RE: cooked mode sessions

["Howard Chu" <hyc%highlandsun.com@localhost>]

> -----Original Message-----
> From: ietf-ssh-owner%netbsd.org@localhost [mailto:ietf-ssh-owner%netbsd.org@localhost]On
> Behalf Of Sami J. Lehtinen

> hyc%highlandsun.com@localhost ("Howard Chu") writes:
>
> > I'd like to see support for client-side input processing, to
> > eliminate
> > the single-character echoing roundtrips that interactive
> sessions currently
> > have.
> > This should be similar to the Telnet LINEMODE option. For the
> majority of
> > terminal
> > sessions operating a command-line, there's no reason the client
> can't do all
> > the
> > input editing and just send complete lines to the server. This kind of
> > feature will
> > improve performance on slow links, and can also lessen the
> effectiveness of
> > traffic-
> > analysis attacks on a session by eliminating keystroke-timing
> information.

> Why can't this be done with the current protocol spec?

Some kind of message is needed to tell the client about pty mode changes.
E.g., if
the app issues an ioctl to turn echo off, a protocol message is needed to
convey this state change. All of the terminal-mode settings that a client
sends in its "pty-req"
could potentially be sent from the server to the client at any time. There
are many
other instances where such a message is needed.