len(t, init.Offer(), OfferSize)
-
-	answer, pskB, err := Respond(init.Offer(), Binding{LocalID: wgB, RemoteID: wgA})
-	require.NoError(t, err)
-	require.Len(t, answer, AnswerSize)
-
-	pskA, err := init.Finish(answer, Binding{LocalID: wgA, RemoteID: wgB})
-	require.NoError(t, err)
-
-	require.Equal(t, pskB, pskA, "both sides must derive the same PSK")
-	require.NotEqual(t, PSK{}, pskA, "PSK must not be zero")
-}
-
-func TestExchange_PSKBoundToPeerIdentities(t *testing.T) {
-	init, err := NewInitiator()
-	require.NoError(t, err)
-
-	// responder computes with the honest pair...
-	_, pskHonest, err := Respond(init.Offer(), Binding{LocalID: wgB, RemoteID: wgA})
-	require.NoError(t, err)
-
-	// ...a second responder run with a different peer identity yields a different PSK,
-	// even though the KEM material would otherwise combine identically.
-	wgC := []byte("peer-C-wireguard-pubkey-32bytes!")
-	_, pskWrong, err := Respond(init.Offer(), Binding{LocalID: wgC, RemoteID: wgA})
-	require.NoError(t, err)
-
-	require.NotEqual(t, pskHonest, pskWrong, "PSK must be bound to the peer pair")
-}
-
-func TestExchange_RejectsMalformedMessages(t *testing.T) {
-	init, err := NewInitiator()
-	require.NoError(t, err)
-
-	_, _, err = Respond(init.Offer()[:10], Binding{})
-	require.Error(t, err)
-
-	_, err = init.Finish([]byte("too short"), Binding{})
-	require.Error(t, err)
-}
-
-// TestExchange_ReportSizesAndTiming is a spike measurement, not a pass/fail gate.
-// Run with: go test -run TestExchange_ReportSizesAndTiming -v ./client/internal/pqkem/
-func TestExchange_ReportSizesAndTiming(t *testing.T) {
-	const iters = 200
-
-	var tInit, tResp, tFinish time.Duration
-	for i := 0; i < iters; i++ {
-		s0 := time.Now()
-		init, err := NewInitiator()
-		require.NoError(t, err)
-		tInit += time.Since(s0)
-
-		s1 := time.Now()
-		answer, _, err := Respond(init.Offer(), Binding{LocalID: wgB, RemoteID: wgA})
-		require.NoError(t, err)
-		tResp += time.Since(s1)
-
-		s2 := time.Now()
-		_, err = init.Finish(answer, Binding{LocalID: wgA, RemoteID: wgB})
-		require.NoError(t, err)
-		tFinish += time.Since(s2)
-	}
-
-	t.Logf("wire sizes:   offer=%d B   answer=%d B   (Rosenpass static pubkey ~524160 B)", OfferSize, AnswerSize)
-	t.Logf("total on-wire per handshake: %d B  (~%.0fx smaller than RP static key)", OfferSize+AnswerSize, 524160.0/float64(OfferSize+AnswerSize))
-	t.Logf("avg NewInitiator (keygen): %s", tInit/iters)
-	t.Logf("avg Respond (encaps+dh):   %s", tResp/iters)
-	t.Logf("avg Finish (decaps+dh):    %s", tFinish/iters)
-	t.Logf("avg full handshake CPU:    %s", (tInit+tResp+tFinish)/iters)
-}

