That's the relatively simple case, but there are a number of corner cases that make the process much more complicated. See https://github.com/letsencrypt/acme-

That's the relatively simple case, but there are a number of corner cases that make the process much more complicated. See https://github.com/letsencrypt/acme-spec/pull/97 https://github.com/letsencrypt/acme-spec/pull/97 for a discussion of why this was scraped from the ACME specification proposal.