Ubuntu/openssl
From r00tedvw.com wiki
common openssl commands http://www.sslshopper.com/article-most-common-openssl-commands.html
generating a SSL cert with a SAN http://apetec.com/support/GenerateSAN-CSR.htm
Oracle Linux
find openssl.cnf
. I found it located at:
/etc/pki/tls/openssl.cnf
Verify this is present and uncommented: distinguished_name = req_distinguished_name
Uncomment req_extensions = v3_req