client/internal/pqkem/manager.go

@@ -1,372 +0,0 @@
-package pqkem
-
-import (
-	"context"
-	"crypto/rand"
-	"fmt"
-	"log/slog"
-	"net/netip"
-	"sync"
-	"time"
-)
-
-const (
-	// DefaultRetryInterval is how often the initiator retransmits its outstanding
-	// data-path offer while awaiting the answer.
-	DefaultRetryInterval = 2 * time.Second
-	// DefaultMaxRetries bounds how many ticks an exchange may run before it is
-	// declared failed. The convergence deadline is thus MaxRetries * RetryInterval.
-	DefaultMaxRetries = 10
-	// DefaultMaxRekeyFailures is how many consecutive rekey (non-initial) failures
-	// are tolerated before OnRekeyFailed. The initial exchange fails immediately.
-	DefaultMaxRekeyFailures = 3
-)
-
-// LocalID and RemoteID are peer identity keys (e.g. WireGuard public keys). They are
-// distinct types so the local and a remote identity cannot be mixed up.
-type (
-	LocalID  string
-	RemoteID string
-)
-
-// Transport is the data-path socket the Manager drives (the analogue of
-// go-rosenpass's Conn). It is a dumb mover of bytes to/from endpoints: the Manager
-// owns the remoteID<->endpoint routing and hands the transport a resolved endpoint
-// to Send, and reverse-resolves the source of each inbound datagram. Its lifecycle
-// belongs to the Manager (Run at Start, Close at Stop).
-type Transport interface {
-	// Send delivers msg to the given data-path endpoint.
-	Send(endpoint netip.AddrPort, msg []byte) error
-	// LocalPort is the bound local UDP port, announced to peers so they know where
-	// to send data-path messages.
-	LocalPort() int
-	// Run starts delivering inbound datagrams as (source endpoint, msg) to onInbound
-	// and returns immediately; it runs until Close.
-	Run(onInbound func(src netip.AddrPort, msg []byte))
-	// Close stops delivery and releases the socket.
-	Close() error
-}
-
-// exchangeState is the single source of truth for an exchange's role and phase.
-type exchangeState uint8
-
-const (
-	stateReserved       exchangeState = iota // responder: deriving the answer
-	stateAwaitingAnswer                      // initiator: offer sent, awaiting the answer
-	stateAwaitingRekey                       // initiator: PSK derived+set, awaiting OnDataPathRekeyed to chain the next offer
-	stateAwaitingAck                         // responder: answer sent, awaiting the next offer that acks this exchange
-)
-
-// exchangeCtl holds all state for one in-flight exchange with a peer, under the
-// Manager's single lock. state drives every decision. lastSent is the current
-// data-path retransmit payload (the offer, for the initiator). initiator is the
-// ephemeral handle used at Finish; pendingPSK is the responder's derived key.
-// viaSignal records that the offer went to the host for the signalling channel, so
-// the loop does not retransmit it on the data path. Only the initiator runs a
-// retransmit loop, so only it sets cancel.
-type exchangeCtl struct {
-	id         ExchangeID
-	state      exchangeState
-	startedAt  time.Time
-	cancel     context.CancelFunc
-	lastSent   []byte
-	initiator  *Initiator
-	pendingPSK PSK
-	viaSignal  bool
-}
-
-// Manager is the stateful orchestrator — the analogue of go-rosenpass's Server. It
-// drives the X25519MLKEM768 exchange, owns the peer endpoint routing and the data-path
-// transport, and surfaces the derived PSK and convergence to the host via
-// CallbackHandler. It is event-driven: the bootstrap is triggered by the host
-// (SignalOffer) and each rotation is clocked by OnDataPathRekeyed. The cryptography is
-// the pure kem.go primitives; all state lives here under one lock.
-type Manager struct {
-	localID   LocalID
-	cbHandler CallbackHandler
-	logger    *slog.Logger
-
-	retryInterval    time.Duration
-	maxRetries       int
-	maxRekeyFailures int
-
-	rootCtx    context.Context
-	rootCancel context.CancelFunc
-
-	mu          sync.Mutex
-	transport   Transport
-	exchanges   map[RemoteID]*exchangeCtl   // in-flight exchange per peer
-	established map[RemoteID]bool           // peer has completed at least one exchange
-	failures    map[RemoteID]int            // consecutive rekey failures per peer
-	psks        map[RemoteID]PSK            // latest derived PSK per peer (pulled at WG peer-config time)
-	peerAddrs   map[RemoteID]netip.AddrPort // remoteID -> data-path endpoint (send routing)
-	peersByAddr map[netip.AddrPort]RemoteID // reverse: source endpoint -> remoteID (inbound)
-	wait        sync.WaitGroup
-}
-
-// NewManager builds a manager for the local peer identified by its peer identity key
-// (used for the deterministic initiator role and the identity binding). A nil logger
-// falls back to slog.Default(). Install the data-path transport with Start.
-func NewManager(localID LocalID, h CallbackHandler, logger *slog.Logger) *Manager {
-	if logger == nil {
-		logger = slog.Default()
-	}
-	ctx, cancel := context.WithCancel(context.Background())
-	return &Manager{
-		localID:          localID,
-		cbHandler:        h,
-		logger:           logger,
-		retryInterval:    DefaultRetryInterval,
-		maxRetries:       DefaultMaxRetries,
-		maxRekeyFailures: DefaultMaxRekeyFailures,
-		rootCtx:          ctx,
-		rootCancel:       cancel,
-		exchanges:        make(map[RemoteID]*exchangeCtl),
-		established:      make(map[RemoteID]bool),
-		failures:         make(map[RemoteID]int),
-		psks:             make(map[RemoteID]PSK),
-		peerAddrs:        make(map[RemoteID]netip.AddrPort),
-		peersByAddr:      make(map[netip.AddrPort]RemoteID),
-	}
-}
-
-// Start installs the data-path transport and begins its inbound delivery. The Manager
-// owns it from here; Stop closes it. Start/Stop are the transport lifecycle pair.
-func (m *Manager) Start(t Transport) {
-	m.mu.Lock()
-	m.transport = t
-	m.mu.Unlock()
-	if t != nil {
-		t.Run(m.onDataPathInbound)
-	}
-}
-
-// LocalPort is the data-path transport's bound UDP port (0 if no transport), to be
-// announced to peers.
-func (m *Manager) LocalPort() int {
-	m.mu.Lock()
-	t := m.transport
-	m.mu.Unlock()
-	if t == nil {
-		return 0
-	}
-	return t.LocalPort()
-}
-
-// IsInitiator reports whether the local peer drives the exchange for this remote
-// peer. Roles are deterministic (lexicographic identity-key compare) so exactly one
-// side initiates, mirroring how Rosenpass picks its handshake initiator.
-func (m *Manager) IsInitiator(remoteID RemoteID) bool {
-	return string(m.localID) > string(remoteID)
-}
-
-// PSK returns the latest PSK derived for the peer, for the host to program at WG
-// peer-config time (the pull path). ok is false until an exchange has derived one.
-func (m *Manager) PSK(remoteID RemoteID) (PSK, bool) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	psk, ok := m.psks[remoteID]
