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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">> For example, the addition of "If a CNAME or DNAME record is found, then the CAA check will start<o:p></o:p></p>
<p class="MsoNormal">> over using the returned value as the new input to the CAA check." is introducing ambiguity, because
<o:p></o:p></p>
<p class="MsoNormal">> it's incompatible with the algorithm described - namely, the CAA check does not start over, because<o:p></o:p></p>
<p class="MsoNormal">> the CAA check would have already accounted for the CNAME/DNAME traversal.<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">There are a couple of things that are not clear to me:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">1) This is the specified processing logic for handling CNAME and DNAME records says:<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">If A(X) is not null (i.e, there is a CNAME or DNAME record for X), and R(A(X)) is not empty, then R(X) = R(A(X)), otherwise <continue…><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">If a CA is looking up foo.example.com and there was a CNAME to bar.domain.com what do they check? As written, the RFC says to check bar.domain.com for a CAA
record and if there is one use it, otherwise continue with processing (look for CAA record for example.com then alias for example.com). I was
<i>assuming</i> that we’d want to dig a little deeper into bar.domain.com by checking CAA record for domain.com and alias for domain.com.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Perhaps my wording of “starting over again” is not accurate, and I should have added step 2.1 that says:<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">2.1 If A(X) is null, then spawn a new CAA check with CAA(A(X)). If this check ends with R(X) being empty, then continue processing with
step 3<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">What is the correct interpretation of the RFC, are the alias’s chased down or just checked at that one level? Does anyone care?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">2) The definition of when to stop CAA checking is not clear. The RFC says: the processing scenario says to stop when X is a top-level domain<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">The BRs define “Base Domain Name”, which is where we should stop for processing BR compliant TLS certificates. Do we want to proceed up to the “top-level domain”
(undefined term) looking for CAA records for TLS certificates, or do we want to stop at Base Domain Name? I think for our purposes we need to stop searching for CAA records when we hit the Base Domain Name.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
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