If you want to know how to create a SSH keypair in Linux, see this manual.

Install putty-tools:

sudo apt-get install putty-tools

Then:

cd ~/.ssh/

puttygen id_rsa -o id_rsa.ppk

If we would like to convert the Putty format key to Openssh key:

• To generate the private key follow this command:

puttygen id_dsa.ppk -O private-openssh -o id_dsa

• To generate public key follow this command:

puttygen id_dsa.ppk -O public-openssh -o id_dsa.pub 

Be sure that the permissions are set correctly for private and public key:

chmod 600 id_dsa
chmod 666 id_dsa.pub

If you would like to learn more about PuTTYgen, learn about the installation or usage guide, we invite you to visit the website www.puttygen.com