Thanks Jim,
First all of the tool kits separate the MIME processing from the CMS
processing so there is no need to tie them together if not needed.
Good.
Questions:
1. Do you expect the inner data to ever be transported independent of a
CMS wrapping?
Yes, the inner data are Diameter AVPs (attr/vals pairs) and will often be
carried, in clear, as "normal" Diameter AVPs. There can be "proxy" things
that wrap/unwrap the AVPs.
2. Do you feel that either a) you can assign an OID for this content or
b) the content is uniquely described else where (this can be in the
protocol as well).
I'd say yes, given that all the AVPs are defined in Diameter specs. However,
I'd expect to get toolkit problems with a new OID. Maybe I'm just a pessimist.
3. Do you expect the wrapped data to be transported using a system that
expects MIME content (i.e. SMTP, HTTP)?
Nope.
If the answer for 1 is yes, then use MIME for the inner wrapping
otherwise use a binary content.
If the answer for 2 is yes, then assign a new OID for the binary
structure (or use id-data). If the answer is no, use a MIME wrapper.
If the answer for 3 is yes, use MIME otherwise don't.
I expect that there may be some people who would disagree with my
response to question #2. Specifically I am allowing for what I assume
is a non ASN.1 binary blob to be assigned an OID value and placed in the
encapsulated data. I feel that this is appropriate and legal. Also,
beware of some completely automated processors (such as a mail client)
which assume that id-data is the equivalent of saying MIME content.
This is not what is specified in the documents but is an assumption in
some environments.
So, given the above, am I right that you'd recommend:
1. EnvelopedData-fnc(MIME-enc(data),receipient-stuff...)
and use id-data as the OID.
Stephen.
PS: I also got off-list recommendations for 2 and 4 (I think:-)
1. EnvelopedData-fnc(MIME-enc(data),receipient-stuff...)
2. MIME-enc(EnvelopedData-fnc(data,receipient-stuff...))
3. MIME-enc(EnvelopedData-fnc(MIME-enc(data),receipient-stuff...))
4. EnvelopedData-fnc(data,receipient-stuff...)
--
____________________________________________________________
Stephen Farrell
Baltimore Technologies, tel: (direct line) +353 1 881 6716
39 Parkgate Street, fax: +353 1 881 7000
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