use go-oidc instead of verifying and extracting tokens ourselves, rename oidc_endpoint to oidc_issuer to be more inline with spec

api.go

@@ -134,7 +134,7 @@ func (h *Headscale) RegistrationHandler(c *gin.Context) {
 			Str("machine", m.Name).
 			Msg("Not registered and not NodeKey rotation. Sending a authurl to register")
 
-		if h.cfg.OIDCEndpoint != "" {
+		if h.cfg.OIDCIssuer != "" {
 			resp.AuthURL = fmt.Sprintf("%s/oidc/register/%s", h.cfg.ServerURL, mKey.HexString())
 		} else {
 			resp.AuthURL = fmt.Sprintf("%s/register?key=%s",
@@ -204,7 +204,7 @@ func (h *Headscale) RegistrationHandler(c *gin.Context) {
 		Str("handler", "Registration").
 		Str("machine", m.Name).
 		Msg("The node is sending us a new NodeKey, sending auth url")
-	if h.cfg.OIDCEndpoint != "" {
+	if h.cfg.OIDCIssuer != "" {
 		resp.AuthURL = fmt.Sprintf("%s/oidc/register/%s", h.cfg.ServerURL, mKey.HexString())
 	} else {
 		resp.AuthURL = fmt.Sprintf("%s/register?key=%s",

app.go

@@ -46,7 +46,7 @@ type Config struct {
 
 	DNSConfig *tailcfg.DNSConfig
 
-	OIDCEndpoint     string
+	OIDCIssuer       string
 	OIDCClientID     string
 	OIDCClientSecret string
 }
@@ -172,11 +172,11 @@ func (h *Headscale) Serve() error {
 	r.GET("/register", h.RegisterWebAPI)
 	r.POST("/machine/:id/map", h.PollNetMapHandler)
 	r.POST("/machine/:id", h.RegistrationHandler)
-	r.GET("/oidc/register/:mKey", h.RegisterOIDC)
+	r.GET("/oidc/register/:mkey", h.RegisterOIDC)
 	r.GET("/oidc/callback", h.OIDCCallback)
 	r.GET("/apple", h.AppleMobileConfig)
 	r.GET("/apple/:platform", h.ApplePlatformConfig)
-  
+
 	var err error
 
 	timeout := 30 * time.Second

cmd/headscale/cli/utils.go

@@ -171,7 +171,7 @@ func getHeadscaleApp() (*headscale.Headscale, error) {
 
 		DNSConfig: GetDNSConfig(),
 
-		OIDCEndpoint:     viper.GetString("oidc_endpoint"),
+		OIDCIssuer:       viper.GetString("oidc_issuer"),
 		OIDCClientID:     viper.GetString("oidc_client_id"),
 		OIDCClientSecret: viper.GetString("oidc_client_secret"),
 	}

go.mod

@@ -7,11 +7,12 @@ require (
 	github.com/Microsoft/go-winio v0.5.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.1.1 // indirect
 	github.com/containerd/continuity v0.1.0 // indirect
+	github.com/coreos/go-oidc/v3 v3.1.0
 	github.com/docker/cli v20.10.8+incompatible // indirect
 	github.com/docker/docker v20.10.8+incompatible // indirect
 	github.com/efekarakus/termcolor v1.0.1
 	github.com/gin-gonic/gin v1.7.4
-	github.com/gofrs/uuid v4.0.0+incompatible // indirect
+	github.com/gofrs/uuid v4.0.0+incompatible
 	github.com/google/go-github v17.0.0+incompatible // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/hako/durafmt v0.0.0-20210608085754-5c1018a4e16b
@@ -28,13 +29,13 @@ require (
 	github.com/spf13/viper v1.8.1
 	github.com/stretchr/testify v1.7.0
 	github.com/tailscale/hujson v0.0.0-20210818175511-7360507a6e88
-	github.com/tcnksm/go-latest v0.0.0-20170313132115-e3007ae9052e // indirect
+	github.com/tcnksm/go-latest v0.0.0-20170313132115-e3007ae9052e
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	golang.org/x/crypto v0.0.0-20210817164053-32db794688a5
 	golang.org/x/net v0.0.0-20210913180222-943fd674d43e // indirect
+	golang.org/x/oauth2 v0.0.0-20210402161424-2e8d93401602
 	golang.org/x/sys v0.0.0-20210910150752-751e447fb3d0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
-	gopkg.in/square/go-jose.v2 v2.3.1
 	gopkg.in/yaml.v2 v2.4.0
 	gorm.io/datatypes v1.0.2
 	gorm.io/driver/postgres v1.1.1

