What is the best way to formally distinguish between the PEM/MIME or IETF
version of X.509 v3 and the ISO/ITU version, perhaps with a unique attribute
ID?
None of PEM 1421-1424 specified attribute OIDs as they did not discuss PEM use
of the Directory.
Historically, several organizations specified (different) OIDs for the
pemRevocationList.
I think it would be a good idea to have the IETF (or some organization speaking
for the IETF process, perhaps ISOC) registered as an "ISO-identified
organization"
(i.e. under the OID 1.3) which would make it easier for any RFC or internet
standard to specify own OIDs in a globally collision-free way if they need it.
The 1422-defined RevocationList is a good example where you have a lack of
specification when you use PEM in conjunction with an X.500 Directory. To get
registered as an ISO-identified organization is an easy process at no cost, and
other organizations like OIW or EWOS did it as well.
BTW, this could be a possibility to get rid of the RSADSI-defined OIDs
1.2.840.113549.x.y.z (from RFC 1423 and PKCS) which can be a pain on platforms
with 16-bit integers (for instance, when using the ISODE pepsy-compiler for
ASN.1 encoding/decoding on a MS-DOS platform).
Wolfgang Schneider
GMD
Darmstadt, Germany