Error on rclone : superfluous leading zeros in length

Dear all,
I have try to connect to a server using ssh:
this is the configuration

type = sftp
host =
user = centos
port =
pass =
key_file = /home/centos/key.pem
use_insecure_cipher = true

I have this error:

clone lsd Cloud:
2018/01/24 16:23:35 Failed to create file system for “Cloud:”: failed to parse private key file: asn1: structure error: superfluous leading zeros in length

That is kind of indicating that you are using the wrong sort of key…

A bit of googling indicates this might be a problem with the ssh library rclone uses.

Here is a workaround put into packer which maybe indicates you can convert your key something like this