[cabfpub] [Servercert-wg] Ballot SC4: Version 3

Corey Bonnell CBonnell at trustwave.com
Thu Aug 23 07:32:46 MST 2018


Hi Tim,
Thanks for incorporating my suggestions and sending out this update. I reviewed the ballot again have a few observations/suggestions based on the updated text:


  1.  Section 1.6.3 of the BRs needs to be updated with a reference to RFC 6532, as is done when an RFC (or other external document) is referenced.
  2.  For consistency, it would be good to use the canonical lowercase “contactemail” form consistently throughout the ballot text (Section 3.2.2.4.13 and the title of Appendix B use the non-canonical “ContactEmail” form).
  3.  Appendix B states that “The syntax for the contactemail property is similar to the iodef property”. I’d recommend dropping this sentence as contactemail specifies an email address, not a URL (which iodef specifies).
  4.  The example for the contactemail CAA record needs to have the rfc6532emailaddress parameter value quoted.
  5.  I’d recommend changing the attrleaf name “_caa_contact_email” to “_caa_contactemail” so that the name matches the corresponding CAA property tag name and establishes the naming convention to be used for future “CAA records encoded as legacy TXT” records (such as “_caa_contactphone”, etc.).

Thanks,
Corey

From: Servercert-wg <servercert-wg-bounces at cabforum.org> on behalf of Tim Hollebeek via Servercert-wg <servercert-wg at cabforum.org>
Reply-To: Tim Hollebeek <tim.hollebeek at digicert.com>, CA/B Forum Server Certificate WG Public Discussion List <servercert-wg at cabforum.org>
Date: Friday, August 17, 2018 at 8:22 AM
To: CA/Browser Forum Public Discussion List <public at cabforum.org>
Cc: CA/B Forum Server Certificate WG Public Discussion List <servercert-wg at cabforum.org>
Subject: [Servercert-wg] Ballot SC4: Version 3


Ballot SC4: CAA Contact Property and Associated E-mail Validation Methods
Purpose of Ballot: Increasingly, contact information is not available in WHOIS due to concerns about potential GDPR violations.  This ballot specifies a method by which domain holders can publish their contact information via DNS, and how CAs can use that information for validating domain control.
The following motion has been proposed by Tim Hollebeek of DigiCert and endorsed by Bruce Morton of Entrust and Doug Beattie of GlobalSign.
--- MOTION BEGINS ---
This ballot modifies the “Baseline Requirements for the Issuance and Management of Publicly-Trusted Certificates” as follows, based on Version 1.6.0:
Add Section 3.2.2.4.13: Domain Owner Email in CAA
Confirm the Applicant's control over the FQDN by (i) sending an email to a DNS domain name holder, (ii) including a Random Value in the email, and (iii) receiving a confirming response utilizing the Random Value. The CA MUST send the email to an email address found in the CAA ContactEmail property record of the Authorization Domain Name as defined in Appendix B.

Each email MAY confirm control of multiple FQDNs, provided the email address used is a DNS contact email address for each ADN being validated.

The Random Value SHALL be unique in each email. The email MAY be re-sent in its entirety, including the re-use of the Random Value, provided that its entire contents and recipient SHALL remain unchanged. The Random Value SHALL remain valid for use in a confirming response for no more than 30 days from its creation. The CPS MAY specify a shorter validity period for Random Values.

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.
Add Section 3.2.2.4.14: Domain Owner Email published in TXT record

Confirm the Applicant's control over the FQDN by (i) sending an email to a DNS domain name holder, (ii) including a Random Value in the email, and (iii) receiving a confirming response utilizing the Random Value. The CA MUST send the email to an email address found in the DNS TXT record of the Authorization Domain Name in the format defined in Appendix B.

Each email MAY confirm control of multiple FQDNs, provided the email address used is a DNS contact email address for each ADN being validated.
The Random Value SHALL be unique in each email. The email MAY be re-sent in its entirety, including the re-use of the Random Value, provided that its entire contents and recipient SHALL remain unchanged. The Random Value SHALL remain valid for use in a confirming response for no more than 30 days from its creation. The CPS MAY specify a shorter validity period for Random Values.

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.

Add Appendix B: CAA ContactEmail Property
The syntax for the contactemail property is similar to the iodef property.  It allows domain owners to publish contact information in DNS in addition to WHOIS for the purpose of validating domain control.
CAA contactemail Property

contactemail <rfc6532emailaddress> :  The contactemail property specifies a means of contacting the domain holder, or another party that is authorized to approve issuance of certificates for the domain in question.
The contactemail property takes an email address as its parameter.  The entire parameter value of the MUST be a valid email address as defined in RFC 6532 section 3.2, with no additional padding or structure, or it cannot be used.

The following is an example where the holder of the domain specified the contact property using an email address.

$ORIGIN example.com<http://scanmail.trustwave.com/?c=4062&d=8r322_xBesBhPnvVGJUMTA23FHuUmXDO4REHW4o7xg&s=5&u=http%3a%2f%2fexample%2ecom>
.              CAA 0 issue “ca.example.net”
.              CAA 0 contactemail domainowner at example.com

_caa_contact_email DNS TXT record

Some systems still do not have sufficient support for CAA records.  To allow users of those systems to specify contact information, a legacy format using text records is allowed.

The DNS TXT record MUST be placed on the "_caa_contact_email" subdomain of the domain being validated.  The entire RDATA value of the "_caa_contact_email" record MUST be a valid email address as defined in RFC 6532 section 3.2, with no additional padding or structure, or it cannot be used.

--- MOTION ENDS ---
*** WARNING ***: USE AT YOUR OWN RISK.  THE REDLINE BELOW IS NOT THE OFFICIAL VERSION OF THE CHANGES (CABF Bylaws, Section 2.4(a)):

A comparison of the changes can be found at: https://github.com/cabforum/documents/compare/Ballot-SC4---CAA-CONTACT-email?diff=unified&expand=1<https://scanmail.trustwave.com/?c=4062&d=8r322_xBesBhPnvVGJUMTA23FHuUmXDO4UILUd8-wA&s=5&u=https%3a%2f%2fgithub%2ecom%2fcabforum%2fdocuments%2fcompare%2fBallot-SC4---CAA-CONTACT-email%3fdiff%3dunified%26amp%3bexpand%3d1>
The procedure for approval of this ballot is as follows:
Discussion (7+ days)
Start Time: 2018-08-17 8:15 Eastern
End Time: Not before 2018-08-24 8:15 Eastern
Vote for approval (7 days)
Start Time: TBD
End Time: TBD

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