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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The requirement it fills is RFC 3647 section 4.3.2.1 (section 3.2.1), unless we want to say “No stipulation”. Bruce should talk with Santosh Chokhani who wrote the RFC and see what he says.<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><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"'> Ryan Sleevi [mailto:sleevi@google.com] <br><b>Sent:</b> Friday, October 24, 2014 10:50 AM<br><b>To:</b> Ben Wilson<br><b>Cc:</b> Jeremy Rowley; Bruce Morton; Rick Andrews; CABFPub<br><b>Subject:</b> Re: [cabfpub] Private key control<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p>Before you go proposing more requirements just to have more requirements, which is the unfortunate way I interpret "so we have something to put in this section", I'd again like to repeat the request that you elaborate on the threats you believe this addresses.<o:p></o:p></p><p>Surely, if this provides any security value, you can at least elaborate one or two actual scenarios that you believe the BRs fail to address, and that this would.<o:p></o:p></p><p>Cheers<o:p></o:p></p><div><p class=MsoNormal>On Oct 24, 2014 9:47 AM, "Ben Wilson" <<a href="mailto:ben.wilson@digicert.com">ben.wilson@digicert.com</a>> wrote:<o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Bruce,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I assume you’re not opposed to coming up with wording that is less specific but would at least eventually fill in content for section 3.2.1 of an RFC-3647-formatted CP, which is what I’d like us to be working toward. If we really want to strip this down, even though I think we should address the MITM concern, then maybe we could just say something like, “Prior to issuing a Certificate, the CA MUST verify that the Applicant possesses the Private Key associated with the Public Key to be included in the Certificate. The CA MAY verify this association by obtaining a CSR from the Applicant.” ?<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>In other words, I don’t think anyone wants to disrupt internal practices of CAs that comply with this textbook CA baseline practice, unless you are saying that for the Web PKI, proof of possession isn’t necessary. If you are, then do you have an alternative you could propose? That’s what I’m looking for—something that we can all agree on that will fill a hole.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thanks,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Ben <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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>Bruce Morton<br><b>Sent:</b> Friday, October 24, 2014 8:19 AM<br><b>To:</b> Rick Andrews; Jeremy Rowley; CABFPub<br><b>Subject:</b> Re: [cabfpub] Private key control</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>I think the requirement should be dropped.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>If we only validate the signature on the CSR, then we do not know if there is a man-in-the-middle. You need some other data.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>If we want to technically validate private key control, then we should take some action such as sending the Subscriber some information out-of-band for signature. The signature would be compared to the signature on the CSR to see if the same key was used.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>The softer way that an OV/EV private key control is confirmed is by contacting the Subscriber out of band to confirm that they made/authenticate the request. I don’t think this works for DV. It will also not work when the Subscriber can approve a certificate issuance with dual-factor login.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>I don’t think we should have the requirement unless we suggest methods that will actually work for all certificate types and our current certificate management methods.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>This requirement is not in the BRs or the EV guidelines and we have not been suffering from an incidents, so again, I think the requirement should be dropped.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Bruce.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> <a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a> [<a href="mailto:public-bounces@cabforum.org" target="_blank">mailto:public-bounces@cabforum.org</a>] <b>On Behalf Of </b>Rick Andrews<br><b>Sent:</b> Thursday, October 23, 2014 2:46 PM<br><b>To:</b> Jeremy Rowley; CABFPub<br><b>Subject:</b> Re: [cabfpub] Private key control<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Jeremy,</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>How about “The CA MAY verify this association by obtaining a CSR from the Applicant and validating the signature on the CSR.”</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>-Rick</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><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> [<a href="mailto:public-bounces@cabforum.org" target="_blank">mailto:public-bounces@cabforum.org</a>] <b>On Behalf Of </b>Jeremy Rowley<br><b>Sent:</b> Wednesday, October 22, 2014 6:57 PM<br><b>To:</b> CABFPub<br><b>Subject:</b> [cabfpub] Private key control</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt;margin-left:.5in'>During the Code Signing BR discussion a few weeks ago, we noticed that the Baseline Requirements lack a definitive requirement for the CA to confirm that the Application is properly associated with the Public Key being included in the certificate. We’d like to remedy this oversight. What does everyone thing about adding a section similar to the following to the BRs?<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'>Section 11.1.5 Verification of Key Pair Association<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'>Prior to issuing a Certificate, the CA MUST verify that the Applicant’s Private Key is properly associated with the Public Key and a subject name to be included in the Certificate. The CA MAY verify this association by obtaining a CSR from the Applicant. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'>Jeremy<o:p></o:p></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br>_______________________________________________<br>Public mailing list<br><a href="mailto:Public@cabforum.org">Public@cabforum.org</a><br><a href="https://cabforum.org/mailman/listinfo/public" target="_blank">https://cabforum.org/mailman/listinfo/public</a><o:p></o:p></p></div></div></body></html>