all: store NL keys per profile

This moves the NetworkLock key from a dedicated StateKey to be part of the persist.Persist struct.
This struct is stored as part for ipn.Prefs and is also the place where we store the NodeKey.

It also moves the ChonkDir from "/tka" to "/tka-profile/<profile-id>". The rename was intentional
to be able to delete the "/tka" dir if it exists.

This means that we will have a unique key per profile, and a unique directory per profile.

Note: `tailscale logout` will delete the entire profile, including any keys. It currently does not
delete the ChonkDir.

Signed-off-by: Maisem Ali <maisem@tailscale.com>

cmd/tailscale/cli/network-lock.go

@@ -93,12 +93,14 @@ func runNetworkLockStatus(ctx context.Context, args []string) error {
 		fmt.Println()
 	}
 
+	if !st.PublicKey.IsZero() {
 		p, err := st.PublicKey.MarshalText()
 		if err != nil {
 			return err
 		}
 		fmt.Printf("This node's public-key: %s\n", p)
 		fmt.Println()
+	}
 
 	if st.Enabled && len(st.TrustedKeys) > 0 {
 		fmt.Println("Keys trusted to make changes to network-lock:")

control/controlclient/direct.go

@@ -70,7 +70,6 @@ type Direct struct {
 	linkMon                *monitor.Mon // or nil
 	discoPubKey            key.DiscoPublic
 	getMachinePrivKey      func() (key.MachinePrivate, error)
-	getNLPrivateKey        func() (key.NLPrivate, error) // or nil
 	debugFlags             []string
 	keepSharerAndUserSplit bool
 	skipIPForwardingCheck  bool
@@ -118,10 +117,6 @@ type Options struct {
 	Dialer               *tsdial.Dialer   // non-nil
 	C2NHandler           http.Handler     // or nil
 
-	// GetNLPrivateKey specifies an optional function to use
-	// Network Lock. If nil, it's not used.
-	GetNLPrivateKey func() (key.NLPrivate, error)
-
 	// Status is called when there's a change in status.
 	Status func(Status)
 
@@ -232,7 +227,6 @@ func NewDirect(opts Options) (*Direct, error) {
 	c := &Direct{
 		httpc:                  httpc,
 		getMachinePrivKey:      opts.GetMachinePrivateKey,
-		getNLPrivateKey:        opts.GetNLPrivateKey,
 		serverURL:              opts.ServerURL,
 		timeNow:                opts.TimeNow,
 		logf:                   opts.Logf,
@@ -494,6 +488,10 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 	if !persist.OldPrivateNodeKey.IsZero() {
 		oldNodeKey = persist.OldPrivateNodeKey.Public()
 	}
+	if persist.NetworkLockKey.IsZero() {
+		persist.NetworkLockKey = key.NewNLPrivate()
+	}
+	nlPub := persist.NetworkLockKey.Public()
 
 	if tryingNewKey.IsZero() {
 		if opt.Logout {
@@ -502,21 +500,12 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 		log.Fatalf("tryingNewKey is empty, give up")
 	}
 
-	var nlPub key.NLPublic
 	var nodeKeySignature tkatype.MarshaledSignature
-	if c.getNLPrivateKey != nil {
-		priv, err := c.getNLPrivateKey()
-		if err != nil {
-			return false, "", nil, fmt.Errorf("get nl key: %v", err)
-		}
-		nlPub = priv.Public()
-
 	if !oldNodeKey.IsZero() && opt.OldNodeKeySignature != nil {
-			if nodeKeySignature, err = resignNKS(priv, tryingNewKey.Public(), opt.OldNodeKeySignature); err != nil {
+		if nodeKeySignature, err = resignNKS(persist.NetworkLockKey, tryingNewKey.Public(), opt.OldNodeKeySignature); err != nil {
 			c.logf("Failed re-signing node-key signature: %v", err)
 		}
 	}
-	}
 
 	if backendLogID == "" {
 		err = errors.New("hostinfo: BackendLogID missing")

