[cabfpub] [EXTERNAL] Verification of Domain Contact and Domain Authorization Document

Bruce Morton Bruce.Morton at entrustdatacard.com
Fri Jan 19 19:51:52 UTC 2018


Rich,

I assume once you have a fraudulent certificate, then you will have to something else to finalize the attack. You could compromise the site, but then you should have used method 6 to validate the domain. You could perform a DNS attack, but then you should have used method 7 to validate the domain. 

I am not sure that compromising ownership makes it easier to fulfill the attack, since you also need control to fulfill the attack.

Bruce.

-----Original Message-----
From: Public [mailto:public-bounces at cabforum.org] On Behalf Of Rich Smith via Public
Sent: January 19, 2018 2:37 PM
To: 'Mads Egil Henriksveen' <Mads.Henriksveen at buypass.no>; 'CA/Browser Forum Public Discussion List' <public at cabforum.org>; 'Gervase Markham' <gerv at mozilla.org>
Subject: Re: [cabfpub] [EXTERNAL] Verification of Domain Contact and Domain Authorization Document

Mads,
I appreciate you trying to save this method, but IMO there is nothing that can be done to strengthen this method enough to protect it against social engineering.  Your proposal relies on the assumption that EVERY validation agent of EVERY CA MUST have at least the same level of understanding of corporate structures as the people in this Forum.  It's an unrealistic assumption.  All I have to do is register a company called Google, Inc., in SOME jurisdiction, get listed in SOME QIIS, then just convince a validation agent from ANY CA that I am a local branch office of the real Google, Inc.
that we all know and love and bam, I've got a cert for google.com.

I picked Google because they are an easy example.  In reality I suspect
(hope) that no CA would fall for this particular example, but a less known company?  Almost certainly.

Through the discussion I've been convinced that we should leave some version of 3.2.2.4.1 (3) in place, but I don't think you'll ever convince me that the other bits of 3.2.2.4.1 or 3.2.2.4.5 are, or ever can be made to be, as secure as the weakest technical demonstration of domain control.

Regards,
Rich

-----Original Message-----
From: Public [mailto:public-bounces at cabforum.org] On Behalf Of Mads Egil Henriksveen via Public
Sent: Friday, January 19, 2018 6:59 AM
To: Gervase Markham <gerv at mozilla.org>; CA/Browser Forum Public Discussion List <public at cabforum.org>
Subject: Re: [cabfpub] [EXTERNAL] Verification of Domain Contact and Domain Authorization Document

Hi Gerv

The current version 3.2.2.4.1 says:
----
3.2.2.4.1 Validating the Applicant as a Domain Contact Confirming the Applicant's control over the FQDN by validating the Applicant is the Domain Contact directly with the Domain Name Registrar. 

This method may only be used if:
1. The CA authenticates the Applicant's identity under BR Section 3.2.2.1 and the authority of the Applicant Representative under BR Section 3.2.5, OR 2. The CA authenticates the Applicant's identity under EV Guidelines Section
11.2 and the agency of the Certificate Approver under EV Guidelines Section 11.8; OR 3. The CA is also the Domain Name Registrar, or an Affiliate of the Registrar, of the Base Domain Name.

Note: Once the FQDN has been validated using this method, the CA MAY also issue Certificates for other FQDNs that end with all the labels of the validated FQDN. This method is suitable for validating Wildcard Domain Names.
-----
 
Our proposal concentrates on the first part, i.e. the following statement: 
>> Confirming the Applicant's control over the FQDN by validating the
Applicant is the Domain Contact directly with the Domain Name Registrar.

Is to be replaced with:
<< Conforming the Applicant's control over the FQDN by validating the Applicant as the Domain Name Registrant by verifying that: 
<< 1.	The name of the Domain Name Registrant matches the Applicant's name
AND
<< 2.	Additional information about the Domain Name Registrant in the WHOIS
meet the following requirements:
<<          i.	The Registrant's postal address in the WHOIS belongs to the
Applicant. CAs MUST verify this by matching it with one of the Applicant's addresses in: (a) a QGIS, QTIS, or QIIS; or (b) a Verified Professional Letter. 
<<                         Note: Address details in the WHOIS are required
to use this option. Address details must include at a minimum the Country and either Locality, State or Province. OR 
<<          ii.	The WHOIS contains the Registration (or similar) Number
assigned to the Applicant by the Incorporating or Registration Agency in its Jurisdiction of Incorporation or Registration as appropriate. CAs MUST verify this by matching the Registration Number in the WHOIS with the Applicant's Registration Number in a QGIS or a QTIS.

The first change is the use of Domain Name Registrant instead of Domain Contact, i.e. the focus is on domain ownership. 

The proposal requires that the name of the Registrant (in WHOIS) matches 1) the name of the Applicant AND either 2 i) the postal address of the Registrant (in WHOIS) matches the postal address of the Applicant (in sources accepted for EV validation) OR 2 ii) a Registration Number for the Registrant (in WHOIS) matches the Registration Number of the Applicant (in a QGIS or QTIS).

The proposal addresses threats due to that organization names are not unique, the combination of organization name and address or organization name and registration number should be unique. It also removes ambiguities the current language permits (according to Jeremy - see attachment). 

Regards
Mads 

-----Original Message-----
From: Public [mailto:public-bounces at cabforum.org] On Behalf Of Gervase Markham via Public
Sent: fredag 19. januar 2018 10:29
To: Mads Egil Henriksveen via Public <public at cabforum.org>
Subject: Re: [cabfpub] [EXTERNAL] Verification of Domain Contact and Domain Authorization Document

On 19/01/18 06:51, Mads Egil Henriksveen via Public wrote:
> Buypass, Entrust Datacard and GlobalSign have been working on some 
> text to strengthen 3.2.2.4.1 instead of removing it - find the draft 
> text below. The draft was discussed in the Validation Working Group 
> meeting yesterday. We would like to offer this as an amendment to 
> Ballot
218.

Is it possible to provide a diff, e.g. by turning the new text into a Github pull request, or some other mechanism?

Once we have a diff, might it be possible for rationale to be provided for each change?

Gerv
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