[cabfpub] On the use of misuse - and the necessity to remove it

Geoff Keating geoffk at apple.com
Thu Jun 7 15:04:11 UTC 2018



> On Jun 7, 2018, at 3:32 PM, Ryan Sleevi <sleevi at google.com> wrote:
> 
> 
> 
> On Thu, Jun 7, 2018 at 10:24 AM, Geoff Keating <geoffk at apple.com <mailto:geoffk at apple.com>> wrote:
> 
> 
> > On Jun 7, 2018, at 1:40 PM, Ryan Sleevi via Public <public at cabforum.org <mailto:public at cabforum.org>> wrote:
> > 
> > In the pursuit of a definition, we tried to work backwards - what are situations we think are misuse.
> 
> The dictionary definition of ‘misuse’ is:
> 
> use (something) in the wrong way or for the wrong purpose
> 
> I'm not sure how this helps us move forward

I’m not sure how any of this discussion helps us move forward.

> - were you suggesting that 4.9.1.1 would read:
> 
> 4. The CA obtains evidence that the Certificate was used for the wrong way or for the wrong purpose;
> 
> With such a definition, this supposes there's a right way or right purpose.

That does not follow but let’s go with it for now.

> 1) Do you believe the right purpose is wholly reflecting in the Subscriber Agreement or Terms of Use?

I’m having great trouble understanding this question.  Why would I have any beliefs in this area?  What does ‘reflected’ mean?  Why are you asking me about a Subscriber Agreement I haven’t seen?

> 2) Do you believe the right way is wholly reflected in the definition I provided (from 1.1),

(see above)

> that the right way is "used for authenticating servers accessible through the Internet”

That does seem like a partial definition of the right way to use a certificate.


Let’s try to make things more concrete.  Your assertion is that auditors are having trouble with this wording.  I presume this means that the following things have happened:

1. A report was made that a certificate was misused.
2. The certificate was not revoked.
3. The auditors couldn’t tell if step 2 was correct.

So, can you tell me more about the circumstances?  What kind of misuse was alleged?

> > Another suggestion was that it involved scenarios where the Subscriber private key was in an HSM, and itself was not compromised, but had signed things it was not expected to. This wasn't elaborated on further - so I'm uncertain if this meant things other than the TLS handshake transcript - but this is already met by our definition of Key Compromise in 1.6.1, that is:
> > ""A Private Key is said to be compromised if its value has been disclosed to an
> >    unauthorized person, an unauthorized person has had access to it, or there exists a
> >    practical technique by which an unauthorized person may discover its value. “""
> 
> If a key is in a HSM and not exportable, then its value is not disclosed, nor does an unauthorized person have access *to the key*.  Dictionary definition of ‘access’ is 'obtain, examine, or retrieve’ none of which apply here.  So it is not covered by Key Compromise.
> 
> I'm not sure - what are you providing an example of?

I didn’t use the word ‘example’ anywhere, I do not know what you are talking about.

> I would think that, say, generating a signed message that was not authorized, then "an unauthorized person has access to it”.

This does not follow.  If I there is an air conditioner behind a locked door, I do not have access to it, but maybe I can operate a thermostat and it will make me cold.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.cabforum.org/pipermail/public/attachments/20180607/f0f8f8d0/attachment-0003.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 3321 bytes
Desc: not available
URL: <http://lists.cabforum.org/pipermail/public/attachments/20180607/f0f8f8d0/attachment-0003.p7s>


More information about the Public mailing list