Re: OpenSSH/scp ->> F-Secure SSH server Problems

[Jason R Thorpe <thorpej%zembu.com@localhost>]

On Tue, Mar 13, 2001 at 10:51:09PM -0500, Greg A. Woods wrote:

 > Well, maybe, but sftp, at least in SSH, currently relies on the
 > "built-in subsystem" feature.

Actually, I don't think that's so -- it only needs a bi-directional,
stream-oriented communication endpoint, right?  "Subsystem" is merely
the mechanism that the SSH protocol uses to create that endpoint and
start the SFTP server.

...at least, that's how I understand it.

Now, a given implementation may choose to make the SFTP server
a built-in of the SSH server -- but that is not required.

 > I'm sure you could rip it out and make it stand alone (eg. work over
 > rsh), but hmmm... wouldn't doing so also make it independent of the
 > "built-in subsystem" in SSH?  Duh!  So yes:
 > 
 > > > The "built-in subsystem" feature is bad design.  It has no business
 > > > being directly in the transport protocol.  It is an ugly wart.

...but I'm not sure I completely agree with this.  I can understand the
argument, but I'm not sure I buy it :-)

I think the problem is the terminology -- "subsystem" ... I think the
term "service" would be better ("Hi, please run this service over this
secure transport"), maybe, but it's probably a little too late to change
it.

-- 
        -- Jason R. Thorpe <thorpej%zembu.com@localhost>