-	return psk, ok
-}
-
-// AddPeer registers where a peer's data-path messages are sent and received: its
-// overlay endpoint (IP:port). Re-adding updates the endpoint.
-func (m *Manager) AddPeer(remoteID RemoteID, endpoint netip.AddrPort) {
-	if !endpoint.IsValid() {
-		return
-	}
-	m.mu.Lock()
-	if old, ok := m.peerAddrs[remoteID]; ok {
-		delete(m.peersByAddr, old)
-	}
-	m.peerAddrs[remoteID] = endpoint
-	m.peersByAddr[endpoint] = remoteID
-	m.mu.Unlock()
-}
-
-// RemovePeer stops any in-flight exchange for a peer and drops its state and routing.
-func (m *Manager) RemovePeer(remoteID RemoteID) {
-	m.mu.Lock()
-	if ex, ok := m.exchanges[remoteID]; ok {
-		if ex.cancel != nil {
-			ex.cancel()
-		}
-		delete(m.exchanges, remoteID)
-	}
-	delete(m.established, remoteID)
-	delete(m.failures, remoteID)
-	delete(m.psks, remoteID)
-	if ep, ok := m.peerAddrs[remoteID]; ok {
-		delete(m.peersByAddr, ep)
-		delete(m.peerAddrs, remoteID)
-	}
-	m.mu.Unlock()
-}
-
-// Stop cancels all in-flight exchanges, closes the transport, and waits for the
-// exchange goroutines to exit.
-func (m *Manager) Stop() {
-	m.rootCancel()
-	m.wait.Wait()
-	m.mu.Lock()
-	t := m.transport
-	m.transport = nil
-	m.exchanges = make(map[RemoteID]*exchangeCtl)
-	m.psks = make(map[RemoteID]PSK)
-	m.mu.Unlock()
-	if t != nil {
-		if err := t.Close(); err != nil {
-			m.logger.Warn("pqkem: closing data-path transport", "err", err)
-		}
-	}
-}
-
-// ---- Signalling channel (host-driven; rides the host's negotiation) ----
-
-// SignalOffer returns the KEM offer for the host to embed in its outgoing offer to
-// remoteID (bootstrap). It returns (nil, nil) when the local peer is not the
-// initiator. It is idempotent for an in-flight bootstrap: a repeat call returns the
-// same offer rather than starting a new exchange.
-func (m *Manager) SignalOffer(remoteID RemoteID) ([]byte, error) {
-	if !m.IsInitiator(remoteID) {
-		return nil, nil
-	}
-	m.mu.Lock()
-	if ex := m.exchanges[remoteID]; ex != nil && ex.viaSignal && ex.state == stateAwaitingAnswer {
-		last := ex.lastSent
-		m.mu.Unlock()
-		return last, nil
-	}
-	m.mu.Unlock()
-	// bootstrap offer acknowledges nothing (zero AckID).
-	return m.startExchange(remoteID, true, ExchangeID{})
-}
-
-// SignalOnOffer processes a KEM offer the host extracted from an incoming offer and
-// returns the KEM answer for the host to embed in its outgoing answer.
-func (m *Manager) SignalOnOffer(remoteID RemoteID, offer []byte) ([]byte, error) {
-	typ, msg, err := Decode(offer)
-	if err != nil {
-		return nil, fmt.Errorf("decode signal offer from %s: %w", remoteID, err)
-	}
-	if typ != MsgOffer {
-		return nil, fmt.Errorf("expected offer from %s, got type %d", remoteID, typ)
-	}
-	return m.processOffer(remoteID, msg.(*OfferMsg))
-}
-
-// SignalOnAnswer processes a KEM answer the host extracted from an incoming answer.
-// There is no reply: the next offer (over the data path) acknowledges this exchange.
-func (m *Manager) SignalOnAnswer(remoteID RemoteID, answer []byte) error {
-	typ, msg, err := Decode(answer)
-	if err != nil {
-		return fmt.Errorf("decode signal answer from %s: %w", remoteID, err)
-	}
-	if typ != MsgAnswer {
-		return fmt.Errorf("expected answer from %s, got type %d", remoteID, typ)
-	}
-	return m.processAnswer(remoteID, msg.(*AnswerMsg))
-}
-
-// ---- Data path ----
-
-// onDataPathInbound is the transport's inbound handler: it reverse-resolves the
-// source endpoint to a peer and dispatches. Unknown sources are dropped.
-func (m *Manager) onDataPathInbound(src netip.AddrPort, msg []byte) {
-	m.mu.Lock()
-	remoteID, ok := m.peersByAddr[src]
-	m.mu.Unlock()
-	if !ok {
-		return
-	}
-	if err := m.OnDataPathMessage(remoteID, msg); err != nil {
-		m.logger.Debug("pqkem: inbound", "peer", remoteID, "err", err)
-	}
-}
-
-// OnDataPathMessage handles a KEM message received over the data path from remoteID
-// and pushes any reply back over the data path.
-func (m *Manager) OnDataPathMessage(remoteID RemoteID, raw []byte) error {
-	typ, msg, err := Decode(raw)
-	if err != nil {
-		return fmt.Errorf("decode data-path msg from %s: %w", remoteID, err)
-	}
-	switch typ {
-	case MsgOffer:
-		answer, err := m.processOffer(remoteID, msg.(*OfferMsg))
-		if err != nil {
-			return err
-		}
-		if answer == nil {
-			return nil
-		}
-		return m.pushDataPath(remoteID, answer)
-	case MsgAnswer:
-		return m.processAnswer(remoteID, msg.(*AnswerMsg))
-	default:
-		return fmt.Errorf("unhandled data-path message type %d from %s", typ, remoteID)
-	}
-}
-
-// OnDataPathRekeyed notifies that the peer's data path is up and freshly keyed with
-// the latest PSK (fired on first establishment AND every rekey). If we are the
-// initiator that just derived a PSK, it chains the next exchange: a fresh offer over
-// the data path that acknowledges the just-completed one (its arrival under the new
-// key proves to the responder that the key works).
-func (m *Manager) OnDataPathRekeyed(remoteID RemoteID) {
-	m.mu.Lock()
-	ex := m.exchanges[remoteID]
-	chain := ex != nil && ex.state == stateAwaitingRekey
-	var ackID ExchangeID
-	if chain {
-		ackID = ex.id
-	}
-	m.mu.Unlock()
-
-	if !chain {
-		return
-	}
-	offer, err := m.startExchange(remoteID, false, ackID)
-	if err != nil {
-		m.logger.Error("pqkem: chain offer failed to start", "peer", remoteID, "err", err)
-		return
-	}
-	if err := m.pushDataPath(remoteID, offer); err != nil {
-		m.logger.Warn("pqkem: send chain offer failed", "peer", remoteID, "err", err)
-	}
-}
-
-// OnDataPathDown notifies that the peer's data path went down. Rotations resume once
-// the host re-bootstraps over signalling on reconnect; in-flight data-path sends will
-// simply fail until then. Reserved as an explicit hook.
-func (m *Manager) OnDataPathDown(remoteID RemoteID) {}
-
-// ---- internals ----
-
-// pushDataPath resolves the peer's endpoint and sends over the data-path transport,
-// erroring if the peer is unknown or no transport is set.
-func (m *Manager) pushDataPath(remoteID RemoteID, msg []byte) error {
-	m.mu.Lock()
-	ep, ok := m.peerAddrs[remoteID]
-	t := m.transport
-	m.mu.Unlock()
-	if !ok {
-		return fmt.Errorf("no data-path endpoint for peer %s", remoteID)
-	}
-	if t == nil {
-		return fmt.Errorf("no data-path transport")
-	}
-	return t.Send(ep, msg)
-}
-
-func (m *Manager) binding(remoteID RemoteID) Binding {
-	return Binding{LocalID: []byte(m.localID), RemoteID: []byte(remoteID)}
-}
-
-func newExchangeID() (ExchangeID, error) {
-	var id ExchangeID
-	if _, err := rand.Read(id[:]); err != nil {
-		return ExchangeID{}, fmt.Errorf("generate exchange id: %w", err)
-	}
-	return id, nil
-}

