From owner-freebsd-questions  Sun Oct 14 19:54: 1 2001
Delivered-To: freebsd-questions@freebsd.org
Received: from koza.acecape.com (koza2.acecape.com [66.9.36.222])
	by hub.freebsd.org (Postfix) with ESMTP id C596E37B40D
	for <questions@FreeBSD.ORG>; Sun, 14 Oct 2001 19:53:58 -0700 (PDT)
Received: from p65-147.acedsl.com (p65-147.acedsl.com [66.114.65.147])
	by koza.acecape.com (8.10.1/8.9.3) with ESMTP id f9F2rv919786;
	Sun, 14 Oct 2001 22:53:57 -0400 (EDT)
Date: Sun, 14 Oct 2001 22:58:27 -0400 (EDT)
From: Francisco Reyes <lists@natserv.com>
X-X-Sender:  <fran@zoraida.natserv.net>
To: <cjclark@alum.mit.edu>
Cc: FreeBSD Questions List <questions@FreeBSD.ORG>
Subject: Re: Automating ssh connections so only one command would run.
In-Reply-To: <20011012222025.I6274@blossom.cjclark.org>
Message-ID: <20011014225334.V18306-100000@zoraida.natserv.net>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-questions.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-questions>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-questions>
X-Loop: FreeBSD.ORG

> > >it is trivial to slip commands through scp(1),
> > >$ scp 'remote:somefile;touch /tmp/scp_test' .
> > > And check for /tmp/scp_test on the remote machine.
> > I don't see how this is a security problem. Could you explain?
>
> I presume you want to limit people to scp(1) so they do not have full
> shell access; they can't execute arbitrary commands on the remote
> machine. With scp(1), you can do,
>
>   $ cat > command.sh <<EOF
>   > exec > command.out 2>&1
>   > <put your arbitrary commands here>
>   > EOF
>   $ scp command.sh remote:
>   $ scp 'remote:nonexistent; /bin/sh command.sh' .
>   $ scp remote:command.out .
>   $ more command.out

I just did what you wrote above. All a person would be able to do is to
copy the command.sh file/command to the other machine. If I could limit
their ability to only run scp and not ssh there would be no harm (in my
setup) just by been able to copy arbitrary files. Of course I still need
to have a quota so they don't override the space on the other machine, but
that is not all too much trouble.

> > Automating scp may not be the most secure way to copy data, but is there a
> > better way?
> scp = ssh = shell access. But I may have misunderstood what you are
> trying to achieve.

I am just trying to copy 2 files every day from one machine to another.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message