feat(csrf): add trusted origins cli flags [BE-11972] (#839)

Co-authored-by: oscarzhou <oscar.zhou@portainer.io>
Co-authored-by: andres-portainer <andres-portainer@users.noreply.github.com>

api/http/csrf/csrf.go

@@ -2,6 +2,7 @@ package csrf
 
 import (
 	"crypto/rand"
+	"errors"
 	"fmt"
 	"net/http"
 	"os"
@@ -9,7 +10,8 @@ import (
 	"github.com/portainer/portainer/api/http/security"
 	httperror "github.com/portainer/portainer/pkg/libhttp/error"
 
-	gorillacsrf "github.com/gorilla/csrf"
+	gcsrf "github.com/gorilla/csrf"
+	"github.com/rs/zerolog/log"
 	"github.com/urfave/negroni"
 )
 
@@ -19,7 +21,7 @@ func SkipCSRFToken(w http.ResponseWriter) {
 	w.Header().Set(csrfSkipHeader, "1")
 }
 
-func WithProtect(handler http.Handler) (http.Handler, error) {
+func WithProtect(handler http.Handler, trustedOrigins []string) (http.Handler, error) {
 	// IsDockerDesktopExtension is used to check if we should skip csrf checks in the request bouncer (ShouldSkipCSRFCheck)
 	// DOCKER_EXTENSION is set to '1' in build/docker-extension/docker-compose.yml
 	isDockerDesktopExtension := false
@@ -34,10 +36,12 @@ func WithProtect(handler http.Handler) (http.Handler, error) {
 		return nil, fmt.Errorf("failed to generate CSRF token: %w", err)
 	}
 
-	handler = gorillacsrf.Protect(
+	handler = gcsrf.Protect(
 		token,
-		gorillacsrf.Path("/"),
-		gorillacsrf.Secure(false),
+		gcsrf.Path("/"),
+		gcsrf.Secure(false),
+		gcsrf.TrustedOrigins(trustedOrigins),
+		gcsrf.ErrorHandler(withErrorHandler(trustedOrigins)),
 	)(handler)
 
 	return withSkipCSRF(handler, isDockerDesktopExtension), nil
@@ -55,7 +59,7 @@ func withSendCSRFToken(handler http.Handler) http.Handler {
 			}
 
 			if statusCode := sw.Status(); statusCode >= 200 && statusCode < 300 {
-				sw.Header().Set("X-CSRF-Token", gorillacsrf.Token(r))
+				sw.Header().Set("X-CSRF-Token", gcsrf.Token(r))
 			}
 		})
 
@@ -73,9 +77,33 @@ func withSkipCSRF(handler http.Handler, isDockerDesktopExtension bool) http.Hand
 		}
 
 		if skip {
-			r = gorillacsrf.UnsafeSkipCheck(r)
+			r = gcsrf.UnsafeSkipCheck(r)
 		}
 
 		handler.ServeHTTP(w, r)
 	})
 }
+
+func withErrorHandler(trustedOrigins []string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		err := gcsrf.FailureReason(r)
+
+		if errors.Is(err, gcsrf.ErrBadOrigin) || errors.Is(err, gcsrf.ErrBadReferer) || errors.Is(err, gcsrf.ErrNoReferer) {
+			log.Error().Err(err).
+				Str("request_url", r.URL.String()).
+				Str("host", r.Host).
+				Str("x_forwarded_proto", r.Header.Get("X-Forwarded-Proto")).
+				Str("forwarded", r.Header.Get("Forwarded")).
+				Str("origin", r.Header.Get("Origin")).
+				Str("referer", r.Header.Get("Referer")).
+				Strs("trusted_origins", trustedOrigins).
+				Msg("Failed to validate Origin or Referer")
+		}
+
+		http.Error(
+			w,
+			http.StatusText(http.StatusForbidden)+" - "+err.Error(),
+			http.StatusForbidden,
+		)
+	})
+}