Okay, lets start at the basics.
man inetd.sec
This will give you the ability to control the connections made by inet.
Now, onto the rest.
System security is not something that someone can simply tell you how to get done, as every site is different in needs.
You can look at Bastille for HP-UX, but if you need any of the services that Bastille locks out, your no good reading any further unless you know how to open services up again in a secure way..
Lets talk about sendmail for a moment:
Sendmail is sendmail. Knowledge of how to secure it in HP-UX is identical to knowledge of how to secure it in Solaris, AIX, Linux, SCO, Irix, Xenix, etc...
If you dont know enough about sendmail to secure it, plan on doing tons and tons of reading and experimenting and taking a long time to get this done. Sendmail 3rd edition I'll mention below has some cook book features, as well as alot of info on security. But, once you can secure sendmail, you can do it on any Unix platform with minimal adaptations.
This is true for almost all major services in Unix. Apache security is Apache security, whether on HP-UX or SunOS.
Other people pointed you to openssh download sites, but remember that running openssh does not shut down telnet, rsh, rexec, etc...
System security and site security is quite an extensive knowledge base, that noone can give you in a simple reply. This literally takes years of doing to fully understand, as well as training (whether professional or self teaching). And even then, if you miss 1 thing all your work can be down the crapper with 1 hacker.
I'd suggest you look at Bastille for HP-UX first. It's alot to digest, but this is a true hardened system. I'd also suggest you start on a nice library. All of the following are published by O'Reilly and Associates.
DNS and Bind cookbook and/or 4th edition
Practical Unix and Internet security
Internet core protocols (definitive guide)
Sendmail 3rd edition
NFS and NIS in a Nutshell
Apache
SSH, The Secure Shell (definitive guide)
Lets not forget the most critical piece of security in this mess either. Monitoring!
It's hard from looking your post to guess how much security you need, and how much knowledge of Unix you have. The biggest concern is the Unix knowledge, and knowledge of internet services for Unix. If your unsure about any of them, you may want to talk to a consultant.
Sincerely,
Shannon Petry
Microsoft. When do you want a virus today?
