Re: [wss] Issue 389: Detection of Duplicate IDs

[ronald monzillo <Ronald.Monzillo@Sun.COM>]

Reid, Irving wrote:
>>From: ronald monzillo [mailto:Ronald.Monzillo@sun.com] 
>>
>>Is is not sufficient to say something like the following
>>
>>The wsse:Security processing MUST generate a fault if it 
>>employs any id attribute in its processing for which there 
>>are multiple elements within the message that share that 
>>same id attribute name and value.
> 
> 
> No, it's not sufficient. The attribute *name* is completely irrelevant. All
> attributes that are given type "ID" by some XML schema or DTD map into the
> same identifier namespace, in a sense. That's why it's such a problem - when
> you get an arbitrary XML document, you need to have access to all the
> applicable schemas in order to determine which attributes are IDs.
> 
>  - irving -
> 

It may be that I didn't communicate clearly enough.

I think the rule I proposed would be more restrictive than necessary, as
the processing COULD avoid generating faults if the id-ness of duplicate
(relative) named attibute can be determined or if the fully qualified
names of such attributes can be determined; but knowing either of these
things would require schema knowledge (which we don't want to require).

If same (relative) named and valued attributes can be detected (without
schema knowledge), and we reject documents where such attribute
instances are employed in the wssee:Security processing performed on the
document, then wouldn't we be throwing away all potentially dangerous
messages and a few others?

Ron