At 18:14 -0800 on 11/14/2011, Carl S. Gutekunst wrote about Re: Any
interest in rigorous definition for SSL certificate:
Alexey Melnikov wrote:
>> ... one of the references for DANE -- RFC 6125 -- seems to be exactly
what I was looking for. Unfortunately, it very deliberately codifies
the language from RFC 2818 for wildcards, with the established
practice for SMTP being a SHOULD NOT.
Backward compatibility might be a sufficient reason to violate the
SHOULD NOT.
I don't think it's that easy. The issue is with Email virtual hosting
implementations that embed the virtual domain name (or any token with
dots in it) in the MX record. For example, if you look up the MX record
for gutekunst.org, you'll see:
gutekunst.org. 86382 IN MX 100
gutekunst.org.s8a1.psmtp.com.
gutekunst.org. 86382 IN MX 200
gutekunst.org.s8a2.psmtp.com.
[snip]
Postini's SSL certificate reads:
Subject: C=US, ST=California, L=Mountain View, O=Google Inc,
CN=*.psmtp.com
Why not use a Certificate with CN=*.*.s8??.psmtp.com (or whatever is
needed to map the s8XX section) to solve this issue? - or is more
than one wild card level invalid or having more than one certificate
with different specificity levels also invalid?