Enforce two-factor auth (2FA: TOTP or WebAuthn) (#34187)

Fix #880

Design:

1. A global setting `security.TWO_FACTOR_AUTH`.
* To support org-level config, we need to introduce a better "owner
setting" system first (in the future)
2. A user without 2FA can login and may explore, but can NOT read or
write to any repositories via API/web.
3. Keep things as simple as possible.
* This option only aggressively suggest users to enable their 2FA at the
moment, it does NOT guarantee that users must have 2FA before all other
operations, it should be good enough for real world use cases.
* Some details and tests could be improved in the future since this
change only adds a check and seems won't affect too much.

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

services/auth/source/oauth2/assert_interface_test.go

@@ -14,7 +14,6 @@ import (
 
 type sourceInterface interface {
 	auth_model.Config
-	auth_model.SourceSettable
 	auth_model.RegisterableSource
 	auth.PasswordAuthenticator
 }

services/auth/source/oauth2/source.go

@@ -10,6 +10,8 @@ import (
 
 // Source holds configuration for the OAuth2 login source.
 type Source struct {
+	auth.ConfigBase `json:"-"`
+
 	Provider                      string
 	ClientID                      string
 	ClientSecret                  string
@@ -25,10 +27,6 @@ type Source struct {
 	GroupTeamMap        string
 	GroupTeamMapRemoval bool
 	RestrictedGroup     string
-	SkipLocalTwoFA      bool `json:",omitempty"`
-
-	// reference to the authSource
-	authSource *auth.Source
 }
 
 // FromDB fills up an OAuth2Config from serialized format.
@@ -41,11 +39,6 @@ func (source *Source) ToDB() ([]byte, error) {
 	return json.Marshal(source)
 }
 
-// SetAuthSource sets the related AuthSource
-func (source *Source) SetAuthSource(authSource *auth.Source) {
-	source.authSource = authSource
-}
-
 func init() {
 	auth.RegisterTypeConfig(auth.OAuth2, &Source{})
 }

services/auth/source/oauth2/source_callout.go

@@ -13,7 +13,7 @@ import (
 // Callout redirects request/response pair to authenticate against the provider
 func (source *Source) Callout(request *http.Request, response http.ResponseWriter) error {
 	// not sure if goth is thread safe (?) when using multiple providers
-	request.Header.Set(ProviderHeaderKey, source.authSource.Name)
+	request.Header.Set(ProviderHeaderKey, source.AuthSource.Name)
 
 	// don't use the default gothic begin handler to prevent issues when some error occurs
 	// normally the gothic library will write some custom stuff to the response instead of our own nice error page
@@ -33,7 +33,7 @@ func (source *Source) Callout(request *http.Request, response http.ResponseWrite
 // this will trigger a new authentication request, but because we save it in the session we can use that
 func (source *Source) Callback(request *http.Request, response http.ResponseWriter) (goth.User, error) {
 	// not sure if goth is thread safe (?) when using multiple providers
-	request.Header.Set(ProviderHeaderKey, source.authSource.Name)
+	request.Header.Set(ProviderHeaderKey, source.AuthSource.Name)
 
 	gothRWMutex.RLock()
 	defer gothRWMutex.RUnlock()

services/auth/source/oauth2/source_register.go

@@ -9,13 +9,13 @@ import (
 
 // RegisterSource causes an OAuth2 configuration to be registered
 func (source *Source) RegisterSource() error {
-	err := RegisterProviderWithGothic(source.authSource.Name, source)
-	return wrapOpenIDConnectInitializeError(err, source.authSource.Name, source)
+	err := RegisterProviderWithGothic(source.AuthSource.Name, source)
+	return wrapOpenIDConnectInitializeError(err, source.AuthSource.Name, source)
 }
 
 // UnregisterSource causes an OAuth2 configuration to be unregistered
 func (source *Source) UnregisterSource() error {
-	RemoveProviderFromGothic(source.authSource.Name)
+	RemoveProviderFromGothic(source.AuthSource.Name)
 	return nil
 }
 

services/auth/source/oauth2/source_sync.go

@@ -18,27 +18,27 @@ import (
 
 // Sync causes this OAuth2 source to synchronize its users with the db.
 func (source *Source) Sync(ctx context.Context, updateExisting bool) error {
-	log.Trace("Doing: SyncExternalUsers[%s] %d", source.authSource.Name, source.authSource.ID)
+	log.Trace("Doing: SyncExternalUsers[%s] %d", source.AuthSource.Name, source.AuthSource.ID)
 
 	if !updateExisting {
-		log.Info("SyncExternalUsers[%s] not running since updateExisting is false", source.authSource.Name)
+		log.Info("SyncExternalUsers[%s] not running since updateExisting is false", source.AuthSource.Name)
 		return nil
 	}
 
-	provider, err := createProvider(source.authSource.Name, source)
+	provider, err := createProvider(source.AuthSource.Name, source)
 	if err != nil {
 		return err
 	}
 
 	if !provider.RefreshTokenAvailable() {
-		log.Trace("SyncExternalUsers[%s] provider doesn't support refresh tokens, can't synchronize", source.authSource.Name)
+		log.Trace("SyncExternalUsers[%s] provider doesn't support refresh tokens, can't synchronize", source.AuthSource.Name)
 		return nil
 	}
 
 	opts := user_model.FindExternalUserOptions{
 		HasRefreshToken: true,
 		Expired:         true,
-		LoginSourceID:   source.authSource.ID,
+		LoginSourceID:   source.AuthSource.ID,
 	}
 
 	return user_model.IterateExternalLogin(ctx, opts, func(ctx context.Context, u *user_model.ExternalLoginUser) error {
@@ -77,7 +77,7 @@ func (source *Source) refresh(ctx context.Context, provider goth.Provider, u *us
 	// recognizes them as a valid user, they will be able to login
 	// via their provider and reactivate their account.
 	if shouldDisable {
-		log.Info("SyncExternalUsers[%s] disabling user %d", source.authSource.Name, user.ID)
+		log.Info("SyncExternalUsers[%s] disabling user %d", source.AuthSource.Name, user.ID)
 
 		return db.WithTx(ctx, func(ctx context.Context) error {
 			if hasUser {

services/auth/source/oauth2/source_sync_test.go

@@ -18,19 +18,21 @@ func TestSource(t *testing.T) {
 
 	source := &Source{
 		Provider: "fake",
-		authSource: &auth.Source{
-			ID:            12,
-			Type:          auth.OAuth2,
-			Name:          "fake",
-			IsActive:      true,
-			IsSyncEnabled: true,
+		ConfigBase: auth.ConfigBase{
+			AuthSource: &auth.Source{
+				ID:            12,
+				Type:          auth.OAuth2,
+				Name:          "fake",
+				IsActive:      true,
+				IsSyncEnabled: true,
+			},
 		},
 	}
 
 	user := &user_model.User{
 		LoginName:   "external",
 		LoginType:   auth.OAuth2,
-		LoginSource: source.authSource.ID,
+		LoginSource: source.AuthSource.ID,
 		Name:        "test",
 		Email:       "external@example.com",
 	}
@@ -47,7 +49,7 @@ func TestSource(t *testing.T) {
 	err = user_model.LinkExternalToUser(t.Context(), user, e)
 	assert.NoError(t, err)
 
-	provider, err := createProvider(source.authSource.Name, source)
+	provider, err := createProvider(source.AuthSource.Name, source)
 	assert.NoError(t, err)
 
 	t.Run("refresh", func(t *testing.T) {