Re: [dss] Is a single <Schema> element adequate?

[Trevor Perrin <trevp@trevp.net>]

Tommy Lindberg wrote:
> Hi Trevor -
> 
> I had accepted bloated payloads as a result of transfering schemas
> inline :) I even wrote the code to do it, but based on what you are
> saying it looks like I may have misunderstood the intended usage of
> the <Schema> element.
> 
> 
>>I think it's possible to chop down such a schema into a single
>>one that contains everything needed?
> 
> 
> I have never had to that. You wouldn't have an example handy?

No - and I may be wrong.  It might not be possible to define things in 
different namespaces with a single schema.

Earlier, we used DTDs for this, which may be more flexible.  See
http://www.aleksey.com/xmlsec/faq.html, section 3.2, for an example.


The server only needs to identify ID attributes in the situation where a 
<ds:Reference> uses a null URI and an XPointer expression, and the 
client doesn't pass the server the exact Input Documents that match the 
<ds:Reference>s (so the server has to resolve the <ds:Reference>s by 
itself).

We could decide not to support that case, and require the client to 
always send Input Documents that match all the <ds:Reference>s.  That 
may be more work for the client, and may result in larger protocol messages.

Trevor


> 
> Regards,
> Tommy
> 
> 
> On 5/5/05, Trevor Perrin <trevp@trevp.net> wrote:
> 
>>Tommy Lindberg wrote:
>>
>>>The <Schema> element in DocumentBaseType and SignatureObject allows
>>>for the optional transfer of a single XML Schema. This seems inadequate
>>
>> > for some use cases such as verifying a signed XML instance that
>> > pertains to a schema that in turn imports additional schemas.
>>
>>Hi Tommy,
>>
>>note that the schema is only needed in certain usage scenarios.  In
>>these scenarios, the schema identifies ID attributes so as to help the
>>server resolve <ds:Reference>s.  The schema doesn't have to be the full
>>schema for the document.  So even if the full schema imports other
>>schemas, I think it's possible to chop down such a schema into a single
>>one that contains everything needed?
>>
>>Trevor
>>
>>ps: When the <Schema> element is described in the core spec, it refers
>>to "section 4.3, step 2".  Those references should be changed to
>>"section 4.3, step 1".
>>
> 
>