ipn/ipnlocal/local.go

@@ -159,7 +159,6 @@ type LocalBackend struct {
 	ccAuto         *controlclient.Auto // if cc is of type *controlclient.Auto
 	inServerMode   bool
 	machinePrivKey key.MachinePrivate
-	nlPrivKey      key.NLPrivate
 	tka            *tkaState
 	state          ipn.State
 	capFileSharing bool // whether netMap contains the file sharing capability
@@ -832,6 +831,9 @@ func (b *LocalBackend) setClientStatus(st controlclient.Status) {
 		if !prefs.Persist.View().Equals(*st.Persist) {
 			prefsChanged = true
 			prefs.Persist = st.Persist.AsStruct()
+			if err := b.initTKALocked(); err != nil {
+				b.logf("initTKALocked: %v", err)
+			}
 		}
 	}
 	if st.URL != "" {
@@ -1174,9 +1176,6 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 			return fmt.Errorf("initMachineKeyLocked: %w", err)
 		}
 	}
-	if err := b.initNLKeyLocked(); err != nil {
-		return fmt.Errorf("initNLKeyLocked: %w", err)
-	}
 
 	loggedOut := prefs.LoggedOut()
 
@@ -1232,7 +1231,6 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 	// but it won't take effect until the next Start().
 	cc, err := b.getNewControlClientFunc()(controlclient.Options{
 		GetMachinePrivateKey: b.createGetMachinePrivateKeyFunc(),
-		GetNLPrivateKey:      b.createGetNLPrivateKeyFunc(),
 		Logf:                 logger.WithPrefix(b.logf, "control: "),
 		Persist:              *persistv,
 		ServerURL:            b.serverURL,
@@ -1759,21 +1757,6 @@ func (b *LocalBackend) createGetMachinePrivateKeyFunc() func() (key.MachinePriva
 	}
 }
 
-func (b *LocalBackend) createGetNLPrivateKeyFunc() func() (key.NLPrivate, error) {
-	var cache syncs.AtomicValue[key.NLPrivate]
-	return func() (key.NLPrivate, error) {
-		b.mu.Lock()
-		defer b.mu.Unlock()
-		if v, ok := cache.LoadOk(); ok {
-			return v, nil
-		}
-
-		priv := b.nlPrivKey
-		cache.Store(priv)
-		return priv, nil
-	}
-}
-
 // initMachineKeyLocked is called to initialize b.machinePrivKey.
 //
 // b.prefs must already be initialized.
@@ -1827,46 +1810,6 @@ func (b *LocalBackend) initMachineKeyLocked() (err error) {
 	return nil
 }
 
-// initNLKeyLocked is called to initialize b.nlPrivKey.
-//
-// b.prefs must already be initialized.
-//
-// b.stateKey should be set too, but just for nicer log messages.
-// b.mu must be held.
-func (b *LocalBackend) initNLKeyLocked() (err error) {
-	if !b.nlPrivKey.IsZero() {
-		// Already set.
-		return nil
-	}
-
-	keyText, err := b.store.ReadState(ipn.NLKeyStateKey)
-	if err == nil {
-		if err := b.nlPrivKey.UnmarshalText(keyText); err != nil {
-			return fmt.Errorf("invalid key in %s key of %v: %w", ipn.NLKeyStateKey, b.store, err)
-		}
-		if b.nlPrivKey.IsZero() {
-			return fmt.Errorf("invalid zero key stored in %v key of %v", ipn.NLKeyStateKey, b.store)
-		}
-		return nil
-	}
-	if err != ipn.ErrStateNotExist {
-		return fmt.Errorf("error reading %v key of %v: %w", ipn.NLKeyStateKey, b.store, err)
-	}
-
-	// If we didn't find one already on disk, generate a new one.
-	b.logf("generating new network-lock key")
-	b.nlPrivKey = key.NewNLPrivate()
-
-	keyText, _ = b.nlPrivKey.MarshalText()
-	if err := b.store.WriteState(ipn.NLKeyStateKey, keyText); err != nil {
-		b.logf("error writing network-lock key to store: %v", err)
-		return err
-	}
-
-	b.logf("network-lock key written to store")
-	return nil
-}
-
 // migrateStateLocked migrates state from the frontend to the backend.
 // It is a no-op if prefs is nil
 // b.mu must be held.
@@ -2705,17 +2648,6 @@ func dnsConfigForNetmap(nm *netmap.NetworkMap, prefs ipn.PrefsView, logf logger.
 	return dcfg
 }
 
