Re: A future for the SSH File Transfer Protocol?

[Thor Simon <tls%cs.stevens-tech.edu@localhost>]

On Sat, Nov 10, 2001 at 01:45:41PM -0500, RJ Atkinson wrote:
> At 13:42 10/11/01, Markus Friedl wrote:
> >i don't understand the problem with SFTP.
> 
> Might not be a problem, but folks want to understand 
> the problem SFTP is trying to solve.
> 
> For example, I'm trying to puzzle out how SFTP
> is different from SCP and why I would care about
> that difference (if I knew what it was)...
> 
> Since this is a standards question, I'm deliberately
> trimming the distribution to the IETF SECSH list.

>From my point of view, there are three differences:

1) SCP is a lightweight protocol which is constrained in purpose and
   function to be a replacement for traditional Berkeley Unix 'rcp';
   SFTP is a much heavier protocol which tries to provide the functionality
   of FTP (and perhaps then some) atop the SSHv2 transport layer.

2) SFTP is standards-track; currently, SCP is very much not so.

3) SFTP is actually documented.  SCP -- because it's just basically rcp
   on top of SSH -- is not; there isn't an rcp RFC, not even an 
   informational.

Personally, my taste runs much more to a simple file transfer protocol than
to a very rich and complex one, but to date the SSH WG has felt otherwise.
I've committed to do an informational RFC on the rcp protocol but keep
failing to find the time for the last 10% of work to get it out the door;
at least then those who cared to implement SCP would have some documentation
other than the Berkeley code.

Thor