feat(oidc): optionally query OIDC UserInfo to gather group claims

Signed-off-by: Nathanael Liechti <[email protected]>

docs/operator-manual/user-management/index.md

@@ -387,6 +387,20 @@ For a simple case this can be:
   oidc.config: |
     requestedIDTokenClaims: {"groups": {"essential": true}}
 ```
+
+### Retrieving group claims when not in the token
+
+Some OIDC providers don't return the group information for a user in the ID token, even if explicitly requested using the `requestedIDTokenClaims` setting (Okta for example). They instead provide the groups on the user info endpoint. With the following config, Argo CD queries the user info endpoint during login for groups information of a user:
+
+```yaml
+oidc.config: |
+    enableUserInfoGroups: true
+    userInfoPath: /userinfo
+    userInfoCacheExpiration: "5m"
+```
+
+**Note: If you omit the `userInfoCacheExpiration` setting or if it's greater than the expiration of the ID token, the argocd-server will cache group information as long as the ID token is valid!**
+
 ### Configuring a custom logout URL for your OIDC provider
 
 Optionally, if your OIDC provider exposes a logout API and you wish to configure a custom logout URL for the purposes of invalidating 

server/server.go

@@ -1121,7 +1121,7 @@ func (a *ArgoCDServer) registerDexHandlers(mux *http.ServeMux) {
 	// Run dex OpenID Connect Identity Provider behind a reverse proxy (served at /api/dex)
 	var err error
 	mux.HandleFunc(common.DexAPIEndpoint+"/", dexutil.NewDexHTTPReverseProxy(a.DexServerAddr, a.BaseHRef, a.DexTLSConfig))
-	a.ssoClientApp, err = oidc.NewClientApp(a.settings, a.DexServerAddr, a.DexTLSConfig, a.BaseHRef)
+	a.ssoClientApp, err = oidc.NewClientApp(a.settings, a.DexServerAddr, a.DexTLSConfig, a.BaseHRef, cacheutil.NewRedisCache(a.RedisClient, a.settings.UserInfoCacheExpiration(), cacheutil.RedisCompressionNone))
 	errorsutil.CheckError(err)
 	mux.HandleFunc(common.LoginEndpoint, a.ssoClientApp.HandleLogin)
 	mux.HandleFunc(common.CallbackEndpoint, a.ssoClientApp.HandleCallback)
@@ -1315,7 +1315,35 @@ func (a *ArgoCDServer) getClaims(ctx context.Context) (jwt.Claims, string, error
 	if err != nil {
 		return claims, "", status.Errorf(codes.Unauthenticated, "invalid session: %v", err)
 	}
-	return claims, newToken, nil
+
+	// Some SSO implementations (Okta) require a call to
+	// the OIDC user info path to get attributes like groups
+	// we assume that everywhere in argocd jwt.MapClaims is used as type for interface jwt.Claims
+	// otherwise this would cause a panic
+	var groupClaims jwt.MapClaims
+	if groupClaims, ok = claims.(jwt.MapClaims); !ok {
+		if tmpClaims, ok := claims.(*jwt.MapClaims); ok {
+			groupClaims = *tmpClaims
+		}
+	}
+	iss := jwtutil.StringField(groupClaims, "iss")
+	if iss != util_session.SessionManagerClaimsIssuer && a.settings.UserInfoGroupsEnabled() && a.settings.UserInfoPath() != "" {
+		userInfo, unauthorized, err := a.ssoClientApp.GetUserInfo(groupClaims, a.settings.IssuerURL(), a.settings.UserInfoPath())
+		if unauthorized {
+			log.Errorf("error while quering userinfo endpoint: %v", err)
+			return claims, "", status.Errorf(codes.Unauthenticated, "invalid session")
+		}
+		if err != nil {
+			log.Errorf("error fetching user info endpoint: %v", err)
+			return claims, "", status.Errorf(codes.Internal, "invalid userinfo response")
+		}
+		if groupClaims["sub"] != userInfo["sub"] {
+			return claims, "", status.Error(codes.Unknown, "subject of claims from user info endpoint didn't match subject of idToken, see https://openid.net/specs/openid-connect-core-1_0.html#UserInfo")
+		}
+		groupClaims["groups"] = userInfo["groups"]
+	}
+
+	return groupClaims, newToken, nil
 }
 
 // getToken extracts the token from gRPC metadata or cookie headers

server/server_test.go

@@ -32,8 +32,10 @@ import (
 	"github.com/argoproj/argo-cd/v2/server/rbacpolicy"
 	"github.com/argoproj/argo-cd/v2/test"
 	"github.com/argoproj/argo-cd/v2/util/assets"
