OpenSSH GSoC Project

[Pavel Labath]

Thanks for the replies,

Jim Knoble wrote:
> Perhaps i misunderstand, but i think the intent of the GSoC description
> is to make sftp(1) a potential replacement for scp(1), insofar as
> non-interactive invocation from the shell prompt is concerned.  Example:
> 
>     scp -p -r ./some_dir remote-host:
> 
> Currently, sftp(1) understands neither '-p' nor '-r'.
I agree, that's what the project description would seem to imply.
However, both can be added in a matter of days. In fact the "get"
command has a -P flag, so that just leaves -r and a command-line
interface. And a comparison of man pages shows, that the remaining scp
flags not available in sftp are:
-2, -4, -6, -c cipher, -i identity, -q: implementation trivial - just
pass to ssh
-P port: the only complication is the presence of a conflicting switch
-l limit: implementation fairly simple
Hardly an all-summer project. That's why I suggested further
improvements that could be done. to ke

> It may be that the best way to do some of this would be the same way
> F-Secure's SSH does it:  use scp2(1), which would eventually completely
> replace scp(1).
I'll keep that in mind, thanks.

> Again, look at LFTP for ideas.
Actually, I did. :) Most of the suggestions are directly inspired by
lftp. The other day I looked at man lftp, and was surprised that it can
connect to sftp servers. So in a way, I would be duplicating work here,
and that's one question I wanted answered (although I didn't state it
explicitly). Is it worth it? One possible reason might be portability.
I'm not sure, but I'd guess openssh runs of more arches than lftp, I'll
have to check that. The other: we don't want them to be better than us :P


Peter Lambrechtsen wrote:
> Few other nice to haves:
>
> Transferring open files.  Such as a "tail -f" being able to copy a
> open log file, even if it is displayed as zero bytes try reading the
> file and seeing how far you can go.
An interesting idea, thank you.

> Plus one other wishlist I had is "man-in-the-middle" scp / sftp.  ie
> scp user at hostname1:/file user2 at hostname2:/destdir.  As I have a number
> of areas where I have a DMZ server that can access two remote servers
> in different zones, but the two servers cannot communicate with each
> other, and I need to find a way to copy from one server to the other,
> difficult if the DMZ server has a small amount of storage and you need
> to copy a large file.
Yes, that's what I meant be "server to server transfer". btw, scp claims
to be able to do that. However, when I tried, it barked at me with the
"remote host identification has changed" message. I'll try to figure it
out when I am be able to keep my eyes open.

peace,
-- 
Pavel Labath