client/internal/pqkem/manager_test.go

@@ -1,169 +0,0 @@
-package pqkem
-
-import (
-	"fmt"
-	"net/netip"
-	"sync"
-	"sync/atomic"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-// netSwitch is an in-memory UDP fabric: transports register their endpoint and get
-// datagrams delivered to their inbound handler.
-type netSwitch struct {
-	mu sync.Mutex
-	h  map[netip.AddrPort]func(netip.AddrPort, []byte)
-}
-
-func newSwitch() *netSwitch {
-	return &netSwitch{h: map[netip.AddrPort]func(netip.AddrPort, []byte){}}
-}
-
-func (s *netSwitch) register(ep netip.AddrPort, fn func(netip.AddrPort, []byte)) {
-	s.mu.Lock()
-	s.h[ep] = fn
-	s.mu.Unlock()
-}
-
-func (s *netSwitch) deliver(dst, src netip.AddrPort, msg []byte) error {
-	s.mu.Lock()
-	fn := s.h[dst]
-	s.mu.Unlock()
-	if fn == nil {
-		return fmt.Errorf("no route to %s", dst)
-	}
-	fn(src, msg)
-	return nil
-}
-
-// loopback is an endpoint-based pqkem.Transport over a netSwitch, with a switchable
-// drop flag.
-type loopback struct {
-	ep   netip.AddrPort
-	sw   *netSwitch
-	drop atomic.Bool
-}
-
-func (l *loopback) Send(dst netip.AddrPort, msg []byte) error {
-	if l.drop.Load() {
-		return nil
-	}
-	return l.sw.deliver(dst, l.ep, append([]byte(nil), msg...))
-}
-
-func (l *loopback) LocalPort() int                             { return int(l.ep.Port()) }
-func (l *loopback) Run(onInbound func(netip.AddrPort, []byte)) { l.sw.register(l.ep, onInbound) }
-func (l *loopback) Close() error                               { return nil }
-
-type fakeWG struct {
-	mu     sync.Mutex
-	psks   map[RemoteID]PSK
-	failed []RemoteID
-}
-
-func newFakeWG() *fakeWG { return &fakeWG{psks: map[RemoteID]PSK{}} }
-
-func (f *fakeWG) OnNewPSKReady(remoteID RemoteID, psk PSK) error {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	f.psks[remoteID] = psk
-	return nil
-}
-
-func (f *fakeWG) OnRekeyFailed(remoteID RemoteID) error {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	f.failed = append(f.failed, remoteID)
-	return nil
-}
-
-func (f *fakeWG) psk(peer RemoteID) PSK {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	return f.psks[peer]
-}
-
-var (
-	epA = netip.MustParseAddrPort("100.64.0.1:51833")
-	epB = netip.MustParseAddrPort("100.64.0.2:51833")
-)
-
-// pair builds two wired managers (B is the initiator, "bbbb" > "aaaa") sharing a
-// netSwitch, with each peer's data-path endpoint registered. lbB is B's loopback
-// (for toggling drop).
-func pair(t *testing.T) (dA, dB *Manager, wgA, wgB *fakeWG, lbB *loopback) {
-	t.Helper()
-	sw := newSwitch()
-	wgA = newFakeWG()
-	wgB = newFakeWG()
-	dA = NewManager("aaaa", wgA, nil)
-	dB = NewManager("bbbb", wgB, nil)
-	dA.Start(&loopback{ep: epA, sw: sw})
-	lbB = &loopback{ep: epB, sw: sw}
-	dB.Start(lbB)
-	dA.AddPeer("bbbb", epB)
-	dB.AddPeer("aaaa", epA)
-	return dA, dB, wgA, wgB, lbB
-}
-
-// bootstrap runs the signalling offer/answer (the test plays the host carrying bytes).
-func bootstrap(t *testing.T, dA, dB *Manager) {
-	t.Helper()
-	offer, err := dB.SignalOffer("aaaa")
-	require.NoError(t, err)
-	require.NotNil(t, offer)
-	answer, err := dA.SignalOnOffer("bbbb", offer)
-	require.NoError(t, err)
-	require.NotNil(t, answer)
-	require.NoError(t, dB.SignalOnAnswer("aaaa", answer))
-}
-
-func TestManager_BootstrapDerivesSamePSK(t *testing.T) {
-	dA, dB, wgA, wgB, _ := pair(t)
-	defer dA.Stop()
-	defer dB.Stop()
-
-	bootstrap(t, dA, dB)
-
-	pskA := wgA.psk("bbbb")
-	pskB := wgB.psk("aaaa")
-	require.NotEqual(t, PSK{}, pskA)
-	require.Equal(t, pskB, pskA, "both sides derive the same PSK from the bootstrap exchange")
-}
-
-func TestManager_ChainRotatesAndAcks(t *testing.T) {
-	dA, dB, wgA, wgB, _ := pair(t)
-	defer dA.Stop()
-	defer dB.Stop()
-
-	bootstrap(t, dA, dB)
-	psk1 := wgB.psk("aaaa")
-
-	// Data path up: B (initiator) chains the next offer over the data path, which
-	// rotates both to a fresh PSK and acknowledges A.
-	dA.OnDataPathRekeyed("bbbb")
-	dB.OnDataPathRekeyed("aaaa")
-
-	psk2A := wgA.psk("bbbb")
-	psk2B := wgB.psk("aaaa")
-	require.Equal(t, psk2B, psk2A, "both sides converge on the rotated PSK")
-	require.NotEqual(t, psk1, psk2B, "the chain rotated to a new PSK")
-}
-
-func TestManager_NonInitiatorReturnsNoOffer(t *testing.T) {
-	dA := NewManager("aaaa", newFakeWG(), nil)
-	defer dA.Stop()
-
-	offer, err := dA.SignalOffer("bbbb") // not the initiator vs "bbbb"
-	require.NoError(t, err)
-	require.Nil(t, offer)
-}
-
-func TestManager_StopIsIdempotent(t *testing.T) {
-	dA := NewManager("aaaa", newFakeWG(), nil)
-	dA.Start(&loopback{ep: epA, sw: newSwitch()})
-	dA.Stop()
-	dA.Stop() // must not panic or hang
-}

