I had another version of the test that tested for actual keys in the response, like 'CN', 'O', 'L', 'ST' etc, but the return value of [openssl_x509_parse](http://php.net/manual/en/function.openssl-x509-parse.php)
states: "The structure of the returned data is (deliberately) not yet documented, as it is still subject to change.", so I submitted it as you saw it above.

But if you think its better, I can test previous for actual keys 'CN', 'O', etc, because the "subject to change" clause, probably has more to do with the X509v3 extensions, than the subject.