Re: [Trans] EXTERNAL: DNSSEC also needs CT

"Mehner, Carl" <> Fri, 09 May 2014 21:58 UTC

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From: "Mehner, Carl" <>
To: Nico Williams <>, "" <>
Thread-Topic: EXTERNAL: [Trans] DNSSEC also needs CT
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Date: Fri, 09 May 2014 21:58:34 +0000
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Subject: Re: [Trans] EXTERNAL: DNSSEC also needs CT
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RFC6698 says:
>This chain is required to prevent a CA from avoiding blame
>   by logging a partial or empty chain.  (Note: This effectively
>   excludes self-signed and DANE-based certificates until some mechanism
>   to control spam for those certificates is found.  The authors welcome
>   suggestions.)

I propose:

To have a DANE certificate (not signed by a public CA) included into a CT log:
1) a pre-certificate be created
2) the pre-certificate submitted to a log
3) the log will verify based on a valid DANE record of type PKIX-EE
4) return a SCT to the submitter to include in the final certificate

Carl Mehner
Info Security

-----Original Message-----
From: Trans [] On Behalf Of Nico Williams
Sent: Friday, May 09, 2014 4:31 PM
Subject: EXTERNAL: [Trans] DNSSEC also needs CT

DNSSEC is a PKI [of sorts; please, no need to pick nits about that].

It stands to reason that DNSSEC should have similar trust problems as
PKIX.  I believe it does indeed.

It follows that things like CT that we're applying to PKIX should be
applied to DNSSEC as well, where possible.

I don't see any reason why CT couldn't be extended to DNSSEC.  IMO, it
should be done.

Note that DNSSEC needs CT independently of protocols like DANE, but
any protocol that allows a DNSSEC MITM to bypass PKIX CT (as DANE
effectively does) should increase the need for CT for DNSSEC.

Note too that I'm not in any way saying that DANE and similar should
block on CT for DNSSEC.



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