client/internal/pqkem/message.go

@@ -1,121 +0,0 @@
-package pqkem
-
-import (
-	"crypto/mlkem"
-	"fmt"
-)
-
-// Wire framing for the PQ-KEM exchange. Messages are self-contained, versioned,
-// transport-agnostic byte blobs: the same bytes ride the signalling channel
-// (initial bootstrap) or a data-tunnel packet (rekey). The library only ever sees
-// opaque []byte at the transport seam.
-//
-// Layout (all messages): [type:1][version:1][exchangeID:16][payload...]
-//
-// There is no confirm message: an exchange is acknowledged by the NEXT offer, which
-// carries the acked exchange's id (see OfferMsg.AckID) and — riding the data path
-// under the freshly adopted key — proves that key works.
-
-const (
-	// ProtocolVersion is bumped on any wire-incompatible change; a peer rejects
-	// messages it does not understand rather than misparsing them.
-	ProtocolVersion uint8 = 1
-
-	// ExchangeIDSize identifies one exchange so answers/acks correlate and stale
-	// messages are dropped.
-	ExchangeIDSize = 16
-
-	headerSize = 1 + 1 + ExchangeIDSize
-)
-
-// MsgType tags the two message kinds of the exchange.
-type MsgType uint8
-
-const (
-	MsgOffer MsgType = iota + 1
-	MsgAnswer
-)
-
-// ExchangeID is the per-exchange correlator. The zero value means "none" (an offer
-// that acknowledges nothing, i.e. the first exchange of a connection).
-type ExchangeID [ExchangeIDSize]byte
-
-// OfferMsg carries the initiator's public material (X25519 pub ‖ ML-KEM encap key)
-// and AckID, the id of the previous exchange this offer acknowledges (zero if none).
-type OfferMsg struct {
-	ExchangeID ExchangeID
-	AckID      ExchangeID
-	// KEMOffer is the raw Initiator.Offer() blob (OfferSize bytes).
-	KEMOffer []byte
-}
-
-// AnswerMsg carries the responder's reply (ML-KEM ciphertext ‖ X25519 pub) for the
-// round identified by ExchangeID.
-type AnswerMsg struct {
-	ExchangeID ExchangeID
-	// KEMAnswer is the raw Respond() answer blob (AnswerSize bytes).
-	KEMAnswer []byte
-}
-
-// Encode serialises the offer with its framed header (payload = AckID ‖ KEMOffer).
-func (m *OfferMsg) Encode() ([]byte, error) {
-	if len(m.KEMOffer) != OfferSize {
-		return nil, fmt.Errorf("offer payload: got %d, want %d", len(m.KEMOffer), OfferSize)
-	}
-	payload := make([]byte, 0, ExchangeIDSize+OfferSize)
-	payload = append(payload, m.AckID[:]...)
-	payload = append(payload, m.KEMOffer...)
-	return frame(MsgOffer, m.ExchangeID, payload), nil
-}
-
-// Encode serialises the answer with its framed header.
-func (m *AnswerMsg) Encode() ([]byte, error) {
-	if len(m.KEMAnswer) != AnswerSize {
-		return nil, fmt.Errorf("answer payload: got %d, want %d", len(m.KEMAnswer), AnswerSize)
-	}
-	return frame(MsgAnswer, m.ExchangeID, m.KEMAnswer), nil
-}
-
-// Decode parses a framed message into one of *OfferMsg / *AnswerMsg.
-func Decode(buf []byte) (MsgType, any, error) {
-	if len(buf) < headerSize {
-		return 0, nil, fmt.Errorf("message too short: %d bytes", len(buf))
-	}
-	typ := MsgType(buf[0])
-	if ver := buf[1]; ver != ProtocolVersion {
-		return typ, nil, fmt.Errorf("unsupported protocol version %d (want %d)", ver, ProtocolVersion)
-	}
-
-	var id ExchangeID
-	copy(id[:], buf[2:headerSize])
-	payload := buf[headerSize:]
-
-	switch typ {
-	case MsgOffer:
-		if len(payload) != ExchangeIDSize+OfferSize {
-			return typ, nil, fmt.Errorf("offer payload: got %d, want %d", len(payload), ExchangeIDSize+OfferSize)
-		}
-		var ack ExchangeID
-		copy(ack[:], payload[:ExchangeIDSize])
-		return typ, &OfferMsg{ExchangeID: id, AckID: ack, KEMOffer: payload[ExchangeIDSize:]}, nil
-	case MsgAnswer:
-		if len(payload) != AnswerSize {
-			return typ, nil, fmt.Errorf("answer payload: got %d, want %d", len(payload), AnswerSize)
-		}
-		return typ, &AnswerMsg{ExchangeID: id, KEMAnswer: payload}, nil
-	default:
-		return typ, nil, fmt.Errorf("unknown message type %d", typ)
-	}
-}
-
-func frame(typ MsgType, id ExchangeID, payload []byte) []byte {
-	buf := make([]byte, headerSize+len(payload))
-	buf[0] = byte(typ)
-	buf[1] = ProtocolVersion
-	copy(buf[2:], id[:])
-	copy(buf[headerSize:], payload)
-	return buf
-}
-
-// compile-time assurance the KEM blob sizes referenced here stay in sync with kem.go.
-var _ = [1]struct{}{}[OfferSize-(32+mlkem.EncapsulationKeySize768)]

client/internal/pqkem/message_test.go

@@ -1,57 +0,0 @@
-package pqkem
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestMessageRoundTrip(t *testing.T) {
-	init, err := NewInitiator()
-	require.NoError(t, err)
-	answer, _, err := Respond(init.Offer(), Binding{LocalID: wgB, RemoteID: wgA})
-	require.NoError(t, err)
-
-	id := ExchangeID{1, 2, 3, 4}
-	ack := ExchangeID{9, 9, 9}
-
-	offBytes, err := (&OfferMsg{ExchangeID: id, AckID: ack, KEMOffer: init.Offer()}).Encode()
-	require.NoError(t, err)
-	typ, decoded, err := Decode(offBytes)
-	require.NoError(t, err)
-	require.Equal(t, MsgOffer, typ)
-	require.Equal(t, id, decoded.(*OfferMsg).ExchangeID)
-	require.Equal(t, ack, decoded.(*OfferMsg).AckID)
-	require.Equal(t, init.Offer(), decoded.(*OfferMsg).KEMOffer)
-
-	ansBytes, err := (&AnswerMsg{ExchangeID: id, KEMAnswer: answer}).Encode()
-	require.NoError(t, err)
-	typ, decoded, err = Decode(ansBytes)
-	require.NoError(t, err)
-	require.Equal(t, MsgAnswer, typ)
-	require.Equal(t, answer, decoded.(*AnswerMsg).KEMAnswer)
-}
-
-func TestDecodeRejects(t *testing.T) {
-	// too short
-	_, _, err := Decode([]byte{1, 1})
-	require.Error(t, err)
-
-	// wrong version
-	bad := make([]byte, headerSize+ExchangeIDSize+OfferSize)
-	bad[0] = byte(MsgOffer)
-	bad[1] = ProtocolVersion + 1
-	_, _, err = Decode(bad)
-	require.Error(t, err)
-
-	// unknown type
-	bad2 := make([]byte, headerSize)
-	bad2[0] = 99
-	bad2[1] = ProtocolVersion
-	_, _, err = Decode(bad2)
-	require.Error(t, err)
-
-	// offer with wrong payload size
-	_, err = (&OfferMsg{KEMOffer: []byte{1, 2, 3}}).Encode()
-	require.Error(t, err)
-}