-// SetTailnetKeyAuthority sets the key authority which should be
-// used for locked tailnets.
-//
-// It should only be called before the LocalBackend is used.
-func (b *LocalBackend) SetTailnetKeyAuthority(a *tka.Authority, storage *tka.FS) {
-	b.tka = &tkaState{
-		authority: a,
-		storage:   storage,
-	}
-}
-
 // SetVarRoot sets the root directory of Tailscale's writable
 // storage area . (e.g. "/var/lib/tailscale")
 //
@@ -4053,11 +3985,58 @@ func (b *LocalBackend) SwitchProfile(profile ipn.ProfileID) error {
 	return b.resetForProfileChangeLockedOnEntry()
 }
 
+func (b *LocalBackend) initTKALocked() error {
+	cp := b.pm.CurrentProfile()
+	if cp.ID == "" {
+		b.tka = nil
+		return nil
+	}
+	if b.tka != nil {
+		if b.tka.profile == cp.ID {
+			// Already initialized.
+			return nil
+		}
+		// As we're switching profiles, we need to reset the TKA to nil.
+		b.tka = nil
+	}
+	root := b.TailscaleVarRoot()
+	if root == "" {
+		b.tka = nil
+		b.logf("network-lock unavailable; no state directory")
+		return nil
+	}
+
+	chonkDir := b.chonkPathLocked()
+	if _, err := os.Stat(chonkDir); err == nil {
+		// The directory exists, which means network-lock has been initialized.
+		storage, err := tka.ChonkDir(chonkDir)
+		if err != nil {
+			return fmt.Errorf("opening tailchonk: %v", err)
+		}
+		authority, err := tka.Open(storage)
+		if err != nil {
+			return fmt.Errorf("initializing tka: %v", err)
+		}
+
+		b.tka = &tkaState{
+			profile:   cp.ID,
+			authority: authority,
+			storage:   storage,
+		}
+		b.logf("tka initialized at head %x", authority.Head())
+	}
+
+	return nil
+}
+
 // resetForProfileChangeLockedOnEntry resets the backend for a profile change.
 func (b *LocalBackend) resetForProfileChangeLockedOnEntry() error {
 	b.setNetMapLocked(nil) // Reset netmap.
 	// Reset the NetworkMap in the engine
 	b.e.SetNetworkMap(new(netmap.NetworkMap))
+	if err := b.initTKALocked(); err != nil {
+		return err
+	}
 	b.enterStateLockedOnEntry(ipn.NoState) // Reset state.
 	return b.Start(ipn.Options{})
 }

ipn/ipnlocal/network-lock.go

@@ -35,6 +35,7 @@ var (
 )
 
 type tkaState struct {
+	profile   ipn.ProfileID
 	authority *tka.Authority
 	storage   *tka.FS
 }
@@ -251,7 +252,7 @@ func (b *LocalBackend) tkaSyncLocked(ourNodeKey key.NodePublic) error {
 // b.mu must be held & TKA must be initialized.
 func (b *LocalBackend) tkaApplyDisablementLocked(secret []byte) error {
 	if b.tka.authority.ValidDisablement(secret) {
-		if err := os.RemoveAll(b.chonkPath()); err != nil {
+		if err := os.RemoveAll(b.chonkPathLocked()); err != nil {
 			return err
 		}
 		b.tka = nil
@@ -260,10 +261,10 @@ func (b *LocalBackend) tkaApplyDisablementLocked(secret []byte) error {
 	return errors.New("incorrect disablement secret")
 }
 
-// chonkPath returns the absolute path to the directory in which TKA
+// chonkPathLocked returns the absolute path to the directory in which TKA
 // state (the 'tailchonk') is stored.
-func (b *LocalBackend) chonkPath() string {
+func (b *LocalBackend) chonkPathLocked() string {
-	return filepath.Join(b.TailscaleVarRoot(), "tka")
+	return filepath.Join(b.TailscaleVarRoot(), "tka-profiles", string(b.pm.CurrentProfile().ID))
 }
 
 // tkaBootstrapFromGenesisLocked initializes the local (on-disk) state of the
@@ -280,7 +281,10 @@ func (b *LocalBackend) tkaBootstrapFromGenesisLocked(g tkatype.MarshaledAUM) err
 		return fmt.Errorf("reading genesis: %v", err)
 	}
 
