headscale/api.go
Kristoffer Dalby cfd53bc4aa Factor wgkey to types/key
This commit converts all the uses of wgkey to the new key interfaces.

It now has specific  machine, node and discovery keys and we now should
use them correctly.

Please note the new logic which strips a key prefix (in utils.go) that
is now standard inside tailscale.

In theory we could put it in the database, but to preserve backwards
compatibility and not spend a lot of resources on accounting for both,
we just strip them.
2021-11-26 23:30:42 +00:00

593 lines
15 KiB
Go

package headscale
import (
"encoding/binary"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"strings"
"time"
"github.com/gin-gonic/gin"
"github.com/klauspost/compress/zstd"
"github.com/rs/zerolog/log"
"go4.org/mem"
"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.publicKey)),
)
}
// 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
}
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(fmt.Sprintf(`
<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 %s</b>
</code>
</p>
</body>
</html>
`, machineKeyStr)))
}
// 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")
machineKey, err := key.ParseMachinePublicUntyped(mem.S(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")
newMachine := Machine{
Expiry: &time.Time{},
MachineKey: MachinePublicKeyStripPrefix(machineKey),
Name: req.Hostinfo.Hostname,
}
if err := h.db.Create(&newMachine).Error; err != nil {
log.Error().
Caller().
Err(err).
Msg("Could not create row")
machineRegistrations.WithLabelValues("unknown", "web", "error", machine.Namespace.Name).
Inc()
return
}
machine = &newMachine
}
if machine.Registered {
// 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 == req.NodeKey.String() {
// 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 == req.OldNodeKey.String() &&
!machine.isExpired() {
h.handleMachineRefreshKey(ctx, machineKey, req, *machine)
return
}
// The machine has expired
h.handleMachineExpired(ctx, machineKey, req, *machine)
return
}
// If the machine has AuthKey set, handle registration via PreAuthKeys
if req.Auth.AuthKey != "" {
h.handleAuthKey(ctx, machineKey, req, *machine)
return
}
h.handleMachineRegistrationNew(ctx, machineKey, req, *machine)
}
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, _ := json.Marshal(resp)
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, _ := json.Marshal(mapResponse)
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, machine)
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,
machine Machine,
) {
resp := tailcfg.RegisterResponse{}
// The machine registration is new, redirect the client to the registration URL
log.Debug().
Str("machine", machine.Name).
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))
}
if !registerRequest.Expiry.IsZero() {
log.Trace().
Caller().
Str("machine", machine.Name).
Time("expiry", registerRequest.Expiry).
Msg("Non-zero expiry time requested, adding to cache")
h.requestedExpiryCache.Set(
machineKey.String(),
registerRequest.Expiry,
requestedExpiryCacheExpiration,
)
}
machine.NodeKey = NodePublicKeyStripPrefix(registerRequest.NodeKey)
// save the NodeKey
h.db.Save(&machine)
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) handleAuthKey(
ctx *gin.Context,
machineKey key.MachinePublic,
registerRequest tailcfg.RegisterRequest,
machine Machine,
) {
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", machine.Name).
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", machine.Name).
Err(err).
Msg("Cannot encode message")
ctx.String(http.StatusInternalServerError, "")
machineRegistrations.WithLabelValues("new", "authkey", "error", machine.Namespace.Name).
Inc()
return
}
ctx.Data(http.StatusUnauthorized, "application/json; charset=utf-8", respBody)
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", machine.Name).
Msg("Failed authentication via AuthKey")
machineRegistrations.WithLabelValues("new", "authkey", "error", machine.Namespace.Name).
Inc()
return
}
if machine.isRegistered() {
log.Trace().
Caller().
Str("machine", machine.Name).
Msg("machine already registered, reauthenticating")
h.RefreshMachine(&machine, registerRequest.Expiry)
} else {
log.Debug().
Str("func", "handleAuthKey").
Str("machine", machine.Name).
Msg("Authentication key was valid, proceeding to acquire an IP address")
ip, err := h.getAvailableIP()
if err != nil {
log.Error().
Caller().
Str("func", "handleAuthKey").
Str("machine", machine.Name).
Msg("Failed to find an available IP")
machineRegistrations.WithLabelValues("new", "authkey", "error", machine.Namespace.Name).
Inc()
return
}
log.Info().
Str("func", "handleAuthKey").
Str("machine", machine.Name).
Str("ip", ip.String()).
Msgf("Assigning %s to %s", ip, machine.Name)
machine.Expiry = &registerRequest.Expiry
machine.AuthKeyID = uint(pak.ID)
machine.IPAddress = ip.String()
machine.NamespaceID = pak.NamespaceID
machine.NodeKey = NodePublicKeyStripPrefix(registerRequest.NodeKey)
// we update it just in case
machine.Registered = true
machine.RegisterMethod = RegisterMethodAuthKey
h.db.Save(&machine)
}
pak.Used = true
h.db.Save(&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", machine.Name).
Err(err).
Msg("Cannot encode message")
machineRegistrations.WithLabelValues("new", "authkey", "error", machine.Namespace.Name).
Inc()
ctx.String(http.StatusInternalServerError, "Extremely sad!")
return
}
machineRegistrations.WithLabelValues("new", "authkey", "success", machine.Namespace.Name).
Inc()
ctx.Data(http.StatusOK, "application/json; charset=utf-8", respBody)
log.Info().
Str("func", "handleAuthKey").
Str("machine", machine.Name).
Str("ip", machine.IPAddress).
Msg("Successfully authenticated via AuthKey")
}