cmd/tailscale,ipn: minor fixes to tailscale lock commands

* Fix broken add/remove key commands
 * Make lock status display whether the node is signed

Signed-off-by: Tom DNetto <tom@tailscale.com>

cmd/tailscale/cli/network-lock.go

@@ -82,11 +82,46 @@ func runNetworkLockStatus(ctx context.Context, args []string) error {
 	} else {
 		fmt.Println("Network-lock is NOT enabled.")
 	}
+	fmt.Println()
+
+	if st.Enabled && st.NodeKey != nil {
+		if st.NodeKeySigned {
+			fmt.Println("This node is trusted by network-lock.")
+		} else {
+			fmt.Println("This node IS NOT trusted by network-lock, and action is required to establish connectivity.")
+			fmt.Printf("Run the following command on a node with a network-lock key:\n\ttailscale lock sign %v\n", st.NodeKey)
+		}
+		fmt.Println()
+	}
+
 	p, err := st.PublicKey.MarshalText()
 	if err != nil {
 		return err
 	}
-	fmt.Printf("our public-key: %s\n", p)
+	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:")
+		for _, k := range st.TrustedKeys {
+			key, err := k.Key.MarshalText()
+			if err != nil {
+				return err
+			}
+
+			var line strings.Builder
+			line.WriteString("\t")
+			line.WriteString(string(key))
+			line.WriteString("\t")
+			line.WriteString(fmt.Sprint(k.Votes))
+			line.WriteString("\t")
+			if k.Key == st.PublicKey {
+				line.WriteString("(us)")
+			}
+			fmt.Println(line.String())
+		}
+	}
+
 	return nil
 }
 
@@ -143,8 +178,8 @@ func runNetworkLockModify(ctx context.Context, addArgs, removeArgs []string) err
 	if err != nil {
 		return fixTailscaledConnectError(err)
 	}
-	if st.Enabled {
+	if !st.Enabled {
-		return errors.New("network-lock is already enabled")
+		return errors.New("network-lock is not enabled")
 	}
 
 	addKeys, err := parseNLKeyArgs(addArgs)

ipn/ipnlocal/network-lock.go

@@ -329,10 +329,17 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
+	var nodeKey *key.NodePublic
+	if p := b.pm.CurrentPrefs(); p.Valid() {
+		nkp := p.Persist().PublicNodeKey()
+		nodeKey = &nkp
+	}
+
 	if b.tka == nil {
 		return &ipnstate.NetworkLockStatus{
 			Enabled:   false,
 			PublicKey: b.nlPrivKey.Public(),
+			NodeKey:   nodeKey,
 		}
 	}
 
@@ -340,10 +347,28 @@ func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
 	h := b.tka.authority.Head()
 	copy(head[:], h[:])
 
+	var selfAuthorized bool
+	if b.netMap != nil {
+		selfAuthorized = b.tka.authority.NodeKeyAuthorized(b.netMap.SelfNode.Key, b.netMap.SelfNode.KeySignature) == nil
+	}
+
+	keys := b.tka.authority.Keys()
+	outKeys := make([]ipnstate.TKAKey, len(keys))
+	for i, k := range keys {
+		outKeys[i] = ipnstate.TKAKey{
+			Key:      key.NLPublicFromEd25519Unsafe(k.Public),
+			Metadata: k.Meta,
+			Votes:    k.Votes,
+		}
+	}
+
 	return &ipnstate.NetworkLockStatus{
 		Enabled:       true,
 		Head:          &head,
 		PublicKey:     b.nlPrivKey.Public(),
+		NodeKey:       nodeKey,
+		NodeKeySigned: selfAuthorized,
+		TrustedKeys:   outKeys,
 	}
 }
 

ipn/ipnstate/ipnstate.go

@@ -67,6 +67,13 @@ type Status struct {
 	User map[tailcfg.UserID]tailcfg.UserProfile
 }
 
+// TKAKey describes a key trusted by network lock.
+type TKAKey struct {
+	Key      key.NLPublic
+	Metadata map[string]string
+	Votes    uint
+}
+
 // NetworkLockStatus represents whether network-lock is enabled,
 // along with details about the locally-known state of the tailnet
 // key authority.
@@ -78,8 +85,19 @@ type NetworkLockStatus struct {
 	// if network lock is not enabled.
 	Head *[32]byte
 
-	// PublicKey describes the nodes' network-lock public key.
+	// PublicKey describes the node's network-lock public key.
 	PublicKey key.NLPublic
+
+	// NodeKey describes the node's current node-key. This field is not
+	// populated if the node is not operating (i.e. waiting for a login).
+	NodeKey *key.NodePublic
+
+	// NodeKeySigned is true if our node is authorized by network-lock.
+	NodeKeySigned bool
+
+	// TrustedKeys describes the keys currently trusted to make changes
+	// to network-lock.
+	TrustedKeys []TKAKey
 }
 
 // TailnetStatus is information about a Tailscale network ("tailnet").

tka/key.go

@@ -85,6 +85,17 @@ func (k Key) ID() tkatype.KeyID {
 	}
 }
 
+// Ed25519 returns the ed25519 public key encoded by Key. An error is
+// returned for keys which do not represent ed25519 public keys.
+func (k Key) Ed25519() (ed25519.PublicKey, error) {
+	switch k.Kind {
+	case Key25519:
+		return ed25519.PublicKey(k.Public), nil
+	default:
+		return nil, fmt.Errorf("key is of type %v, not ed25519", k.Kind)
+	}
+}
+
 const maxMetaBytes = 512
 
 func (k Key) StaticValidate() error {

tka/tka.go

@@ -705,3 +705,12 @@ func (a *Authority) KeyTrusted(keyID tkatype.KeyID) bool {
 	_, err := a.state.GetKey(keyID)
 	return err == nil
 }
+
+// Keys returns the set of keys trusted by the tailnet key authority.
+func (a *Authority) Keys() []Key {
+	out := make([]Key, len(a.state.Keys))
+	for i := range a.state.Keys {
+		out[i] = a.state.Keys[i].Clone()
+	}
+	return out
+}

types/key/nl.go

@@ -100,6 +100,17 @@ type NLPublic struct {
 	k [ed25519.PublicKeySize]byte
 }
 
+// NLPublicFromEd25519Unsafe converts an ed25519 public key into
+// a type of NLPublic.
+//
+// New uses of this function should be avoided, as its possible to
+// accidentally construct an NLPublic from a non network-lock key.
+func NLPublicFromEd25519Unsafe(public ed25519.PublicKey) NLPublic {
+	var out NLPublic
+	copy(out.k[:], public)
+	return out
+}
+
 // MarshalText implements encoding.TextUnmarshaler.
 func (k *NLPublic) UnmarshalText(b []byte) error {
 	return parseHex(k.k[:], mem.B(b), mem.S(nlPublicHexPrefix))