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RE: Proposed Infoset Addendum to SOAP Messages with Attachments

From: Martin Gudgin <mgudgin@microsoft.com>
Date: Wed, 26 Mar 2003 09:17:39 -0800
Message-ID: <7C083876C492EB4BAAF6B3AE0732970E0AE6ABC0@red-msg-08.redmond.corp.microsoft.com>
To: "Marc Hadley" <Marc.Hadley@Sun.COM>
Cc: <xml-dist-app@w3.org>

 

> 
> -----Original Message-----
> From: Marc Hadley [mailto:Marc.Hadley@Sun.COM] 
> Sent: 26 March 2003 08:19
> To: Martin Gudgin
> Cc: xml-dist-app@w3.org
> 
> I'm generally in favor of this approach but I think there are 
> a couple of problems it doesn't adequately address:
> 
> (i) Attachments are an optimization to avoid having to base64 
> encode binary data. Section 8 of the proposal requires that 
> 'signatures over elements with xbinc:Include children MUST be 
> signatures over the base64 data'. If you buy the premise that 
> security in the form of DSIGs etc is going to be widely used 
> then this requirement basically nullifies the advantage of 
> using attachments since you'll have to run the base64 
> encoding to compute and verify signatures.
> 
> I think a better approach would be a xbinc:Include aware XML 
> DSIG C14N algorithm that just streams the binary data in the 
> case of attachments (hence preserving the optimization) and 
> does base64 decoding in the case of embedded data.

Don and I were discussing this approach last night, definitely worth
investigating I think.

> 
> (ii) the current formulation misses an important facet of included
> attachments: their identity - i'll try to illustrate with a 
> (contrived) example.
<SNIP>example</SNIP>
> 
> I suspect that a constrained use of the swa:Representation 
> element might help with this problem - that is if there is 
> only 1 representation of a given resource in the MIME package 
> the swa:Representation/@href can be used. Alternatively an 
> application specific attachment reference mechanism could be 
> used but that kind of defeats the purpose.

Certainly I was thinking that where identity was important
swa:Representation would be used.


Gudge
Received on Wednesday, 26 March 2003 12:17:32 GMT

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