Subject: Re: Global PKI on DNS?

From: Johnny Eriksson <[email-masked]>
Date: Sun, 9 Jun 2002 11:17:03 WET DST

"Eric A. Hall" <[email-masked]>

> > I was wondering if the best system to build a global PKI wouldn't be the
> > DNS system already in place?
> 
> This is an ongoing argument. Essentially there are two camps:
> 
>   Pro--there's a global database out there, let's put useful stuff
>        into it. Certs is a no-brainer, but people have also argued for
>        baseball scores, usernames, and everything else short of kitchen
>        sink inventories.

Just FYI: the Kitchen Sink RR has been proposed...

--Johnny

---

From: James Seng <[email-masked]>
Date: Sun, 9 Jun 2002 19:57:02 +0800 (SGT)

Shouldnt we have this discussion in keydist instead? I know keydist isnt a 
working group yet but we do have a list for such discussion...

-James Seng

[email-masked] wrote:
> 
> on 6/8/2002 8:22 AM Franck Martin said the following:
> 
>   Con--the more crap you put into DNS, the less usable it becomes for
>        its primary purpose of providing fast and lightweight lookups
>        for Internet resources. While certs can be argued to be in that
>        camp, they cannot be handled with fast and lightweight lookups.
> 
> As other people have already pointed out, the use of large objects
> requires that clients and servers use TCP for lookups. TCP imposes a large
> burden on servers (especially busy servers) in comparison to UDP. Add to
> that the fact that many DNS systems do not support the use of TCP for
> queries whatsoever, meaning that it just won't work with a large number of
> systems in the first place. And even if it did work, it would result in
> other simple lookups failing, essentially punishing everybody for the
> benefit of a single application.
> 
> > It would be the easiest way as apparently nobody is trying to build a
> > global PKI infrastructure and LDAP people can't agree on a global
> > standard to link each ldap server to each other, which DNS has...
> 
> There is some work underway to develop an LDAP infrastructure for the
> Internet community, with DNS being used as a stub to kickstart the
> process. That will get you the same thing as what you want, but without
> crushing DNS as a result.
> 
> -- 
> Eric A. Hall                                        http://www.ehsco.com/
> Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/
>

---

From: "Christian Huitema" <[email-masked]>
Date: Mon, 10 Jun 2002 11:42:28 -0700

> >> What is the average size of a CERT (honest question, I have no
idea)?
> > Good question -- and I don't think there's any one answer.
> 
> Hmm.  "Average"?

Key certificates contain, among other things, four variable size
components: the X.500 name of the issuer, the X.500 name of the target,
the public key of the target, and a signature of the certificate using
the private key of the issuer. The X.500 names are typically somewhat
larger than DNS names, as they include explicit typing of name parts
using object identifiers. The key size depends of the security
consciousness, or paranoia, of the actors; 1024 bits (128 octets) is
frequent, but 2048 bits is often recommended (256 octets). Key and
signature have roughly the same size, so having 512 octets or more for
the key material is not uncommon. Given the size of names, the size of
keys, and the amount of goo in the X.509 representation, you don't have
to be too creative to get a certificate that is larger than 1KO, or even
the classic 1.5KO limit of Ethernet-like networks. As time passes,
things are going to get worse, not better; we will probably see people
using even larger keys, because their CPU can handle it and that makes
them feel more secure. 

In general, we should realize that PKI & UDP are not compatible. In
fact, we see that already in IKE, an UDP-based protocol that has to
exchange certificate chains, composed of several certificates. We end up
relying on UDP fragmentation, which has all kinds of issues. In the case
of the DNS, certificates would most probably have to be handed over TCP.
Randy's warning of old horses and saddlebags comes to mind.

-- Christian Huitema

---

From: Franck Martin <[email-masked]>
Date: Thu, 13 Jun 2002 17:10:19 +1200

The CERT extension to DNS allows to place there a URI, a URI is smaller than
a cert and stays in a udp packet.
The x509v3 extension allows you to place a URI to look for PKI and CRL, so
client are already able to deal with a lot of URIs (mainly http and ldap)

Now you are looking for a cert or public key of a site or e-mail, you query
the DNS that gives you the URI where to look for the PKI...

As someone said the main problem is S/MIME which does not have a protocol to
look for public keys globally, I think DNS can do the job...

There just need to be a little bit of coordination and an agreed mapping and
protocol to use DNS for a global PKI.

Franck Martin
Network and Database Development Officer
SOPAC South Pacific Applied Geoscience Commission
Fiji
E-mail: [email-masked] <mailto:[email-masked]> 
Web site: http://www.sopac.org/
<http://www.sopac.org/> Support FMaps: http://fmaps.sourceforge.net/
<http://fmaps.sourceforge.net/> 
Certificate: https://www.sopac.org/ssl/ 

This e-mail is intended for its addresses only. Do not forward this e-mail
without approval. The views expressed in this e-mail may not be necessarily
the views of SOPAC.

-----Original Message-----
From: Chris Evans [mailto:[email-masked]]
Sent: Thursday, 13 June 2002 4:46 
To: David Conrad; Derek Atkins
Cc: Eric A. Hall; John Stracke; ietf; [email-masked]; Key Distribution;
[email-masked]
Subject: Re: Global PKI on DNS?

Then a global PKI protocol server needs to be invented so you can just get
the 
certs from the domain in question.   i dont wanna see DNS system bogged down
by 
this stuff. IMHOOC!

use dns to get the IP and request from its IP the pki doc.. duh.

