Subject: Extension name divergence between PKIX profile and X.509 4th Edit ion

From: "Covey, Carlin" <[email-masked]>
Date: Wed, 11 Apr 2001 12:48:31 -0700

There appears to be a bit of divergence between certain extension names and
definitions used in X.509 4th Edition X.509_4thEditionDraftV6.pdf and the
PKIX profile (draft-ietf-pkix-new-part1-05.txt).

draft-ietf-pkix-new-part1-05.txt describes a "Freshest CRL" extension (which
is also called "Delta CRL Distribution Point").  The extension is described
in section 4.2.1.16, a subsection under 4.2 Standard Certificate Extensions,
and it is described again in section 5.2.6, a subsection under 5.2 CRL
Extensions.  So according to the PKIX profile the extension appears to be
usable as either a certificate extension or a CRL extension, with identical
syntax.  Section 8.6.2.6 of X.509 4th edition draft V6 describes a "Freshest
CRL Extension" with the same syntax as in the PKIX profile, but says it
shall be used only as a certificate extension.  There is a CRL extension
defined in X.509 called "Delta Information extension" whose usage appears to
more or less match the PKIX CRL extension "Freshest CRL," but whose syntax
is not the same as the X.509 "Freshest CRL" certificate extension.  

Are my document versions out of date, or is this divergence intentional, or
is it time for a little mid-course correction? 

- Carlin Covey
  Cylink Corporation

------------------------------------------------------------

P.S. Here are some quotes from the documents:

From draft-ietf-pkix-new-part1-05.txt:

4.2 Standard Certificate Extensions 
...
4.2.1.16   Freshest CRL (a.k.a. Delta CRL Distribution Point) 
The freshest CRL extension identifies how delta-CRL information is obtained.
The same syntax is used for this extension and the 
cRLDistributionPoints extension, and is described in section 4.2.1.14.

5.2 CRL Extensions 
...
5.2.6 Freshest CRL (a.k.a. Delta CRL Distribution Point) 
The freshest CRL extension identifies how delta-CRL information for this CRL
is obtained.
The extension MUST be non-critical. The same syntax is used for this
extension as the cRLDistributionPoints certificate extension, and is
described in section 4.2.1.14. The same conventions apply to both
extensions.

From X.509_4thEditionDraftV6.pdf:

8.5.2.9	Delta Information extension
This CRL extension is for use in CRLs that are not dCRLs and is used to
indicate to relying parties that dCRLs are also available for the CRL
containing this extension. The extension provides the location at which the
related dCRLs can be found and optionally the time at which the next dCRL is
to be issued. 

8.6.2.6   Freshest CRL extension
The freshest CRL extension shall be used only as a certificate extension and
may be used in certificates issued to authorities as well as certificates
issued to users. This field identifies the CRL to which a certificate user
should refer to obtain the freshest revocation information (e.g.: latest
dCRL).