[Servercert-wg] Ballot SC 13 version 4

[Ryan Sleevi]

On Fri, Nov 30, 2018 at 1:36 PM Tim Hollebeek via Servercert-wg <
servercert-wg at cabforum.org> wrote:

>
> https://github.com/cabforum/documents/commit/4665e375300d928bf0e2451aef9c1059d6c8373f
>
>
>
>    - fixed an issue with the syntax of an example that was copied from
>    RFC 6844 (see errata 4070)
>    - fixed a reference to “contactemail” in the DNS TXT record validation
>    method
>    - clarify that Authorization Domain Names are selected per FQDN
>    validation
>    - consistently use “DNS TXT Record Email Contact”
>
>
>
>
>
> Ballot SC13: 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: Email to DNS CAA Contact
>
> Confirming the Applicant's control over the FQDN by sending a Random Value
> via email and then receiving a confirming response utilizing the Random
> Value. The Random Value MUST be sent to an email address identified as a
> CAA contactemail property record as defined in Appendix B.  The relevant
> CAA Resource Record Set MUST be found using the search algorithm defined in
> RFC 6844 Section 4, as amended by Errata 5065 (Appendix A).
>
>
>
> Each email MAY confirm control of multiple FQDNs, provided that the DNS
> contactemail email address is the same for each Authorized Domain Name
> being validated.
>

TYPO: Authorized Domain Name -> Authorization Domain Name

DESGIN: Apologies that it was lost in the broader conversation, but the
asymmetry here with the other methods creates confusion about intent. The
CAA Resource Record Set MAY contain multiple contactemail properties.
3.2.2.4.2 allows you to send a single email to multiple recipients,
provided those recipients are all authoritative. One reading is to think
"Oh, it's like 3.2.2.4.2, which this replaces" - and thus presume a single
email can be sent to multiple contactemail recipients. However, unlike
3.2.2.4.2, this section does not permit mass-sending, and the choice of "an
email address" and the singular recpient (below) raise the question about
whether it is intended to be expressly forbidden about sending a single
email with multiple recipients.

If it's intended, we probably need to tweak the language to agree on
plurality and include a clause similar to paragraph 3 of 3.2.2.4.2.
If it's not intended to be permitted, a more explicit declaration here
(MUST / MUST NOT) seems useful to resolve any ambiguity.

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.
>

TYPO? Should this be Recipient(s)? A given domain may have multiple CAA
contactemail properties. See above.


> 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: Email to DNS TXT Contact
>
>
>
> Confirming the Applicant's control over the FQDN by sending a Random Value
> via email and then receiving a confirming response utilizing the Random
> Value. The Random Value MUST be sent to an email address identified as a
> DNS TXT record email contact for
>
> the Authorization Domain Name selected to validate the FQDN.  See Appendix
> B for the format of the DNS TXT record email contact.
>
>
>
> Each email MAY confirm control of multiple FQDNs, provided that the email
> address from the DNS TXT record is the same for each Authorized Domain Name
> being validated.
>

TYPO: Authorized -> Authorization


> 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.
>

DESIGN: The same design issue applies here, including the remark about
recipient(s)?


>
>
> 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: DNS Contact Properties
>
> These methods allow domain owners to publish contact information in DNS
> for the purpose of validating domain control.
>
> B.1. CAA Methods
>
>
>
> B.1.1. CAA contactemail Property
>
>
>
> SYNTAX: contactemail <rfc6532emailaddress>
>
>
>
> The CAA contactemail property takes an email address as its parameter.
> The entire parameter value 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.
>
>                CAA 0 contactemail "domainowner at example.com"
>
>
>
> The contactemail property MAY be critical, if the domain owner does not
> want CAs who do not understand it to issue certificates for the domain.
>
>
>
> B.2. DNS TXT Methods
>
>
>
> B.2.1. DNS TXT Record Email Contact
>
>
>
> The DNS TXT record MUST be placed on the "_validation-contactemail"
> subdomain of the domain being validated.  The entire RDATA value of this
> TXT 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
>
>
>
> The changes between version 4 and version 3 are here:
>
>
> https://github.com/cabforum/documents/commit/4665e375300d928bf0e2451aef9c1059d6c8373f
>
> The procedure for approval of this ballot is as follows:
>
> Discussion (7+ days)
>
> Start Time: 2018-11-30 13:35 Eastern
>
> End Time: Not before 2018-12-07 13:35 Eastern
>
> Vote for approval (7 days)
>
> Start Time: TBD
>
> End Time: TBD
> _______________________________________________
> Servercert-wg mailing list
> Servercert-wg at cabforum.org
> http://cabforum.org/mailman/listinfo/servercert-wg
>
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