Hi Clint,

I think the requirement should apply to a certificate to a CA, which can issue 
CA certificates. I’m not sure of the right terminology, but I categorize this 
as a Root-to-Root CA or a Root-to-Intermediate CA Certificate. It would not 
apply to a CA certificate where the CA issues Subscriber certificates.


Bruce.

From: Validation <[email protected]> On Behalf Of Clint Wilson 
via Validation
Sent: Friday, September 6, 2024 2:45 PM
To: Paul van Brouwershaven <[email protected]>; CA/Browser 
Forum Validation SC List <[email protected]>
Subject: [EXTERNAL] Re: [cabf_validation] Section 7.1.2.10.5 CA Certificate 
Certificate Policies for cross signing certificates

Hi Paul,

One concern I have with this change is its impact on the cross-certification of 
subordinate CAs which directly issue end-entity TLS certificates. That is, I 
think it appropriate to maintain the requirement/limitation that only one 
Reserved Certificate Policy Identifier be included in the Cross-Certified 
Subordinate CA Certificate where the CA Certificate being signed/certified is a 
Subordinate CA Certificate as opposed to a Root CA Certificate.

Since the introduction to this Profile in Section 7.1.2.2 states that the 
Profile is the same regardless of whether the “source” CA Certificate is a Root 
CA Certificate or a Subordinate CA Certificate, I think this newly added 
Section 7.1.2.2.6 would need to indicate clearly its scope of applicability 
against Cross-Certified Subordinate CA Certificate which are the result of 
issuing a CA Certificate using the same Subject Name and Subject Public Key 
Information as an existing Root CA Certificate.

It also seems like it may be helpful to clarify that the Certificate Policies 
extension defined in this newly added Section 7.1.2.2.6 needs to be compatible 
between the Cross-Certified Subordinate CA and its Issuing CA (though, perhaps, 
obvious, this would also help ensure that the separation of pre- and 
post-SC-062 CA Certificates is maintained, at least in the cases where the 
`anyPolicy` Policy Identifier is not used). I’m not entirely sure this is 
necessary, as I suspect it’s required elsewhere within Section 7, but I 
couldn’t find it in a quick search so thought I’d mention it.

Thanks!
-Clint




On Sep 6, 2024, at 6:21 AM, Paul van Brouwershaven via Validation 
<[email protected]<mailto:[email protected]>> wrote:

Following yesterday's discussion in the validation subcommittee teleconference, 
we are now seeking two members to endorse the ballot. Feedback is also welcome, 
either here or on the pull request.
### Purpose of the Ballot

This ballot duplicates the content of section 7.1.2.10.5 (CA Certificate 
Certificate Policies) into section 7.1.2.2 (Cross-Certified Subordinate CA 
Certificate Profile) as section 7.1.2.2.6 (Cross-Certified Subordinate CA 
Certificate Certificate Policies), modifying the requirement from "MUST contain 
exactly one Reserved Certificate Policy Identifier" to "MUST include at least 
one Reserved Certificate Policy Identifier" to allow the inclusion of multiple 
Reserved Certificate Policy Identifiers in a Cross-Certified Subordinate CA 
Certificate.

The following motion has been proposed by Paul van Brouwershaven (Entrust) and 
endorsed by XXX (XXX) and XXX (XXX).

GitHub pull request for this ballot: 
https://github.com/cabforum/servercert/pull/544

### Motion begins

MODIFY the "Baseline Requirements for the Issuance and Management of 
Publicly-Trusted TLS Server Certificates" ("TLS Baseline Requirements") based 
on Version 2.0.6 as specified in the following redline:

https://github.com/cabforum/servercert/compare/929d9b4a1ed1f13f92f6af672ad6f6a2153b8230...89f80028b40ce6a1a5c52b406d37e5534460a1a1

### Motion ends

This ballot proposes a Final Maintenance Guideline. The procedure for approval 
of this ballot is as follows:

Discussion (7+ days)

- Start time: TBC
- End time: TBC

Vote for approval (7 days)

- Start time: TBC
- End time: TBC
________________________________
From: Validation 
<[email protected]<mailto:[email protected]>> on 
behalf of Paul van Brouwershaven via Validation 
<[email protected]<mailto:[email protected]>>
Sent: Thursday, September 5, 2024 16:40
To: CABforum3 <[email protected]<mailto:[email protected]>>
Subject: [EXTERNAL] [cabf_validation] Section 7.1.2.10.5 CA Certificate 
Certificate Policies for cross signing certificates

We would like to clarify the following requirement in section 7.1.2.10.5 CA 
Certificate Certificate Policies, specifically for cross signing certificates.

RFC 5280 states that you can have one CertPolicyId within the 
PolicyInformation, see below:

certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation

PolicyInformation ::= SEQUENCE {
        policyIdentifier   CertPolicyId,
        policyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                PolicyQualifierInfo OPTIONAL }

CertPolicyId ::= OBJECT IDENTIFIER

Section 7.1.2.10.5 of the TLS BR states for the policyIdentifier:

The CA MUST include at least one Reserved Certificate Policy Identifier (see 
Section 7.1.6.1) associated with the given Subscriber Certificate type (see 
Section 7.1.2.7.1) directly or transitively issued by this Certificate.

This 'at least one' seems to contradict RFC 5280 which indicates that we can 
only have one policyIdentifier in the PolicyInformation sequence.

Then at the bottom of this section the TLS BRs states that entire certificate 
policies extension MUST contain exactly one Reserved Certificate Policy 
Identifier:

Regardless of the order of PolicyInformation values, the Certificate Policies 
extension MUST contain exactly one Reserved Certificate Policy Identifier.

While we can repeat the PolicyInformation within the certificatePolicies 
extension does this mean that CAs are prohibited from issuing a cross signing 
certificate (from a multi-purpose root to another multi-purpose root) with 
policy contrains that include DV, OV and EV reserved certificate policy 
identifiers. If our reading of this section is correct, this would mean that 
CAs need to issue three seperate cross signing certificates in that case.

Paul



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