Gentoo Archives: gentoo-user

From: Willie Wong <wwong@××××××××××××××.EDU>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Copying a file via ssh with no password, keeping the system safe
Date: Fri, 08 Oct 2010 10:19:38
Message-Id: 20101008101847.GA8636@math.princeton.edu
In Reply to: Re: [gentoo-user] Copying a file via ssh with no password, keeping the system safe by Andrea Conti
1 On Fri, Oct 08, 2010 at 10:05:50AM +0200, Andrea Conti wrote:
2 > Now, the remote sshd is never sent any information about what is
3 > connected to the local end of the pipe (which is not even known to
4 > ssh!), so there is no way to alter its behavior depending on that.
5 >
6 > IOW, nothing in the setup you and I proposed prevents the user from
7 > piping an arbitrary command into ssh (or even using a ssh-invoking
8 > wrapper such as scp or rsync) and getting successfully authenticated on
9 > the server. You are only guaranteed that the server will run tar in
10 > place of whatever remote command the client requests, so that the
11 > connection will break if the client side sends non-tar data.
12 >
13 > In my opinion this is quite different from "[allowing] only one single
14 > command from a single cronjob to operate passwordless", but then I might
15 > just be splitting hairs.
16
17 Okay, reading your explanation I agree with you on both counts: the
18 behaviour does not exactly fit the letter of the question, and that
19 you are splitting hairs because I think the behaviour is good enough
20 for the spirit of the message.
21
22 Cheers,
23
24 W
25 --
26 Willie W. Wong wwong@××××××××××××××.edu
27 Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
28 et vice versa ~~~ I. Newton