Re:SSH hacks – a little sanity for remote workers
by beagle3 on Thursday April 30, 2020 @10:47AM
(#23031372)
> So it's purely for performance?
It's not just for performance - it "reuses authentication" by not needing it. The authentication is an encapsulation, within which multiple channels get used. Usually, it's just the main "shell" channel; but occasionally it's also forwarding (-L / -R / -D), sftp; what ControlMaster does is let you open more "shell" channels when you run the "ssh" command again, instead of establishing a whole new connection.
> The other neat-looking directive that I've never tried is `ProxyUseFdpass`,
It's so you can use whatever weird communication hardware/protocol you like (serial? non-tcp satellite modem?), and all you have to do to get all of ssh's wonderful features over it, is make provide a file descriptor that works well enough (serial port; pipe you create; etc.)
It's not just for performance - it "reuses authentication" by not needing it. The authentication is an encapsulation, within which multiple channels get used. Usually, it's just the main "shell" channel; but occasionally it's also forwarding (-L / -R / -D), sftp; what ControlMaster does is let you open more "shell" channels when you run the "ssh" command again, instead of establishing a whole new connection.
> The other neat-looking directive that I've never tried is `ProxyUseFdpass`,
It's so you can use whatever weird communication hardware/protocol you like (serial? non-tcp satellite modem?), and all you have to do to get all of ssh's wonderful features over it, is make provide a file descriptor that works well enough (serial port; pipe you create; etc.)