-	chonkDir := b.chonkPath()
+	chonkDir := b.chonkPathLocked()
+	if err := os.Mkdir(filepath.Dir(chonkDir), 0755); err != nil && !os.IsExist(err) {
+		return fmt.Errorf("creating chonk root dir: %v", err)
+	}
 	if err := os.Mkdir(chonkDir, 0755); err != nil && !os.IsExist(err) {
 		return fmt.Errorf("mkdir: %v", err)
 	}
@@ -295,6 +299,7 @@ func (b *LocalBackend) tkaBootstrapFromGenesisLocked(g tkatype.MarshaledAUM) err
 	}
 
 	b.tka = &tkaState{
+		profile:   b.pm.CurrentProfile().ID,
 		authority: authority,
 		storage:   chonk,
 	}
@@ -329,17 +334,27 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
-	var nodeKey *key.NodePublic
+	var (
+		nodeKey *key.NodePublic
+		nlPriv  key.NLPrivate
+	)
 	if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist() != nil && !p.Persist().PrivateNodeKey.IsZero() {
 		nkp := p.Persist().PublicNodeKey()
 		nodeKey = &nkp
+		nlPriv = p.Persist().NetworkLockKey
 	}
 
+	if nlPriv.IsZero() {
+		return &ipnstate.NetworkLockStatus{
+			Enabled: false,
+			NodeKey: nodeKey,
+		}
+	}
 	if b.tka == nil {
 		return &ipnstate.NetworkLockStatus{
 			Enabled:   false,
-			PublicKey: b.nlPrivKey.Public(),
 			NodeKey:   nodeKey,
+			PublicKey: nlPriv.Public(),
 		}
 	}
 
@@ -365,7 +380,7 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 	return &ipnstate.NetworkLockStatus{
 		Enabled:       true,
 		Head:          &head,
-		PublicKey:     b.nlPrivKey.Public(),
+		PublicKey:     nlPriv.Public(),
 		NodeKey:       nodeKey,
 		NodeKeySigned: selfAuthorized,
 		TrustedKeys:   outKeys,
@@ -387,12 +402,14 @@ func (b *LocalBackend) NetworkLockInit(keys []tka.Key, disablementValues [][]byt
 	}
 
 	var ourNodeKey key.NodePublic
+	var nlPriv key.NLPrivate
 	b.mu.Lock()
 	if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist() != nil && !p.Persist().PrivateNodeKey.IsZero() {
 		ourNodeKey = p.Persist().PublicNodeKey()
+		nlPriv = p.Persist().NetworkLockKey
 	}
 	b.mu.Unlock()
-	if ourNodeKey.IsZero() {
+	if ourNodeKey.IsZero() || nlPriv.IsZero() {
 		return errors.New("no node-key: is tailscale logged in?")
 	}
 
@@ -407,7 +424,7 @@ func (b *LocalBackend) NetworkLockInit(keys []tka.Key, disablementValues [][]byt
 		//    - DisablementSecret: value needed to disable.
 		//    - DisablementValue: the KDF of the disablement secret, a public value.
 		DisablementSecrets: disablementValues,
-	}, b.nlPrivKey)
+	}, nlPriv)
 	if err != nil {
 		return fmt.Errorf("tka.Create: %v", err)
 	}
@@ -430,7 +447,7 @@ func (b *LocalBackend) NetworkLockInit(keys []tka.Key, disablementValues [][]byt
 	// satisfy network-lock checks.
 	sigs := make(map[tailcfg.NodeID]tkatype.MarshaledSignature, len(initResp.NeedSignatures))
 	for _, nodeInfo := range initResp.NeedSignatures {
-		nks, err := signNodeKey(nodeInfo, b.nlPrivKey)
+		nks, err := signNodeKey(nodeInfo, nlPriv)
 		if err != nil {
 			return fmt.Errorf("generating signature: %v", err)
 		}
@@ -470,10 +487,18 @@ func (b *LocalBackend) NetworkLockSign(nodeKey key.NodePublic, rotationPublic []
 		b.mu.Lock()
 		defer b.mu.Unlock()
 
+		var nlPriv key.NLPrivate
+		if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist() != nil {
+			nlPriv = p.Persist().NetworkLockKey
+		}
+		if nlPriv.IsZero() {
+			return key.NodePublic{}, tka.NodeKeySignature{}, errMissingNetmap
+		}
+
 		if b.tka == nil {
 			return key.NodePublic{}, tka.NodeKeySignature{}, errNetworkLockNotActive
 		}
-		if !b.tka.authority.KeyTrusted(b.nlPrivKey.KeyID()) {
+		if !b.tka.authority.KeyTrusted(nlPriv.KeyID()) {
 			return key.NodePublic{}, tka.NodeKeySignature{}, errors.New("this node is not trusted by network lock")
 		}
 
