Subject: Re: Online Certificate Revocation Protocol

From: [email-masked] (Peter Gutmann)
Date: Wed, 13 Jun 2001 10:56:39 (NZST)

Marc Branchaud <[email-masked]> writes:
 
>Perhaps the existing cessationOfOperation code could be used as a "key 
>destroyed" reason.  X.509 states: "cessationOfOperation indicates that the 
>certificate is no longer needed for the purpose for which it was issued but 
>there is no cause to suspect that the private key has been compromised." That 
>doesn't quite fit, but it might work.
 
There's another revocation status which needs a way of indicating it which is 
somewhat trickier, I'll bring it up here in case anyone has any ideas: 
Sometimes a cert can be issued in error, what's needed here is a revocation 
reason which says that not only is the cert revoked, it should never be and 
was never valid at any time for any reason.  You can sort of achieve this by 
setting the revocation time to the cert start time, but there's no real way to 
indicate that the cert should never have been issued (I guess X.500 assumed, 
along with many other things, that all CAs are perfect and never make 
mistakes :-).  The reason why this is more than a theoretical concern is that 
for CMP it's a fairly standard part of CA operations to have to undo a cert 
issue, however there's no CRL reason code to indicate this operation.
 
Peter.

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From: Massimiliano Pala <[email-masked]>
Date: Wed, 13 Jun 2001 15:10:07 +0200

> was never valid at any time for any reason.  You can sort of achieve this by

In this case, when will br the entry removed from the CRL ? When the certificate
will be expired ?? Or should it be left in all future CRLs ?

-- 

C'you,

	Massimiliano Pala

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Massimiliano Pala [OpenCA Project Manager]                [email-masked]
                                                     [email-masked]
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From: Tony Bartoletti <[email-masked]>
Date: Wed, 13 Jun 2001 10:40:40 -0700

>issue, however there's no CRL reason code to indicate this operation.

Does this relate to why the "emergency CRL" published after the bogus 
Microsoft code-signing certs were issued was not a "real CRL"?  I 
understood that Microsoft supported one form of "CRL mechanism" while they 
routinely employed certificates incompatible with that mechanism, and that 
was the reason they cold not "just revoke" the (bad) certificates that were 
issued.

Also, if a CA (in error) issues several certificates to company X and then 
simply lists them as revoked (to fix the error), might this look as if 
company X were at fault (poor key management, invalid requests, etc.,) when 
in fact there were no such requests?  The ambiguity is disturbing.

___tony___

Tony Bartoletti 925-422-3881 <[email-masked]>
Information Operations, Warfare and Assurance Center
Lawrence Livermore National Laboratory
Livermore, CA 94551-9900