"ssh-xfer uses the local SSH agent to transfer files using an
existing connection. It can also do this over multiple connections:
So if you've sshed into desktop A and then through that to server
B, ssh-xfer will allow you to transfer a file directly from server
B to your local machine. To make this work, you must patch your
ssh-agent locally, and install the ssh-xfer binary remotely. Note
that it is limited in that you can transfer files only from the
remote machine to the local machine, not vice versa."
