Blake,
These discussions occured when we were still meeting in San Fransico. If we
allow for this to occur in the S/MIME world we immeadiately hit the demon of
backwards compatability. I don't know about your product, but ours does not
look at capabilites of recipients when sending signed mail. Thus we MUST
use the Issuer/Serial Number identification as we have no idea if the
receiving client has the ability to understand anything new.
This is a fine change for CMS but verboten for S/MIME
jim
-----Original Message-----
From: Blake Ramsdell [mailto:BlakeR(_at_)deming(_dot_)com]
Sent: Monday, November 23, 1998 1:32 PM
To: 'Russ Housley'; pgut001(_at_)cs(_dot_)aucKland(_dot_)ac(_dot_)nz
Cc: ietf-smime(_at_)imc(_dot_)org
Subject: RE: RecipientInfo vs SignerInfo key identification
-----Original Message-----
From: Russ Housley [mailto:housley(_at_)spyrus(_dot_)com]
Sent: Monday, November 23, 1998 8:16 AM
To: pgut001(_at_)cs(_dot_)aucKland(_dot_)ac(_dot_)nz
Cc: ietf-smime(_at_)imc(_dot_)org
Subject: Re: RecipientInfo vs SignerInfo key identification
The addition of SubjectKeyIdentifier to SignerInfo was
considered. Many
developers felt that backward compatibility with PKCS#7 v1.5
and S/MIME v2
was more important that the shorter certificate reference.
When was this considered? I can't find a discussion about it in the past
(of course, that refers more to my blindness than anything else.)
It woulf be very easy to add SubjectKeyIdentifier to SignerInfo if the
group concensus has changed.
It seems that you can tick the version number as we do if ACs or
encapsulated content other than id-data is present.
I really don't recall discussing this, and it seems that certificate
references should be the same across the board. I do agree that backward
compatibility is paramount, and we can accomplish that by using the version
number tick that we are already using for other non-backward-compatible
things.
Blake
--
Blake C. Ramsdell
Worldtalk Corporation
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