What's your favourite SFTP client?

[ewx]

I've been writing an SFTP server. It's not complete but it is good enough to start testing against a wider variety of clients.

So what other SFTP clients should I test against? I'm disinclined to pay money merely to test interoperability but don't mind looking at free-as-in-beer clients; obviously free software clients are better in that I can look inside and see why they're doing things. I've got Windows XP, OS X and Linux and home and can get access to several other UNIX platforms.

The list so far.

If you're brave enough to try out incomplete, undocumented and scantily tested software, then see this page for instructions. It runs on OS X and Linux, though at any given point one or the other might be temporarily broken.

Why is it better than the OpenSSH server? It supports SFTP protocol versions up to 6 (although some of the v6 support isn't done yet), which implies support for filename encoding translating, text mode transfers, string chown/chgrp, sub-second timestamps, hard links and extra rename semantics.

As part of the process I've summarized information about SFTP protocol version differences here.

Comments

[sevenstring.livejournal.com]

The GNOME VFS stuff has an sftp client in it (sftp://... urls). But my preferred sftp client is also my preferred ftp client: lftp (http://lftp.yar.ru/).

[uisgebeatha.livejournal.com]

I shall try it out when I get Ubuntu happening on HP Beast. :)

I tend to use WinSCP or CuteFTP for all my file transporting needs, though I've also used SSH (http://www.ssh.com/downloads/) during my course. As long as the client is nice and graphical drag-and-drop, it suits me fine. ;)

[emperor]

You may have mentioned this before, but why start afresh, rather than produce patches for openssh?

[fanf]

Does it address the small-window performance problem?

[ewx.livejournal.com]

What problem did you have in mind? It can cope with clients stacking up multiple read/write requests without waiting for responses, if that's what you mean.

[fanf]

http://www.cs.auckland.ac.nz/~pgut001/pubs/app_sec.pdf p.20

[ewx.livejournal.com]

That appears to be an SSH design flaw that can be exacerbated by sufficiently poor choices in SFTP clients. My program is neither an SSH implementation nor an SFTP client, so I'm not sure what I'm supposed to do about it.

(It does include an SFTP client, in fact, but that is intended for testing only, and doesn't get installed.)

[ewx.livejournal.com]

Ooh, excellent, someone else claiming v6 support.

[ewx.livejournal.com]

I wanted to support request re-ordering, which implies a fairly different architecture. I didn't want to be tied to the OpenSSH source tree and I certainly didn't want to have to deal with getting patches into upstream projects (mailing list and bug tracker traffic don't fill me with confidence that the OpenSSH developers are gung-ho for SFTP development). The whole two-branch portable/non-portable thing would potentially be a speedbump too (if the OpenSSH developers like to work that way that's fine but I don't).

I suspect I'd not have spotted their symlink bug if I'd started from their code, too, so I think it's already had one good result.

[pne.livejournal.com]

I was going to suggest the SFTP client that's part of Servant Salamander, but I believe that's a plugin based on WinSCP code, so the behaviour would likely be similar, if not identical, to that of stock WinSCP.

[ewx.livejournal.com]

...pity it doesn't even build...

[ewx.livejournal.com]

------------------------------------------------------------
revno: 71
committer: Richard Kettlewell <rjk@greenend.org.uk>
branch nick: sftpserver/mainline/kakajou
timestamp: Thu 2007-03-08 21:07:46 +0000
message:
  Correct conversion from nanoseconds to, er, nanoseconds.  In my
  defence I offer the conversion from nanoseconds to microseconds
  further down the same file.
  
  Correct sense of existence test for SSH_FXF_OPEN_OR_CREATE and
  SSH_FXF_CREATE_TRUNCATE.
  
  Both bugs discovered when testing against lftp 3.5.9.  This defaults
  to SFTP protocol version 4 but can be told to request version 6.
------------------------------------------------------------
revno: 70
committer: Richard Kettlewell <rjk@greenend.org.uk>
branch nick: sftpserver/mainline/kakajou
timestamp: Thu 2007-03-08 19:42:35 +0000
message:
  don't claim creation time in attributes

[ewx.livejournal.com]

CuteFTP appears to be payware.

[nassus.livejournal.com]

I use whatever default sftp that comes with the ssh client under unix/macos but macos has a lovely freeware gui for sftp called fugu that does a nice job. On PC's I generally use WinSCP which I'm happy with cause it's based on putty and has a friendly interface.

[ewx.livejournal.com]

I've added Fugu to the list.

[ewx.livejournal.com]

In fact it turns out that Fugu is just a wrapper around the OpenSSH client, rather than an SFTP implementation in its own right, meaning it adds no extra value to testing.