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xkms 2.0 issues

From: Aleksey Sanin <aleksey@aleksey.com>
Date: Wed, 30 Apr 2003 22:03:20 -0700
Message-ID: <1057787593.IAA22192@phantom.w3.org>
To: www-xkms@w3.org

Hi, All!

I am preparing to do the XKMS 2 implementation in XML Security Library
(http://www.aleksey.com/xmlsec) and after reading the spec I found some
issues:

0) As far as can see, there is no way to specify the desired key type 
(RSA/DSA/...)
in <xkms:LocateRequest/> or <xkms:ValidateRequest/>. This is not a major
problem because XKISS server may return a list of keys but I think that in
most case the desired key type is known to the client and could be used
to narrow key search on the server side (and reduce network traffic :) ).
For example, I can easily imagine that RSA and DSA keys would be stored
in different database tables. Key type may limit key search to one table 
instead of two.

1) It does not seem that there is a way to use symmetric keys. While public
key cryptography is became more and more afordable, there are still 
situations
when symmetric key cryptography is usefull either because of performance,
legacy or some other reasons. An use case example might be a couple of
high traffic servers when one stores some sensitive data on the client 
in an
encrypted format (say, in cookies) and another one decrypt this data. 
These two
servers may use XKISS server as a central keys storage (for example,
to provide keys rotation). Using symmetric keys might be desirable 
because of
performance reasons as well as small encrypted data size.

2) In the schema for <xkms:ValidityInreval/> element "NotBefore" and 
"NotAfter"
attributes do not have "use=\"optional\"" specified.

3) The "maxOccurs=\"3\"" for <xkms:KeyUsage/> element may prevent schema 
extension
in the future, I would suggest to change this to "maxOccurs=\"unbound\"".

Most likely it's already too late to for any changes but I would like to 
note these issues.
Also I wonder if there exist any kind of interop test suite (I could not 
find one on the XKMS
working group page).

Thanks,

Aleksey Sanin
Received on Thursday, 1 May 2003 01:04:03 GMT

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