Add support to ensure user belongs in required groups when using the OIDC provider

CHANGELOG.md

@@ -4,11 +4,14 @@
 
 ## Important Notes
 
+- [#616](https://github.com/oauth2-proxy/oauth2-proxy/pull/616) Ensure you have configured oauth2-proxy to use the `groups` scope. The user may be logged out initially as they may not currently have the `groups` claim however after going back through login process wil be authenticated.
+
 ## Breaking Changes
 
 ## Changes since v6.1.1
 
 - [#764](https://github.com/oauth2-proxy/oauth2-proxy/pull/764) Document bcrypt encryption for htpasswd (and hide SHA) (@lentzi90)
+- [#616](https://github.com/oauth2-proxy/oauth2-proxy/pull/616) Add support to ensure user belongs in required groups when using the OIDC provider (@stefansedich)
 
 # v6.1.1
 

docs/configuration/configuration.md

@@ -78,12 +78,13 @@ An example [oauth2-proxy.cfg]({{ site.gitweb }}/contrib/oauth2-proxy.cfg.example
 | `--insecure-oidc-skip-issuer-verification` | bool | allow the OIDC issuer URL to differ from the expected (currently required for Azure multi-tenant compatibility) | false |
 | `--oidc-issuer-url` | string | the OpenID Connect issuer URL, e.g. `"https://accounts.google.com"` | |
 | `--oidc-jwks-url` | string | OIDC JWKS URI for token verification; required if OIDC discovery is disabled | |
+| `--oidc-groups-claim` | string | which claim contains the user groups | `"groups"` |
 | `--pass-access-token` | bool | pass OAuth access_token to upstream via X-Forwarded-Access-Token header | false |
 | `--pass-authorization-header` | bool | pass OIDC IDToken to upstream via Authorization Bearer header | false |
 | `--pass-basic-auth` | bool | pass HTTP Basic Auth, X-Forwarded-User, X-Forwarded-Email and X-Forwarded-Preferred-Username information to upstream | true |
 | `--prefer-email-to-user` | bool | Prefer to use the Email address as the Username when passing information to upstream. Will only use Username if Email is unavailable, e.g. htaccess authentication. Used in conjunction with `--pass-basic-auth` and `--pass-user-headers` | false |
 | `--pass-host-header` | bool | pass the request Host Header to upstream | true |
-| `--pass-user-headers` | bool | pass X-Forwarded-User, X-Forwarded-Email and X-Forwarded-Preferred-Username information to upstream | true |
+| `--pass-user-headers` | bool | pass X-Forwarded-User, X-Forwarded-Groups, X-Forwarded-Email and X-Forwarded-Preferred-Username information to upstream | true |
 | `--profile-url` | string | Profile access endpoint | |
 | `--prompt` | string | [OIDC prompt](https://openid.net/specs/openid-connect-core-1_0.html#AuthRequest); if present, `approval-prompt` is ignored | `""` |
 | `--provider` | string | OAuth provider | google |
@@ -112,7 +113,7 @@ An example [oauth2-proxy.cfg]({{ site.gitweb }}/contrib/oauth2-proxy.cfg.example
 | `--scope` | string | OAuth scope specification | |
 | `--session-cookie-minimal` | bool | strip OAuth tokens from cookie session stores if they aren't needed (cookie session store only) | false |
 | `--session-store-type` | string | [Session data storage backend](configuration/sessions); redis or cookie | cookie |
-| `--set-xauthrequest` | bool | set X-Auth-Request-User, X-Auth-Request-Email and X-Auth-Request-Preferred-Username response headers (useful in Nginx auth_request mode) | false |
+| `--set-xauthrequest` | bool | set X-Auth-Request-User, X-Auth-Request-Groups, X-Auth-Request-Email and X-Auth-Request-Preferred-Username response headers (useful in Nginx auth_request mode) | false |
 | `--set-authorization-header` | bool | set Authorization Bearer response header (useful in Nginx auth_request mode) | false |
 | `--set-basic-auth` | bool | set HTTP Basic Auth information in response (useful in Nginx auth_request mode) | false |
 | `--signature-key` | string | GAP-Signature request signature key (algorithm:secretkey) | |
@@ -131,6 +132,7 @@ An example [oauth2-proxy.cfg]({{ site.gitweb }}/contrib/oauth2-proxy.cfg.example
 | `--tls-key-file` | string | path to private key file | |
 | `--upstream` | string \| list | the http url(s) of the upstream endpoint, file:// paths for static files or `static://<status_code>` for static response. Routing is based on the path | |
 | `--user-id-claim` | string | which claim contains the user ID | \["email"\] |
+| `--allowed-group` | string \| list | restrict logins to members of this group (may be given multiple times) | |
 | `--validate-url` | string | Access token validation endpoint | |
 | `--version` | n/a | print version string | |
 | `--whitelist-domain` | string \| list | allowed domains for redirection after authentication. Prefix domain with a `.` to allow subdomains (e.g. `.example.com`)&nbsp;\[[2](#footnote2)\] | |