client/internal/pqkem_adapter.go

@@ -1,102 +0,0 @@
-package internal
-
-import (
-	"net/netip"
-
-	log "github.com/sirupsen/logrus"
-	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
-
-	"github.com/netbirdio/netbird/client/internal/pqkem"
-)
-
-// pqPresharedKeySetter is the subset of the WireGuard interface the ML-KEM callback
-// needs: programming a peer's preshared key. *iface.WGIface satisfies it.
-type pqPresharedKeySetter interface {
-	SetPresharedKey(peerKey string, psk wgtypes.Key, updateOnly bool) error
-}
-
-// pqCallbackHandler programs the derived PQ PSK onto the WireGuard peer. It is the
-// engine-side implementation of pqkem.CallbackHandler.
-type pqCallbackHandler struct {
-	wg pqPresharedKeySetter
-}
-
-// OnNewPSKReady programs the freshly derived PSK for the peer (updateOnly: a no-op
-// if the peer is not present, mirroring Rosenpass). remoteID is the peer's WG pubkey.
-func (h pqCallbackHandler) OnNewPSKReady(remoteID pqkem.RemoteID, psk pqkem.PSK) error {
-	// updateOnly: applies to an already-configured peer (rotation). At bootstrap the
-	// peer is not configured yet, so this is a no-op there and the PSK is instead
-	// pulled at peer-config time (pqHandshaker.PSK / conn.presharedKey).
-	log.Debugf("pqkem: programming PSK for peer %s", remoteID)
-	return h.wg.SetPresharedKey(string(remoteID), wgtypes.Key(psk), true)
-}
-
-// OnRekeyFailed reports a failed PQ (re)key convergence.
-// TODO(NET-1406): tear the peer connection down / trigger ICE reconnect.
-func (h pqCallbackHandler) OnRekeyFailed(remoteID pqkem.RemoteID) error {
-	log.Warnf("pqkem: post-quantum rekey failed for peer %s", remoteID)
-	return nil
-}
-
-// pqHandshaker adapts the pqkem manager to peer.PQHandshaker (string peer keys),
-// wiring the host's signalling offers/answers to the KEM exchange.
-type pqHandshaker struct {
-	mgr *pqkem.Manager
-}
-
-func (p pqHandshaker) OfferPayload(remoteKey string) ([]byte, int) {
-	payload, err := p.mgr.SignalOffer(pqkem.RemoteID(remoteKey))
-	if err != nil {
-		log.Warnf("pqkem: build offer for %s: %v", remoteKey, err)
-	}
-	return payload, p.mgr.LocalPort()
-}
-
-func (p pqHandshaker) AnswerPayload(remoteKey string, recvOffer []byte) ([]byte, int) {
-	if len(recvOffer) == 0 {
-		return nil, p.mgr.LocalPort()
-	}
-	payload, err := p.mgr.SignalOnOffer(pqkem.RemoteID(remoteKey), recvOffer)
-	if err != nil {
-		log.Warnf("pqkem: build answer for %s: %v", remoteKey, err)
-	}
-	return payload, p.mgr.LocalPort()
-}
-
-func (p pqHandshaker) OnAnswer(remoteKey string, recvAnswer []byte) {
-	if len(recvAnswer) == 0 {
-		return
-	}
-	if err := p.mgr.SignalOnAnswer(pqkem.RemoteID(remoteKey), recvAnswer); err != nil {
-		log.Warnf("pqkem: process answer from %s: %v", remoteKey, err)
-	}
-}
-
-// PSK exposes the peer's derived PSK for the conn to program at WG peer-config time.
-func (p pqHandshaker) PSK(remoteKey string) (wgtypes.Key, bool) {
-	psk, ok := p.mgr.PSK(pqkem.RemoteID(remoteKey))
-	if !ok {
-		return wgtypes.Key{}, false
-	}
-	return wgtypes.Key(psk), true
-}
-
-// SetRemoteAddr registers the peer's data-path endpoint (overlay IP + pq UDP port)
-// learned from signalling. Sends only ever fire once the tunnel is up (clocked by
-// OnDataPathRekeyed), so registering here is safe even before connection-up.
-func (p pqHandshaker) SetRemoteAddr(remoteKey string, addr netip.AddrPort) {
-	if !addr.IsValid() || addr.Port() == 0 {
-		return
-	}
-	p.mgr.AddPeer(pqkem.RemoteID(remoteKey), addr)
-}
-
-// OnDataPathRekeyed clocks the next chained PSK rotation on a fresh WG handshake.
-func (p pqHandshaker) OnDataPathRekeyed(remoteKey string) {
-	p.mgr.OnDataPathRekeyed(pqkem.RemoteID(remoteKey))
-}
-
-// OnDataPathDown signals the peer's tunnel went down.
-func (p pqHandshaker) OnDataPathDown(remoteKey string) {
-	p.mgr.OnDataPathDown(pqkem.RemoteID(remoteKey))
-}

client/internal/pqkem_transport.go

@@ -1,72 +0,0 @@
-package internal
-
-import (
-	"fmt"
-	"net"
-	"net/netip"
-
-	log "github.com/sirupsen/logrus"
-)
-
-// DefaultPort is the preferred UDP port for the ML-KEM data-path service, bound on
-// the WG overlay IP. Since each client owns a distinct overlay IP, this port is
-// almost always free, so it need not be announced (peers assume it). A peer only
-// announces Body.mlkemPort when a collision forced it onto a different port.
-const DefaultPort = 51833
-
-// pqTransport is the ML-KEM data-path transport: a dumb UDP socket bound on the WG
-// overlay IP. It implements pqkem.Transport — the manager owns the remoteID<->endpoint
-// routing and drives this socket's lifecycle (Run / Close).
-type pqTransport struct {
-	conn *net.UDPConn
-	port int
-}
-
-// newPQTransport binds a UDP socket on the WG overlay IP, preferring DefaultPort and
-// falling back to an OS-assigned ephemeral port if it is in use. Call it after the WG
-// interface is up so the overlay IP is assigned; when the bound port is not
-// DefaultPort it must be announced to peers via Body.mlkemPort.
-func newPQTransport(overlayIP netip.Addr) (*pqTransport, error) {
-	if !overlayIP.IsValid() {
-		return nil, fmt.Errorf("invalid overlay IP for pqkem transport")
-	}
-	ip := net.IP(overlayIP.AsSlice())
-	conn, err := net.ListenUDP("udp4", &net.UDPAddr{IP: ip, Port: DefaultPort})
-	if err != nil {
-		log.Debugf("pqkem: default port %d unavailable on %s (%v), using an ephemeral port", DefaultPort, overlayIP, err)
-		conn, err = net.ListenUDP("udp4", &net.UDPAddr{IP: ip, Port: 0})
-		if err != nil {
-			return nil, fmt.Errorf("bind pqkem udp on overlay %s: %w", overlayIP, err)
-		}
-	}
-	return &pqTransport{conn: conn, port: conn.LocalAddr().(*net.UDPAddr).Port}, nil
-}
-
-// Send implements pqkem.Transport.
-func (t *pqTransport) Send(endpoint netip.AddrPort, msg []byte) error {
-	_, err := t.conn.WriteToUDPAddrPort(msg, endpoint)
-	return err
-}
-
-// LocalPort implements pqkem.Transport.
-func (t *pqTransport) LocalPort() int { return t.port }
-
-// Run implements pqkem.Transport: the receive loop, delivering each datagram as
-// (source endpoint, msg). Exits when the socket is closed.
-func (t *pqTransport) Run(onInbound func(src netip.AddrPort, msg []byte)) {
-	go func() {
-		buf := make([]byte, 2048)
-		for {
-			n, src, err := t.conn.ReadFromUDPAddrPort(buf)
-			if err != nil {
-				return
-			}
-			msg := make([]byte, n)
-			copy(msg, buf[:n])
-			onInbound(src, msg)
-		}
-	}()
-}
-
-// Close implements pqkem.Transport.
-func (t *pqTransport) Close() error { return t.conn.Close() }

