I need help writing a grep with regular expression command for the following scenario.

The /etc/ssl/openssl.cnf file contains a number of name, value pairs of the form name = value. It also contains a number of other things including headers, in which the line starts with a [, and comments, which have a # as the first character. Write a command that lists the unique values (remember, name/value pairs) that are actually set (i.e. ignore commented lines).