Converting PuTTY private keys to OpenSSH format

because it is in Putty-format. Please use Putty-Keygen to convert it to OpenSSH format

1. Make a copy of your private key just in case you lose it when changing the format.
2. From the Start menu, go to All Programs then PuTTY and then PuTTYgen and run the PuTTYgen program.
3. In the Parameters section:
   • For Type of Key to generate, select SSH-2 RSA. (hoặc chọn RSA)
   • For Number of bits in a generated key, leave the default value of 2048.
4. Click Load.

Open your private key in PuTTYGen
Top menu “Conversions”->”Export OpenSSH key”.
Save the new OpenSSH key when prompted.