django-rest-framework - raise permission denied instead of not found

HideNotFoundSubClass.py

def HideNotFoundSubClass(base_class):
    '''
    So apparently, django-rest-framework's permission checks aren't quite enough
     for me.
    It has 2 steps:
    1. Check global permissions by calling has_permission for each of the
        permission classes
    2. Check object permissions by calling has_object_permission for each
        of the permission classes
    Between 1 and 2, it tries to find the object with get_object().
    Now, if the object does not exist, we get a 404, which would make sense
        in most cases. However, if the object does exist but test 2 fails, we get
        403. That allows authenticated users to know whether a resource
        exists or not, even though they wouldn't have permissions for it if it did.
    This is quite a serious problem for me, so I made this function.
    Basically, this wraps a given class by a subclass that overrides get_object().
    The new get_object() function catches the 404 and raises a 403 instead.
    '''
    cls = type(base_class.__name__+'_HideNotFoundSubClass', (base_class,), {})
    def get_object(self, queryset=None):
        try:
            obj = super(cls, self).get_object(queryset)
            return obj
        except Http404 as e:
            raise PermissionDenied()
    cls.get_object = get_object
    return cls