Re: [TLS] HTTPS client-certificate-authentication in browsers

Henry Story <> Mon, 25 July 2011 13:05 UTC

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From: Henry Story <>
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Date: Mon, 25 Jul 2011 15:05:52 +0200
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To: Anders Rundgren <>
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Subject: Re: [TLS] HTTPS client-certificate-authentication in browsers
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On 25 Jul 2011, at 14:58, Anders Rundgren wrote:

> On 2011-07-25 14:31, Henry Story wrote:
>> Hi Anders, I kind of lurk here, but I don't think that client side
>> CAs are impossible to get right in the browsers. They are pretty close
>> to doing things right. Logout from the browsers would not be that difficult
>> to do. I kept thinking that the W3C project could stimulate
>> the improvement of these pieces.
>> But I would be interested in feedback from this list on the subject.
> Hi Henry,
> If there had been a *single* mainstream service of US origin who used
> HTTPS CCA this would be fixed in record time.

What about the army? They are pretty big in the US, representing a huge portion
of the budget I believe.

> The tenths of millions of users of "homegrown" PKI authentication schemes
> in the EU and Asia apparently don't think HTTPS CCA is particularly useful,
> neither do I.  

I believe that is only because of the naming problem. Distinguished Names of companies
don't scale to the world.

> TLS' session context is incompatible with web sessions.

Why?  A TLS Session can work very well with web sessions. You can 
just make your TLS session be a web session.

> For our mutual interest, PKI for consumers, it doesn't really matter what
> the end-solution will be, but an educated guess is that will not build
> on HTTPS CCA, but on HTTPS with + an application.  This is BTW pretty
> much what has happened with HTTP auth versus form-based auth.

yes, but there is no argument for why this is the case. And you don't 
even consider

> Fortunately this can be introduced without redeploying PKI so it is a
> true "migration solution".

IT's odd that people want to move away from something that is close to working.
I wonder why... What is the agenda?

> Anders
>> Henry
>> On 25 Jul 2011, at 14:06, Anders Rundgren wrote:
>>> Hi Guys,
>>> I don't really know who "owns" this question but presumably you do...
>>> HTTPS client-certificate-authentication in browsers
>>> ===================================================
>>> I don't believe that TLS CCA (Client Certificate Authentication) in the
>>> form of HTTPS as implemented in current browsers has much of a future.
>>> In fact, quite a bunch of the entities in the EU working with consumer PKI
>>> have replaced HTTPS CCA with an application level scheme which wasn't such
>>> a big deal since they anyway were forced writing a browser PKI client more
>>> or less from scratch since the ones shipped with browsers doesn't support
>>> PKI as defined by banks and government (like mandatory PIN codes also
>>> for on-line enrolled keys).
>>> That the TLS CCA protocol doesn't even support "Logout" haven't made
>>> it a logical choice for web developers either.  Well, there are some
>>> workarounds but they are by no means straightforward, supported
>>> out-of-the-box by server authentication schemes, and are (of course)
>>> entirely undocumented.
>>> The button "Clear SSL state" in MSIE is an indication how horribly bad it
>>> can go when security experts design systems for "people".
>>> There's no way you can hide the fact that TLS CCA is only truly useful
>>> securing tunnels between "boxes".
>>> Anders
>>> _______________________________________________
>>> TLS mailing list
>> Social Web Architect

Social Web Architect