SCP without passwords
In embedded development, there is the problem that after you build the
code on your host PC, you have to load onto the target. My normal
solution for this is to create an NFS mount to a folder on the
host that contains the binaries and the necessary auxiliary files. I
was motivated to load the files via scp, but I prefer to automate my
development cycle as much as possible. This means calling scp from
the makefile, which means calling it without a password. I knew it
was possible to set up a system that allowed this, so I turned to
Google.
I searched for “scp in scripts”. The first link seemed very
authoritative and gave instructions that used ssh-keygen to create a
public RSA key to put in the host’s ~\.ssh\authorized_keys file.
Possibly because the target is using Dropbear for ssh, these
instructions didn’t work and I spent a significant amount of time
trying to debug the system.
A co-worker that I had dragged into the problem gave me a different solution that did work. When I asked him where he found his solution, he said “Google”. To my frustration, his link was the first link for him on the search “scp without password”. This illustrates the principle that you should always ask Google for exactly what you want.
Tags: Programming