oauthproxy.go

@@ -102,6 +102,7 @@ type OAuthProxy struct {
 	trustedIPs              *ip.NetSet
 	Banner                  string
 	Footer                  string
+	AllowedGroups           []string
 
 	sessionChain alice.Chain
 }
@@ -215,6 +216,7 @@ func NewOAuthProxy(opts *options.Options, validator func(string) bool) (*OAuthPr
 		Banner:                  opts.Banner,
 		Footer:                  opts.Footer,
 		SignInMessage:           buildSignInMessage(opts),
+		AllowedGroups:           opts.AllowedGroups,
 
 		basicAuthValidator:  basicAuthValidator,
 		displayHtpasswdForm: basicAuthValidator != nil,
@@ -888,7 +890,10 @@ func (p *OAuthProxy) getAuthenticatedSession(rw http.ResponseWriter, req *http.R
 		return nil, ErrNeedsLogin
 	}
 
-	if session != nil && session.Email != "" && !p.Validator(session.Email) {
+	invalidEmail := session != nil && session.Email != "" && !p.Validator(session.Email)
+	invalidGroups := session != nil && !p.validateGroups(session.Groups)
+
+	if invalidEmail || invalidGroups {
 		logger.Printf(session.Email, req, logger.AuthFailure, "Invalid authentication via session: removing session %s", session)
 		// Invalid session, clear it
 		err := p.ClearSessionCookie(rw, req)
@@ -942,6 +947,14 @@ func (p *OAuthProxy) addHeadersForProxying(rw http.ResponseWriter, req *http.Req
 		} else {
 			req.Header.Del("X-Forwarded-Preferred-Username")
 		}
+
+		if len(session.Groups) > 0 {
+			for _, group := range session.Groups {
+				req.Header.Add("X-Forwarded-Groups", group)
+			}
+		} else {
+			req.Header.Del("X-Forwarded-Groups")
+		}
 	}
 
 	if p.SetXAuthRequest {
@@ -964,6 +977,14 @@ func (p *OAuthProxy) addHeadersForProxying(rw http.ResponseWriter, req *http.Req
 				rw.Header().Del("X-Auth-Request-Access-Token")
 			}
 		}
+
+		if len(session.Groups) > 0 {
+			for _, group := range session.Groups {
+				rw.Header().Add("X-Auth-Request-Groups", group)
+			}
+		} else {
+			rw.Header().Del("X-Auth-Request-Groups")
+		}
 	}
 
 	if p.PassAccessToken {
@@ -1012,6 +1033,7 @@ func (p *OAuthProxy) addHeadersForProxying(rw http.ResponseWriter, req *http.Req
 func (p *OAuthProxy) stripAuthHeaders(req *http.Request) {
 	if p.PassBasicAuth {
 		req.Header.Del("X-Forwarded-User")
+		req.Header.Del("X-Forwarded-Groups")
 		req.Header.Del("X-Forwarded-Email")
 		req.Header.Del("X-Forwarded-Preferred-Username")
 		req.Header.Del("Authorization")
@@ -1019,6 +1041,7 @@ func (p *OAuthProxy) stripAuthHeaders(req *http.Request) {
 