release_files/install.sh

@@ -134,6 +134,72 @@ repo_gpgcheck=1
 EOF
 }
 
+# The desktop app renders in a GTK 4 WebKit webview and needs GTK 4.10+ with
+# WebKitGTK 6.0. The netbird-ui packages do not declare these libraries, so
+# the installer resolves them and degrades to a CLI-only install when the
+# system cannot provide them.
+UI_MIN_GTK_VERSION="4.10"
+
+skip_ui_app() {
+    SKIP_UI_APP=true
+    echo "NetBird UI installation will be omitted: $1"
+}
+
+install_ui_apt() {
+    GTK_CANDIDATE="$(apt-cache policy libgtk-4-1 2>/dev/null | awk '/Candidate:/ {print $2}')"
+    if [ -z "$GTK_CANDIDATE" ] || [ "$GTK_CANDIDATE" = "(none)" ]; then
+        skip_ui_app "GTK 4 is not available in the configured APT repositories"
+        return 0
+    fi
+    if ! dpkg --compare-versions "$GTK_CANDIDATE" ge "$UI_MIN_GTK_VERSION"; then
+        skip_ui_app "the desktop app needs GTK ${UI_MIN_GTK_VERSION}+ and this release provides ${GTK_CANDIDATE} (Ubuntu 24.04+ or Debian 13+ required)"
+        return 0
+    fi
+    if ! ${SUDO} apt-get install netbird-ui libgtk-4-1 libwebkitgtk-6.0-4 xdg-utils -y; then
+        skip_ui_app "the desktop app dependencies could not be installed"
+    fi
+}
+
+# Enabling EPEL changes the system's repository configuration, so it needs
+# an explicit go-ahead: either NETBIRD_INSTALL_EPEL=true in the environment
+# or an interactive confirmation. Returns 0 when EPEL is available.
+confirm_epel() {
+    if rpm -q epel-release >/dev/null 2>&1; then
+        return 0
+    fi
+    if [ "${NETBIRD_INSTALL_EPEL:-}" = "true" ]; then
+        echo "NETBIRD_INSTALL_EPEL=true is set, enabling the EPEL repository"
+        ${SUDO} dnf -y install epel-release
+        return $?
+    fi
+    if (exec < /dev/tty) 2>/dev/null; then
+        printf "The desktop app needs WebKitGTK 6.0 from the EPEL repository (https://docs.fedoraproject.org/en-US/epel/). Enable EPEL and continue? [y/N] "
+        read -r EPEL_REPLY < /dev/tty
+        case "$EPEL_REPLY" in
+            y|Y|yes|YES)
+                ${SUDO} dnf -y install epel-release
+                return $?
+            ;;
+        esac
+    fi
+    return 1
+}
+
+install_ui_dnf() {
+    # webkitgtk6.0 comes from EPEL on RHEL, AlmaLinux and Rocky Linux 10.
+    case "$OS_NAME" in
+        rhel|almalinux|rocky|centos)
+            if ! confirm_epel; then
+                skip_ui_app "the desktop app needs WebKitGTK 6.0 from EPEL; re-run with NETBIRD_INSTALL_EPEL=true to enable it"
+                return 0
+            fi
+        ;;
+    esac
+    if ! ${SUDO} dnf -y install netbird-ui gtk4 webkitgtk6.0 xdg-utils; then
+        skip_ui_app "GTK 4.10+ and WebKitGTK 6.0 are not available on this system (Fedora 43+ or RHEL 10+ required)"
+    fi
+}
+
 prepare_tun_module() {
   # Create the necessary file structure for /dev/net/tun
   if [ ! -c /dev/net/tun ]; then
@@ -226,14 +292,16 @@ install_netbird() {
         ${SUDO} apt-get install netbird -y
 
         if ! $SKIP_UI_APP; then
-            ${SUDO} apt-get install netbird-ui -y
+            install_ui_apt
         fi
     ;;
     yum)
         add_rpm_repo
         ${SUDO} yum -y install netbird
         if ! $SKIP_UI_APP; then
-            ${SUDO} yum -y install netbird-ui
+            # Systems where dnf is absent (RHEL 9, Amazon Linux) do not
+            # provide GTK 4.10+ or WebKitGTK 6.0.
+            skip_ui_app "this system does not provide the desktop app dependencies (RHEL 10+ required)"
         fi
     ;;
     dnf)
@@ -241,7 +309,7 @@ install_netbird() {
         ${SUDO} dnf -y install netbird
 
         if ! $SKIP_UI_APP; then
-            ${SUDO} dnf -y install netbird-ui
+            install_ui_dnf
         fi
     ;;
     rpm-ostree)
@@ -401,9 +469,8 @@ if type uname >/dev/null 2>&1; then
               OS_NAME="$(. /etc/os-release && echo "$ID")"
               INSTALL_DIR="/usr/bin"
 