@@ -483,11 +508,11 @@ func (b *LocalBackend) NetworkLockSign(nodeKey key.NodePublic, rotationPublic []
 		}
 		sig := tka.NodeKeySignature{
 			SigKind:        tka.SigDirect,
-			KeyID:          b.nlPrivKey.KeyID(),
+			KeyID:          nlPriv.KeyID(),
 			Pubkey:         p,
 			WrappingPubkey: rotationPublic,
 		}
-		sig.Signature, err = b.nlPrivKey.SignNKS(sig.SigHash())
+		sig.Signature, err = nlPriv.SignNKS(sig.SigHash())
 		if err != nil {
 			return key.NodePublic{}, tka.NodeKeySignature{}, fmt.Errorf("signature failed: %w", err)
 		}
@@ -527,11 +552,18 @@ func (b *LocalBackend) NetworkLockModify(addKeys, removeKeys []tka.Key) (err err
 	if err := b.CanSupportNetworkLock(); err != nil {
 		return err
 	}
+	var nlPriv key.NLPrivate
+	if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist() != nil {
+		nlPriv = p.Persist().NetworkLockKey
+	}
+	if nlPriv.IsZero() {
+		return errMissingNetmap
+	}
 	if b.tka == nil {
 		return errNetworkLockNotActive
 	}
 
-	updater := b.tka.authority.NewUpdater(b.nlPrivKey)
+	updater := b.tka.authority.NewUpdater(nlPriv)
 
 	for _, addKey := range addKeys {
 		if err := updater.AddKey(addKey); err != nil {

ipn/ipnlocal/network-lock_test.go

@@ -122,7 +122,10 @@ func TestTKAEnablementFlow(t *testing.T) {
 	cc := fakeControlClient(t, client)
 	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
 	must.Do(pm.SetPrefs((&ipn.Prefs{
-		Persist: &persist.Persist{PrivateNodeKey: nodePriv},
+		Persist: &persist.Persist{
+			PrivateNodeKey: nodePriv,
+			NetworkLockKey: nlPriv,
+		},
 	}).View()))
 	b := LocalBackend{
 		varRoot: temp,
@@ -151,15 +154,25 @@ func TestTKAEnablementFlow(t *testing.T) {
 func TestTKADisablementFlow(t *testing.T) {
 	envknob.Setenv("TAILSCALE_USE_WIP_CODE", "1")
 	defer envknob.Setenv("TAILSCALE_USE_WIP_CODE", "")
-	temp := t.TempDir()
-	os.Mkdir(filepath.Join(temp, "tka"), 0755)
 	nodePriv := key.NewNode()
 
 	// Make a fake TKA authority, to seed local state.
 	disablementSecret := bytes.Repeat([]byte{0xa5}, 32)
 	nlPriv := key.NewNLPrivate()
 	key := tka.Key{Kind: tka.Key25519, Public: nlPriv.Public().Verifier(), Votes: 2}
-	chonk, err := tka.ChonkDir(filepath.Join(temp, "tka"))
+
+	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
+	must.Do(pm.SetPrefs((&ipn.Prefs{
+		Persist: &persist.Persist{
+			PrivateNodeKey: nodePriv,
+			NetworkLockKey: nlPriv,
+		},
+	}).View()))
+
+	temp := t.TempDir()
+	tkaPath := filepath.Join(temp, "tka-profile", string(pm.CurrentProfile().ID))
+	os.Mkdir(tkaPath, 0755)
+	chonk, err := tka.ChonkDir(tkaPath)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -217,10 +230,6 @@ func TestTKADisablementFlow(t *testing.T) {
 	defer ts.Close()
 
 	cc := fakeControlClient(t, client)
-	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
-	must.Do(pm.SetPrefs((&ipn.Prefs{
-		Persist: &persist.Persist{PrivateNodeKey: nodePriv},
-	}).View()))
 	b := LocalBackend{
 		varRoot: temp,
 		cc:      cc,
@@ -260,7 +269,7 @@ func TestTKADisablementFlow(t *testing.T) {
 	if b.tka != nil {
 		t.Fatal("tka was not shut down")
 	}
-	if _, err := os.Stat(b.chonkPath()); err == nil || !os.IsNotExist(err) {
+	if _, err := os.Stat(b.chonkPathLocked()); err == nil || !os.IsNotExist(err) {
 		t.Errorf("os.Stat(chonkDir) = %v, want ErrNotExist", err)
 	}
 }
@@ -345,10 +354,15 @@ func TestTKASync(t *testing.T) {
 
