ipn/ipnlocal,cmd/tailscale: minor improvements to lock modify command

* Do not print the status at the end of a successful operation
 * Ensure the key of the current node is actually trusted to make these changes

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

client/tailscale/localclient.go

@@ -805,7 +805,7 @@ func (lc *LocalClient) NetworkLockInit(ctx context.Context, keys []tka.Key, disa
 }
 
 // NetworkLockModify adds and/or removes key(s) to the tailnet key authority.
-func (lc *LocalClient) NetworkLockModify(ctx context.Context, addKeys, removeKeys []tka.Key) (*ipnstate.NetworkLockStatus, error) {
+func (lc *LocalClient) NetworkLockModify(ctx context.Context, addKeys, removeKeys []tka.Key) error {
 	var b bytes.Buffer
 	type modifyRequest struct {
 		AddKeys    []tka.Key
@@ -813,14 +813,13 @@ func (lc *LocalClient) NetworkLockModify(ctx context.Context, addKeys, removeKey
 	}
 
 	if err := json.NewEncoder(&b).Encode(modifyRequest{AddKeys: addKeys, RemoveKeys: removeKeys}); err != nil {
-		return nil, err
+		return err
 	}
 
-	body, err := lc.send(ctx, "POST", "/localapi/v0/tka/modify", 200, &b)
-	if err != nil {
-		return nil, fmt.Errorf("error: %w", err)
+	if _, err := lc.send(ctx, "POST", "/localapi/v0/tka/modify", 204, &b); err != nil {
+		return fmt.Errorf("error: %w", err)
 	}
-	return decodeJSON[*ipnstate.NetworkLockStatus](body)
+	return nil
 }
 
 // NetworkLockSign signs the specified node-key and transmits that signature to the control plane.

cmd/tailscale/cli/network-lock.go

@@ -28,7 +28,7 @@ var netlockCmd = &ffcli.Command{
 	Name:       "lock",
 	ShortUsage: "lock <sub-command> <arguments>",
 	ShortHelp:  "Manage tailnet lock",
-	LongHelp:  "Manage tailnet lock",
+	LongHelp:   "Manage tailnet lock",
 	Subcommands: []*ffcli.Command{
 		nlInitCmd,
 		nlStatusCmd,
@@ -155,7 +155,7 @@ var nlStatusCmd = &ffcli.Command{
 	Name:       "status",
 	ShortUsage: "status",
 	ShortHelp:  "Outputs the state of network lock",
-	LongHelp:  "Outputs the state of network lock",
+	LongHelp:   "Outputs the state of network lock",
 	Exec:       runNetworkLockStatus,
 }
 
@@ -229,7 +229,7 @@ var nlAddCmd = &ffcli.Command{
 	Name:       "add",
 	ShortUsage: "add <public-key>...",
 	ShortHelp:  "Adds one or more trusted signing keys to tailnet lock",
-	LongHelp:  "Adds one or more trusted signing keys to tailnet lock",
+	LongHelp:   "Adds one or more trusted signing keys to tailnet lock",
 	Exec: func(ctx context.Context, args []string) error {
 		return runNetworkLockModify(ctx, args, nil)
 	},
@@ -239,7 +239,7 @@ var nlRemoveCmd = &ffcli.Command{
 	Name:       "remove",
 	ShortUsage: "remove <public-key>...",
 	ShortHelp:  "Removes one or more trusted signing keys from tailnet lock",
-	LongHelp:  "Removes one or more trusted signing keys from tailnet lock",
+	LongHelp:   "Removes one or more trusted signing keys from tailnet lock",
 	Exec: func(ctx context.Context, args []string) error {
 		return runNetworkLockModify(ctx, nil, args)
 	},
@@ -310,12 +310,9 @@ func runNetworkLockModify(ctx context.Context, addArgs, removeArgs []string) err
 		return err
 	}
 
-	status, err := localClient.NetworkLockModify(ctx, addKeys, removeKeys)
-	if err != nil {
+	if err := localClient.NetworkLockModify(ctx, addKeys, removeKeys); err != nil {
 		return err
 	}
-
-	fmt.Printf("Status: %+v\n\n", status)
 	return nil
 }
 
@@ -323,7 +320,7 @@ var nlSignCmd = &ffcli.Command{
 	Name:       "sign",
 	ShortUsage: "sign <node-key> [<rotation-key>]",
 	ShortHelp:  "Signs a node key and transmits the signature to the coordination server",
-	LongHelp:  "Signs a node key and transmits the signature to the coordination server",
+	LongHelp:   "Signs a node key and transmits the signature to the coordination server",
 	Exec:       runNetworkLockSign,
 }
 
@@ -363,7 +360,7 @@ Once this secret is used, it has been distributed
 to all nodes in the tailnet and should be considered public.
 
 `),
-	Exec:       runNetworkLockDisable,
+	Exec: runNetworkLockDisable,
 }
 
 func runNetworkLockDisable(ctx context.Context, args []string) error {
@@ -392,7 +389,7 @@ that the current node will accept traffic from other nodes in the tailnet
 that are locked out.
 
 `),
-	Exec:       runNetworkLockLocalDisable,
+	Exec: runNetworkLockLocalDisable,
 }
 
 func runNetworkLockLocalDisable(ctx context.Context, args []string) error {
@@ -403,7 +400,7 @@ var nlDisablementKDFCmd = &ffcli.Command{
 	Name:       "disablement-kdf",
 	ShortUsage: "disablement-kdf <hex-encoded-disablement-secret>",
 	ShortHelp:  "Computes a disablement value from a disablement secret (advanced users only)",
-	LongHelp:  "Computes a disablement value from a disablement secret (advanced users only)",
+	LongHelp:   "Computes a disablement value from a disablement secret (advanced users only)",
 	Exec:       runNetworkLockDisablementKDF,
 }
 
@@ -427,7 +424,7 @@ var nlLogCmd = &ffcli.Command{
 	Name:       "log",
 	ShortUsage: "log [--limit N]",
 	ShortHelp:  "List changes applied to tailnet lock",
-	LongHelp:  "List changes applied to tailnet lock",
+	LongHelp:   "List changes applied to tailnet lock",
 	Exec:       runNetworkLockLog,
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("lock log")

ipn/ipnlocal/network-lock.go

@@ -654,6 +654,9 @@ func (b *LocalBackend) NetworkLockModify(addKeys, removeKeys []tka.Key) (err err
 	if b.tka == nil {
 		return errNetworkLockNotActive
 	}
+	if !b.tka.authority.KeyTrusted(nlPriv.KeyID()) {
+		return errors.New("this node does not have a trusted tailnet lock key")
+	}
 
 	updater := b.tka.authority.NewUpdater(nlPriv)
 

ipn/localapi/localapi.go

@@ -1254,14 +1254,7 @@ func (h *Handler) serveTKAModify(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "network-lock modify failed: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
-
-	j, err := json.MarshalIndent(h.b.NetworkLockStatus(), "", "\t")
-	if err != nil {
-		http.Error(w, "JSON encoding error", 500)
-		return
-	}
-	w.Header().Set("Content-Type", "application/json")
-	w.Write(j)
+	w.WriteHeader(204)
 }
 
 func (h *Handler) serveTKADisable(w http.ResponseWriter, r *http.Request) {