go.sum

@@ -143,6 +143,8 @@ github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkE
 github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-iptables v0.6.0/go.mod h1:Qe8Bv2Xik5FyTXwgIbLAnv2sWSBmvWdFETJConOQ//Q=
+github.com/coreos/go-oidc/v3 v3.1.0 h1:6avEvcdvTa1qYsOZ6I5PRkSYHzpTNWgKYmaJfaYbrRw=
+github.com/coreos/go-oidc/v3 v3.1.0/go.mod h1:rEJ/idjfUyfkBit1eI1fvyr+64/g9dcKpAm8MJMesvo=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
@@ -1067,6 +1069,7 @@ golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200501053045-e0ff5e5a1de5/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20200505041828-1ed23360d12c/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200506145744-7e3656a0809f/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200513185701-a91f0712d120/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
@@ -1101,6 +1104,7 @@ golang.org/x/oauth2 v0.0.0-20201208152858-08078c50e5b5/go.mod h1:KelEdhl1UZF7XfJ
 golang.org/x/oauth2 v0.0.0-20210218202405-ba52d332ba99/go.mod h1:KelEdhl1UZF7XfJ4dDtk6s++YSgaE7mD/BuKKDLBl4A=
 golang.org/x/oauth2 v0.0.0-20210220000619-9bb904979d93/go.mod h1:KelEdhl1UZF7XfJ4dDtk6s++YSgaE7mD/BuKKDLBl4A=
 golang.org/x/oauth2 v0.0.0-20210313182246-cd4f82c27b84/go.mod h1:KelEdhl1UZF7XfJ4dDtk6s++YSgaE7mD/BuKKDLBl4A=
+golang.org/x/oauth2 v0.0.0-20210402161424-2e8d93401602 h1:0Ja1LBD+yisY6RWM/BH7TJVXWsSjs2VwBSmvSX4HdBc=
 golang.org/x/oauth2 v0.0.0-20210402161424-2e8d93401602/go.mod h1:KelEdhl1UZF7XfJ4dDtk6s++YSgaE7mD/BuKKDLBl4A=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -1355,6 +1359,7 @@ google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7
 google.golang.org/appengine v1.6.1/go.mod h1:i06prIuMbXzDqacNJfV5OdTW448YApPu5ww/cMBSeb0=
 google.golang.org/appengine v1.6.5/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
 google.golang.org/appengine v1.6.6/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
+google.golang.org/appengine v1.6.7 h1:FZR1q0exgwxzPzp/aF+VccGrSfxfPpkBqjIIEq3ru6c=
 google.golang.org/appengine v1.6.7/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
@@ -1452,8 +1457,9 @@ gopkg.in/ini.v1 v1.51.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=
 gopkg.in/ini.v1 v1.62.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
-gopkg.in/square/go-jose.v2 v2.3.1 h1:SK5KegNXmKmqE342YYN2qPHEnUYeoMiXXl1poUlI+o4=
 gopkg.in/square/go-jose.v2 v2.3.1/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
+gopkg.in/square/go-jose.v2 v2.5.1 h1:7odma5RETjNHWJnR32wx8t+Io4djHE1PqxCFx3iiZ2w=
+gopkg.in/square/go-jose.v2 v2.5.1/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/warnings.v0 v0.1.2/go.mod h1:jksf8JmL6Qr/oQM2OXTHunEvvTAsrWBLb6OOjuVWRNI=
 gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=

machine.go

@@ -50,6 +50,11 @@ func (m Machine) isAlreadyRegistered() bool {
 	return m.Registered
 }
 
+// isExpired returns whether the machine registration has expired
+func (m Machine) isExpired() bool {
+	return time.Now().UTC().After(*m.Expiry)
+}
+
 // toNode converts a Machine into a Tailscale Node. includeRoutes is false for shared nodes
 // as per the expected behaviour in the official SaaS
 func (m Machine) toNode(includeRoutes bool) (*tailcfg.Node, error) {

oidc.go

@@ -1,186 +1,37 @@
 package headscale
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/hex"
-	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/gin-gonic/gin"
 	"github.com/patrickmn/go-cache"
 	"github.com/rs/zerolog/log"
-	"github.com/s12v/go-jwks"
+	"golang.org/x/oauth2"
-	"gopkg.in/square/go-jose.v2/jwt"
 	"gorm.io/gorm"
-	"io"
 	"net/http"
-	"net/url"
-	"strings"
 	"time"
 )
 
