[cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

Fri Oct 14 01:52:31 UTC 2016

Fair enough – we can all file away Peter’s list for future use.  But in my mind, the second example is equivalent to a Certificate Problem Report that is requesting revocation, and I think each CA can develop its own methods for how to handle that – I don’t think we need mandatory provisions in the BRs.

From: Rick Andrews [mailto:Rick_Andrews at symantec.com]
Sent: Thursday, October 13, 2016 4:45 PM
To: Kirk Hall <Kirk.Hall at entrust.com>
Cc: public at cabforum.org
Subject: RE: [cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

Kirk, in my years with VeriSign and Symantec, I also can’t recall a domain owner asking for more info about a cert that we had issued, but

a)      The request probably would not have come to or through me

b)      It’s a lot more likely to happen today because of CT

The first example you gave is (in my opinion) relatively easy to resolve. The more challenging one is the second. I’m trying to see if we can agree that, for example, the CA should not necessarily give out details about the subscriber to the requester. Peter suggested a list of things that the requester should and should not expect to get. I agree with most of that but need to re-read it more carefully.

-Rick

From: Kirk Hall [mailto:Kirk.Hall at entrust.com]
Sent: Wednesday, October 12, 2016 6:14 PM
To: Rick Andrews <Rick_Andrews at symantec.com<mailto:Rick_Andrews at symantec.com>>; Ryan Sleevi <sleevi at google.com<mailto:sleevi at google.com>>
Cc: public at cabforum.org<mailto:public at cabforum.org>
Subject: RE: [cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

In roughly 15 years of involvement with 4 CAs, I don’t recall any domain owner asking for more information about a cert we had issued that the domain owner (presumably) didn’t recognize.  I suppose if Foo Corp. is actually your customer, and Anne Jones of Foo Corp. (whom you can verify) asks “Did we order this server2.foo.com cert?  No one remembers that”, it would be ok for the CA to look in its systems and see what it can find.

If someone from Foo Corp. contacts the CA and says “Foo Corp. is not a customer of your CA – why did you issue a cert for server2.foo.com?”, the CA would likely treat that as a Certificate Problem Report under BR 4.9.2, investigate according to the CA’s own procedures, and revoke if justified.

I’m reluctant to create new requirements for how the CA responds to questions about an unrecognized cert until we know more whether this situation is likely to occur.  It seems to me the current BRs already cover problem reports and revocation requests from third parties.

From: Rick Andrews [mailto:Rick_Andrews at symantec.com]
Sent: Wednesday, October 12, 2016 5:56 PM
To: Ryan Sleevi <sleevi at google.com<mailto:sleevi at google.com>>; Kirk Hall <Kirk.Hall at entrust.com<mailto:Kirk.Hall at entrust.com>>
Cc: public at cabforum.org<mailto:public at cabforum.org>
Subject: RE: [cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

Ryan, as I stated in my initial post, this is not about redaction. I’d prefer to keep that out of the discussion, and focus on a use case where a domain owner learns about a fully-disclosed certificate (maybe they see it on a public-facing website) and wants to learn more about it.

-Rick

From: Public [mailto:public-bounces at cabforum.org] On Behalf Of Ryan Sleevi via Public
Sent: Tuesday, October 11, 2016 6:35 PM
To: Kirk Hall <Kirk.Hall at entrust.com<mailto:Kirk.Hall at entrust.com>>
Cc: public at cabforum.org<mailto:public at cabforum.org>
Subject: Re: [cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

Kirk,

The point is to remove the degree of "CA discretion" that you suggest, to ensure there's a normalized, reasonable, and reliable set of options for domain holders. As Rick noted in the introduction, this is certainly one of the concerns with allowing redaction.

For example, it would be undesirable for a CA to allow redacted certificates, and then say "No, we won't revoke, because that's what our privacy policy says." The concern is related to CA's interpretation of those sections, and ensuring that we avoid any areas for CAs to interpret in a way conflicting with community norms.

So I don't believe the current sections provide sufficient recourse - especially as discussed in the discussions Rick linked to.

On Tue, Oct 11, 2016 at 6:22 PM, Kirk Hall via Public <public at cabforum.org<mailto:public at cabforum.org>> wrote:

As I read through the string, remember that we all have a Privacy Policy (BR 9.4 covers this, although we presently have no BR stipulations on privacy policies).  So whatever we decide to do in responding to information requests from claimed domain owners will have to comply with our individual Privacy Policies (which may need to be modified).

