[ebxml-cppa] Certificate Element under PartyInfo

[Dale Moberg <dmoberg@cyclonecommerce.com>]

With the emergence of Certificates that form
the set of TrustAnchors (or trusted roots)
in the SecurityDetails, the possibility arises
that the same Certificates may be used in
distinct PartyInfos in the CPA. So an opportunity
for reuse (much like that of Packaging) arises.

It may not be worth it. However, ds:KeyInfos
can be large items (base 64 encodings of entire
certificate chains, maybe 2 to 6 K range), 
it may be worth raising the Certificate element sequence
up to just under the root elements-- 
/CollaborationProtocolProfile or /CollaborationProtocolAgreement.

While thinking about how large these items are,
should we also generalize Certificate to be either
a ds:KeyInfo or a URI for retrieval? If so, what
forms of URI should be allowed? Should any exotic
URIs for PKIX  protocols be included? Should we avoid
requiring or promoting any Cert access method 
and just leave it as anyURI? I think it is worthwhile
thinking about just what implementations would be expected
to support for these URIs in terms of access (ftp, http,
ldap, etc etc).

Thanks,
Dale
(Working on 1.1 Security updates)