RE: Security requirements

Dear Ugo and other Choreographers,
 
See below for comments embedded.
 

Best Regards,

Tony                           


 <http://www.choreology.com/>  

Tony Fletcher

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-----Original Message-----
From: Ugo Corda [mailto:UCorda@SeeBeyond.com] 
Sent: 21 November 2003 19:40
To: Fletcher, Tony; public-ws-chor@w3.org
Subject: RE: Security requirements


Hi Tony,
 
I imagine that when you talk about "language implementation" you mean
"detailed definition of language constructs".
<Tony> Yes </Tony>
 
I understand your point about first clearly specifying language
requirements. My point was about also keeping an eye on what is already
supported out there in the same policy area.  
<Tony> Agreed, I do realise that one needs to be realistic in specifying
requirements and not 'require' things that you have no hope of
delivering with out very good reason.  However, in general, I believe
that requirements should be considered on the merits and how to
implement them or even if it is possible/ practical to implement
especially in a V1 specification. </Tony>
 
Since the policy discussions are still ongoing within the WSDL WG, I
cannot guarantee that the type of abstract policies you are talking
about will actually be fully supported in WSDL. All I am saying is that,
IF WSDL support that type of abstract policy definitions, and IF the CDL
relies on the existence of WSDL files, then it might not be necessary to
duplicate the same information within the CDL itself but just rely on
what WSDL already specifies.  
<Tony> This may be the core of the discussion between us.  I am saying
as clearly as I can that you can not do it ALL in WSDL - by the nature
of WSDL - and that is why we need a Choreography language on top of
WSDL.  What you can specify in the WSDL is the mandatory security
features / policies.  For instance that this Web Service always requires
mutual authentication, or that confidentiality shall never be used with
this web service.  Such mandatory features should not appear in a
choreography description.  If a choreography description tries to
override a mandatory feature then it should either be ignored (if its
effect is to weaken security contrary to the mandatory policy), or
generate a fault (if it is trying to demand something that is just not
available).
 
The WSDL should also be able to state that one or more security features
are optional for the web service.  So for instance it can do
confidentiality but one does not have to use it on every instance of use
of the web service.  These are the cases where you can use the
choreography description to state exactly which messages have to be sent
confidentially and which do not.  I hope this is clear.</Tony>
 
Ugo