On Thu, Jul 20, 2017 at 10:16 AM, Erwann Abalea <[email protected]> wrote: > Bonjour, > > Looking back in time on the list for a reason to allow for underscore in > SAN:dNSName, I found basically 2 potential reasons: > - allow things such as « _sip._tls.xxxxxxx.com » > - provide certificates for names that are not internet routable, such as « > m_staging9.xxxxxxx.com » > > The first option is avoided here (and it’s fine), because this should go > into an SRV-type entry (or in the SAN:URI for this example). > The text of the proposed ballot opens the path to having underscores into > the the « xxxxxx » portion. This path is closed later by the validation of > domain authorization or control (except if method 3.2.2.4.11 is used). > > > Text in 7.1.4.2.1 disallows FQDNs that contain a label within the class of > R-LDH labels than don’t start with « xn-- ». IIUC, such domains are still > allowed under some TLDs that don’t support IDNA (such as « in--valid.am », « > in--valid.gov », or « in--valid.co.uk »). I just validated that Safari, > Firefox, and Chrome (on MacOSX) are happy to connect to > http://in--valid.mydomain.com (for a properly owned my domain.com). > Is that the intention of the ballot to disallow CAs to provide certificates > for such domains?
Yes. See the terminology discussion in https://tools.ietf.org/html/rfc5890#section-2.3.1 (as well as Figure-1) . In effect, this prohibits CAs from issuing for Reserved LDH Labels - except for those explicitly noted (IDNA). The existing RFCs already prohibit issuance to non-LDH labels, by virtue of RFC 5280 (4.2.1.6 - "When the subjectAltName extension contains a domain name system label, the domain name MUST be stored in the dNSName (an IA5String). The name MUST be in the "preferred name syntax", as specified by Section 3.5 of [RFC1034] and as modified by Section 2.1 of [RFC1123].") _______________________________________________ Public mailing list [email protected] https://cabforum.org/mailman/listinfo/public
