# convert ed to openssh format puttygen id_ecdsa -o id_ecdsa.ppk # password protected will not work (error: unrecognized cipher name) # need to remove password first ssh-keygen -p -f id_ecdsa # then run puttygen convert # convert ppk to pem puttygen id_ecdsa.ppk -O private-openssh -o id_ecdsa.pem