Re: Does OpenSSH use RCP?

tonij67@xxxxxxxxxxx writes:

>I know the question sounds silly, but I have been having a discusion
>with someone about the difference between OpenSSH and SFTP. In my
>experience I have found that using SCP to transfer files actually uses
>the SFTP subsystem. Am I correct in thinking this? The reason I came
>to that conclusion is, if a system does not have SFTP configured
>properly (i.e. sshd_config file not pointing to the correct location of
>SFTP) than SCP will fail. This has lead me to believe that running SCP
>actually uses SFTP to some degree.

You would be wrong; SFTP is an extremely poor execuse of a protocol
(it's got several issues such as being slow and cumbersome and largely
unnecessary)

>Or am I missing something?

>Either way, this discussion has brought up the difference between using
>SCP and SFTP to move files. The person I am having a hard time
>agreeing with is telling me that Openssh uses the RCP protocol.

He is right: scp uses the "rcp" protocol.

>*boggle*

>Anyone ever heard of such a thing? This makes no sense to me, as every
>system I have OpenSSH running on does not have any of the 'R' commands
>configured (inetd.conf doesnt even start the services, so RCP fails)
>and the whole point of using SSH is to replace the R commands (rcp,
>rsh, etc....)

Ah, you are confusing the "rcp" protocol with the "R" cmd authentication
mechanism.

"rcp" uses the "R" protocol to establish a connection and then starts
a "rcp" slave command and starts exchanging files.

"scp" uses the "SSH" protocol to establish a connection and then starts
a slave "scp" command to exchange files.

The rcp and scp client/server protocols are very similar.

Casper
--
Expressed in this posting are my opinions. They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.
.