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			temp := t.TempDir()
-			os.Mkdir(filepath.Join(temp, "tka"), 0755)
 			nodePriv := key.NewNode()
 			nlPriv := key.NewNLPrivate()
+			pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
+			must.Do(pm.SetPrefs((&ipn.Prefs{
+				Persist: &persist.Persist{
+					PrivateNodeKey: nodePriv,
+					NetworkLockKey: nlPriv,
+				},
+			}).View()))
 
 			// Setup the tka authority on the control plane.
 			key := tka.Key{Kind: tka.Key25519, Public: nlPriv.Public().Verifier(), Votes: 2}
@@ -366,8 +380,11 @@ func TestTKASync(t *testing.T) {
 				}
 			}
 
+			temp := t.TempDir()
+			tkaPath := filepath.Join(temp, "tka-profile", string(pm.CurrentProfile().ID))
+			os.Mkdir(tkaPath, 0755)
 			// Setup the TKA authority on the node.
-			nodeStorage, err := tka.ChonkDir(filepath.Join(temp, "tka"))
+			nodeStorage, err := tka.ChonkDir(tkaPath)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -467,10 +484,6 @@ func TestTKASync(t *testing.T) {
 
 			// Setup the client.
 			cc := fakeControlClient(t, client)
-			pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
-			must.Do(pm.SetPrefs((&ipn.Prefs{
-				Persist: &persist.Persist{PrivateNodeKey: nodePriv},
-			}).View()))
 			b := LocalBackend{
 				varRoot: temp,
 				cc:      cc,
@@ -564,15 +577,25 @@ func TestTKAFilterNetmap(t *testing.T) {
 func TestTKADisable(t *testing.T) {
 	envknob.Setenv("TAILSCALE_USE_WIP_CODE", "1")
 	defer envknob.Setenv("TAILSCALE_USE_WIP_CODE", "")
-	temp := t.TempDir()
-	os.Mkdir(filepath.Join(temp, "tka"), 0755)
 	nodePriv := key.NewNode()
 
 	// Make a fake TKA authority, to seed local state.
 	disablementSecret := bytes.Repeat([]byte{0xa5}, 32)
 	nlPriv := key.NewNLPrivate()
+
+	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
+	must.Do(pm.SetPrefs((&ipn.Prefs{
+		Persist: &persist.Persist{
+			PrivateNodeKey: nodePriv,
+			NetworkLockKey: nlPriv,
+		},
+	}).View()))
+
+	temp := t.TempDir()
+	tkaPath := filepath.Join(temp, "tka-profile", string(pm.CurrentProfile().ID))
+	os.Mkdir(tkaPath, 0755)
 	key := tka.Key{Kind: tka.Key25519, Public: nlPriv.Public().Verifier(), Votes: 2}
-	chonk, err := tka.ChonkDir(filepath.Join(temp, "tka"))
+	chonk, err := tka.ChonkDir(tkaPath)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -623,17 +646,13 @@ func TestTKADisable(t *testing.T) {
 	defer ts.Close()
 
 	cc := fakeControlClient(t, client)
-	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
-	must.Do(pm.SetPrefs((&ipn.Prefs{
-		Persist: &persist.Persist{PrivateNodeKey: nodePriv},
-	}).View()))
-
 	b := LocalBackend{
 		varRoot: temp,
 		cc:      cc,
 		ccAuto:  cc,
 		logf:    t.Logf,
 		tka: &tkaState{
+			profile:   pm.CurrentProfile().ID,
 			authority: authority,
 			storage:   chonk,
 		},
@@ -653,16 +672,26 @@ func TestTKADisable(t *testing.T) {
 func TestTKASign(t *testing.T) {
 	envknob.Setenv("TAILSCALE_USE_WIP_CODE", "1")
 	defer envknob.Setenv("TAILSCALE_USE_WIP_CODE", "")
-	temp := t.TempDir()
-	os.Mkdir(filepath.Join(temp, "tka"), 0755)
 	nodePriv := key.NewNode()
 	toSign := key.NewNode()
+	nlPriv := key.NewNLPrivate()
+
+	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
+	must.Do(pm.SetPrefs((&ipn.Prefs{
+		Persist: &persist.Persist{
+			PrivateNodeKey: nodePriv,
+			NetworkLockKey: nlPriv,
+		},
+	}).View()))
 
