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RE: Planning for EXI review of XML Encryption 1.1 Last Call

From: Taki Kamiya <tkamiya@us.fujitsu.com>
Date: Wed, 19 May 2010 15:14:06 -0700
To: "'Frederick Hirsch'" <frederick.hirsch@nokia.com>, <public-xmlsec@w3.org>
Cc: <public-exi@w3.org>, <john.schneider@agiledelta.com>
Message-ID: <EEBCBA892F0D40A8B90EC0474D65F4AF@homunculus>
Dear Frederick and XMLSEC members,

Thank you for having heralded us of the upcoming release of drafts, which allowed
us to initiate the review in a timely fashion.

Please find below is our initial set of comments and questions regarding the XML
Encryption working draft [1]. We may have additional comments and questions,
and will send them out in separate emails when we have any and they become
ready.

Best regards,

Taki Kamiya for the EXI Working Group

------

Section 2.1.4 "Encrypting Arbitrary Data and XML Documents" defines a way to
encrypt a document as a whole, and shows an example that demonstrates the
ability to encode a whole XML document. A natural corollary would be encrypting
the whole EXI stream, with MimeType="application/exi", which may not necessarily
be stated there, however, I would like to confirm that such use of EXI within
EncryptedData is both legal and within the expectation of the WG.

Section 4.2 "Well-known Type parameter values" defines a reserved value for EXI.
It also states that:
"Encryptors and Decryptors should handle unknown or empty Type attribute values
 as a signal that the cleartext is to be handled as an opaque octet-stream,
 whose specific processing is up to the invoking application. In this case, the
 Type, MimeType and Encoding parameters should be treated as opaque data whose
 appropriate processing is up to the application."

It is not clear to me what is expected of a processor that does not implement
EXI have encountered Type value of "http://www.w3.org/2009/xmlenc11#EXI".
Since the value "http://www.w3.org/2009/xmlenc11#EXI" is well-known, the quoted
paragraph does not seem to apply to the value.

When I think that the encryption of EXI stream as a whole is covered by section
2.1.4, I start to wonder what the mention of EXI in section 4.2 would add beyond
that in terms of function. It appears as though the two mechanisms are
functionally same with regards to how they relate to EXI, since both provide
ways to encrypt and contain EXI streams within XML.

[1] http://www.w3.org/TR/2010/WD-xmlenc-core1-20100513/


-taki


-----Original Message-----
From: Frederick Hirsch [mailto:frederick.hirsch@nokia.com]
Sent: Monday, May 03, 2010 10:26 AM
To: john.schneider@agiledelta.com Schneider; Taki Kamiya
Cc: Frederick Hirsch; msc@mitre.org Cokus; Carine Bournez; public-exi@w3.org; public-xmlsec@w3.org Public List; ext Thomas Roessler
Subject: Planning for EXI review of XML Encryption 1.1 Last Call

John, Taki

The XML Security WG anticipates bringing  XML Encryption 1.1 [1] and
Generic Hybrid Ciphers  [2] to Last Call in the near future, as well
as having a short Last Call for an added feature to XML Signature 1.1
[3].

EXI is specifically mentioned in XML Encryption 1.1 in Section  3.1
"The EncryptedType Element", 4.1 "Intended Application Model", 4.2
"Well-known Type parameter values" and in the References.

We would like EXI review of the drafts, in particular the material
related to EXI. Would a 4 week Last Call period be sufficient, say
starting on 13 May and running until 10 June?

Thanks

regards, Frederick

Frederick Hirsch
Nokia

[1] <http://www.w3.org/2008/xmlsec/Drafts/xmlenc-core-11/Overview.htm>

[2] <http://www.w3.org/2008/xmlsec/Drafts/generic-hybrid-ciphers/Overview.html
 >

[3] KeyInfoReference, section 4.5.10 <http://www.w3.org/2008/xmlsec/Drafts/xmldsig-core-11/Overview.htm#sec-KeyInfoReference
 >
Received on Wednesday, 19 May 2010 22:22:55 GMT

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