6/11/02 6:51:26 PM, Derek Atkins <[email-masked]> wrote:

>David Conrad <[email-masked]> writes:
>
>> Why do you think the roots and TLDs would get millions of TCP queries for
>> their certs?  Why would anyone want to get the certs of the roots or
tlds?

---

From: "Christian Huitema" <[email-masked]>
Date: Thu, 13 Jun 2002 12:51:47 -0700

> > > A PKI modeled on the DNS would parallel
> > > the existing hierarchy and merely codify the 
> relationships expressed
> > > by it in the form of public key certs.
> >
> > so what you're saying is that the cert would mean something like:
> 
> ;-) actually, to a lawyer, a PKI cert says something like:
> 
> [deleted]

Part of the problem is that we are mixing to issues, i.e. "am I speaking
to the server that is legitimely designated by the name
www.example.com", and "am I speaking to the service that is supposed to
manage my examples." Attaching certificates to names may solve the
former; solving the latter requires that the user discovers in a trusted
way the DNS name associated to the service. We know that there are many
psychology-based attacks that can fool users to connect to use the wrong
name; PKI certificates attached to the DNS name is not going to solve
that.

There is in addition an even more murky area, which is the validity of
the binding over time. Some artists specialize in grabbing DNS names
that their legitimate users fail to renew in time. Suddenly,
www.example.com is not managing my examples anymore, it has become a
gateway to a porn site. Yet, that porn portal has a perfectly valid and
up-to-date PKI certificate. Amusing, isn't it?

-- Christian Huitema

---

From: "VILLARREAL, STEVE (SBC-MSI)" <[email-masked]>
Date: Thu, 13 Jun 2002 17:14:29 -0500

You gents have way too much time on your hands..... this list should be used
as a means to assist with questions regarding technologies ... not used as a
forum for posturing....

-----Original Message-----
From: Christian Huitema [mailto:[email-masked]]
Sent: Thursday, June 13, 2002 2:52 PM
To: Ed Gerck; Keith Moore
Cc: Stephen Kent; Einar Stefferud; ietf
Subject: RE: Global PKI on DNS?

-- Christian Huitema

---

From: Ari Ollikainen <[email-masked]>
Date: Thu, 13 Jun 2002 16:46:02 -0700

At 5:14 PM -0500 6/13/02, VILLARREAL, STEVE (SBC-MSI) wrote:
>You gents have too much time on your hands..... this list should be 
>used as a means to assist with questions regarding technologies ... 
>not used as a forum for posturing....
>

	Really?
	Here's the scoop from http://www.ietf.org/maillist.html

The IETF discussion list serves two purposes. It furthers the 
development and specification of Internet technology through 
discussion of technical issues. It also hosts discussions of IETF 
direction, policy, and procedures. As this is the most general IETF 
mailing list, considerable latitude is allowed. Advertising, whether 
to solicit business or promote
employment opportunities, falls well outside the range of acceptable 
topics, as do discussions of a personal nature.

This list is meant for initial discussion only. Discussions that fall 
within the area of any working group or well established list should 
be moved to such more specific forum as soon as this is pointed out, 
unless the issue is one for which the working group needs wider input 
or direction.

In addition to the topics noted above, appropriate postings include:
 
+  Last Call discussions of proposed protocol actions
+  Discussion of technical issues that are candidates for IETF work, but
    do not yet have an appropriate e-mail venue
+  Discussion of IETF administrative policies
+  Questions and clarifications concerning IETF meetings.

Inappropriate postings include:
-  Unsolicited bulk e-mail
-  Discussion of subjects unrelated to IETF policy, meetings, activities,
    or technical concerns
-  Unprofessional commentary, regardless of the general subject.

	Back to your SOP bickering...

---------------------------------------------------------------------
Dilbert's words of wisdom #18: Never argue with an idiot. They drag
you down to their level then beat you with experience.
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        OLTECO                    Ari Ollikainen
        P.O. BOX 20088            Networking Architecture and Technology
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        94309-0088                415.517.3519

---

From: Stephen Kent <[email-masked]>
Date: Fri, 14 Jun 2002 07:44:07 -0400

>name; PKI certificates attached to the DNS name is not going to solve

Well said. I think there would be considerable benefit from trying to 
solve the former problem. The latter problem is very hard, and does 
enter the realm of "who do you trust" which is a very complex realm, 
one in which the lack of transitivity of trust becomes a big issue.

>up-to-date PKI certificate. Amusing, isn't it?

Yes. But, the problems does not get better or worse with certs so 
long as the validity periods are matched to the renewal periods.

Steve

---

From: "John Stracke" <John_Stracke/[email-masked]>
Date: Tue, 25 Jun 2002 15:17:23 -0400

>        How does Jon know that the dollar Jon received from Mike is a
dollar?
>
>        A dollar has specifications that tell you it's a dollar (type of
paper, ink, micro printing, etc)

I don't think the dollar analogy is all that useful.  A dollar is backed up
by people with guns, who hunt down and punish counterfeiters, which means
that ordinary people don't have to know how to validate a dollar bill,
because the incidence of forgery is low.

/==============================================================\
|John Stracke                    |Principal Engineer           |
[email-masked]   |Incentive Systems, Inc.      |
|http://www.incentivesystems.com |My opinions are my own.      |
|==============================================================|
|"HTTP is what happens in the absence of good design." -- Keith|
|Moore                                                         |
\==============================================================/