Subject: I-D ACTION:draft-ietf-pkix-logotypes-03.txt

From: [email-masked]
Date: Mon, 01 Jul 2002 06:38:46 -0400

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Public-Key Infrastructure (X.509) Working Group of the IETF.

	Title		: Internet X.509 Public Key Infrastructure Logotypes in 
                          X.509 certificates
	Author(s)	: S. Santesson, R. Housley, T. Freeman
	Filename	: draft-ietf-pkix-logotypes-03.txt
	Pages		: 18
	Date		: 28-Jun-02
	
This document specifies a certificate extension for including
logotypes in public key certificates and attribute certificates.
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---

From: Juergen Brauckmann <[email-masked]>
Date: Mon, 01 Jul 2002 14:17:51 +0200

>         Filename        : draft-ietf-pkix-logotypes-03.txt

Hi.

**** Page 6, at the end of chapter 3:
   Applications SHOULD enhance processing and off-line functionality by
   cashing logotype data.
   ^^^^^
Funny typo:-) Who cashes whom?;-)

**** LogotypeImageInfo and LogotypeAudioInfo:
In my opinion these data structures lack something like "descriptiveText
UTF8String OPTIONAL" that could be displayed if the source of the images
or audio data is currently unavailable or the data cannot be retrieved. 

I can imagine many situations where retrieval of data is not possible,
but nevertheless the functionality of community branding is desired. And
in such situations it would be helpful if the application could present
a simple string to the user.

**** ASN.1: 
You declare the Module as IMPLICIT TAGS. But the only use of tags is 
LogotypeExtn ::= SEQUENCE {
         communityLogo  [0] LogotypeInfo OPTIONAL,
         issuerLogo     [1] LogotypeInfo OPTIONAL,
         subjectLogo    [2] LogotypeInfo OPTIONAL,
         otherLogos     [3] SEQUENCE OF OtherLogotypeInfo OPTIONAL }

      LogotypeInfo ::= CHOICE {
         direct          LogotypeData,
         indirect        LogotypeReference }

Here, the tags are converted silently by clause 30.6 c) of X.680 into
EXPLICIT tags because LogotypeInfo is a CHOICE (IMPLICIT tags on CHOICEs
are implicitely EXPLICIT or something like that). In my opinion the
module would be better readable for implementors if you would declare it
as EXPLICIT.

The LogotypeInfo CHOICE misses a tag when you use module-wide IMPLICIT
or EXPLICIT tagging. LogotypeData and LogotypeReference are both
SEQUENCEs, and for the CHOICE to be parseable, you have to tag the
elements (Clause 28.2. of X.680).

Regards,
    Juergen

---

From: "Housley, Russ" <[email-masked]>
Date: Mon, 01 Jul 2002 12:41:21 -0400

>Funny typo:-) Who cashes whom?;-)

Obviously, this is a typo.  It will be fixed in draft -04.

>a simple string to the user.

This is an interesting idea.  I would like to hear what others think before 
a change is made.

>elements (Clause 28.2. of X.680).

How about:

    LogotypeInfo ::= CHOICE {
       direct          [0] LogotypeData,
       indirect        [1] LogotypeReference }

Russ