Re: updated XML Encryption 1.1 editors draft for 6.1.3 security consideration ( LC-2735)

We're all confused about that.  Not sure what happened there.
-- 
Thomas Roessler, W3C <tlr@w3.org> (@roessler)



On 2013-01-07, at 19:47 +0100, Donald Eastlake <d3e3e3@gmail.com> wrote:

> Hi,
> 
> I'm unclear why my email address is given as the response address...
> 
> Thanks,
> Donald
> =============================
> Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
> 155 Beaver Street, Milford, MA 01757 USA
> d3e3e3@gmail.com
> 
> 
> On Mon, Jan 7, 2013 at 1:37 PM,  <frederick.hirsch@nokia.com> wrote:
>> Dear Juraj Somorovsky ,
>> 
>> The XML Security Working Group has reviewed the comments you sent [1] on
>> the Last Call Working Draft [2] of the XML Encryption Syntax and Processing
>> Version 1.1 published on 18 Oct 2012. Thank you for having taken the time
>> to review the document and to send us comments!
>> 
>> The Working Group's response to your comment is included below.
>> 
>> Please review it carefully and let us know by email at d3e3e3@gmail.com if
>> you agree with it or not before 11 January 2013. In case of disagreement,
>> you are requested to provide a specific solution for or a path to a
>> consensus with the Working Group. If such a consensus cannot be achieved,
>> you will be given the opportunity to raise a formal objection which will
>> then be reviewed by the Director during the transition of this document to
>> the next stage in the W3C Recommendation Track.
>> 
>> Thanks,
>> 
>> For the XML Security Working Group,
>> Thomas Roessler
>> W3C Staff Contact
>> 
>> 1. http://www.w3.org/mid/50BE1B56.90406@rub.de
>> 2. http://www.w3.org/TR/2012/WD-xmlenc-core1-20121018/
>> 
>> 
>> =====
>> 
>> Your comment on :
>>> Frederick
>>> 
>>> yes, we were thinking about including some concrete examples how a
>>> secure key derivation should (must) look like. But we are not experts
>>> in
>>> this concrete field and for the construction of a secure derivation we
>>> would need more time...
>>> 
>>> Best Regards
>>> Juraj
>>> 
>>> On 12/04/2012 04:05 PM, Frederick.Hirsch@nokia.com wrote:
>>>> Juraj
>>>> 
>>>> I think what you are saying is that it would help to clarify how key
>>> derivation using the algorithm identifier is done. We have definitions
>>> for key derivation functions in the spec as well as algorithm ids. Are
>>> you suggesting that we need to be clear how to create the master secret,
>>> e.g. prepend the master key with the algorithm id, etc? What kind of
>>> text would you be suggesting?
>>>> 
>>>> If this is the case, would an informative example suffice?
>>>> 
>>>> I'm concerned because the specification is already "frozen" and we are
>>> on path to publish final recommendation. We decided to incorporate the
>>> security consideration at the last minute since is informative, but
>>> adding normative text would imply a new cycle of interop testing, repeat
>>> of all process steps, and a significant delay in publication, which may
>>> not be possible.
>>>> 
>>>> Perhaps there is a way we can avoid another cycle yet address the
>>> concern.
>>>> 
>>>> regards, Frederick
>>>> 
>>>> Frederick Hirsch, Nokia
>>>> Chair XML Security WG
>>>> 
>>>> 
>>>> 
>>>> On Dec 4, 2012, at 9:25 AM, ext Juraj Somorovsky wrote:
>>>> 
>>>>> Hi Frederick,
>>>>> 
>>>>> thanks for CC'ing us, there are our thoughts.
>>>>> 
>>>>> On 12/03/2012 03:51 PM, Frederick.Hirsch@nokia.com wrote:
>>>>>> 2.  Implementations using symetric keys should not use the same key
>>> material for different algorithms, even if serving the same purpose. Key
>>> derivation based on a single key and the algorithm identifier can be
>>> used to accomplish this, for example.
>>>>>> 3.  Implementations that plan to use the same symetric key for both
>>> confidentiality and integrity functions should use it as the basis for a
>>> key derivation producing different keys for those functions.
>>>>> We are puzzled what is the difference between these two points.
>>>>> Is 2. meant to be specifically for AES-CBC / AES-GCM and 3.
>>> specifically
>>>>> for AES-CBC / HMAC ?
>>>>> 
>>>>> If yes, would it be not better readable to summarize 2. and 3. into
>>> one
>>>>> point?
>>>>>> On a related note, should we define in XML Encryption 1.1 the
>>> specific key derivation function to derive a key based on algorithm
>>> identifier and key? I'm concerned about what this means for interop and
>>> progressing the specification. If we do need this I suggest we might
>>> progress it as an independent specification, but am not sure we need to
>>> do this. Thoughts?
>>>>> We think it is necessary to include the key derivation function into
>>> the
>>>>> standard (for interoperability reasons as well as for better
>>> understanding).
>>>>> 
>>>>> Thank you
>>>>> Juraj and Tibor
>>>> 
>> 
>> 
>> Working Group Resolution (LC-2735):
>> Defer definition of key derivation based on algorithm identifier to a
>> version 1.2 of XML Encryption
>> 
>> (see item #1 in CfC
>> http://lists.w3.org/Archives/Public/public-xmlsec/2012Dec/0015.html )
>> 
>> ----
>> 
>> 
> 

Received on Monday, 7 January 2013 18:49:29 UTC