As I'm working on an OpenSource application, that application is to serve Web pages to clients. It also supports a mailserver, DNS, and runs with the Cassandra database.
What I have done is setup a firewall that gets installed with the application. This means it is available with the OpenSource application (i.e. anyone, including hackers, can see the rules that are going to be applied to the firewall.)
The rules are as restrictive as possible, as far as I can tell, so I'm not too worried about that in particular.
However, I'm wondering whether having the firewall rules in clear for anyone to see would include blackhats that could then benefit from having the source of such. Is that indeed a potential problem? Are there recommendations available out there on this subject?
Obviously, the firewall is not the only security feature included in the system, but that's certainly one important one.