 	// Make a fake TKA authority, to seed local state.
 	disablementSecret := bytes.Repeat([]byte{0xa5}, 32)
-	nlPriv := key.NewNLPrivate()
 	key := tka.Key{Kind: tka.Key25519, Public: nlPriv.Public().Verifier(), Votes: 2}
-	chonk, err := tka.ChonkDir(filepath.Join(temp, "tka"))
+
+	temp := t.TempDir()
+	tkaPath := filepath.Join(temp, "tka-profile", string(pm.CurrentProfile().ID))
+	os.Mkdir(tkaPath, 0755)
+	chonk, err := tka.ChonkDir(tkaPath)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -709,10 +738,6 @@ func TestTKASign(t *testing.T) {
 		}
 	}))
 	defer ts.Close()
-	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ""))
-	must.Do(pm.SetPrefs((&ipn.Prefs{
-		Persist: &persist.Persist{PrivateNodeKey: nodePriv},
-	}).View()))
 	cc := fakeControlClient(t, client)
 	b := LocalBackend{
 		varRoot: temp,
@@ -725,7 +750,6 @@ func TestTKASign(t *testing.T) {
 		},
 		pm:    pm,
 		store: pm.Store(),
-		nlPrivKey: nlPriv,
 	}
 
 	if err := b.NetworkLockSign(toSign.Public(), nil); err != nil {

ipn/ipnlocal/profiles.go

@@ -252,8 +252,8 @@ func (pm *profileManager) loadSavedPrefs(key ipn.StateKey) (ipn.PrefsView, error
 	return savedPrefs.View(), nil
 }
 
-// CurrentProfile returns the name and ID of the current profile, or "" if the profile
+// CurrentProfile returns the current LoginProfile.
-// is not named.
+// The value may be zero if the profile is not persisted.
 func (pm *profileManager) CurrentProfile() ipn.LoginProfile {
 	return *pm.currentProfile
 }

ipn/ipnserver/server.go

@@ -42,7 +42,6 @@ import (
 	"tailscale.com/net/tsdial"
 	"tailscale.com/safesocket"
 	"tailscale.com/smallzstd"
-	"tailscale.com/tka"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/groupmember"
 	"tailscale.com/util/pidowner"
@@ -751,24 +750,7 @@ func New(logf logger.Logf, logid string, store ipn.StateStore, eng wgengine.Engi
 	})
 
 	if root := b.TailscaleVarRoot(); root != "" {
-		chonkDir := filepath.Join(root, "tka")
-		if _, err := os.Stat(chonkDir); err == nil {
-			// The directory exists, which means network-lock has been initialized.
-			storage, err := tka.ChonkDir(chonkDir)
-			if err != nil {
-				return nil, fmt.Errorf("opening tailchonk: %v", err)
-			}
-			authority, err := tka.Open(storage)
-			if err != nil {
-				return nil, fmt.Errorf("initializing tka: %v", err)
-			}
-			b.SetTailnetKeyAuthority(authority, storage)
-			logf("tka initialized at head %x", authority.Head())
-		}
-
 		dnsfallback.SetCachePath(filepath.Join(root, "derpmap.cached.json"))
-	} else {
-		logf("network-lock unavailable; no state directory")
 	}
 
 	dg := distro.Get()

ipn/ipnstate/ipnstate.go

@@ -86,6 +86,7 @@ type NetworkLockStatus struct {
 	Head *[32]byte
 
 	// PublicKey describes the node's network-lock public key.
+	// It may be zero if the node has not logged in.
 	PublicKey key.NLPublic
 
 	// NodeKey describes the node's current node-key. This field is not

types/key/nl.go

@@ -60,6 +60,11 @@ func (k NLPrivate) MarshalText() ([]byte, error) {
 	return toHex(k.k[:], nlPrivateHexPrefix), nil
 }
 
