> Am 17.01.2018 um 10:45 schrieb Yann Ylavic <ylavic....@gmail.com>: > > On Wed, Jan 17, 2018 at 10:30 AM, Stefan Eissing > <stefan.eiss...@greenbytes.de> wrote: >> >>> Am 16.01.2018 um 21:26 schrieb William A Rowe Jr <wr...@rowe-clan.net>: >>> >>> Color me very confused, but I can't distinguish a difference between vhost >>> based >>> Host: header selection in the "http-01" case, and SNI identification >>> in the case of >>> "tls-sni-01". Am I missing something? Discussion pointers? >> >> "http-01" makes a request against the dns name to be validated. It is >> usually not (easily) possible to intercept that from the wrong user account. >> >> "tls-sni-0[12]" just opens a TLS connection with SNI <challenge>.acme.invalid >> Some shared hosters have allowed people to upload a certificate for that. So, >> you sign up via ACME (from anywhere) for a shared hosted not-my-domain.com >> where you are also customer. Wait for the challenge token, create the cert >> and >> upload it to the hoster. > > I think what is missing is simply "https-01", just like "http-01" but > on TLS and a self signed cert (SNI is irrelevant). > It don't see how it's less (nor more) secure than "http-01", but > admins that don't want to or can't use port 80 have their way...
Agreed. Maybe they do it that way. But since this security weakness affects the IETF proposed "tls-sni-02" challenge in the ACMEv2 protocol also, any fix will first go through the working group there. And then maybe backported be LE to their ACMEv1 offering or not.
