On Fri, 22 Jan 2016 18:54:43 +0000 Hugo Landau <[email protected]> wrote:
> Certificates should probably contain SAN A. If they don't, this is > liable to confuse TLS implementations and supporting infrastructure, > which doesn't expect that an SNI request for x should result in a > certificate not listing x. Agreed, but that doesn't mean the ACME server has to check for such a SAN. What the client has to do and what the server has to do are separate things, and the server should only do what's necessary to ensure the security of the challenge. Superfluous checks obscure the security-critical checks, which makes the challenge harder to reason about, and makes it harder to audit server implementations. So I say keep the client-side part of the spec the same, but change item three of the server-side part to say: "Verify that the certificate contains a subjectAltName extension containing a dNSName entry of SAN B. The comparison MUST be insensitive to case and ordering of names." -- Andrew _______________________________________________ Acme mailing list [email protected] https://www.ietf.org/mailman/listinfo/acme
