Newbie Questions...

bopo119 · 03-29-2004, 07:50 PM

Sorry but I am a

and I have a few stupid questions but:

a.) When creating a telnet/SSH server, how can I create/edit a greeting message?

b.) How can you limit a users commands from a shell? Ex. A "user creating" user to just have a command to create users and a logout command.

I have looked

all around to no avail for both of these questions... perhaps it is not possible, but I think I have come to the right place to find that out.

rose_bud4201 · 03-29-2004, 07:57 PM

As far as I can see, using forced commands can do exactly what you need. (i.e. associating a file with a particular ssh user, listing the command they're allowed to run). Even though this is only a sample chapter, it's the right one

:http://www.oreilly.com/catalog/sshtd...h08.html#22858.
It may require a little more research into how exactly to implement it, but I hope this at least gives some useful search terms

G'luck (and I learned something in looking this up, too!) Let me know how it goes,
-Laura

rose_bud4201 · 03-29-2004, 08:03 PM

Oh, and the contents of the file /etc/motd is output to the ssh user upon connection to your server.
http://os2.ru/materials/internet/sshd.shtml.en

bopo119 · 03-29-2004, 08:06 PM

Wonderful. I am still a big newbie so if you find any more stuff go ahead and put it on here. At the moment, however, thank you.

bopo119 · 03-29-2004, 08:09 PM

Hmmmm.... just went and looked at my /etc/motd file and it seems to be empty. Have you found anything pertaining to the format of the file? or even write to it in the first place

rose_bud4201 · 03-29-2004, 08:29 PM

Nice and easy - just put the text in there

For instance, my server says "Linux 2.4.20" when someone connects. I did a 'cat /etc/motd' and 'Linux 2.4.20' comes back. It seems like sshd just dumps the contents of that file to the user

Code:

bash-2.05b$ ssh 127.0.0.1
laura@127.0.0.1's password: 
Last login: Mon Mar 29 21:30:42 2004 from localhost
Linux 2.4.20.
laura@cleopatra:~$ exit 
logout
Connection to 127.0.0.1 closed.
bash-2.05b$ cat /etc/motd
Linux 2.4.20.
bash-2.05b$

bopo119 · 03-29-2004, 08:41 PM

You must be root to edit it however correct? Do I have to restart my computer before /etc/motd will take effect?

rose_bud4201 · 03-29-2004, 09:08 PM

Yes, you must be root. And restarting the machine shouldn't be necessary, but restarting sshd p'bly is.

liamoboyle · 03-29-2004, 11:28 PM

It's generally good practive that you should the only user you ever allow to create user accounts is root. And you generally don't want to give anyone remote access to a super user account, they should be forced to log in as a normal user and then use su / sudo. If a user can create another user, then they can just reconnect as that user and run any commands they want, after all... so you wouldn't really be limiting much.