proposed addition to application/pkcs7-mime smime parameter

[Rohan Mahy <[e-mail]>]

Hello,

At IETF 56, I presented about SIP's use of S/MIME and CMS. One of the 
suggestions that I received from the group was that SIP should use raw 
CMS instead of S/MIME.  In order to convey CMS types not used by S/MIME 
(especially AuthenticatedData), it would be very convenient to have a 
MIME type registration for CMS which incorporated these types.

When draft-ietf-smime-2633bis progresses, it will hold the MIME type 
registration for application/pkcs7-mime.  Today, we could represent 
authenticated data by using the smime-type parameter with the complete 
oid for authentcated data but that is very cumbersome.  It would be 
very convenient for future uses of CMS if the types were already 
defined with the application/pkcs7-mime MIME type.

I have included some proposed text to add the other CMS types to the 
smime-type mime parameter.  Alternatively a new cms-type mime parameter 
could be defined, but this seems a but pedantic to me.

thanks,
-rohan


from 2633bis:
> 3.2.2 The smime-type parameter
>
> The application/pkcs7-mime content type defines the optional "smime-
> type" parameter. The intent of this parameter is to convey details
> about the security applied (signed or enveloped) along with infomation
> about the contained content. This specification defines the following
> smime-types.
>
> Name                   CMS type                Inner Content
>
> enveloped-data         EnvelopedData           id-data
>
> signed-data            SignedData              id-data
>
> certs-only             SignedData              none
>
> compressed-data        CompressedData          id-data


Proposed replacement text follows:

3.2.2 The smime-type parameter

The application/pkcs7-mime content type defines the optional "smime-
type" parameter. The intent of this parameter is to convey details
about the security applied (signed or enveloped) along with infomation
about the contained content. This specification defines the following
smime-types. (For completeness all CMS types are defined, even
those not used by S/MIME)

Name                   CMS type                Inner Content

enveloped-data         EnvelopedData           id-data

signed-data            SignedData              id-data

certs-only             SignedData              none

compressed-data        CompressedData          id-data

authenticated-data     AuthenticatedData  *    id-data

digested-data          DigestedData       *    id-data

encrypted-data         EncryptedData      *    id-data

*Note that these CMS types are not used by S/MIME