+// Equal reports whether k and other are the same key.
+func (k NLPrivate) Equal(other NLPrivate) bool {
+	return subtle.ConstantTimeCompare(k.k[:], other.k[:]) == 1
+}
+
 // Public returns the public component of this key.
 func (k NLPrivate) Public() NLPublic {
 	var out NLPublic

types/persist/persist.go

@@ -16,7 +16,8 @@ import (
 //go:generate go run tailscale.com/cmd/viewer -type=Persist
 
 // Persist is the JSON type stored on disk on nodes to remember their
-// settings between runs.
+// settings between runs. This is stored as part of ipn.Prefs and is
+// persisted per ipn.LoginProfile.
 type Persist struct {
 	_ structs.Incomparable
 
@@ -36,6 +37,7 @@ type Persist struct {
 	Provider          string
 	LoginName         string
 	UserProfile       tailcfg.UserProfile
+	NetworkLockKey    key.NLPrivate
 }
 
 // PublicNodeKey returns the public key for the node key.
@@ -65,7 +67,8 @@ func (p *Persist) Equals(p2 *Persist) bool {
 		p.OldPrivateNodeKey.Equal(p2.OldPrivateNodeKey) &&
 		p.Provider == p2.Provider &&
 		p.LoginName == p2.LoginName &&
-		p.UserProfile == p2.UserProfile
+		p.UserProfile == p2.UserProfile &&
+		p.NetworkLockKey.Equal(p2.NetworkLockKey)
 }
 
 func (p *Persist) Pretty() string {

types/persist/persist_clone.go

@@ -32,4 +32,5 @@ var _PersistCloneNeedsRegeneration = Persist(struct {
 	Provider                        string
 	LoginName                       string
 	UserProfile                     tailcfg.UserProfile
+	NetworkLockKey                  key.NLPrivate
 }{})

types/persist/persist_test.go

@@ -22,7 +22,7 @@ func fieldsOf(t reflect.Type) (fields []string) {
 }
 
 func TestPersistEqual(t *testing.T) {
-	persistHandles := []string{"LegacyFrontendPrivateMachineKey", "PrivateNodeKey", "OldPrivateNodeKey", "Provider", "LoginName", "UserProfile"}
+	persistHandles := []string{"LegacyFrontendPrivateMachineKey", "PrivateNodeKey", "OldPrivateNodeKey", "Provider", "LoginName", "UserProfile", "NetworkLockKey"}
 	if have := fieldsOf(reflect.TypeOf(Persist{})); !reflect.DeepEqual(have, persistHandles) {
 		t.Errorf("Persist.Equal check might be out of sync\nfields: %q\nhandled: %q\n",
 			have, persistHandles)
@@ -30,6 +30,7 @@ func TestPersistEqual(t *testing.T) {
 
 	m1 := key.NewMachine()
 	k1 := key.NewNode()
+	nl1 := key.NewNLPrivate()
 	tests := []struct {
 		a, b *Persist
 		want bool
@@ -112,6 +113,16 @@ func TestPersistEqual(t *testing.T) {
 			}},
 			false,
 		},
+		{
+			&Persist{NetworkLockKey: nl1},
+			&Persist{NetworkLockKey: nl1},
+			true,
+		},
+		{
+			&Persist{NetworkLockKey: nl1},
+			&Persist{NetworkLockKey: key.NewNLPrivate()},
+			false,
+		},
 	}
 	for i, test := range tests {
 		if got := test.a.Equals(test.b); got != test.want {

types/persist/persist_view.go

@@ -70,6 +70,7 @@ func (v PersistView) OldPrivateNodeKey() key.NodePrivate { return v.ж.OldPrivat
 func (v PersistView) Provider() string                   { return v.ж.Provider }
 func (v PersistView) LoginName() string                  { return v.ж.LoginName }
 func (v PersistView) UserProfile() tailcfg.UserProfile   { return v.ж.UserProfile }
+func (v PersistView) NetworkLockKey() key.NLPrivate      { return v.ж.NetworkLockKey }
 
 // A compilation failure here means this code must be regenerated, with the command at the top of this file.
 var _PersistViewNeedsRegeneration = Persist(struct {
@@ -80,4 +81,5 @@ var _PersistViewNeedsRegeneration = Persist(struct {
 	Provider                        string
 	LoginName                       string
 	UserProfile                     tailcfg.UserProfile
+	NetworkLockKey                  key.NLPrivate
 }{})