Encrypt cookies

internal/server/pages.go

@@ -61,13 +61,19 @@ type indexPage struct {
 func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 	// A remembered token is resolved server-side, so the page can show the real
 	// limits without the cookie ever being readable by a script.
-	lim, err := s.limitsFor(r, cookieCredential(r))
+	lim, err := s.limitsFor(r, s.cookieCredential(r))
 	stale := false
-	if err != nil {
+	switch {
+	case err != nil:
 		// The token was revoked or the file was edited; end the session rather
 		// than leave the caller wondering why uploads fail.
 		s.forget(w, r)
 		lim, stale = auth.Anonymous(s.cfg), true
+	case s.staleSession(r):
+		// A cookie this server cannot open. Same treatment: it is not a
+		// session, and it should stop being sent.
+		s.forget(w, r)
+		stale = true
 	}
 
 	s.render(w, http.StatusOK, "index.html", indexPage{
@@ -122,7 +128,7 @@ func (s *Server) renderInfo(w http.ResponseWriter, r *http.Request, m *store.Met
 		Size:      config.FormatSize(m.Size),
 		Expires:   describeExpiry(m.Expires, s.now()),
 		URL:       s.objectURL(r, m.ID),
-		CanDelete: s.mayDelete(r, m, credential(r)),
+		CanDelete: s.mayDelete(r, m, s.credential(r)),
 		Error:     errMsg,
 	})
 }