Subject: RE: Policy User Interfaces (was RE: Setting X.509 Policy Data in IE, IIS, Outlook)

From: [email-masked] (Peter Gutmann)
Date: Fri, 6 Feb 2004 03:17:32 +1300

"Al Arsenault" <[email-masked]> writes:

>Okay, then how about the Canadian Government?  See
>http://www.cio-dpi.gc.ca/pki-icp/guidedocs/cert-policy/aboutCP_e.asp

The problem is that at the moment we're stuck with having to support an
extremely complex and awkward mechanism to accomodate a vanishingly small
number of users at the expense of a large majority who don't want to know or
care about it, being quite happy with policy=CA.  The "vanishingly small"
number currently stands at two, in theory there'd be at least a third,
Gatekeeper, but since the government department in charge of it has had a
spokesman announce that "I am very grateful for the fact that, at the moment,
none of my colleagues has come up with a good use for it. When they do, I will
have to do something about it" we'll call it two, and maybe even one
eventually depending on whether the Canadian work has reached the Gatekeeper
stage yet or not.

>Or maybe just change 3280 to make cert policies optional vice mandatory, so
>those people who need policy!=CA but aren't subject to SDN.706 can still find
>the information?

Exactly.  So in order to be useful (and applicable) to all users, the RFC
could say something like:

  There's an easy way and a hard way to do this.  The easy way involves
  CA=policy.  The certificatePolicies MUST contain a single policy entry with
  a policy URL or text, MUST NOT contain user notices and notice numbers and
  whatnot, and DEFINITELY MUST NOT involve policy constraints, policy
  mappings, fuzzy dice, and two-tone paint jobs.  The hard way involves multi-
  policy CAs and a lot of Tylenol, for which see the current text.

That way the majority of users can pick the straightforward option that does
what they want, and everyone who wants to do it the complex way can also do
that.

Peter.

---

From: Lars Johansson <[email-masked]>
Date: Tue, 10 Feb 2004 10:53:03 +0100

Dear list,

Let me add my 0.01 euros to this thread...

Several people have argued that a CA <-> Policy paradigm would 
be much simpler for most PKI users (specifically outside the 
government sector) to grasp and use. However I object that this 
paradigm would be the most simple one. Stated formally, what I 
claim is the following:

Claim: There exists a PKI paradigm that is simpler than the CA 
<-> Policy paradigm. In particular the specific PKI paradigm 
requires that the correspondence between CA and Policy mustn't 
be 1-1 (injective).

Proof: The proof works by giving a counterexample. Consider 
an "utopic" world in which all existing CA:s have agreed on a 
common single Policy. Clearly this PKI paradigm would be much 
simpler to grasp and use for all relying parties in all sectors! 
However this implies a many-to-one mapping between CA:s and the 
single policy, a mapping which is impossible to achieve with the 
CA <-> Policy paradigm. QED.

Conclusion: If simplicity is a goal (and I agree that it should) 
then let's focus on standardisation of practical certificate-
policies which can be shared by several different CA:s instead 
of debating wheather policy-OID:s should exist or not. 

That's my opinion!
_________________________________________________
Lars Johansson M.Sc.| Consultant
[email-masked] | www.omegapoint.se
phone +46 70 915 88 40 | fax +46 8 545 106 93
Omegapoint AB

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

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From: "Jean Pawluk" <[email-masked]>
Date: Tue, 10 Feb 2004 05:41:46 -0600

Bravo

 Practical PKI as a goal should to be encouraged as much as possible.

 The sheer complexity and awesome flexibility of the many standards in this
area is limiting the everyday use of PKI technology in new application
areas.

Jean

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Lars Johansson
Sent: Tuesday, February 10, 2004 3:53 AM
To: Peter Gutmann
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]
Subject: RE: Policy User Interfaces (was RE: Setting X.509 Policy Data
in IE, IIS, Outlook)

Dear list,

That's my opinion!

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

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From: "Anders Rundgren" <[email-masked]>
Date: Tue, 10 Feb 2004 15:05:15 +0100

Lars,
From RFC3280:

   "To promote interoperability, this profile RECOMMENDS that policy
    information terms consist of only an OID"

That effectively means that any issuance characteristic including
liability, subject verification method, certificate format, and
usage (web-server, e-mail, etc) are lumped together in a single
blob-like element.

