Add registration handler over Noise protocol

app.go

@@ -466,7 +466,7 @@ func (h *Headscale) createRouter(grpcMux *runtime.ServeMux) *mux.Router {
 func (h *Headscale) createNoiseMux() *mux.Router {
 	router := mux.NewRouter()
 
-	//router.HandleFunc("/machine/register", h.NoiseRegistrationHandler).Methods(http.MethodPost)
+	router.HandleFunc("/machine/register", h.NoiseRegistrationHandler).Methods(http.MethodPost)
 	//router.HandleFunc("/machine/map", h.NoisePollNetMapHandler).Methods(http.MethodPost)
 
 	return router

noise_api.go

@@ -0,0 +1,427 @@
+package headscale
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog/log"
+	"gorm.io/gorm"
+	"tailscale.com/tailcfg"
+)
+
+// // NoiseRegistrationHandler handles the actual registration process of a machine
+func (h *Headscale) NoiseRegistrationHandler(
+	writer http.ResponseWriter,
+	req *http.Request,
+) {
+	log.Trace().Caller().Msgf("Noise registration handler for client %s", req.RemoteAddr)
+	if req.Method != http.MethodPost {
+		http.Error(writer, "Wrong method", http.StatusMethodNotAllowed)
+		return
+	}
+	body, _ := io.ReadAll(req.Body)
+	registerRequest := tailcfg.RegisterRequest{}
+	if err := json.Unmarshal(body, &registerRequest); err != nil {
+		log.Error().
+			Caller().
+			Err(err).
+			Msg("Cannot parse RegisterRequest")
+		machineRegistrations.WithLabelValues("unknown", "web", "error", "unknown").Inc()
+		http.Error(writer, "Internal error", http.StatusInternalServerError)
+
+		return
+	}
+
+	log.Trace().Caller().
+		Str("node_key", registerRequest.NodeKey.ShortString()).
+		Str("old_node_key", registerRequest.OldNodeKey.ShortString()).
+		Msg("New node is registering")
+
+	now := time.Now().UTC()
+	machine, err := h.GetMachineByAnyNodeKey(registerRequest.NodeKey, registerRequest.OldNodeKey)
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		// If the machine has AuthKey set, handle registration via PreAuthKeys
+		if registerRequest.Auth.AuthKey != "" {
+			h.handleNoiseAuthKey(writer, req, registerRequest)
+
+			return
+		}
+
+		// Check if the node is waiting for interactive login.
+		//
+		// TODO(juan): We could use this field to improve our protocol implementation,
+		// and hold the request until the client closes it, or the interactive
+		// login is completed (i.e., the user registers the machine).
+		// This is not implemented yet, as it is no strictly required. The only side-effect
+		// is that the client will hammer headscale with requests until it gets a
+		// successful RegisterResponse.
+		if registerRequest.Followup != "" {
+			if _, ok := h.registrationCache.Get(NodePublicKeyStripPrefix(registerRequest.NodeKey)); ok {
+				log.Debug().
+					Caller().
+					Str("machine", registerRequest.Hostinfo.Hostname).
+					Str("node_key", registerRequest.NodeKey.ShortString()).
+					Str("node_key_old", registerRequest.OldNodeKey.ShortString()).
+					Str("follow_up", registerRequest.Followup).
+					Msg("Machine is waiting for interactive login")
+
+				ticker := time.NewTicker(registrationHoldoff)
+				select {
+				case <-req.Context().Done():
+					return
+				case <-ticker.C:
+					h.handleNoiseMachineRegistrationNew(writer, req, registerRequest)
+
+					return
+				}
+			}
+		}
+
+		log.Info().
+			Caller().
+			Str("machine", registerRequest.Hostinfo.Hostname).
+			Str("node_key", registerRequest.NodeKey.ShortString()).
+			Str("node_key_old", registerRequest.OldNodeKey.ShortString()).
+			Str("follow_up", registerRequest.Followup).
+			Msg("New Noise machine not yet in the database")
+
+		givenName, err := h.GenerateGivenName(registerRequest.Hostinfo.Hostname)
+		if err != nil {
+			log.Error().
+				Caller().
+				Str("func", "RegistrationHandler").
+				Str("hostinfo.name", registerRequest.Hostinfo.Hostname).
+				Err(err)
+
+			return
+		}
+
+		// The machine did not have a key to authenticate, which means
+		// that we rely on a method that calls back some how (OpenID or CLI)
+		// We create the machine and then keep it around until a callback
+		// happens
+		newMachine := Machine{
+			MachineKey: "",
+			Hostname:   registerRequest.Hostinfo.Hostname,
+			GivenName:  givenName,
+			NodeKey:    NodePublicKeyStripPrefix(registerRequest.NodeKey),
+			LastSeen:   &now,
+			Expiry:     &time.Time{},
+		}
+
+		if !registerRequest.Expiry.IsZero() {
+			log.Trace().
