KeepassXC SSH Agent in WSL and OpenSSH for Windows
I use KeepassXC for managing passwords – it is a fantastic FOSS tool for that. If you don’t use a password manager or use a paid one, do give it a try, I used to be a paid LastPass user few years ago till I discovered KeepassXC.
It also has support for storing SSH keys inside the database file and exporting it via SSH-Agent when the database file is unlocked and removing it when it is locked. An excellent feature which eliminates the need to store the ssh keys un-encrypted.
I never got around setting up the SSH agent thing using KeepassXC, because I just used to copy my ~/.ssh folder around – primarily two devices, Windows desktop and Linux laptop. In my .zshrc I use keychain so that the keys are added to my agent whenever I open the terminal – in WSL as well as in Linux.
Now the catch here is that KeepassXC cannot export SSH keys to the SSH Agent running inside WSL, this means either I have to ditch the idea of storing ssh keys inside Keepass or use native Windows OpenSSH. While searching I came across this article A Better Windows 10+WSL SSH Experience in which the author has done agent sharing setup between native Windows OpenSSH and WSL using a named pipe <=> socket proxy (since inside WSL the applications speak Unix stuff and Windows OpenSSH agent listens on named pipe instead of Unix socket, obviously).
In the process I also updated the Windows OpenSSH version because the one installed by default was giving me a warning when SSHing to one of the servers and ssh was switching back to password based authentication:
warning: agent returned different signature type ssh-rsa (expected rsa-sha2-512)
The solution for this problem is basically to update OpenSSH to a newer version. The Windows OpenSSH version in my system was 7.7, updated to 8.1.
Now with the current setup my keys are safely stored inside the KeepassXC database file, and agent forwarding works in both native Windows OpenSSH and WSL! 😀
NileshGR 