SSH command when uploading files

[Reckhard, Tobias]

Hello

I've searched quite a bit, but have so far been unsuccessful in finding an
answer to a question I have concerning the upload of files via rsync over
SSH.

When downloading, I have been able to make use of SSH's benefits, yet still
keep the rsync server safe from a shell accessible with a private SSH key
lacking a passphrase by restricting the public key used by the rsync client
to the one rsync operation it shall perform, something of the sort "rsync
--sender --server <blabla>". That command showed up the in the sshd debug
(or verbose) info on the rsync server. So far so good.

Now I'm in a situation where I have to push data from the rsync client to
the server. I'd also like to use SSH. Since this is an automated process I
again need to use an empty SSH private key passphrase on the client. To make
things worse, we're talking about access to the root account on the rsync
server. I'd really like to restrict the capabilities of that SSH key.

However, from the output of "rsync -vvv ..." on the client and "sshd -d ..."
on the server it appears to me that no command is passed to the sshd on the
server when uploading data. Is this correct? And is there a way to do what I
want or do I need to drop SSH and resort to pure rsync, over IPSec perhaps
(which doesn't provide for user auth, but rsync can do that, can't it)?

Thanks for any help.

Cheers,
Tobias
-- 
Tobias Reckhard
secunet 
Security Networks AG      Tel   : +49(6196)95888-42
Mergenthalerallee 77      Fax   : +49(6196)95888-88
D-65760 Eschborn          E-Mail: tobias.reckhard at secunet.com