Subject: NEW Data type for certificate selection ?

From: Stefan Santesson <[email-masked]>
Date: Thu, 24 Sep 1998 14:41:23 +0200

All,

During the TLS session in Chicago (IETF meeting) I discussed with Jeff
Weinstein, Netscape, the problem of certificate selection in an environment
where the client is populated with many similar certificates for different
purposes.

We concluded that this is a general problem, not only for TLS, but for
S/MIME, Java, Java script, etc, where signing and encryption based on an
X.509 PKI is an option. I also conclude that the current TLS approach,
using Issuer name as selection criteria, is hopelessly insufficient for the
general case.

In fact we can NEVER claim that we have an X.509 based architecture ready
for the big market IF WE DON'T SOLVE THIS PROBLEM.

A normal user (I.e grandmother) will never be able to pick the right
certificate by herself, if there is more than 1 to pick.

The question raised here is:

WOULD A STANDARDIZED DATA TYPE FOR CERTIFICATE SELECTION BE A GOOD START.

If we could create a standardized ASN.1 data type with the purpose of
defining the criteria for selecting 1 out of n certificates, then this
could be used as a common base for enhancing TLS, Java, Java script, S/MIME
etc.

The data type could be communicated from server to client, client to
server, server to server, client to client; I.e in any case where one party
which to assist another party in selecting an appropriate certificate for
any purpose (defined by the context).

Do anyone have a better idea.

I think this is a lost problem that has to be fixed, hopefully in a
standardized way.

Comments, suggestions.

/Stefan Santesson
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Stefan Santesson                <[email-masked]>
Accurata Systemsäkerhet AB     
Lotsgatan 27 D                  Tel. +46-40 152211              
216 42  Malmö                   Fax. +46-40 150790              
Sweden                        Mobile +46-70 5247799

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From: "吉武 淳" <[email-masked]>
Date: Fri, 25 Sep 1998 18:29:35 +0900

I have two comments.

1. I'd like to clarify the scope.

Is it limited to the case where one party
which to assist another party ?
I suggest that it include the case
where a person has multiple certificates
in his / her PC, WS, etc. It will be more
useful and more efficient if there is
a standardized mechanism for the case
like this rather than that each application
manages its certificates in its own way
on one machine. Some applications could
hold a certificate in common.

2. It would be better that we consider
the generation management of a certificate.

Suppose a certificate has expired and you
get the new certificate on your PC. Namely,
you have two certificates on your PC, the old
one and the new one. Attention should be paid
not to let an application select the old one.
(Of course, things are easy if the old one is deleted.
But is it really always good for all the cases, all applications,...?)
(Issuer and Serial Number is nice, but you need
the mechanism to record "this serial number is for
the new one" when you get it for the first time.)

Jun Yoshitake
Mitsubishi Electric Corp.

Stefan Santesson wrote:

> Accurata Systems$BgL(Berhet AB
> 216 42  Malm$Bö (B                  Fax. +46-40 150790