+	"github.com/argoproj/argo-cd/v2/util/cache"
 	cacheutil "github.com/argoproj/argo-cd/v2/util/cache"
 	appstatecache "github.com/argoproj/argo-cd/v2/util/cache/appstate"
+	"github.com/argoproj/argo-cd/v2/util/oidc"
 	"github.com/argoproj/argo-cd/v2/util/rbac"
 	settings_util "github.com/argoproj/argo-cd/v2/util/settings"
 	testutil "github.com/argoproj/argo-cd/v2/util/test"
@@ -533,7 +535,7 @@ func dexMockHandler(t *testing.T, url string) func(http.ResponseWriter, *http.Re
 	}
 }
 
-func getTestServer(t *testing.T, anonymousEnabled bool, withFakeSSO bool, useDexForSSO bool) (argocd *ArgoCDServer, oidcURL string) {
+func getTestServer(t *testing.T, anonymousEnabled bool, withFakeSSO bool, useDexForSSO bool, additionalOIDCConfig settings_util.OIDCConfig) (argocd *ArgoCDServer, oidcURL string) {
 	cm := test.NewFakeConfigMap()
 	if anonymousEnabled {
 		cm.Data["users.anonymous.enabled"] = "true"
@@ -562,13 +564,12 @@ connectors:
     clientID: test-client
     clientSecret: $dex.oidc.clientSecret`
 		} else {
-			oidcConfig := settings_util.OIDCConfig{
-				Name:         "Okta",
-				Issuer:       oidcServer.URL,
-				ClientID:     "argo-cd",
-				ClientSecret: "$oidc.okta.clientSecret",
-			}
-			oidcConfigString, err := yaml.Marshal(oidcConfig)
+			// override required oidc config fields but keep other configs as passed in
+			additionalOIDCConfig.Name = "Okta"
+			additionalOIDCConfig.Issuer = oidcServer.URL
+			additionalOIDCConfig.ClientID = "argo-cd"
+			additionalOIDCConfig.ClientSecret = "$oidc.okta.clientSecret"
+			oidcConfigString, err := yaml.Marshal(additionalOIDCConfig)
 			require.NoError(t, err)
 			cm.Data["oidc.config"] = string(oidcConfigString)
 			// Avoid bothering with certs for local tests.
@@ -589,9 +590,109 @@ connectors:
 		argoCDOpts.DexServerAddr = ts.URL
 	}
 	argocd = NewServer(context.Background(), argoCDOpts)
+	var err error
+	argocd.ssoClientApp, err = oidc.NewClientApp(argocd.settings, argocd.DexServerAddr, argocd.DexTLSConfig, argocd.BaseHRef, cache.NewInMemoryCache(24*time.Hour))
+	require.NoError(t, err)
 	return argocd, oidcServer.URL
 }
 
+func TestGetClaims(t *testing.T) {
+
+	defaultExpiry := jwt.NewNumericDate(time.Now().Add(time.Hour * 24))
+	defaultExpiryUnix := float64(defaultExpiry.Unix())
+
+	type testData struct {
+		test                  string
+		claims                jwt.MapClaims
+		expectedErrorContains string
+		expectedClaims        jwt.MapClaims
+		expectNewToken        bool
+		additionalOIDCConfig  settings_util.OIDCConfig
+	}
+	var tests = []testData{
+		{
+			test: "GetClaims",
+			claims: jwt.MapClaims{
+				"aud": "argo-cd",
+				"exp": defaultExpiry,
+				"sub": "randomUser",
+			},
+			expectedErrorContains: "",
+			expectedClaims: jwt.MapClaims{
+				"aud": "argo-cd",
+				"exp": defaultExpiryUnix,
+				"sub": "randomUser",
+			},
+			expectNewToken:       false,
+			additionalOIDCConfig: settings_util.OIDCConfig{},
+		},
+		{
+			// note: a passing test with user info groups can never be achieved since the user never logged in properly
+			// therefore the oidcClient's cache contains no accessToken for the user info endpoint
+			// and since the oidcClient cache is unexported (for good reasons) we can't mock this behaviour
+			test: "GetClaimsWithUserInfoGroupsEnabled",
+			claims: jwt.MapClaims{
+				"aud": common.ArgoCDClientAppID,
+				"exp": defaultExpiry,
+				"sub": "randomUser",
+			},
+			expectedErrorContains: "invalid session",
+			expectedClaims: jwt.MapClaims{
+				"aud": common.ArgoCDClientAppID,
+				"exp": defaultExpiryUnix,
+				"sub": "randomUser",
+			},
+			expectNewToken: false,
+			additionalOIDCConfig: settings_util.OIDCConfig{
+				EnableUserInfoGroups:    true,
+				UserInfoPath:            "/userinfo",
+				UserInfoCacheExpiration: "5m",
+			},
+		},
+	}
+
+	for _, testData := range tests {
+		testDataCopy := testData
+
+		t.Run(testDataCopy.test, func(t *testing.T) {
+			t.Parallel()
+
+			// Must be declared here to avoid race.
