Add support for signed URLs used by the render_file function

app/policies/code_ocean/file_policy.rb

@@ -26,6 +26,14 @@ module CodeOcean
       end
     end
 
+    def render_protected_upload?
+      return no_one if @record.native_file? && !@record.native_file_location_valid?
+      return no_one if @record.context.is_a?(Exercise) && (@record.context.unpublished || @record.hidden)
+
+      # The AuthenticatedUrlHelper will check for more details, but we cannot determine a specific user
+      everyone
+    end
+
     def create?
       if @record.context.is_a?(Exercise)
         admin? || author?

app/policies/submission_policy.rb

@@ -6,11 +6,15 @@ class SubmissionPolicy < ApplicationPolicy
   end
 
   # insights? is used in the flowr_controller.rb as we use it to authorize the user for a submission
-  %i[download? download_file? render_file? run? score? show? statistics? stop? test?
+  %i[download? download_file? run? score? show? statistics? stop? test?
      insights?].each do |action|
     define_method(action) { admin? || author? }
   end
 
+  def render_file?
+    everyone
+  end
+
   def index?
     admin?
   end