I have a bash script that ssh's into a server, twice, like so:

ssh user@server 'ls /dir1/' > /tmp/file_listing

to get a directory listing (which I then pass to "select")

and

ssh user@server ’cat /dir1/backupX.img.gz’ | gunzip -c | ntfsclone --restore-image --overwrite /dev/hda1 -

to, obviously, write an ntfsclone image to a partition.


I would like this script to only ask for the ssh password once, then pass it to both ssh commands, and the only way I can find to do this is with "expect".

But the problem is that both ssh commands need to return data to the shell. The first redirects the ls listing to a temp file, and the second pipes the output to gunzip and ntfsclone.

Is this possible?

Bret

While you could put the password in you're violating the benefit of ssh by having to store your password in clear text. Why not instead set up an ssh trust so that when ssh logs in it doesn't ask for the password at all?

I had thought of that, but I'm making a custom linux cd, and thought that might be dangerous - having a cd that has the key to the image server.

But I think I may just do that, because of the plain text password issue, and because I can't figure out how to do it anyway.

Thanks!

Bret

No problem.

The CD bit is new information.

I'd thought you were just doing a machine to machine setup. If you're trying to propagate this out to multiple insecure locations you probably want to have a jail area on your main system for each of the remove locations (that is don't use the same user for every one of them). That would allow them to dump the file to the jail area. You'd then put a process in place on your main system that copied the information out of the jail into an area none of the CD based systems could reach.

Better yet might be doing an ssh FROM the main system to the CD based systems so the security is controlled by the main system and you don't have to worry about compromise of the remotes except as it affects their invidual data.

Thanks for the advice. I'm not too familiar with chroot jails (if that's what you're talking about), so for now, I guess I'll stick to my inelegant-put-your-ssh-password-in-twice setup.

But thanks again!

Bret

You can use connection multiplexing to make ssh ask for the password only once:
If you put ControlPath /home/user/%r@%h:%p.ssh in /home/user/.ssh/config you don't need to put it in all the commands.