The point is, you don’t really connect to the Certificate on the Authorization Domain Name, you connect to a certificate on the same IP address as the ADN, but you actually intentionally ask for a different server name, which has no relationship to the ADN (except they happen to share the same IP address). It seems like misissuance to me.
From: Alex Gaynor [mailto:agay...@mozilla.com] Sent: Thursday, January 18, 2018 3:47 PM To: Doug Beattie <doug.beat...@globalsign.com> Cc: mozilla-dev-security-pol...@lists.mozilla.org Subject: Re: TLS-SNI-01 and compliance with BRs I guess it depends how you define "Certificate on the ADN" -- TLS-SNI-01 performs a DNS lookup for the ADN, connects to that IP, and initiatives a TLS connection with the .acme.invalid SNI value. Certificates don't exist on Domain Names if we think really hard about it, but servers with IPs that domain names point to can serve certificates, and that seems like a reasonable interpretation of the intent of that sentence, which TLS-SNI-01 fulfills. Alex On Thu, Jan 18, 2018 at 3:43 PM, Doug Beattie via dev-security-policy <dev-security-policy@lists.mozilla.org<mailto:dev-security-policy@lists.mozilla.org>> wrote: Now that I'm more familiar with method 9 and 10 domain validation methods and heard a few side discussions about the topic, it's made me (and others) wonder if the ACME TLS-SNI-01 is compliant with BR Method 10. The BRs say: 3.2.2.4.10. TLS Using a Random Number Confirming the Applicant's control over the FQDN by confirming the presence of a Random Value within a Certificate on the Authorization Domain Name which is accessible by the CA via TLS over an Authorized Port. But it's my understanding that the CA validates the presence of the random number on "random.acme.invalid" and not on the ADN specifically. Is the validation done by confirming the presence of a random number within the certificate on the ADN, or some other location? I'm probably misreading the ACME spec, but is sure seems like the validation is not being done on the ADN. Doug _______________________________________________ dev-security-policy mailing list dev-security-policy@lists.mozilla.org<mailto:dev-security-policy@lists.mozilla.org> https://lists.mozilla.org/listinfo/dev-security-policy _______________________________________________ dev-security-policy mailing list dev-security-policy@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-security-policy
