Programming

Dear friends,
Before putting my questions forward, I would like to put some data infront of you, hope you will help me at the end.
This website
Cray-Cyber - Welcome
provides free access to many supercomputers and mainframe computers. When you login through ssh, they provide you with a screen, welcoming you, and listing all the systems which are online and offline. When you choose an online system, they take you to that particular system, and then the authorization takes place, and after you provide the login details, they redirect you to that particular system with a particular operating system, then another authorization takes place after that you start using that system. The login that they provide is available on all online systems running different operating systems. They have different systems running Operating systems like unicos unix, solaris, vms, etc.
Now my question is that I want to build such a system, for example
In my case, I will be having 5 computers running linux, solaris, windows, dos, z/os. These 5 computers will be behind a 6th computer which will be running linux, running the software which handles all the authorization and redirection jobs, and this system will be available on the internet, allowing users to use all those 5 computers and their operating systems.
This whole setup looks a bit complex I guess, maybe you can guide me. I think it requires system and networking programming in unix using C language, if I am wrong please correct me.
And do you know of an open source project similar to this, which could help me, and books which, after reading it, would enable me to build such a system. I am familiar with C, but apart from a number of small programs, I don't have much experience building systems as complex as this.

Please help me,
I am looking forward to your wonderful replies!

Thanks in advance!

Well, what's required really depends on what you want to do, but I suspect little to no C programming. There's existing tools to do a lot of what you want -- sharing accounts and so forth -- like lDAP. Please explain in more detail how it's supposed to work -- are the accounts anonymous or not, are the accounts persistent or not, etc, etc.

Well bro, I am not really in a position right now to give you all that technical details, as I am still in the process of learning advanced UNIX stuff. I have obtained a guest account for you on cray-cyber, here is the account id and password. Could you please ssh to that system and see it for yourself, you will see exactly what I want to build. It will be so nice of you, my brother!
Waiting desperately for your wonderful reply
Thanks bro!
login: guest
password: e2f13b0

I do have a job, so you shouldn't depend on my replies. I may be busy or unavailable (and will be very shortly)

In any case, logging into cray-cyber doesn't tell me how you generated the account, what happened on their machines when you requested an account, how their login system works, and if/how they share accounts among machines. That happens on their end where you can't see it. It's just a guest account with very limited control.

I suspect they'd be happy to answer questions about their systems if the information won't compromise their security. Otherwise you'll need to start thinking about how you want to do this.

Thanks for all these replies. I just want you to just point me to some direction so that I will be able to build such a system in the next couple of years. Here are a few topics that my mind is telling me which would be helpful to me building such system, what do you think about them?
1. UNIX system programming using c
2. UNIX network and socket programming using c
3. UNIX Shell scripting
Do you agree with me on this or not?

---------- Post updated at 11:20 AM ---------- Previous update was at 11:18 AM ----------

And you asked that how I got that guest account, I applied for it through their website and they emailed me the password for the guest account. That password will be valid for 24 hours only, and I have to apply again. I also have my own account on that system, but as you said, this account of mine is very limited. I am only allowed to do programming stuff, and I can't mess around with the security and system stuff.

I don't think the first two will be useful for this. Certainly you wouldn't want to be coding your own authentication systems in raw C, you want to depend on something known secure. Systems like the one I've been name-dropping already, LDAP, already exist to do things like this, though it's not a drop-in solution, there's a lot of fiddly bits.

Same goes for networking. ssh already exists and, as far as I can tell, is all you need for people to connect with ssh, so no need to play with networking in C. It's what scripts happen when they ssh into this system, and what login trickery is happening to let the accounts work everywhere, that's the question.

Of course, I don't know they actually use LDAP for what they're doing. I can't really tell.

Shell scripting will definitely be useful. Yes.. so if you want to find out how their system works, asking them would be a good first step.