Re: [tlug] [thread hijack] sftp

[Neil Bortnak <nbortnak@example.com>]

Hi David,

If I'm not mistaken, sftp works in a fashion similar to scp or rsync.
You run scp, which calls ssh, which runs scp on the remote machine and
then the two scp's work together to transfer the file using the ssh
session for transport. It really *is* just an ssh session. rsync over
ssh works the same way. sftp is similar but is a openssh "subsystem"
(check your sshd_config file) which implies the execution mechanism is
slighly different.

In any case it's just an ssh connection to the packet sniffer/IDS.

Regarding a tunnel, I've done this a bunch of times and it works really
well. Instead of running scp or rsync, you run pppd which makes ppp
interfaces at either end. It looks just like a modem connection and you
can just route normally. The only caveat is that it breaks down quickly
when there is packet loss on the connection because you're doing tcp
over tcp which weirds things up from a packet retransmission and timing
perspective. Since you're not doing a long haul connection over bad
links, don't worry about it. I threw it in for completeness. There is a
faq on how to do this here:

http://www.tldp.org/HOWTO/ppp-ssh/index.html

Knock yourself out :),

Neil


P.S. Spend some time with ssh. It's an **incredibly** useful and
versatile tool. Look into public key authentication too. You will be
blindingly happy that you did.



On Sun, 2003-09-28 at 01:08, David Oftedal wrote:
> >> sftp commands to download files through a secure connection (it uses the
> >> secure shell protocol).  You may also want to look at rsync, which 
> >> also uses
> >> ssh to communicate.
> >
> To start off, my sincerest (ish) apologies for the thread hijacking.
> 
> I totally don't know what I'm talking about here, but am I right in 
> assuming that SFTP is not only encrypted, but also runs on a single 
> port, contrary to FTP?
> 
> I'm behind one of those uni firewalls that block all inward ports with 
> no exceptions, and although I can TUNNEL over ssh, I can only tunnel 
> single-port stuff like HTTP with my limited time and knowledge. (Unless 
> I use a VPN client from the outside, that is, and it's heavily monitored 
> and I really can't be bothered.)
> 
> Also, what servers and clients are available for Gentoo? Are any of them 
> good? ;)
> 
> -- 
> http://home.no.net/david/
>