+				Caller().
+				Str("machine", registerRequest.Hostinfo.Hostname).
+				Time("expiry", registerRequest.Expiry).
+				Msg("Non-zero expiry time requested")
+			newMachine.Expiry = &registerRequest.Expiry
+		}
+
+		h.registrationCache.Set(
+			NodePublicKeyStripPrefix(registerRequest.NodeKey),
+			newMachine,
+			registerCacheExpiration,
+		)
+
+		h.handleNoiseMachineRegistrationNew(writer, req, registerRequest)
+
+		return
+	}
+
+	// The machine is already registered, so we need to pass through reauth or key update.
+	if machine != nil {
+		// If the NodeKey stored in headscale is the same as the key presented in a registration
+		// request, then we have a node that is either:
+		// - Trying to log out (sending a expiry in the past)
+		// - A valid, registered machine, looking for the node map
+		// - Expired machine wanting to reauthenticate
+		if machine.NodeKey == NodePublicKeyStripPrefix(registerRequest.NodeKey) {
+			// The client sends an Expiry in the past if the client is requesting to expire the key (aka logout)
+			//   https://github.com/tailscale/tailscale/blob/main/tailcfg/tailcfg.go#L648
+			if !registerRequest.Expiry.IsZero() && registerRequest.Expiry.UTC().Before(now) {
+				h.handleNoiseNodeLogOut(writer, req, *machine)
+
+				return
+			}
+
+			// If machine is not expired, and is register, we have a already accepted this machine,
+			// let it proceed with a valid registration
+			if !machine.isExpired() {
+				h.handleNoiseNodeValidRegistration(writer, req, *machine)
+
+				return
+			}
+		}
+
+		// The NodeKey we have matches OldNodeKey, which means this is a refresh after a key expiration
+		if machine.NodeKey == NodePublicKeyStripPrefix(registerRequest.OldNodeKey) &&
+			!machine.isExpired() {
+			h.handleNoiseNodeRefreshKey(writer, req, registerRequest, *machine)
+
+			return
+		}
+
+		// The node has expired
+		h.handleNoiseNodeExpired(writer, req, registerRequest, *machine)
+
+		return
+	}
+}
+
+func (h *Headscale) handleNoiseAuthKey(
+	w http.ResponseWriter,
+	r *http.Request,
+	registerRequest tailcfg.RegisterRequest,
+) {
+	log.Debug().
+		Caller().
+		Str("machine", registerRequest.Hostinfo.Hostname).
+		Msgf("Processing auth key for %s over Noise", registerRequest.Hostinfo.Hostname)
+	resp := tailcfg.RegisterResponse{}
+
+	pak, err := h.checkKeyValidity(registerRequest.Auth.AuthKey)
+	if err != nil {
+		log.Error().
+			Caller().
+			Str("machine", registerRequest.Hostinfo.Hostname).
+			Err(err).
+			Msg("Failed authentication via AuthKey")
+		resp.MachineAuthorized = false
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusUnauthorized)
+		json.NewEncoder(w).Encode(resp)
+
+		log.Error().
+			Caller().
+			Str("machine", registerRequest.Hostinfo.Hostname).
+			Msg("Failed authentication via AuthKey over Noise")
+
+		if pak != nil {
+			machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
+				Inc()
+		} else {
+			machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", "unknown").Inc()
+		}
+
+		return
+	}
+
+	log.Debug().
+		Caller().
+		Str("machine", registerRequest.Hostinfo.Hostname).
+		Msg("Authentication key was valid, proceeding to acquire IP addresses")
+
+	nodeKey := NodePublicKeyStripPrefix(registerRequest.NodeKey)
+
+	// retrieve machine information if it exist
+	// The error is not important, because if it does not
+	// exist, then this is a new machine and we will move
+	// on to registration.
+	machine, _ := h.GetMachineByAnyNodeKey(registerRequest.NodeKey, registerRequest.OldNodeKey)
+	if machine != nil {
+		log.Trace().
+			Caller().
+			Str("machine", machine.Hostname).
+			Msg("machine already registered, refreshing with new auth key")
+
+		machine.NodeKey = nodeKey
+		machine.AuthKeyID = uint(pak.ID)
+		h.RefreshMachine(machine, registerRequest.Expiry)
+	} else {
+		now := time.Now().UTC()
+
+		givenName, err := h.GenerateGivenName(registerRequest.Hostinfo.Hostname)
+		if err != nil {
+			log.Error().
+				Caller().
+				Str("func", "RegistrationHandler").
+				Str("hostinfo.name", registerRequest.Hostinfo.Hostname).
+				Err(err)
+
+			return
+		}
+
+		machineToRegister := Machine{
+			Hostname:       registerRequest.Hostinfo.Hostname,
+			GivenName:      givenName,
+			NamespaceID:    pak.Namespace.ID,
+			MachineKey:     "",
+			RegisterMethod: RegisterMethodAuthKey,
