Policy-Discussion

[Ian G <iang AT systemics.com>]

Some more idle comments outside any formal capacity...



mfolimun AT elitemail.org
 wrote:
> On Thu, 10 May 2007 12:53:23 -0700, "Greg Stark"
> <gstark AT electrorent.com>
>  said:
> > Mondior,
> > I think cryptographic strength misses the point.  You don't need CAcert
> > to create certificates to secure your internet activities.  YOU do not need
> > US.
> >
> > So why do you want to use our certificate service for?  So you or
> > visitors to your website don't get the annoying SSL popup window?
>
> It was my understanding that CAcert was aiming to be a widely 
> accepted certificate authority to provide domain certificates for 
> HTTPS/IMAPS/SMTPS/whateverS for free: Ted's second point in his post. 


Um.  CAcert's mission is a work-in-progress.  Yes, it was 
originally to "provide certs for free" and that is likely to 
remain part of the DNA, come what may.

But I don't think it is to provide *domain-control* certs 
for free.  That's just something that is done right now as 
part of the above mission.  CAcert might decide one day to 
drop them completely.

Also, CAcert's mission is likely to limit its bounty in the 
future to just registered users ... (with the assumption 
that they become Assured.)

That's because of all the Risks/Liabilities/Obligations work 
that was done in 2006.


> I did not realize that you guys were looking to replace the GPG 
> web-of-trust with something tied to domains and openssl. If that is 
> your real mission, then I am barking up the wrong tree.. 


The web-of-trust is not the mission but a tool, I would have 
said.

> But then I also argue you are using a screwdriver to hammer in a 
> nail...


Welcome to the Alice in Wonderland of PKI.

> certificates exist primarily to secure and authenticate 
> internet traffic from Internet domains, not to verify content comes 
> from a particular person.


LOL... I defy anyone to come up with an accurate description 
of why certificates exist.

There are two opposing world views here.

(1) You see that you want to use certificates.  And that 
they don't do much in your world except annoy you and stop 
you using crypto.  Fine, I agree with that.

(2) But, most the people who *implement* PKI and 
certificates believe something else.  They believe that 
crypto should only be used from person to person in an 
environment of reliance.  I agree with that, to the extent 
that it exists, as a world.

CAcert has to live in both worlds.  So far it is doing this 
double life fairly well.  From both sides it looks sort of 
kinda like what is expected.

But it's not perfect, I grant.  Your complaint here is 
fairly minor compared to the complaints that CAcert receives 
from the PKI world.


> > You wish to be anonymous!  A 6 month certificate is what CAcert offers. 
> > 6 months, no user name. Frankly, I think it should be a 30 day certificate.
>
> Why? Exactly what am I doing with this certificate? I'll tell you: I 
> am using it to certify that content from my domain name is actually 
> from my domain name, so that no one can intercept it and try to fool 
> my users, or read their traffic. If I prove conclusively to you that 
> I AM my domain name, what is the risk? There is no uncertainty here. 
> If I demonstrably control all properties of domain X, there is no harm 
> in you certifying I am domain X, unless I have hacked domain X, stole 
> its mail, stole the passwords to the registrar, and hijacked its 
> webserver, and convinced their ISP to update reverse DNS. All without 
> the domain admin knowing.. If I am this much of an uber-ninja, why don't 
> I just do this to domains Y and Z that have already been granted
> CAcerts, and steal their private keys?


So, you answered your own question by explaining the 
uncertainty.

As I see it, in the first case, you would have made a 
misrepresentation to the CA, and the CA has relied upon your 
misrepresentation ... and our users have relied upon the 
CA's due diligence.  Thus there is a risk and consequent 
liability.  People have explained how they manage that risk: 
 6 months if we don't know you and it is anonymous, more if 
we know you.

In the second case, you've stolen some other user's private 
key, so the user revokes, dusts off the damage and moves on. 
 CA has little or nothing to do with it.  It's more between 
you (external person) and a CAcert user.

Very different cases as far as the CA is concerned, as the 
Risks/Liabilities/Obligations are different.


> > Look, What CAcert offers its users, for free is, trusted identity on the
> > internet.


Actually, to be nitpicky, that would be "assured identity" 
where this is defined by the assurance process.

As OBL would say, "a jihad on the word 'trust' !"

:)


> > To do this we look at one another's official identity
> > documents to confirm who we, and if that is not posible we ask you to provide 
> > us
> > with documentation (TTP Form).  Having done that I can feel confident that
> > when I get a signed document from you.  It is you.  For you to have your name 
> > on
> > the certificate you have met the requirements of our community.  You are
> > established in our Web-Of-Trust.  A member of the Club.
>
> But this is NOT what you do! This is what the GPG web of trust does! 
> What YOU do is certify that content that claims to be from domain X 
> *really is* from domain X. Particular individuals have nothing 
> to do with the content you certify.


Sorry, where did you read that?  The CPS doesn't say that, 
did this come from anywhere in particular?

Let's be careful here.  A certificate makes a claim.

*What that claim is, is specified in the CPS.*

If you think there is any statement to that effect, please 
shout!  This would be a serious issue and has to be dealt with.


> Consider a wiki that is the collaborative product of many individuals
> operating with a CAcert. Or a webhost that has multiple users on 
> independent subdomains. That content is only certified to be from 
> the toplevel domain, not any particular individual.


Nope.  The CA -- all user-facing CAs afaik -- issue 
certificates to individuals.  The claim in the certificate 
relates to the individual, and it may include as a benefit 
something about the individual owning some server.

(I use individual here in the sense of "legal persons" and 
"natural persons" so organisations are included.)


> It makes complete sense for you to have a well-linked web of trust
> for your assurers and among other volunteers of your organization, 
> but it makes little sense to force people who just want security to 
> become members of this web as well.

As a long time promoter of psuedonymous security, I know 
what you are saying.  But, consider this:  you can do 
psuedonymous security by yourself.

OTOH, if you do it with CAcert, then you have to offer 
CAcert something, else it has no interest in taking on the 
liability and risk of working with you.  What would you offer?

Or, are you simply asking CAcert to issue you with a 
self-signed cert?  As in, do the heavy lifting of creating 
and running the self-signing CA for you?

That's maybe a valuable product ... who would like that?

> Especially when you are ultimately
> certifying domains and their content, not people.


Nope, and I'm mystified.  How can CAcert make a claim about 
the content?  It has never seen it.

The claim is about the people that control the domain.  It 
begins with the people, always.


> > Anonymous identity just does not exist here.


Again to be nitpickety:  They are opposites, technically.

Anonymity is where there is no identifying information at 
all.  Think "anonymous pamphlets" being handed out in the 
streets, only the content is there.

Certificates do not do anonymity, they do psuedonomyity.  In 
practice, all "anon" certs issued CAcert are psuedonymous, 
and CAcert knows who is behind them, to a greater or lesser 
degree of assurance.  (0 points being zero assurance.)


> Privacy does.  No address
> > is asked for.
>
> And if I (as an assured natural person using my real idenity) were to 
> host a domain that allows anonymous users to post content to https 
> secured subdomains using a wildcard cert, would cacert.org invalidate 
> my certificate because the content is no longer assured to be from the 
> original applicant?


CAcert does not make any claim about your content.  Why 
would it care if you post content from another person?

The *content* is not a claim in the certificate.

Unless you are suggesting that the content is being sent to 
CAcert to be read and certified???


* mostly informal remarks of no import except the one about 
the statement of certificate claim in the CPS. *


iang