converting putty key to open ssh keys

Used the method given here to convert, using
puttygen mykeyfile.ppk -o ~/.ssh/id_rsa.pub -O public-openssh

and
puttygen mykeyfile.ppk -o ~/.ssh/id_rsa -O private-openssh

After moving the keys to .ssh, we also have to chmod 600 or else ssh will not take these keys by default. We also need to name them id_rsa and id_rsa.pub for ssh to use them by default, without having to specify ssh -i keyname username@server.