Add ssh ProxyJump option

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justme
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ProxyJump lets you connect to a intermediate jumphost (or two, or three) that form a chain to get to some host.
e.g. User Laptop --> company proxy --> DMZ jumphost --> Application server

Of course you can log in to each of those machines and use port forwarding to the next hop, but that quickly becomes tedious.
PuTTY 0.77 solved this by allowing to enter the name of a saved session as SSH proxy target, which in turn could have another proxy target.
When importing such a session in WinSCP it currently states "unknown proxy method".

And yeah, I agree ProxyJump is very close to SSH tunnel in WinSCP - only that it stops at one proxy (and I think technically ProxyJump does something different, too).

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martin
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@justme: WinSCP SSH Tunnel, PuTTY SSH proxy and OpenSSH ProxyJump are all equivalents. They are all built on top of SSH port forwarding technology. So I believe it's not ProxyJump that you are after, but multi-hop SSH tunnel, right? WinSCP still allows it, with use of Local proxy and plink. That's actually how OpenSSH ProxyJump is implemented. ProxyJump is just a shorthand for ssh -W ... ProxyCommand.

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justme
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WinSCP SSH Tunnel, PuTTY SSH proxy and OpenSSH ProxyJump are all equivalents. They are all built on top of SSH port forwarding technology
So I thought, too, but this RedHat article suggests it's forwarding stdin/stdout
https://www.redhat.com/en/blog/ssh-proxy-bastion-proxyjump

But you're right I'm after the multi-hop, and stdin/out would in fact be counter-productive here, as that would prevent SFTP as far as I can tell.

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martin
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Well, that's technicality. All are built of top of what is exactly called "TCP forwarding" feature of SSH. Where does the local traffic comes from is up to the local client. WinSCP uses local ports (even between two session in the same process). OpenSSH uses process input/output, as ProxyJump actually starts separate process (and no, it does not prevent SFTP). PuTTY passes data between the sessions directly in process.

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