The description of the <cert> and <crl> productions in draft-ietf-pem-mime-07
section 5.2 (application/pemkey-data) provide only that the values of the
"Certificate" and "CRL" fields are in a particular <encbin> encoding, but do
not provide a reference for an ASN.1 value which should be encoded and placed
there.
As in sections 2.1.3 and 2.2.4 there are explicit references for new ASN.1
values being used (the 'Name' of X.501 and the 'SubjectPublicKeyInfo' of
X.509)
, and formats similar to those of PEM other than certificates and CRLs are
described in section 14 as being imported from RFC 1421/1423, would it be
clearer if in section 5.2 there was a comment inserted, similar in style to
those in 1421:
The definitions and semantics of certificates and CRLs are to be
found in [4].
([4] is RFC 1422)
I think that it is one thing to cite a standard such as X.509 which contains a
specific version, but something else to cite RFC1421/23 for the definitions and
semantics. X.509 v1 isn't going to change, but RFC1422 might, leaving the
certificate format for PEM/MIME iomplementations somewhat ambiguous.
If it were only a difference in a data template it might not make much
difference. But supporting the CRITICAL extensions requires support in the
code, not just a recompilation somewhere down the line, and I think that it is
VERY important to get that functionality included at this juncture. (I
understand that versions that do not support v3 should reject the entire
certificate, whether or not they udnerstand certain extensions. But that will
just make it much harder to add support later on, since most implementations
won't support it. In partiuclar, it will make it impossible to add optional,
non-critical extensions on an incremental basis.
Since citing RFC1422 would probably have the effect of making it much harder to
get v3 adopted, I think that if we want to move forward on the standards track
(several years after the orignal v1 was adopted for PEM), we should explicitly
specify the appropriate ASN.1 encodings, etc. for v3 in the PEM/MIME spec
itself at this time.
Bob
--------------------------------
Robert R. Jueneman
GTE Laboratories
40 Sylvan Road
Waltham, MA 02254
FAX: 1-617-466-2603
Voice: 1-617-466-2820