Subject: Rollover pair sufficient or not?

From: Joel Rees <[email-masked]>
Date: Tue, 23 Aug 2005 15:09:17 +0900

I'm reading Planning for PKI and and I've got this ambiguity in my  
head. The rollover pair is sufficient for building a path back to the  
original certificate. Therefore, it kind of seems that there might be  
no need for a normal new CA certificate with just the new key.

Or would you want, in addition, a plain CA certificate with just the  
new key, so that end users who have never seen the old key don't need  
to think about the old key?

Joel Rees   <[email-masked]>
digitcom, inc.   株式会社デジコム
Kobe, Japan   +81-78-672-8800
** <http://www.ddcom.co.jp> **

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From: sravan <[email-masked]>
Date: Wed, 24 Aug 2005 19:25:03 +0530

Hi,
Is there any place where this key rollover & certificate rollover issues 
are documented?
I was searching(in vain) for them in the internet for the past one week.
Please point me to some resources where I can get the following info:
- certificate rollover process
- key rollover process
also, during the certificate and/ or key rollover process should the CA 
maintain 2 sets of CRL dps(one of the old cert & one for new cert) ?

thnx,
sravan

PS: Russ Housley, I am sorry for my previous post. I thought it was 
posted to the group; but it was posted to you.

Russ Housley wrote:

>
> End users that have the new key as a trust anchor will be able to 
> validate certificates signed with the new key in the usual way. 
> However, if they encounter a certificate that is signed with the old 
> key, the key rollover certificate allow them to validate it with a 
> path that leads to the new key trust anchor.
>
> Hope this helps,
> Russ
>
> At 02:09 AM 8/23/2005, Joel Rees wrote:
>
>> digitcom, inc. æ ªå¼ä¼šç¤¾ãƒ‡ã‚¸ã‚³ãƒ

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From: Russ Housley <[email-masked]>
Date: Wed, 24 Aug 2005 09:32:06 -0400

End users that have the new key as a trust anchor will be able to validate 
certificates signed with the new key in the usual way.  However, if they 
encounter a certificate that is signed with the old key, the key rollover 
certificate allow them to validate it with a path that leads to the new key 
trust anchor.

Hope this helps,
   Russ

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From: Jean-Marc Desperrier <[email-masked]>
Date: Wed, 24 Aug 2005 18:30:28 +0200

sravan wrote:
> Is there any place where this key rollover & certificate rollover 
> issues are documented?
In the standard you should check rfc2510 2.4., and 4.2.
If you need an operational description, you'll need other resources.

> also, during the certificate and/ or key rollover process should the 
> CA maintain 2 sets of CRL dps(one of the old cert & one for new cert) ?
If you do a key rollover, you *must* do the following to simultaneously 
be compatible with existing implementation and do the right thing 
according to the correct implementation of the standard :
- have 2 sets of CRL
- the serial numbers of the certificates issued under the new key must 
not overlap the serial numbers of the certificate issued under the old key
- the crl emitted with the new key must also include the serial numbers 
of the revoked certificat issued under the old key (until the end of the 
validity of the old CA)
- the crl emitted with the old key must also include the serial numbers 
of the revoked certificat issued under the new key (until the old CA is 
no more valid and you can stop creating new one)

Unfortunately, not all software will allow you to do things that way.
If all softwares were doing the right thing according to the standard, 
you could issue only one crl with the new key and including all serial 
numbers. When they are not correct, they need both the crl with the old 
and the new key, but don't care about the serial number issues listed above.

In constrast if you do a cert rollover where you only change the 
validity date, the impact is only to update the cert everywhere.