So, I was bored and tried to deploy new ssh keys. But my OpenSSH server refused to start with the following error message:
Unable to load host key "/etc/ssh/ssh_host_rsa_key": invalid format
However, the key was ok and worked in another setup.
Apparently, there was only a newline missing at the end of the file. It got lost while deploying it. Happened to me on Alpine 3.2.1 on Docker…