Subject: RE: I-D ACTION:draft-ietf-smime-x400transport-00.txt

From: Graeme Lunt <[email-masked]>
Date: Thu, 16 Nov 2000 10:41:46 -0000

Russ,

> The CMS contentInfo uses id-data when the content is expected to be 
> MIME.  This choice is for historical reasons (S/MIME v2 did 
> it that way).
> 
> I think that the authors are trying to avoid a layer of MIME 
> encapsulation.  

Yes - I can see that you would want to avoid this.

> Did I miss something?

My comment was a little different. 

What is being proposed is that the OID id-data must be used for the
X.400 content type when the CMS object is covered by an outer MIME 
wrapper. 

However, a more generic option is to use an OID (say "id-mime") for 
the X.400 content type that represents MIME. 
Using this content type I could still carry my MIME wrapped CMS object, 
but I could also carry other arbitray MIME objects. For example, I 
could carry multipart/signed with this method.

In fact, thinking about it a little more, does the draft as it stands
actually allow me to do this? If I use id-data as the content-type, 
MUST the content be a MIME wrapped CMS object? Could it just be arbitrary
MIME?

This would certainly be a useful feature.

Graeme

---

From: "Bonatti, Chris" <[email-masked]>
Date: Thu, 16 Nov 2000 09:44:06 -0500

> This would certainly be a useful feature.

Graeme,

    I think that 'id-data' covers any MIME object, not just CMS.  Since it's
defined in the S/MIME standards, the door is certainly open for somebody to
question the scope of its use as a generally applicable identifier for all
MIME.  However, since (to my knowledge) nothing like this exists elsewhere,
it's the best choice available.

Chris