+			Expiry:         &registerRequest.Expiry,
+			NodeKey:        nodeKey,
+			LastSeen:       &now,
+			AuthKeyID:      uint(pak.ID),
+		}
+
+		machine, err = h.RegisterMachine(
+			machineToRegister,
+		)
+		if err != nil {
+			log.Error().
+				Caller().
+				Err(err).
+				Msg("could not register machine")
+			machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
+				Inc()
+			http.Error(w, "Internal error", http.StatusInternalServerError)
+
+			return
+		}
+	}
+
+	h.UsePreAuthKey(pak)
+
+	resp.MachineAuthorized = true
+	resp.User = *pak.Namespace.toUser()
+
+	machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "success", pak.Namespace.Name).
+		Inc()
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+
+	log.Info().
+		Caller().
+		Str("machine", registerRequest.Hostinfo.Hostname).
+		Str("ips", strings.Join(machine.IPAddresses.ToStringSlice(), ", ")).
+		Msg("Successfully authenticated via AuthKey on Noise")
+}
+
+func (h *Headscale) handleNoiseNodeValidRegistration(
+	w http.ResponseWriter,
+	r *http.Request,
+	machine Machine,
+) {
+	resp := tailcfg.RegisterResponse{}
+
+	// The machine registration is valid, respond with redirect to /map
+	log.Debug().
+		Str("machine", machine.Hostname).
+		Msg("Client is registered and we have the current NodeKey. All clear to /map")
+
+	resp.AuthURL = ""
+	resp.MachineAuthorized = true
+	resp.User = *machine.Namespace.toUser()
+	resp.Login = *machine.Namespace.toLogin()
+
+	machineRegistrations.WithLabelValues("update", "web", "success", machine.Namespace.Name).
+		Inc()
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+}
+
+func (h *Headscale) handleNoiseMachineRegistrationNew(
+	w http.ResponseWriter,
+	r *http.Request,
+	registerRequest tailcfg.RegisterRequest,
+) {
+	resp := tailcfg.RegisterResponse{}
+
+	// The machine registration is new, redirect the client to the registration URL
+	log.Debug().
+		Str("machine", registerRequest.Hostinfo.Hostname).
+		Msg("The node is sending us a new NodeKey, sending auth url")
+	if h.cfg.OIDC.Issuer != "" {
+		resp.AuthURL = fmt.Sprintf(
+			"%s/oidc/register/%s",
+			strings.TrimSuffix(h.cfg.ServerURL, "/"),
+			NodePublicKeyStripPrefix(registerRequest.NodeKey),
+		)
+	} else {
+		resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
+			strings.TrimSuffix(h.cfg.ServerURL, "/"), NodePublicKeyStripPrefix(registerRequest.NodeKey))
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+}
+
+func (h *Headscale) handleNoiseNodeLogOut(
+	w http.ResponseWriter,
+	r *http.Request,
+	machine Machine,
+) {
+	resp := tailcfg.RegisterResponse{}
+
+	log.Info().
+		Str("machine", machine.Hostname).
+		Msg("Client requested logout")
+
+	h.ExpireMachine(&machine)
+
+	resp.AuthURL = ""
+	resp.MachineAuthorized = false
+	resp.User = *machine.Namespace.toUser()
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+}
+
+func (h *Headscale) handleNoiseNodeRefreshKey(
+	w http.ResponseWriter,
+	r *http.Request,
+	registerRequest tailcfg.RegisterRequest,
+	machine Machine,
+) {
+	resp := tailcfg.RegisterResponse{}
+
+	log.Debug().
+		Str("machine", machine.Hostname).
+		Msg("We have the OldNodeKey in the database. This is a key refresh")
+	machine.NodeKey = NodePublicKeyStripPrefix(registerRequest.NodeKey)
+	h.db.Save(&machine)
+
+	resp.AuthURL = ""
+	resp.User = *machine.Namespace.toUser()
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+}
+
+func (h *Headscale) handleNoiseNodeExpired(
+	w http.ResponseWriter,
+	r *http.Request,
+	registerRequest tailcfg.RegisterRequest,
+	machine Machine,
+) {
+	resp := tailcfg.RegisterResponse{}
+
+	// The client has registered before, but has expired
+	log.Debug().
+		Caller().
+		Str("machine", machine.Hostname).
+		Msg("Machine registration has expired. Sending a authurl to register")
+
+	if registerRequest.Auth.AuthKey != "" {
+		h.handleNoiseAuthKey(w, r, registerRequest)
+
+		return
+	}
+
+	if h.cfg.OIDC.Issuer != "" {
+		resp.AuthURL = fmt.Sprintf("%s/oidc/register/%s",
+			strings.TrimSuffix(h.cfg.ServerURL, "/"), machine.NodeKey)
+	} else {
+		resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
+			strings.TrimSuffix(h.cfg.ServerURL, "/"), machine.NodeKey)
+	}
+
+	machineRegistrations.WithLabelValues("reauth", "web", "success", machine.Namespace.Name).
+		Inc()
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(resp)
+}