we have wildcard ssl certificate for *.domain.com, and have a website with sub1.sub2.domain.com
safari 4.0.4 on MacOsx pops up a certificate error(presumably because of wildcard interpretation), while safari 4 on windows does not.
also ie8 behaviour is mixed at best, some ie8 do not display the certificate error and some do not.
What causes this strange behavior on Safari and IE?
If you need a wildcard certificate that contains *.domain.com sites and also work with sub1.sub2.domain.com or another domain like *.domain2.com, you can solve that with a single wildcard certificate with what is called a subject alternative name (SAN) extension for each of the other sub sub domains. A SAN cert is not just for multiple specific host names, it can be created for wildcards entries as well.
For example, *.domain.com, sub1.sub2.domain.com, and *.domain2.com would have a Common Name of *.domain.com then you would attach a subject alternative name of both *.domain2.com and *.sub2.domain.com. It might depend on the Certificate Authority as to how they would charge you (or not) for the certificate, but there are some out there where this offering is available. Also, SAN is support is pretty widespread in the web browser space. The best real world example of this use, it Google's SSL cert. Go open google and view its SSL certificate, you will see it works for *.google.com, *.youtube.com, *.gmail.com, and a bunch more where they are listed as subject alternative names.
A wildcard SSL certificate for *.example.net will match sub.example.net but not sub.sub.example.net.
From RFC 2818:
The wildcard is only applied to the first part (from the left) of you domain. So you'll need a certificate for *.sub2.domain.com
If you meant that you have sub1.domain.com and sub2.domain.com, then it should work.