-type OpenIDConfiguration struct {
+type IDTokenClaims struct {
-	Issuer                string `json:"issuer"`
-	AuthorizationEndpoint string `json:"authorization_endpoint"`
-	TokenEndpoint         string `json:"token_endpoint"`
-	JWKSURI               string `json:"jwks_uri"`
-}
-
-type OpenIDTokens struct {
-	AccessToken      string `json:"access_token"`
-	ExpiresIn        int    `json:"expires_in"`
-	IdToken          string `json:"id_token"`
-	NotBeforePolicy  int    `json:"not-before-policy,omitempty"`
-	RefreshExpiresIn int    `json:"refresh_expires_in"`
-	RefreshToken     string `json:"refresh_token"`
-	Scope            string `json:"scope"`
-	SessionState     string `json:"session_state,omitempty"`
-	TokenType        string `json:"token_type,omitempty"`
-}
-
-type AccessToken struct {
-	jwt.Claims
 	Name     string   `json:"name,omitempty"`
 	Groups   []string `json:"groups,omitempty"`
 	Email    string   `json:"email"`
 	Username string   `json:"preferred_username,omitempty"`
 }
 
-var oidcConfig *OpenIDConfiguration
+var oidcProvider *oidc.Provider
+var oauth2Config *oauth2.Config
 var stateCache *cache.Cache
-var jwksSource *jwks.WebSource
-var jwksClient jwks.JWKSClient
-
-func verifyToken(token string) (*AccessToken, error) {
-
-	if jwksClient == nil {
-		jwksSource = jwks.NewWebSource(oidcConfig.JWKSURI)
-		jwksClient = jwks.NewDefaultClient(
-			jwksSource,
-			time.Hour,    // Refresh keys every 1 hour
-			12*time.Hour, // Expire keys after 12 hours
-		)
-	}
-
-	//decode jwt
-	tok, err := jwt.ParseSigned(token)
-	if err != nil {
-		return nil, err
-	}
-
-	if tok.Headers[0].KeyID != "" {
-		log.Debug().Msgf("Checking KID %s\n", tok.Headers[0].KeyID)
-
-		jwk, err := jwksClient.GetSignatureKey(tok.Headers[0].KeyID)
-		if err != nil {
-			return nil, err
-		}
-
-		claims := AccessToken{}
-
-		err = tok.Claims(jwk.Certificates[0].PublicKey, &claims)
-		if err != nil {
-			return nil, err
-		} else {
-
-			err = claims.Validate(jwt.Expected{
-				Time: time.Now(),
-			})
-			if err != nil {
-				return nil, err
-			}
-
-			return &claims, nil
-		}
-
-	} else {
-		return nil, errors.New("JWT does not contain a key id")
-	}
-}
-
-func getOIDCConfig(oidcConfigURL string) (*OpenIDConfiguration, error) {
-	client := &http.Client{}
-	req, err := http.NewRequest("GET", oidcConfigURL, nil)
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-
-	log.Debug().Msgf("Requesting OIDC Config from %s", oidcConfigURL)
-
-	oidcConfigResp, err := client.Do(req)
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-	defer oidcConfigResp.Body.Close()
-
-	var oidcConfig OpenIDConfiguration
-
-	err = json.NewDecoder(oidcConfigResp.Body).Decode(&oidcConfig)
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-	return &oidcConfig, nil
-}
-
-func (h *Headscale) exchangeCodeForTokens(code string, redirectURI string) (*OpenIDTokens, error) {
-	var err error
-
-	if oidcConfig == nil {
-		oidcConfig, err = getOIDCConfig(fmt.Sprintf("%s.well-known/openid-configuration", h.cfg.OIDCEndpoint))
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	params := url.Values{}
-	params.Add("grant_type", "authorization_code")
-	params.Add("code", code)
-	params.Add("client_id", h.cfg.OIDCClientID)
-	params.Add("client_secret", h.cfg.OIDCClientSecret)
-	params.Add("redirect_uri", redirectURI)
-
-	client := &http.Client{}
-	req, err := http.NewRequest("POST", oidcConfig.TokenEndpoint, strings.NewReader(params.Encode()))
-	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
-
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-
-	tokenResp, err := client.Do(req)
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-	defer tokenResp.Body.Close()
-
-	if tokenResp.StatusCode != 200 {
-		b, _ := io.ReadAll(tokenResp.Body)
-		log.Error().Msgf("%s", b)
-	}
-
-	var tokens OpenIDTokens
-
-	err = json.NewDecoder(tokenResp.Body).Decode(&tokens)
-	if err != nil {
-		log.Error().Msgf("%v", err)
-		return nil, err
-	}
-
-	log.Info().Msg("Successfully exchanged code for tokens")
-
-	return &tokens, nil
-}
 
