headscale/api.go
Kristoffer Dalby 5e92ddad43 Remove redundant caches
This commit removes the two extra caches (oidc, requested time) and uses
the new central registration cache instead. The requested time is
unified into the main machine object and the oidc key is just added to
the same cache, as a string with the state as a key instead of machine
key.
2022-02-28 22:42:30 +00:00

627 lines
16 KiB
Go

package headscale
import (
"bytes"
"encoding/binary"
"encoding/json"
"errors"
"fmt"
"html/template"
"io"
"net/http"
"strings"
"time"
"github.com/gin-gonic/gin"
"github.com/klauspost/compress/zstd"
"github.com/rs/zerolog/log"
"gorm.io/gorm"
"tailscale.com/tailcfg"
"tailscale.com/types/key"
)
const (
reservedResponseHeaderSize = 4
RegisterMethodAuthKey = "authkey"
RegisterMethodOIDC = "oidc"
RegisterMethodCLI = "cli"
ErrRegisterMethodCLIDoesNotSupportExpire = Error(
"machines registered with CLI does not support expire",
)
)
// KeyHandler provides the Headscale pub key
// Listens in /key.
func (h *Headscale) KeyHandler(ctx *gin.Context) {
ctx.Data(
http.StatusOK,
"text/plain; charset=utf-8",
[]byte(MachinePublicKeyStripPrefix(h.privateKey.Public())),
)
}
type registerWebAPITemplateConfig struct {
Key string
}
var registerWebAPITemplate = template.Must(
template.New("registerweb").Parse(`<html>
<body>
<h1>headscale</h1>
<p>
Run the command below in the headscale server to add this machine to your network:
</p>
<p>
<code>
<b>headscale -n NAMESPACE nodes register --key {{.Key}}</b>
</code>
</p>
</body>
</html>`),
)
// RegisterWebAPI shows a simple message in the browser to point to the CLI
// Listens in /register.
func (h *Headscale) RegisterWebAPI(ctx *gin.Context) {
machineKeyStr := ctx.Query("key")
if machineKeyStr == "" {
ctx.String(http.StatusBadRequest, "Wrong params")
return
}
var content bytes.Buffer
if err := registerWebAPITemplate.Execute(&content, registerWebAPITemplateConfig{
Key: machineKeyStr,
}); err != nil {
log.Error().
Str("func", "RegisterWebAPI").
Err(err).
Msg("Could not render register web API template")
ctx.Data(
http.StatusInternalServerError,
"text/html; charset=utf-8",
[]byte("Could not render register web API template"),
)
}
ctx.Data(http.StatusOK, "text/html; charset=utf-8", content.Bytes())
}
// RegistrationHandler handles the actual registration process of a machine
// Endpoint /machine/:id.
func (h *Headscale) RegistrationHandler(ctx *gin.Context) {
body, _ := io.ReadAll(ctx.Request.Body)
machineKeyStr := ctx.Param("id")
var machineKey key.MachinePublic
err := machineKey.UnmarshalText([]byte(MachinePublicKeyEnsurePrefix(machineKeyStr)))
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot parse machine key")
machineRegistrations.WithLabelValues("unknown", "web", "error", "unknown").Inc()
ctx.String(http.StatusInternalServerError, "Sad!")
return
}
req := tailcfg.RegisterRequest{}
err = decode(body, &req, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot decode message")
machineRegistrations.WithLabelValues("unknown", "web", "error", "unknown").Inc()
ctx.String(http.StatusInternalServerError, "Very sad!")
return
}
now := time.Now().UTC()
machine, err := h.GetMachineByMachineKey(machineKey)
if errors.Is(err, gorm.ErrRecordNotFound) {
log.Info().Str("machine", req.Hostinfo.Hostname).Msg("New machine")
machineKeyStr := MachinePublicKeyStripPrefix(machineKey)
// If the machine has AuthKey set, handle registration via PreAuthKeys
if req.Auth.AuthKey != "" {
h.handleAuthKey(ctx, machineKey, req)
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: machineKeyStr,
Name: req.Hostinfo.Hostname,
NodeKey: NodePublicKeyStripPrefix(req.NodeKey),
LastSeen: &now,
}
if !req.Expiry.IsZero() {
log.Trace().
Caller().
Str("machine", req.Hostinfo.Hostname).
Time("expiry", req.Expiry).