 	if p.PassUserHeaders {
 		req.Header.Del("X-Forwarded-User")
+		req.Header.Del("X-Forwarded-Groups")
 		req.Header.Del("X-Forwarded-Email")
 		req.Header.Del("X-Forwarded-Preferred-Username")
 	}
@@ -1049,3 +1072,23 @@ func (p *OAuthProxy) ErrorJSON(rw http.ResponseWriter, code int) {
 	rw.Header().Set("Content-Type", applicationJSON)
 	rw.WriteHeader(code)
 }
+
+func (p *OAuthProxy) validateGroups(groups []string) bool {
+	if len(p.AllowedGroups) == 0 {
+		return true
+	}
+
+	allowedGroups := map[string]struct{}{}
+
+	for _, group := range p.AllowedGroups {
+		allowedGroups[group] = struct{}{}
+	}
+
+	for _, group := range groups {
+		if _, ok := allowedGroups[group]; ok {
+			return true
+		}
+	}
+
+	return false
+}

oauthproxy_test.go

@@ -592,6 +592,37 @@ func TestPassUserHeadersWithEmail(t *testing.T) {
 	}
 }
 
+func TestPassGroupsHeadersWithGroups(t *testing.T) {
+	opts := baseTestOptions()
+	err := validation.Validate(opts)
+	assert.NoError(t, err)
+
+	const emailAddress = "john.doe@example.com"
+	const userName = "9fcab5c9b889a557"
+
+	groups := []string{"a", "b"}
+	created := time.Now()
+	session := &sessions.SessionState{
+		User:        userName,
+		Groups:      groups,
+		Email:       emailAddress,
+		AccessToken: "oauth_token",
+		CreatedAt:   &created,
+	}
+	{
+		rw := httptest.NewRecorder()
+		req, _ := http.NewRequest("GET", opts.ProxyPrefix+"/testCase0", nil)
+		proxy, err := NewOAuthProxy(opts, func(email string) bool {
+			return email == emailAddress
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		proxy.addHeadersForProxying(rw, req, session)
+		assert.Equal(t, groups, req.Header["X-Forwarded-Groups"])
+	}
+}
+
 func TestStripAuthHeaders(t *testing.T) {
 	testCases := map[string]struct {
 		SkipAuthStripHeaders bool
@@ -609,6 +640,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    false,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               true,
+				"X-Forwared-Groups":              true,
 				"X-Forwarded-Email":              true,
 				"X-Forwarded-Preferred-Username": true,
 				"X-Forwarded-Access-Token":       false,
@@ -623,6 +655,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    false,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               true,
+				"X-Forwared-Groups":              true,
 				"X-Forwarded-Email":              true,
 				"X-Forwarded-Preferred-Username": true,
 				"X-Forwarded-Access-Token":       true,
@@ -637,6 +670,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    false,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               true,
+				"X-Forwared-Groups":              true,
 				"X-Forwarded-Email":              true,
 				"X-Forwarded-Preferred-Username": true,
 				"X-Forwarded-Access-Token":       true,
@@ -651,6 +685,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    true,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               false,
+				"X-Forwared-Groups":              false,
 				"X-Forwarded-Email":              false,
 				"X-Forwarded-Preferred-Username": false,
 				"X-Forwarded-Access-Token":       false,
@@ -665,6 +700,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    false,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               false,
+				"X-Forwared-Groups":              false,
 				"X-Forwarded-Email":              false,
 				"X-Forwarded-Preferred-Username": false,
 				"X-Forwarded-Access-Token":       false,
@@ -679,6 +715,7 @@ func TestStripAuthHeaders(t *testing.T) {
 			PassAuthorization:    false,
 			StrippedHeaders: map[string]bool{
 				"X-Forwarded-User":               false,
+				"X-Forwared-Groups":              false,
 				"X-Forwarded-Email":              false,
 				"X-Forwarded-Preferred-Username": false,
 				"X-Forwarded-Access-Token":       false,
@@ -690,6 +727,7 @@ func TestStripAuthHeaders(t *testing.T) {
 	initialHeaders := map[string]string{
 		"X-Forwarded-User":               "9fcab5c9b889a557",
 		"X-Forwarded-Email":              "john.doe@example.com",
+		"X-Forwarded-Groups":             "a,b,c",
 		"X-Forwarded-Preferred-Username": "john.doe",
 		"X-Forwarded-Access-Token":       "AccessToken",
 		"Authorization":                  "bearer IDToken",
@@ -1333,6 +1371,7 @@ func TestAuthOnlyEndpointSetXAuthRequestHeaders(t *testing.T) {
 
 	pcTest.opts = baseTestOptions()
 	pcTest.opts.SetXAuthRequest = true
+	pcTest.opts.AllowedGroups = []string{"oauth_groups"}
 	err := validation.Validate(pcTest.opts)
 	assert.NoError(t, err)
 
