Re: [Trans] Precertificate format
Stephen Kent <kent@bbn.com> Mon, 08 September 2014 20:16 UTC
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Date: Mon, 08 Sep 2014 16:16:16 -0400
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Subject: Re: [Trans] Precertificate format
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Melinda, The problem is bigger than just the choice of format for the SCT response. The current pre-cert model requires a CA to be able to issue two certs with the same serial number. This would, in general, be a very bad thing for a CA to do. So, mandating this behavior is very worrisome. And, as you noted, it clearly violates 4.1.2.2 of 5280. (Thanks, I should have noted that.) Thus, I suggest we use a different format. I suggest sticking with ASN.1, since the data used to compute the SCT will come from a cert, and ASN.1 is the native cert format description language. DER encoding is also good for creating a canonical representation for signature generation. However, Ben has noted that even if we use a different format for the pre-cert data, the data MUST contain the serial number of the cert that is eventually issued. This is almost as much of a problem for CAs, at least in principle. Remember that the DigiNotar breach (which is a major motivation for CT) was especially bad because the attackers were able erase all evidence of the bogus certs that they issued. Countermeasures to such attacks might preclude a CA from knowing what serial number will appear in a cert until it is issued. (I mentioned one such counter- measure in a FIPS level 3 HSM from long ago, in a prior post.) I suggest that the CT designers list which data items from a cert that is being logged need to be in the SCT request, and why each item has to be present. Maybe that will show us how to avoid the concern that I and others have raised. It would also provide us with a starting point for the format of a new data structure for the SCT request, and the set of data that is input to the SCT hash computation. Steve
- [Trans] Precertificate format Melinda Shore
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Melinda Shore
- Re: [Trans] Precertificate format Brian Smith
- Re: [Trans] Precertificate format Rick Andrews
- Re: [Trans] Precertificate format Hill, Brad
- Re: [Trans] Precertificate format Matt Palmer
- Re: [Trans] Precertificate format Matt Palmer
- Re: [Trans] Precertificate format Eran Messeri
- Re: [Trans] Precertificate format Tomas Gustavsson
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Carl Wallace
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Hill, Brad
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Brian Smith
- Re: [Trans] Precertificate format Hill, Brad
- Re: [Trans] Precertificate format Brian Smith
- Re: [Trans] Precertificate format Brian Smith
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Brian Smith
- Re: [Trans] Precertificate format Kyle Hamilton
- Re: [Trans] Precertificate format Watson Ladd
- Re: [Trans] Precertificate format Tomas Gustavsson
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Melinda Shore
- Re: [Trans] Precertificate format Melinda Shore
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Jeremy Rowley
- Re: [Trans] Precertificate format Erwann Abalea
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Erwann Abalea
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Rob Stradling
- Re: [Trans] Precertificate format Erwann Abalea
- [Trans] Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Melinda Shore
- Re: [Trans] Precertificate format Stephen Davidson
- Re: [Trans] Precertificate format Ben Laurie
- [Trans] Fwd: Precertificate format Erwann Abalea
- Re: [Trans] Fwd: Precertificate format Ben Laurie
- Re: [Trans] Precertificate format Stephen Kent
- Re: [Trans] Precertificate format Russ Housley
- Re: [Trans] Precertificate format Rob Stradling