Msg("Non-zero expiry time requested")
newMachine.Expiry = &req.Expiry
}
h.registrationCache.Set(
machineKeyStr,
newMachine,
registerCacheExpiration,
)
h.handleMachineRegistrationNew(ctx, machineKey, req)
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(req.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 !req.Expiry.IsZero() && req.Expiry.UTC().Before(now) {
h.handleMachineLogOut(ctx, machineKey, *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.handleMachineValidRegistration(ctx, machineKey, *machine)
return
}
}
// The NodeKey we have matches OldNodeKey, which means this is a refresh after a key expiration
if machine.NodeKey == NodePublicKeyStripPrefix(req.OldNodeKey) &&
!machine.isExpired() {
h.handleMachineRefreshKey(ctx, machineKey, req, *machine)
return
}
// The machine has expired
h.handleMachineExpired(ctx, machineKey, req, *machine)
return
}
}
func (h *Headscale) getMapResponse(
machineKey key.MachinePublic,
req tailcfg.MapRequest,
machine *Machine,
) ([]byte, error) {
log.Trace().
Str("func", "getMapResponse").
Str("machine", req.Hostinfo.Hostname).
Msg("Creating Map response")
node, err := machine.toNode(h.cfg.BaseDomain, h.cfg.DNSConfig, true)
if err != nil {
log.Error().
Caller().
Str("func", "getMapResponse").
Err(err).
Msg("Cannot convert to node")
return nil, err
}
peers, err := h.getValidPeers(machine)
if err != nil {
log.Error().
Caller().
Str("func", "getMapResponse").
Err(err).
Msg("Cannot fetch peers")
return nil, err
}
profiles := getMapResponseUserProfiles(*machine, peers)
nodePeers, err := peers.toNodes(h.cfg.BaseDomain, h.cfg.DNSConfig, true)
if err != nil {
log.Error().
Caller().
Str("func", "getMapResponse").
Err(err).
Msg("Failed to convert peers to Tailscale nodes")
return nil, err
}
dnsConfig := getMapResponseDNSConfig(
h.cfg.DNSConfig,
h.cfg.BaseDomain,
*machine,
peers,
)
resp := tailcfg.MapResponse{
KeepAlive: false,
Node: node,
Peers: nodePeers,
DNSConfig: dnsConfig,
Domain: h.cfg.BaseDomain,
PacketFilter: h.aclRules,
DERPMap: h.DERPMap,
UserProfiles: profiles,
}
log.Trace().
Str("func", "getMapResponse").
Str("machine", req.Hostinfo.Hostname).
// Interface("payload", resp).
Msgf("Generated map response: %s", tailMapResponseToString(resp))
var respBody []byte
if req.Compress == "zstd" {
src, err := json.Marshal(resp)
if err != nil {
log.Error().
Caller().
Str("func", "getMapResponse").
Err(err).
Msg("Failed to marshal response for the client")
return nil, err
}
encoder, _ := zstd.NewWriter(nil)
srcCompressed := encoder.EncodeAll(src, nil)
respBody = h.privateKey.SealTo(machineKey, srcCompressed)
} else {
respBody, err = encode(resp, &machineKey, h.privateKey)
if err != nil {
return nil, err
}
}
// declare the incoming size on the first 4 bytes
data := make([]byte, reservedResponseHeaderSize)
binary.LittleEndian.PutUint32(data, uint32(len(respBody)))
data = append(data, respBody...)
return data, nil
}
func (h *Headscale) getMapKeepAliveResponse(
machineKey key.MachinePublic,
mapRequest tailcfg.MapRequest,
) ([]byte, error) {
mapResponse := tailcfg.MapResponse{
KeepAlive: true,
}
var respBody []byte
var err error
if mapRequest.Compress == "zstd" {
src, err := json.Marshal(mapResponse)
if err != nil {
log.Error().
Caller().
Str("func", "getMapKeepAliveResponse").
Err(err).
Msg("Failed to marshal keepalive response for the client")
return nil, err
}
encoder, _ := zstd.NewWriter(nil)
srcCompressed := encoder.EncodeAll(src, nil)
respBody = h.privateKey.SealTo(machineKey, srcCompressed)
} else {
respBody, err = encode(mapResponse, &machineKey, h.privateKey)
if err != nil {
return nil, err
}
}
data := make([]byte, reservedResponseHeaderSize)
binary.LittleEndian.PutUint32(data, uint32(len(respBody)))
data = append(data, respBody...)
return data, nil
}
func (h *Headscale) handleMachineLogOut(
ctx *gin.Context,
machineKey key.MachinePublic,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
log.Info().