@@ -1354,13 +1393,14 @@ func TestAuthOnlyEndpointSetXAuthRequestHeaders(t *testing.T) {
 
 	created := time.Now()
 	startSession := &sessions.SessionState{
-		User: "oauth_user", Email: "oauth_user@example.com", AccessToken: "oauth_token", CreatedAt: &created}
+		User: "oauth_user", Groups: []string{"oauth_groups"}, Email: "oauth_user@example.com", AccessToken: "oauth_token", CreatedAt: &created}
 	err = pcTest.SaveSession(startSession)
 	assert.NoError(t, err)
 
 	pcTest.proxy.ServeHTTP(pcTest.rw, pcTest.req)
 	assert.Equal(t, http.StatusAccepted, pcTest.rw.Code)
 	assert.Equal(t, "oauth_user", pcTest.rw.Header().Get("X-Auth-Request-User"))
+	assert.Equal(t, startSession.Groups, pcTest.rw.Header().Values("X-Auth-Request-Groups"))
 	assert.Equal(t, "oauth_user@example.com", pcTest.rw.Header().Get("X-Auth-Request-Email"))
 }
 
@@ -2199,3 +2239,108 @@ func TestTrustedIPs(t *testing.T) {
 		})
 	}
 }
+
+func TestProxyAllowedGroups(t *testing.T) {
+	tests := []struct {
+		name               string
+		allowedGroups      []string
+		groups             []string
+		expectUnauthorized bool
+	}{
+		{"NoAllowedGroups", []string{}, []string{}, false},
+		{"NoAllowedGroupsUserHasGroups", []string{}, []string{"a", "b"}, false},
+		{"UserInAllowedGroup", []string{"a"}, []string{"a", "b"}, false},
+		{"UserNotInAllowedGroup", []string{"a"}, []string{"c"}, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			emailAddress := "test"
+			created := time.Now()
+
+			session := &sessions.SessionState{
+				Groups:      tt.groups,
+				Email:       emailAddress,
+				AccessToken: "oauth_token",
+				CreatedAt:   &created,
+			}
+
+			upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(200)
+			}))
+			t.Cleanup(upstream.Close)
+
+			test, err := NewProcessCookieTestWithOptionsModifiers(func(opts *options.Options) {
+				opts.AllowedGroups = tt.allowedGroups
+				opts.UpstreamServers = options.Upstreams{
+					{
+						ID:   upstream.URL,
+						Path: "/",
+						URI:  upstream.URL,
+					},
+				}
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			test.req, _ = http.NewRequest("GET", "/", nil)
+
+			test.req.Header.Add("accept", applicationJSON)
+			test.SaveSession(session)
+			test.proxy.ServeHTTP(test.rw, test.req)
+
+			if tt.expectUnauthorized {
+				assert.Equal(t, http.StatusUnauthorized, test.rw.Code)
+			} else {
+				assert.Equal(t, http.StatusOK, test.rw.Code)
+			}
+		})
+	}
+}
+
+func TestAuthOnlyAllowedGroups(t *testing.T) {
+	tests := []struct {
+		name               string
+		allowedGroups      []string
+		groups             []string
+		expectUnauthorized bool
+	}{
+		{"NoAllowedGroups", []string{}, []string{}, false},
+		{"NoAllowedGroupsUserHasGroups", []string{}, []string{"a", "b"}, false},
+		{"UserInAllowedGroup", []string{"a"}, []string{"a", "b"}, false},
+		{"UserNotInAllowedGroup", []string{"a"}, []string{"c"}, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			emailAddress := "test"
+			created := time.Now()
+
+			session := &sessions.SessionState{
+				Groups:      tt.groups,
+				Email:       emailAddress,
+				AccessToken: "oauth_token",
+				CreatedAt:   &created,
+			}
+
+			test, err := NewAuthOnlyEndpointTest(func(opts *options.Options) {
+				opts.AllowedGroups = tt.allowedGroups
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			err = test.SaveSession(session)
+			assert.NoError(t, err)
+
+			test.proxy.ServeHTTP(test.rw, test.req)
+
+			if tt.expectUnauthorized {
+				assert.Equal(t, http.StatusUnauthorized, test.rw.Code)
+			} else {
+				assert.Equal(t, http.StatusAccepted, test.rw.Code)
+			}
+		})
+	}
+}