WebTrust for CAs has this general statement: “The Certification Authority must disclose its key and certificate life cycle management business and information privacy practices” and Requirement 6.6 on Certificate Revocation says “The CA maintains controls to provide reasonable assurance that certificates are revoked, based on authorized and validated certificate revocation requests within the time frame in accordance with the CA’s disclosed business practices.“

We already have some BR provisions 4.9.2 through 4.9.5 on who can request revocation, and the process the CA is required to follow.  See below.  Does this adequately cover your straw man situations below?  Don’t many of your situations fit within the language for reporting Certificate Problem Reports?  (“I see this cert you issued for a domain I own – I don’t remember or recognize it.”)  I think it may be best for the CA to set up its own internal procedures for how it will respond to this type of Report, and then make sure the Subscriber Agreement and Privacy Policy allow what the CA wants to do.

4.9.2. Who Can Request Revocation

The Subscriber, RA, or Issuing CA can initiate revocation. Additionally, Subscribers, Relying Parties,

Application Software Suppliers, and other third parties may submit Certificate Problem Reports informing the

issuing CA of reasonable cause to revoke the certificate.

4.9.3. Procedure for Revocation Request

The CA SHALL provide a process for Subscribers to request revocation of their own Certificates. The process

MUST be described in the CA’s Certificate Policy or Certification Practice Statement. The CA SHALL maintain a

continuous 24x7 ability to accept and respond to revocation requests and related inquiries.

The CA SHALL provide Subscribers, Relying Parties, Application Software Suppliers, and other third parties with

clear instructions for reporting suspected Private Key Compromise, Certificate misuse, or other types of fraud,

compromise, misuse, inappropriate conduct, or any other matter related to Certificates. The CA SHALL publicly

disclose the instructions through a readily accessible online means.

4.9.4. Revocation Request Grace Period

No stipulation.

4.9.5. Time within which CA Must Process the Revocation Request

The CA SHALL begin investigation of a Certificate Problem Report within twenty-four hours of receipt, and decide

whether revocation or other appropriate action is warranted based on at least the following criteria:

1. The nature of the alleged problem;

2. The number of Certificate Problem Reports received about a particular Certificate or Subscriber;

3. The entity making the complaint (for example, a complaint from a law enforcement official that a Web site is

engaged in illegal activities should carry more weight than a complaint from a consumer alleging that she didn’t

receive the goods she ordered); and

4. Relevant legislation.

-----Original Message-----
From: Public [mailto:public-bounces at cabforum.org<mailto:public-bounces at cabforum.org>] On Behalf Of Peter Bowen via Public
Sent: Monday, October 10, 2016 8:35 PM
To: Rick Andrews <Rick_Andrews at symantec.com<mailto:Rick_Andrews at symantec.com>>
Cc: public at cabforum.org<mailto:public at cabforum.org>
Subject: Re: [cabfpub] Recourse for domain owners who discover unknown certificates issued to their domain

> On Oct 10, 2016, at 5:31 PM, public at cabforum.org<mailto:public at cabforum.org> wrote:

>

> During the discussions about CT name redaction ([1], [2]), it became

> clear that there is no formal policy regarding what actions a CA

> should take if a domain owner approached the CA to get information

> about a certificate issued by the CA for a domain owned by the domain

> owner. We'd like to start a discussion to craft such a policy. Note

> that this is not specific to name redaction. A domain owner might

> discover a non-redacted certificate in a CT log or public web crawl,

> and if the owner doesn't recognize the certificate, they should be

> able to get detailed information from the CA so that the domain owner

> can determine if the cert was properly issued, and request revocation if it was not.

Rick,

Before we discuss how we authenticate the domain registrant, I think need to discuss what a CA must do when so asked by a domain registrant.

As a straw man, I’m going to suggest that an authenticated domain registrant can do the following:

- Require revocation of a certificate containing a FQDN or Wildcard DN under their registered domain by providing the CA the issuer DN and serial number of the certificate

- Require revocation of all certificates containing a FQDN or Wildcard DN under their registered domain or a portion of the namespace under their registered domain

- Authorize the issuance of certificates containing a FQDN or Wildcard DN under their registered domain

- Require the CA to only allow certain named people or email addresses to authorize future issuance

The registrant cannot:

- Require the CA to provide a list of all certificates containing a FQDN or Wildcard DN under their registered domain

- Require the CA to provide details on the applicant/subscriber for a certificate containing a FQDN or Wildcard DN under their registered domain

- Require the CA to provide an unredacted version of a redacted certificate containing a FQDN or Wildcard DN under their registered domain

To come up with this list, I considered the situation where domain foo.example is registered to Alice (potentially using a proxy as the registrant).  Mallory is a nefarious individual and wants to bring harm to Alice or Alice’s organization.  Mallory manages to take over foo.example (either due to Alice letting it expire or via domain transfer fraud) and then proceeds to contact CAs to get info about foo.example and Alice.  What should a CA be required to release?

Thanks,

Peter

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