Str("machine", machine.Name).
Msg("Client requested logout")
h.ExpireMachine(&machine)
resp.AuthURL = ""
resp.MachineAuthorized = false
resp.User = *machine.Namespace.toUser()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
ctx.String(http.StatusInternalServerError, "")
return
}
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
}
func (h *Headscale) handleMachineValidRegistration(
ctx *gin.Context,
machineKey key.MachinePublic,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
// The machine registration is valid, respond with redirect to /map
log.Debug().
Str("machine", machine.Name).
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()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("update", "web", "error", machine.Namespace.Name).
Inc()
ctx.String(http.StatusInternalServerError, "")
return
}
machineRegistrations.WithLabelValues("update", "web", "success", machine.Namespace.Name).
Inc()
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
}
func (h *Headscale) handleMachineExpired(
ctx *gin.Context,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
// The client has registered before, but has expired
log.Debug().
Str("machine", machine.Name).
Msg("Machine registration has expired. Sending a authurl to register")
if registerRequest.Auth.AuthKey != "" {
h.handleAuthKey(ctx, machineKey, registerRequest)
return
}
if h.cfg.OIDC.Issuer != "" {
resp.AuthURL = fmt.Sprintf("%s/oidc/register/%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"), machineKey.String())
} else {
resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"), machineKey.String())
}
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("reauth", "web", "error", machine.Namespace.Name).
Inc()
ctx.String(http.StatusInternalServerError, "")
return
}
machineRegistrations.WithLabelValues("reauth", "web", "success", machine.Namespace.Name).
Inc()
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
}
func (h *Headscale) handleMachineRefreshKey(
ctx *gin.Context,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
log.Debug().
Str("machine", machine.Name).
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()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
ctx.String(http.StatusInternalServerError, "Extremely sad!")
return
}
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
}
func (h *Headscale) handleMachineRegistrationNew(
ctx *gin.Context,
machineKey key.MachinePublic,
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, "/"),
machineKey.String(),
)
} else {
resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
strings.TrimSuffix(h.cfg.ServerURL, "/"), MachinePublicKeyStripPrefix(machineKey))
}
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Err(err).
Msg("Cannot encode message")
ctx.String(http.StatusInternalServerError, "")
return
}
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
}
// TODO: check if any locks are needed around IP allocation.
func (h *Headscale) handleAuthKey(
ctx *gin.Context,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
) {
machineKeyStr := MachinePublicKeyStripPrefix(machineKey)
log.Debug().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msgf("Processing auth key for %s", registerRequest.Hostinfo.Hostname)
resp := tailcfg.RegisterResponse{}
pak, err := h.checkKeyValidity(registerRequest.Auth.AuthKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Failed authentication via AuthKey")
resp.MachineAuthorized = false
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Cannot encode message")
ctx.String(http.StatusInternalServerError, "")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
return
}
ctx.Data(http.StatusUnauthorized, "application/json; charset=utf-8", respBody)
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msg("Failed authentication via AuthKey")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
return
}
log.Debug().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Msg("Authentication key was valid, proceeding to acquire IP addresses")
nodeKey := NodePublicKeyStripPrefix(registerRequest.NodeKey)
now := time.Now().UTC()
machineToRegister := Machine{
Name: registerRequest.Hostinfo.Hostname,
NamespaceID: pak.Namespace.ID,
MachineKey: machineKeyStr,
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()
ctx.String(
http.StatusInternalServerError,
"could not register machine",
)
return
}
h.UsePreAuthKey(pak)
resp.MachineAuthorized = true
resp.User = *pak.Namespace.toUser()
respBody, err := encode(resp, &machineKey, h.privateKey)
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "error", pak.Namespace.Name).
Inc()
ctx.String(http.StatusInternalServerError, "Extremely sad!")
return
}
machineRegistrations.WithLabelValues("new", RegisterMethodAuthKey, "success", pak.Namespace.Name).
Inc()
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
log.Info().
Str("func", "handleAuthKey").
Str("machine", registerRequest.Hostinfo.Hostname).
Str("ips", strings.Join(machine.IPAddresses.ToStringSlice(), ", ")).
Msg("Successfully authenticated via AuthKey")
}