-              # Allow netbird UI installation for x64 arch only
-              if [ "$ARCH" != "amd64" ] && [ "$ARCH" != "arm64" ] \
-                  && [ "$ARCH" != "x86_64" ];then
+              # The netbird-ui Linux packages are built for x86_64 only
+              if [ "$ARCH" != "amd64" ] && [ "$ARCH" != "x86_64" ];then
                   SKIP_UI_APP=true
                   echo "NetBird UI installation will be omitted as $ARCH is not a compatible architecture"
               fi

shared/signal/client/client.go

@@ -52,11 +52,6 @@ type CredentialPayload struct {
 	Credential      *Credential
 	RosenpassPubKey []byte
 	RosenpassAddr   string
-	// MlkemPayload is the opaque post-quantum KEM handshake message riding this
-	// OFFER/ANSWER (see Body.mlkemPayload). Nil when not running the PQ exchange.
-	MlkemPayload []byte
-	// MlkemPort is the sender's ML-KEM PQ service UDP port (0 when not running).
-	MlkemPort       int
 	RelaySrvAddress string
 	RelaySrvIP      netip.Addr
 	SessionID       []byte
@@ -94,13 +89,6 @@ func MarshalCredential(myKey wgtypes.Key, remoteKey string, p CredentialPayload)
 	if p.RelaySrvIP.IsValid() {
 		body.RelayServerIP = p.RelaySrvIP.Unmap().AsSlice()
 	}
-	if len(p.MlkemPayload) > 0 {
-		body.MlkemPayload = p.MlkemPayload
-	}
-	if p.MlkemPort > 0 {
-		port := uint32(p.MlkemPort)
-		body.MlkemPort = &port
-	}
 	return &proto.Message{
 		Key:       myKey.PublicKey().String(),
 		RemoteKey: remoteKey,

shared/signal/proto/signalexchange.pb.go

@@ -239,16 +239,6 @@ type Body struct {
 	// fallback dial target when DNS resolution of relayServerAddress fails.
 	// SNI/TLS verification still uses relayServerAddress.
 	RelayServerIP []byte `protobuf:"bytes,11,opt,name=relayServerIP,proto3,oneof" json:"relayServerIP,omitempty"`
-	// mlkemPayload carries a post-quantum X25519MLKEM768 handshake message that
-	// seeds the WireGuard PSK, riding this Body's OFFER/ANSWER: on an OFFER it is
-	// the KEM offer, on an ANSWER the KEM answer. It is opaque to signal — the
-	// pqkem library frames and parses it. Absent when the sender does not run the
-	// ML-KEM PQ exchange; unknown to older clients, which ignore it.
-	MlkemPayload []byte `protobuf:"bytes,12,opt,name=mlkemPayload,proto3,oneof" json:"mlkemPayload,omitempty"`
-	// mlkemPort is the UDP port of the sender's ML-KEM PQ service, bound on its
-	// WireGuard overlay IP. Peers send subsequent rekey messages there over the
-	// data path. Zero/absent when the ML-KEM PQ exchange is not running.
-	MlkemPort *uint32 `protobuf:"varint,13,opt,name=mlkemPort,proto3,oneof" json:"mlkemPort,omitempty"`
 }
 
 func (x *Body) Reset() {
@@ -353,20 +343,6 @@ func (x *Body) GetRelayServerIP() []byte {
 	return nil
 }
 
-func (x *Body) GetMlkemPayload() []byte {
-	if x != nil {
-		return x.MlkemPayload
-	}
-	return nil
-}
-
-func (x *Body) GetMlkemPort() uint32 {
-	if x != nil && x.MlkemPort != nil {
-		return *x.MlkemPort
-	}
-	return 0
-}
-
 // Mode indicates a connection mode
 type Mode struct {
 	state         protoimpl.MessageState
@@ -490,7 +466,7 @@ var file_signalexchange_proto_rawDesc = []byte{
 	0x52, 0x09, 0x72, 0x65, 0x6d, 0x6f, 0x74, 0x65, 0x4b, 0x65, 0x79, 0x12, 0x28, 0x0a, 0x04, 0x62,
 	0x6f, 0x64, 0x79, 0x18, 0x04, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x14, 0x2e, 0x73, 0x69, 0x67, 0x6e,
 	0x61, 0x6c, 0x65, 0x78, 0x63, 0x68, 0x61, 0x6e, 0x67, 0x65, 0x2e, 0x42, 0x6f, 0x64, 0x79, 0x52,
-	0x04, 0x62, 0x6f, 0x64, 0x79, 0x22, 0xbd, 0x05, 0x0a, 0x04, 0x42, 0x6f, 0x64, 0x79, 0x12, 0x2d,
+	0x04, 0x62, 0x6f, 0x64, 0x79, 0x22, 0xd2, 0x04, 0x0a, 0x04, 0x42, 0x6f, 0x64, 0x79, 0x12, 0x2d,
 	0x0a, 0x04, 0x74, 0x79, 0x70, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0e, 0x32, 0x19, 0x2e, 0x73,
 	0x69, 0x67, 0x6e, 0x61, 0x6c, 0x65, 0x78, 0x63, 0x68, 0x61, 0x6e, 0x67, 0x65, 0x2e, 0x42, 0x6f,
 	0x64, 0x79, 0x2e, 0x54, 0x79, 0x70, 0x65, 0x52, 0x04, 0x74, 0x79, 0x70, 0x65, 0x12, 0x18, 0x0a,
@@ -518,46 +494,39 @@ var file_signalexchange_proto_rawDesc = []byte{
 	0x52, 0x09, 0x73, 0x65, 0x73, 0x73, 0x69, 0x6f, 0x6e, 0x49, 0x64, 0x88, 0x01, 0x01, 0x12, 0x29,
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-	0x65, 0x6d, 0x50, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64, 0x18, 0x0c, 0x20, 0x01, 0x28, 0x0c, 0x48,
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-	0x01, 0x01, 0x12, 0x21, 0x0a, 0x09, 0x6d, 0x6c, 0x6b, 0x65, 0x6d, 0x50, 0x6f, 0x72, 0x74, 0x18,
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 }
 
 var (

shared/signal/proto/signalexchange.proto

@@ -75,18 +75,6 @@ message Body {
   // fallback dial target when DNS resolution of relayServerAddress fails.
   // SNI/TLS verification still uses relayServerAddress.
   optional bytes relayServerIP = 11;
-
-  // mlkemPayload carries a post-quantum X25519MLKEM768 handshake message that
-  // seeds the WireGuard PSK, riding this Body's OFFER/ANSWER: on an OFFER it is
-  // the KEM offer, on an ANSWER the KEM answer. It is opaque to signal — the
-  // pqkem library frames and parses it. Absent when the sender does not run the
-  // ML-KEM PQ exchange; unknown to older clients, which ignore it.
-  optional bytes mlkemPayload = 12;
-
-  // mlkemPort is the UDP port of the sender's ML-KEM PQ service, bound on its
-  // WireGuard overlay IP. Peers send subsequent rekey messages there over the
-  // data path. Zero/absent when the ML-KEM PQ exchange is not running.
-  optional uint32 mlkemPort = 13;
 }
 
 // Mode indicates a connection mode