<div dir="ltr">No, fraudulent doesn't really change a thing.<div><br></div><div>If the answer is No (they don't need to be revoked), then it creates an incentive for cloud operators to be lax on name validation policies, since there is no penalty. It also creates incentives for phishers/attackers to use a few layers of abstraction, so that they can claim independence, even when acting in coercion. This is, unfortunately, not outside the realm of possibilities.</div>
<div><br></div><div>However, if the answer is Yes (they do need to be revoked), well obviously that creates a clear disincentive towards cloud operators offering SSL, since they'd need to be cycling certs every time they discovered a potentially fraudulent customer. I think we can all agree that "less SSL" is an unquestionably bad thing.</div>
<div><br></div><div>This is related to Brad Hill's remarks on wildcards and IDNs. That is, allowing wildcards essentially allows phishables/spoofables in at least one label of the URI. I know Brad was, in the past, opposed to wildcards on this basis, but at the same time, I think we can agree that having cloud hosts offer scalable SSL is a net-win for the web (since SNI still remains uncommon enough to be a market differentiator)</div>
</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, May 5, 2014 at 10:41 AM, Ben Wilson <span dir="ltr"><<a href="mailto:ben@digicert.com" target="_blank">ben@digicert.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">For clarification on #2, does the word “fraudulent” change anything? In other words, in your minds, what is the scenario that is considered “fraudulent”? <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a> [mailto:<a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a>] <b>On Behalf Of </b>Ryan Sleevi<br>
<b>Sent:</b> Monday, May 05, 2014 11:23 AM<br><b>To:</b> Kelvin Yiu<br><b>Cc:</b> <a href="mailto:public@cabforum.org" target="_blank">public@cabforum.org</a><br><b>Subject:</b> Re: [cabfpub] Use of wildcard certificates by cloud operators<u></u><u></u></span></p>
<div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p><div><p class="MsoNormal"><u></u> <u></u></p><div><p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p><div><p class="MsoNormal">On Mon, May 5, 2014 at 10:10 AM, Kelvin Yiu <<a href="mailto:kelviny@exchange.microsoft.com" target="_blank">kelviny@exchange.microsoft.com</a>> wrote:<u></u><u></u></p>
<div><div><p class="MsoNormal">This Netcraft post (<a href="http://news.netcraft.com/archives/2014/04/28/phishers-find-microsoft-azure-30-day-trial-irresistible.html" target="_blank">http://news.netcraft.com/archives/2014/04/28/phishers-find-microsoft-azure-30-day-trial-irresistible.html</a>) has highlighted some questions for us about wildcard certificate requirements in the BR and how they apply to cloud operators. <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p><p class="MsoNormal">Microsoft Azure customers can create sub domain names under specific MS registered domains (e.g. <a href="http://myservice.azurewebsites.net" target="_blank">myservice.azurewebsites.net</a>). Users can access these FQDNs using HTTPS, which is is secured with a wildcard certificate managed by Azure. Customers do not have access to the private key of the wildcard certificate. Azure also maintains a process to monitor for fraudulent activities and will take down such sites. AFAIK, other cloud operators such as Google App Engine and Amazon Web Services uses wildcard certificates in a similar way. <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p><p class="MsoNormal">Here are my questions to the forum:<u></u><u></u></p><p class="MsoNormal"> <u></u><u></u></p><p>1.<span style="font-size:7.0pt"> </span>Section 11.1.3 of the BR explicitly disallow wildcard certificates for registry controlled domains (e.g. *.com). The Mozilla maintained <a href="http://publicsuffix.org" target="_blank">http://publicsuffix.org</a> is cited as an example of a public suffix list where Azure, GAE, and AWS domains can be found. Does the current usage of wildcard certificates by cloud operators violate the BR? If so, is this intentional and what is the reason?<u></u><u></u></p>
</div></div><div><p class="MsoNormal">The Public Suffix List is presently divided into two sections - ICANN-assigned suffices (eg: gTLDs, ccTLDs) and "Private" (enterprise) suffices, for which Azure falls under (as do many other hosted services, such as AWS and Google App Engine)<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">In both cases, things are fuzzy - in a know-it-when-I-see-it sort of way. That is, it's easy to say something like "*.com" should be invalid. For something like *.<a href="http://appspot.com" target="_blank">appspot.com</a> or *.<a href="http://azurewebsites.net" target="_blank">azurewebsites.net</a>, one would say that it should be invalid for "just anyone" to register, but it should be valid for Google/Microsoft (respectively) to register - as they have. So perhaps we'd say this is a "high-risk domain" and requires manual vetting, but it's hard to say as a general rule it should be prohibited.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Further, it gets more troubling with something like *.nike (as a hypothetical). If Nike doesn't allow third-party registrations, but instead fully operates the domain - much like *.<a href="http://appspot.com" target="_blank">appspot.com</a> or *.<a href="http://azurewebsites.net" target="_blank">azurewebsites.net</a> - should it be allowed to register a wildcard cert? Maybe, maybe not. (For the record, Chrome, in present form, would reject it, as it would any wildcard to an ICANN/IANA-assigned gTLD)<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Note that Section 11.1.3 provides for registrations in *.<a href="http://azurewebsites.net" target="_blank">azurewebsites.net</a> and *.<a href="http://appspot.com" target="_blank">appspot.com</a> - as well as *.nike - in its present form, in the first sentence of the second paragraph:<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">"If a wildcard would fall within the label immediately to the left of a registry-controlled† or public suffix, CAs MUST refuse issuance unless the applicant proves its rightful control of the entire Domain Namespace."<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><div><p>2.<span style="font-size:7.0pt"> </span>Section 13.1.5 of the BR explicitly require wildcard certificates that were “used to authenticate fraudulently misleading subordinate FQDN” to be revoked within 24 hours. If the fraudulent sites never had access to the private key of the wildcard certificate and the cloud operator has a process to take down fraudulent sites, should these wildcard certificates be required to be revoked?<u></u><u></u></p>
</div></div></blockquote><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">I don't have a good answer for this, and will probably need to think more before responding. I can see positive and negative outcomes with either answer.<u></u><u></u></p>
</div><div><p class="MsoNormal"> <u></u><u></u></p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><div><p class="MsoNormal"><span style="color:#888888"> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#888888">Kelvin<u></u><u></u></span></p></div></div><p class="MsoNormal" style="margin-bottom:12.0pt"><br>_______________________________________________<br>Public mailing list<br><a href="mailto:Public@cabforum.org" target="_blank">Public@cabforum.org</a><br>
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