The chance of making such a low-granularity system become
"standard" except for qualified certificates seems pretty slim.

Note: I don't object to the idea of including a policy OID, I just
claim that forward-thinking CA organizations should have separate
roots, etc for each supported policy (OID).  I.e. like VeriSign and
most other TTP CAs.   Because then the interpretation of the Policy
OID becomes redundant and can be left as "decoration" or things to
show legal folks or marketing.

But I cannot really see that my suggestion is in conflict with your
suggestion, Í just want to "cut PKI down to size".

However, adding policy-related metadata to single-policy CA
certificates would in my opinion be a more workable approach
as it does not require competitors to agree on things that they
may not want to.  Such metadata could be something like:
usage=e-mail, liability=zero, subject verification=passport,
hardware key protection=yes

Anders

----- Original Message -----
From: "Lars Johansson" <[email-masked]>
To: "Peter Gutmann" <[email-masked]>
Cc: <[email-masked]>; <[email-masked]>; <[email-masked]>; <[email-masked]>
Sent: Tuesday, February 10, 2004 10:53
Subject: RE: Policy User Interfaces (was RE: Setting X.509 Policy Data in IE, IIS, Outlook)

Dear list,

That's my opinion!

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

---

From: "Santosh Chokhani" <[email-masked]>
Date: Tue, 10 Feb 2004 14:11:29 -0500

To All Those who want to simplify 3280 and get rid of policy stuff:

What problems are your applications encountering with the certificates in
the area of policy processing?  Specific examples only.

Based on the knowledge I have of some of the PKIs and based on your
statements that no one wants to use this stuff, and your applications do not
prime the path validation engine with any policy (no pun intended), the only
likely failure I see is the one for require explicit policy.  For that, I
have told X.509 folks that a better design will be to output the value of
require explicit policy to the application without causing a failure.

If that is done and you do not care about policies, certification path
validation engine could be 3280 and X.509 compliant and you can ignore all
policy related inputs and output and go on you merry way doing PKI and
policy geeks can dance with their policy crap.

Sounds like a great solution (not even compromise) to make both camps happy.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of Jean Pawluk
Sent: Tuesday, February 10, 2004 6:42 AM
To: 'Lars Johansson'; 'Peter Gutmann'
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]
Subject: RE: Policy User Interfaces (was RE: Setting X.509 Policy Data in
IE, IIS, Outlook)

Bravo

Jean

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Lars Johansson
Sent: Tuesday, February 10, 2004 3:53 AM
To: Peter Gutmann
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]
Subject: RE: Policy User Interfaces (was RE: Setting X.509 Policy Data in
IE, IIS, Outlook)

Dear list,

Several people have argued that a CA <-> Policy paradigm would be much
simpler for most PKI users (specifically outside the government sector) to
grasp and use. However I object that this paradigm would be the most simple
one. Stated formally, what I claim is the following:

Claim: There exists a PKI paradigm that is simpler than the CA <-> Policy
paradigm. In particular the specific PKI paradigm requires that the
correspondence between CA and Policy mustn't be 1-1 (injective).

Proof: The proof works by giving a counterexample. Consider
an "utopic" world in which all existing CA:s have agreed on a common single
Policy. Clearly this PKI paradigm would be much simpler to grasp and use for
all relying parties in all sectors! However this implies a many-to-one
mapping between CA:s and the single policy, a mapping which is impossible to
achieve with the CA <-> Policy paradigm. QED.

Conclusion: If simplicity is a goal (and I agree that it should) then let's
focus on standardisation of practical certificate- policies which can be
shared by several different CA:s instead of debating wheather policy-OID:s
should exist or not.

That's my opinion! _________________________________________________
Lars Johansson M.Sc.| Consultant
[email-masked] | www.omegapoint.se
phone +46 70 915 88 40 | fax +46 8 545 106 93
Omegapoint AB

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

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From: Michael Ströder <[email-masked]>
Date: Tue, 10 Feb 2004 17:44:05 +0100

> area is limiting the everyday use of PKI technology in new application

Yes.

Ciao, Michael.