The nice thing about computer standards are that there are so many to choose from.
I use PuTTY on Windows to login to my Bitnami Ubuntu machines on the Amazon Cloud. PuTTY uses the .pkk key format.
I develop using Intellij. This can deploy to remote hosts but uses the OpenSSH key format. To convert a PuTTY key to OpenSSH.
- Open your private key in PuTTYGen
- Top menu “Conversions”->”Export OpenSSH key”.
- Save the new OpenSSH key when prompted (e.g. my-server-name.openssh)
Thanks to Jesse Yowell for the tip.