Re: [TLS] [pkix] Proposing CAA as PKIX Working Group Item

Yoav Nir <ynir@checkpoint.com> Wed, 08 June 2011 07:32 UTC

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From: Yoav Nir <ynir@checkpoint.com>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
Date: Wed, 08 Jun 2011 10:32:48 +0300
Thread-Topic: [TLS] [pkix] Proposing CAA as PKIX Working Group Item
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Subject: Re: [TLS] [pkix] Proposing CAA as PKIX Working Group Item
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On Jun 8, 2011, at 9:56 AM, Peter Gutmann wrote:

> Yoav Nir <ynir@checkpoint.com> writes:
> 
>> CAA works if all root CAs and affiliates follow it. That's hundreds or
>> thousands of entities. Any one of them that fails to comply might ignore the
>> CAA record.
> 
> That was my problem with it, any CA (and/or RA) that's already diligent about 
> cert issuance doesn't need CAA, and any one that isn't won't use it anyway, so 
> it doesn't address any existing problem.
> 
> Peter.

It would have prevented what has become known as "Comodo-gate". The attacker subverted an RA. If the CA was doing the CAA checking, the attacker would be foiled. If checking the CAA is delegated to the RA, it would not help, but the draft specifically talks about certification authorities.