PuTTY

You won’t be able to directly use your PuTTY‘s key in Linux‘s OpenSSH because the keys are of different format. You’ll need to first convert PuTTY‘s key to OpenSSH‘s key format by following these steps;

1. Download PuTTY Key Generator (puttygen.exe) from the following URL

   https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

2. Launch the program and click on the Load button and select your PuTTY‘s key file, which normally ends with .ppk extension.
   
   
3. Enter the key’s passphrase if prompted.
   
4. Details of the imported key will be displayed.
   
5. Go to Conversions → Export OpenSSH key from the menu.
   
6. Save your converted key to a new file and location.
   

SSH and PuTTY keys are of different formats and will have to be converted to each other’s format if you want to use the same key between the 2 programs. Follow these steps to convert SSH‘s key to PuTTY‘s.

1. Download PuTTY Key Generator (puttygen.exe) from the following URL.

   https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

2. Launch the program and click on the Load button.
   
3. Set the Files of type to All Files (*.*) and select your SSH‘s key file.
   
4. Enter your key’s passphrase if prompted.
   
5. A prompt will pop up once conversion is successful. Click on Save private key.
   
6. Choose the filename and folder to save the file to.