pkg/apis/options/options.go

@@ -93,6 +93,7 @@ type Options struct {
 	InsecureOIDCSkipIssuerVerification bool     `flag:"insecure-oidc-skip-issuer-verification" cfg:"insecure_oidc_skip_issuer_verification"`
 	SkipOIDCDiscovery                  bool     `flag:"skip-oidc-discovery" cfg:"skip_oidc_discovery"`
 	OIDCJwksURL                        string   `flag:"oidc-jwks-url" cfg:"oidc_jwks_url"`
+	OIDCGroupsClaim                    string   `flag:"oidc-groups-claim" cfg:"oidc_groups_claim"`
 	LoginURL                           string   `flag:"login-url" cfg:"login_url"`
 	RedeemURL                          string   `flag:"redeem-url" cfg:"redeem_url"`
 	ProfileURL                         string   `flag:"profile-url" cfg:"profile_url"`
@@ -102,6 +103,7 @@ type Options struct {
 	Prompt                             string   `flag:"prompt" cfg:"prompt"`
 	ApprovalPrompt                     string   `flag:"approval-prompt" cfg:"approval_prompt"` // Deprecated by OIDC 1.0
 	UserIDClaim                        string   `flag:"user-id-claim" cfg:"user_id_claim"`
+	AllowedGroups                      []string `flag:"allowed-group" cfg:"allowed_groups"`
 
 	SignatureKey    string `flag:"signature-key" cfg:"signature_key"`
 	AcrValues       string `flag:"acr-values" cfg:"acr_values"`
@@ -167,6 +169,7 @@ func NewOptions() *Options {
 		InsecureOIDCAllowUnverifiedEmail: false,
 		SkipOIDCDiscovery:                false,
 		Logging:                          loggingDefaults(),
+		OIDCGroupsClaim:                  "groups",
 	}
 }
 
@@ -248,6 +251,7 @@ func NewFlagSet() *pflag.FlagSet {
 	flagSet.Bool("insecure-oidc-skip-issuer-verification", false, "Do not verify if issuer matches OIDC discovery URL")
 	flagSet.Bool("skip-oidc-discovery", false, "Skip OIDC discovery and use manually supplied Endpoints")
 	flagSet.String("oidc-jwks-url", "", "OpenID Connect JWKS URL (ie: https://www.googleapis.com/oauth2/v3/certs)")
+	flagSet.String("oidc-groups-claim", "groups", "which claim contains the user groups")
 	flagSet.String("login-url", "", "Authentication endpoint")
 	flagSet.String("redeem-url", "", "Token redemption endpoint")
 	flagSet.String("profile-url", "", "Profile access endpoint")
@@ -265,6 +269,7 @@ func NewFlagSet() *pflag.FlagSet {
 	flagSet.Bool("gcp-healthchecks", false, "Enable GCP/GKE healthcheck endpoints")
 
 	flagSet.String("user-id-claim", "email", "which claim contains the user ID")
+	flagSet.StringSlice("allowed-group", []string{}, "restrict logins to members of this group (may be given multiple times)")
 
 	flagSet.AddFlagSet(cookieFlagSet())
 	flagSet.AddFlagSet(loggingFlagSet())

pkg/apis/sessions/session_state.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"reflect"
 	"time"
 	"unicode/utf8"
 
@@ -24,6 +25,7 @@ type SessionState struct {
 	RefreshToken      string     `json:",omitempty" msgpack:"rt,omitempty"`
 	Email             string     `json:",omitempty" msgpack:"e,omitempty"`
 	User              string     `json:",omitempty" msgpack:"u,omitempty"`
+	Groups            []string   `json:",omitempty" msgpack:"g,omitempty"`
 	PreferredUsername string     `json:",omitempty" msgpack:"pu,omitempty"`
 }
 
@@ -61,6 +63,9 @@ func (s *SessionState) String() string {
 	if s.RefreshToken != "" {
 		o += " refresh_token:true"
 	}
+	if len(s.Groups) > 0 {
+		o += fmt.Sprintf(" groups:%v", s.Groups)
+	}
 	return o + "}"
 }
 
