The most people want to use OpenCA for issuing certificates to users or they want to test a PKI without buying a commercial trustcenter only for testing. So they want create a request, approve the request and issue a certificate. The problem is that they forget to the edit the request and the subjct alternative name was not set.
OpenCA knows two switches in ca.conf to set the subject alternative name automatically. The switch AUTOMATIC_SUBJECT_ALT_NAME enables the mechanism to set the subject alternative name automatically if it was not set in the header of the request. The second switch DEFAULT_SUBJECT_ALT_NAME defines the type of the default value. Actually we implemented only support for the emailaddress. If you need support for DNS name(s) or IP addresse(s) then contact us. We only don't implement it because nobody need it until now.
If you edit the subject alternative name on the RA interface then you see only four fields where you can enter parts of the alternative name. If you fill all fields then you will get at next time you want to edit the alternative name one additional field. If you know that you need more or less fields then you can change the option CSR_MAX_SUBJECT_ALT_NAMES in the configuration files. The option defines the number of the displayed fields by default. It is NOT a hard limit.