 // RegisterOIDC redirects to the OIDC provider for authentication
 // Puts machine key in cache so the callback can retrieve it using the oidc state param
 // Listens in /oidc/register/:mKey
 func (h *Headscale) RegisterOIDC(c *gin.Context) {
-	mKeyStr := c.Param("mKey")
+	mKeyStr := c.Param("mkey")
 	if mKeyStr == "" {
 		c.String(http.StatusBadRequest, "Wrong params")
 		return
@@ -189,13 +40,23 @@ func (h *Headscale) RegisterOIDC(c *gin.Context) {
 	var err error
 
 	// grab oidc config if it hasn't been already
-	if oidcConfig == nil {
+	if oauth2Config == nil {
-		oidcConfig, err = getOIDCConfig(fmt.Sprintf("%s.well-known/openid-configuration", h.cfg.OIDCEndpoint))
+		oidcProvider, err = oidc.NewProvider(context.Background(), h.cfg.OIDCIssuer)
 
 		if err != nil {
+			log.Error().Msgf("Could not retrieve OIDC Config: %s", err.Error())
 			c.String(http.StatusInternalServerError, "Could not retrieve OIDC Config")
 			return
 		}
+
+		oauth2Config = &oauth2.Config{
+			ClientID:     h.cfg.OIDCClientID,
+			ClientSecret: h.cfg.OIDCClientSecret,
+			Endpoint:     oidcProvider.Endpoint(),
+			RedirectURL:  fmt.Sprintf("%s/oidc/callback", h.cfg.ServerURL),
+			Scopes:       []string{oidc.ScopeOpenID, "profile", "email"},
+		}
+
 	}
 
 	b := make([]byte, 16)
@@ -217,21 +78,16 @@ func (h *Headscale) RegisterOIDC(c *gin.Context) {
 	// place the machine key into the state cache, so it can be retrieved later
 	stateCache.Set(stateStr, mKeyStr, time.Minute*5)
 
-	params := url.Values{}
+	authUrl := oauth2Config.AuthCodeURL(stateStr)
-	params.Add("response_type", "code")
+	log.Debug().Msgf("Redirecting to %s for authentication", authUrl)
-	params.Add("client_id", h.cfg.OIDCClientID)
-	params.Add("redirect_uri", fmt.Sprintf("%s/oidc/callback", h.cfg.ServerURL))
-	params.Add("scope", "openid")
-	params.Add("state", stateStr)
-
-	authUrl := fmt.Sprintf("%s?%s", oidcConfig.AuthorizationEndpoint, params.Encode())
-	log.Debug().Msg(authUrl)
 
 	c.Redirect(http.StatusFound, authUrl)
 }
 
 // OIDCCallback handles the callback from the OIDC endpoint
-// Retrieves the mkey from the state cache, if the machine is not registered, presents a confirmation
+// Retrieves the mkey from the state cache and adds the machine to the users email namespace
+// TODO: A confirmation page for new machines should be added to avoid phishing vulnerabilities
+// TODO: Add groups information from OIDC tokens into machine HostInfo
 // Listens in /oidc/callback
 func (h *Headscale) OIDCCallback(c *gin.Context) {
 
@@ -243,20 +99,36 @@ func (h *Headscale) OIDCCallback(c *gin.Context) {
 		return
 	}
 
-	redirectURI := fmt.Sprintf("%s/oidc/callback", h.cfg.ServerURL)
+	oauth2Token, err := oauth2Config.Exchange(context.Background(), code)
-
-	tokens, err := h.exchangeCodeForTokens(code, redirectURI)
-
 	if err != nil {
 		c.String(http.StatusBadRequest, "Could not exchange code for token")
 		return
 	}
 
-	//verify tokens
+	rawIDToken, rawIDTokenOK := oauth2Token.Extra("id_token").(string)
-	claims, err := verifyToken(tokens.AccessToken)
+	if !rawIDTokenOK {
+		c.String(http.StatusBadRequest, "Could not extract ID Token")
+		return
+	}
 
+	verifier := oidcProvider.Verifier(&oidc.Config{ClientID: h.cfg.OIDCClientID})
+
+	idToken, err := verifier.Verify(context.Background(), rawIDToken)
 	if err != nil {
-		c.String(http.StatusBadRequest, "invalid tokens")
+		c.String(http.StatusBadRequest, "Failed to verify id token: %s", err.Error())
+		return
+	}
+
+	//userInfo, err := oidcProvider.UserInfo(context.Background(), oauth2.StaticTokenSource(oauth2Token))
+	//if err != nil {
+	//	c.String(http.StatusBadRequest, "Failed to retrieve userinfo: "+err.Error())
+	//	return
+	//}
+
+	// Extract custom claims
+	var claims IDTokenClaims
+	if err = idToken.Claims(&claims); err != nil {
+		c.String(http.StatusBadRequest, "Failed to decode id token claims: "+err.Error())
 		return
 	}