@@ -233,7 +238,7 @@ func (s *SessionState) validate() error {
 	}
 
 	empty := new(SessionState)
-	if *s == *empty {
+	if reflect.DeepEqual(*s, *empty) {
 		return errors.New("invalid empty session unmarshalled")
 	}
 

pkg/apis/sessions/session_state_test.go

@@ -186,6 +186,17 @@ func TestEncodeAndDecodeSessionState(t *testing.T) {
 			IDToken:     "IDToken.12349871293847fdsaihf9238h4f91h8fr.1349f831y98fd7",
 			ExpiresOn:   &expires,
 		},
+		"With groups": {
+			Email:             "username@example.com",
+			User:              "username",
+			PreferredUsername: "preferred.username",
+			AccessToken:       "AccessToken.12349871293847fdsaihf9238h4f91h8fr.1349f831y98fd7",
+			IDToken:           "IDToken.12349871293847fdsaihf9238h4f91h8fr.1349f831y98fd7",
+			CreatedAt:         &created,
+			ExpiresOn:         &expires,
+			RefreshToken:      "RefreshToken.12349871293847fdsaihf9238h4f91h8fr.1349f831y98fd7",
+			Groups:            []string{"group-a", "group-b"},
+		},
 	}
 
 	for _, secretSize := range []int{16, 24, 32} {

pkg/validation/options.go

@@ -152,6 +152,10 @@ func Validate(o *options.Options) error {
 		}
 		if o.Scope == "" {
 			o.Scope = "openid email profile"
+
+			if len(o.AllowedGroups) > 0 {
+				o.Scope += " groups"
+			}
 		}
 	}
 
@@ -279,6 +283,7 @@ func parseProviderInfo(o *options.Options, msgs []string) []string {
 	case *providers.OIDCProvider:
 		p.AllowUnverifiedEmail = o.InsecureOIDCAllowUnverifiedEmail
 		p.UserIDClaim = o.UserIDClaim
+		p.GroupsClaim = o.OIDCGroupsClaim
 		if o.GetOIDCVerifier() == nil {
 			msgs = append(msgs, "oidc provider requires an oidc issuer URL")
 		} else {

providers/oidc.go

@@ -22,6 +22,7 @@ type OIDCProvider struct {
 	Verifier             *oidc.IDTokenVerifier
 	AllowUnverifiedEmail bool
 	UserIDClaim          string
+	GroupsClaim          string
 }
 
 // NewOIDCProvider initiates a new OIDCProvider
@@ -123,6 +124,7 @@ func (p *OIDCProvider) redeemRefreshToken(ctx context.Context, s *sessions.Sessi
 		s.IDToken = newSession.IDToken
 		s.Email = newSession.Email
 		s.User = newSession.User
+		s.Groups = newSession.Groups
 		s.PreferredUsername = newSession.PreferredUsername
 	}
 
@@ -204,6 +206,7 @@ func (p *OIDCProvider) createSessionStateInternal(ctx context.Context, idToken *
 	newSession.Email = claims.UserID // TODO Rename SessionState.Email to .UserID in the near future
 
 	newSession.User = claims.Subject
+	newSession.Groups = claims.Groups
 	newSession.PreferredUsername = claims.PreferredUsername
 
 	verifyEmail := (p.UserIDClaim == emailClaim) && !p.AllowUnverifiedEmail
@@ -222,6 +225,7 @@ func (p *OIDCProvider) ValidateSessionState(ctx context.Context, s *sessions.Ses
 
 func (p *OIDCProvider) findClaimsFromIDToken(ctx context.Context, idToken *oidc.IDToken, token *oauth2.Token) (*OIDCClaims, error) {
 	claims := &OIDCClaims{}
+
 	// Extract default claims.
 	if err := idToken.Claims(&claims); err != nil {
 		return nil, fmt.Errorf("failed to parse default id_token claims: %v", err)
@@ -236,6 +240,8 @@ func (p *OIDCProvider) findClaimsFromIDToken(ctx context.Context, idToken *oidc.
 		claims.UserID = fmt.Sprint(userID)
 	}
 
+	claims.Groups = p.extractGroupsFromRawClaims(claims.rawClaims)
+
 	// userID claim was not present or was empty in the ID Token
 	if claims.UserID == "" {
 		// BearerToken case, allow empty UserID
@@ -273,10 +279,27 @@ func (p *OIDCProvider) findClaimsFromIDToken(ctx context.Context, idToken *oidc.
 	return claims, nil
 }
 
