Re: [Trans] Certificate and Precertificate extensions ordering

Rob Stradling <rob.stradling@comodo.com> Thu, 11 September 2014 11:17 UTC

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Date: Thu, 11 Sep 2014 12:17:11 +0100
From: Rob Stradling <rob.stradling@comodo.com>
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To: Eran Messeri <eranm@google.com>, Erwann Abalea <eabalea@gmail.com>
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Subject: Re: [Trans] Certificate and Precertificate extensions ordering
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On 11/09/14 11:56, Eran Messeri wrote:
> The poison extension is removed from the Precertificate prior to the log
> producing an SCT over it, so a client never has to know about it. What
> the TLS client has to do is to remove the "embedded SCTs" extension
>   from the certificate prior to validating the signature.

Ditto for the future "redactedlabels" extension.

> On Thu, Sep 11, 2014 at 11:40 AM, Erwann Abalea <eabalea@gmail.com
> <mailto:eabalea@gmail.com>> wrote:
>
>     Bonjour,
>
>     It seems there's no constraint on the order of extensions in the
>     final certificate regarding to the Precert.
>     Won't it be problematic if the browser wants to validate the SCT
>     signatures by constructing the Precert from the final certificate?
>     Where should a CA add the poisonous extension? And the future
>     "redactedlabels" extension (it has no name)?
>
>     --
>     Erwann.
>
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-- 
Rob Stradling
Senior Research & Development Scientist
COMODO - Creating Trust Online
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