+			ctx := context.Background() //nolint:ineffassign,staticcheck
+
+			argocd, oidcURL := getTestServer(t, false, true, false, testDataCopy.additionalOIDCConfig)
+
+			// create new JWT and store it on the context to simulate an incoming request
+			testDataCopy.claims["iss"] = oidcURL
+			testDataCopy.expectedClaims["iss"] = oidcURL
+			token := jwt.NewWithClaims(jwt.SigningMethodRS512, testDataCopy.claims)
+			key, err := jwt.ParseRSAPrivateKeyFromPEM(testutil.PrivateKey)
+			require.NoError(t, err)
+			tokenString, err := token.SignedString(key)
+			require.NoError(t, err)
+			ctx = metadata.NewIncomingContext(context.Background(), metadata.Pairs(apiclient.MetaDataTokenKey, tokenString))
+
+			gotClaims, newToken, err := argocd.getClaims(ctx)
+
+			// Note: testutil.oidcMockHandler currently doesn't implement reissuing expired tokens
+			// so newToken will always be empty
+			if testDataCopy.expectNewToken {
+				assert.NotEmpty(t, newToken)
+			}
+			if testDataCopy.expectedClaims == nil {
+				assert.Nil(t, gotClaims)
+			} else {
+				assert.Equal(t, testDataCopy.expectedClaims, gotClaims)
+			}
+			if testDataCopy.expectedErrorContains != "" {
+				assert.ErrorContains(t, err, testDataCopy.expectedErrorContains, "getClaims should have thrown an error and return an error")
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
+
 func TestAuthenticate_3rd_party_JWTs(t *testing.T) {
 	// Marshaling single strings to strings is typical, so we test for this relatively common behavior.
 	jwt.MarshalSingleStringAsArray = false
@@ -723,7 +824,7 @@ func TestAuthenticate_3rd_party_JWTs(t *testing.T) {
 			// Must be declared here to avoid race.
 			ctx := context.Background() //nolint:ineffassign,staticcheck
 
-			argocd, oidcURL := getTestServer(t, testDataCopy.anonymousEnabled, true, testDataCopy.useDex)
+			argocd, oidcURL := getTestServer(t, testDataCopy.anonymousEnabled, true, testDataCopy.useDex, settings_util.OIDCConfig{})
 
 			if testDataCopy.useDex {
 				testDataCopy.claims.Issuer = fmt.Sprintf("%s/api/dex", oidcURL)
@@ -779,7 +880,7 @@ func TestAuthenticate_no_request_metadata(t *testing.T) {
 		t.Run(testDataCopy.test, func(t *testing.T) {
 			t.Parallel()
 
-			argocd, _ := getTestServer(t, testDataCopy.anonymousEnabled, true, true)
+			argocd, _ := getTestServer(t, testDataCopy.anonymousEnabled, true, true, settings_util.OIDCConfig{})
 			ctx := context.Background()
 
 			ctx, err := argocd.Authenticate(ctx)
@@ -825,7 +926,7 @@ func TestAuthenticate_no_SSO(t *testing.T) {
 			// Must be declared here to avoid race.
 			ctx := context.Background() //nolint:ineffassign,staticcheck
 
-			argocd, dexURL := getTestServer(t, testDataCopy.anonymousEnabled, false, true)
+			argocd, dexURL := getTestServer(t, testDataCopy.anonymousEnabled, false, true, settings_util.OIDCConfig{})
 			token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.RegisteredClaims{Issuer: fmt.Sprintf("%s/api/dex", dexURL)})
 			tokenString, err := token.SignedString([]byte("key"))
 			require.NoError(t, err)
@@ -933,7 +1034,7 @@ func TestAuthenticate_bad_request_metadata(t *testing.T) {
 			// Must be declared here to avoid race.
 			ctx := context.Background() //nolint:ineffassign,staticcheck
 
-			argocd, _ := getTestServer(t, testDataCopy.anonymousEnabled, true, true)
+			argocd, _ := getTestServer(t, testDataCopy.anonymousEnabled, true, true, settings_util.OIDCConfig{})
 			ctx = metadata.NewIncomingContext(context.Background(), testDataCopy.metadata)
 
 			ctx, err := argocd.Authenticate(ctx)

util/cache/inmemory.go

@@ -16,6 +16,10 @@ func NewInMemoryCache(expiration time.Duration) *InMemoryCache {
 	}
 }
 
+func init() {
+	gob.Register([]interface{}{})
+}
+
 // compile-time validation of adherance of the CacheClient contract
 var _ CacheClient = &InMemoryCache{}