+func (p *OIDCProvider) extractGroupsFromRawClaims(rawClaims map[string]interface{}) []string {
+	groups := []string{}
+
+	rawGroups, ok := rawClaims[p.GroupsClaim].([]interface{})
+	if rawGroups != nil && ok {
+		for _, rawGroup := range rawGroups {
+			group, ok := rawGroup.(string)
+			if ok {
+				groups = append(groups, group)
+			}
+		}
+	}
+
+	return groups
+}
+
 type OIDCClaims struct {
 	rawClaims         map[string]interface{}
 	UserID            string
 	Subject           string `json:"sub"`
 	Verified          *bool  `json:"email_verified"`
 	PreferredUsername string `json:"preferred_username"`
+	Groups            []string
 }

providers/oidc_test.go

@@ -33,6 +33,8 @@ type idTokenClaims struct {
 	Email       string   `json:"email,omitempty"`
 	Phone       string   `json:"phone_number,omitempty"`
 	Picture     string   `json:"picture,omitempty"`
+	Groups      []string `json:"groups,omitempty"`
+	OtherGroups []string `json:"other_groups,omitempty"`
 	jwt.StandardClaims
 }
 
@@ -49,6 +51,8 @@ var defaultIDToken idTokenClaims = idTokenClaims{
 	"janed@me.com",
 	"+4798765432",
 	"http://mugbook.com/janed/me.jpg",
+	[]string{"test:a", "test:b"},
+	[]string{"test:c", "test:d"},
 	jwt.StandardClaims{
 		Audience:  "https://test.myapp.com",
 		ExpiresAt: time.Now().Add(time.Duration(5) * time.Minute).Unix(),
@@ -65,6 +69,8 @@ var minimalIDToken idTokenClaims = idTokenClaims{
 	"",
 	"",
 	"",
+	[]string{},
+	[]string{},
 	jwt.StandardClaims{
 		Audience:  "https://test.myapp.com",
 		ExpiresAt: time.Now().Add(time.Duration(5) * time.Minute).Unix(),
@@ -274,24 +280,38 @@ func TestCreateSessionStateFromBearerToken(t *testing.T) {
 
 	testCases := map[string]struct {
 		IDToken        idTokenClaims
+		GroupsClaim    string
 		ExpectedUser   string
 		ExpectedEmail  string
+		ExpectedGroups []string
 	}{
 		"Default IDToken": {
 			IDToken:        defaultIDToken,
+			GroupsClaim:    "groups",
 			ExpectedUser:   defaultIDToken.Subject,
 			ExpectedEmail:  defaultIDToken.Email,
+			ExpectedGroups: []string{"test:a", "test:b"},
 		},
 		"Minimal IDToken with no email claim": {
 			IDToken:        minimalIDToken,
+			GroupsClaim:    "groups",
 			ExpectedUser:   minimalIDToken.Subject,
 			ExpectedEmail:  minimalIDToken.Subject,
+			ExpectedGroups: []string{},
+		},
+		"Custom Groups Claim": {
+			IDToken:        defaultIDToken,
+			GroupsClaim:    "other_groups",
+			ExpectedUser:   defaultIDToken.Subject,
+			ExpectedEmail:  defaultIDToken.Email,
+			ExpectedGroups: []string{"test:c", "test:d"},
 		},
 	}
 	for testName, tc := range testCases {
 		t.Run(testName, func(t *testing.T) {
 			jsonResp := []byte(fmt.Sprintf(`{"email":"%s"}`, profileURLEmail))
 			server, provider := newTestSetup(jsonResp)
+			provider.GroupsClaim = tc.GroupsClaim
 			defer server.Close()
 
 			rawIDToken, err := newSignedTestIDToken(tc.IDToken)
@@ -311,6 +331,7 @@ func TestCreateSessionStateFromBearerToken(t *testing.T) {
 			assert.Equal(t, tc.ExpectedEmail, ss.Email)
 			assert.Equal(t, rawIDToken, ss.IDToken)
 			assert.Equal(t, rawIDToken, ss.AccessToken)
+			assert.Equal(t, tc.ExpectedGroups, ss.Groups)
 			assert.Equal(t, "", ss.RefreshToken)
 		})
 	}