add RefreshingValidationHandler when refershing token, you can confir…

…m authorization is vaild

server/handler.go

@@ -27,6 +27,9 @@ type (
 	// RefreshingScopeHandler check the scope of the refreshing token
 	RefreshingScopeHandler func(newScope, oldScope string) (allowed bool, err error)
 
+	//RefreshingValidationHandler check if refresh_token is still valid. eg no revocation or other
+	RefreshingValidationHandler func(ti oauth2.TokenInfo) (allowed bool, err error)
+
 	// ResponseErrorHandler response error handing
 	ResponseErrorHandler func(re *errors.Response)
 

server/server.go

@@ -47,6 +47,7 @@ type Server struct {
 	ClientScopeHandler           ClientScopeHandler
 	UserAuthorizationHandler     UserAuthorizationHandler
 	PasswordAuthorizationHandler PasswordAuthorizationHandler
+	RefreshingValidationHandler  RefreshingValidationHandler
 	RefreshingScopeHandler       RefreshingScopeHandler
 	ResponseErrorHandler         ResponseErrorHandler
 	InternalErrorHandler         InternalErrorHandler
@@ -392,6 +393,22 @@ func (s *Server) GetAccessToken(ctx context.Context, gt oauth2.GrantType, tgr *o
 			}
 		}
 
+		if validationFn := s.RefreshingValidationHandler; validationFn != nil {
+			rti, err := s.Manager.LoadRefreshToken(ctx, tgr.Refresh)
+			if err != nil {
+				if err == errors.ErrInvalidRefreshToken || err == errors.ErrExpiredRefreshToken {
+					return nil, errors.ErrInvalidGrant
+				}
+				return nil, err
+			}
+			allowed, err := validationFn(rti)
+			if err != nil {
+				return nil, err
+			} else if !allowed {
+				return nil, errors.ErrInvalidScope
+			}
+		}
+
 		ti, err := s.Manager.RefreshAccessToken(ctx, tgr)
 		if err != nil {
 			if err == errors.ErrInvalidRefreshToken || err == errors.ErrExpiredRefreshToken {

server/server_config.go

@@ -54,6 +54,12 @@ func (s *Server) SetRefreshingScopeHandler(handler RefreshingScopeHandler) {
 	s.RefreshingScopeHandler = handler
 }
 
+// SetRefreshingValidationHandler check if refresh_token is still valid. eg no revocation or other
+func (s *Server) SetRefreshingValidationHandler(handler RefreshingValidationHandler) {
+	s.RefreshingValidationHandler = handler
+}
+
+
 // SetResponseErrorHandler response error handling
 func (s *Server) SetResponseErrorHandler(handler ResponseErrorHandler) {
 	s.ResponseErrorHandler = handler