Convert PuTTY .ppk key to OpenSSH in Ubuntu

convert_key.sh

sudo apt-get install putty-tools

# Place your keys in some directory, e.g. your home folder. Now convert the PPK keys to SSH keypairs:cache search

# To generate the private key:
puttygen your_private_key.ppk -O private-openssh -o your_new_key
chmod 600 your_new_key

# Move these keys to ~/.ssh and make sure the permissions are set to private for your private key:
mkdir -p ~/.ssh
mv -i ~/id_dsa* ~/.ssh
chmod 600 ~/.ssh/id_dsa

#based on answer at superuser
#https://superuser.com/questions/232362/how-to-convert-ppk-key-to-openssh-key-under-linux