Not a valid key file format (see man sshd) at /opt/vyatta/sbin/vyatta-load-user-key.pl line 96, <$in> line 1.
Turned out that the key needs to:
- have a comment
- not have any spaces in the comment
- be on a line of it’s own in the imported file (e.g. do not add a newline at the end)
loadkey to accept it.