Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Eddy Nigg (StartCom Ltd.)
Arshad Noor wrote: > They would know the CA that issued the particular client certificate and > include it in it's Request/Not require client auth message. > Actually funny that I never thought myself about such an option. But a competing CA could harvest the email addresses, which are usually

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Arshad Noor
]> Cc: [EMAIL PROTECTED], dev-tech-crypto@lists.mozilla.org Sent: Friday, September 7, 2007 4:24:15 PM (GMT-0800) America/Los_Angeles Subject: Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates Arshad Noor wrote: > See below, Alex. > > Arshad Noor >

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Robert Relyea
Arshad Noor wrote: See below, Alex. Arshad Noor StrongAuth, Inc. - Original Message - From: "Alexander Klink" <[EMAIL PROTECTED]> The typical user does not have a client authentication certificate, so after installing one for him, the browser will send that out to anyone who is asking.

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Eddy Nigg (StartCom Ltd.)
Arshad Noor wrote: > > My understanding of the TLS protocol is that the browser only sends > the certificates signed by CAs that the server trusts; are you saying > that the protocol allows for asking ANY certificate from the browser > cert-store, regardless of who signed it? > Yes, one

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Arshad Noor
See below, Alex. Arshad Noor StrongAuth, Inc. - Original Message - From: "Alexander Klink" <[EMAIL PROTECTED]> The typical user does not have a client authentication certificate, so after installing one for him, the browser will send that out to anyone who is asking. My understanding

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Alexander Klink
[Cc's restricted to the mozilla lists] Hi Eddy, On Fri, Sep 07, 2007 at 07:57:49PM +0300, Eddy Nigg (StartCom Ltd.) wrote: > >Granted, if this is a "real" CA. But if you use it like in my PoC not > >for the typical CA scenario, but for user tracking, you could put all > >kinds of data in the cert

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Alexander Klink
[restricted the Cc's to the mozilla lists] Arshad, On Fri, Sep 07, 2007 at 10:04:53AM -0400, Arshad Noor wrote: > Do you presume that the websites in the domains that you intend > to track users will install the self-signed CA certificate that > issued the client-certificate to the unsuspecting u

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Arshad Noor
Alex, Do you presume that the websites in the domains that you intend to track users will install the self-signed CA certificate that issued the client-certificate to the unsuspecting user? If not, how will the browser know which client certificate to send to the website during client-auth? And

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Eddy Nigg (StartCom Ltd.)
Hi Alexander, Alexander Klink wrote: > Granted, if this is a "real" CA. But if you use it like in my PoC not > for the typical CA scenario, but for user tracking, you could put all > kinds of data in the certificate. > That's right. Still I believe that the generation of a private key and issu

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Alexander Klink
On Fri, Sep 07, 2007 at 05:00:51PM +0300, Eddy Nigg (StartCom Ltd.) wrote: > However information stated in certificates signed by CAs isn't usually > "private" and depending on the CA policy even published via directories > and other different channels, so I'm not sure if this could be an > inva

Re: Firefox 2.0.x: tracking unsuspecting users using TLS client certificates

2007-09-07 Thread Eddy Nigg (StartCom Ltd.)
Alexander Klink wrote: > Here is how it works: > - Because Firefox's standard configuration is to automatically choose a > TLS client certificate to be sent out, the certificate including > the personal data will now be sent out to any website that requests it. > Contrary to a typical cookie,