Unable to Change Password for Private SSH Key

Question

I'm running PuTTY Pageant on Windows, and I used it to generate a private SSH key with a .ppk extension.

Now I want to change the password to that key, so I opened my Git bash terminal, cd'd to my .ssh directory, and typed:

ssh-keygen -f private.ppk -p

It then asks me to enter my old passphrase, but after entering it, it says "Bad passphrase." I'm absolutely certain I'm entering the passphrase correctly.

Does Pageant do some weird encryption with the SSH keys it generates so I can't update the password? The password works fine when unlocking the key within Pageant, and the key itself works fine, too.

Answer 1

Putty does not store keys in an OpenSSH-compatible format. You need to use the "puttygen" tool to manipulate your private key.

(via this document, via Google):

To change or set a passphrase on an SSH key under PuTTY, do the following:

1. Run the puttygen.exe program.
2. Click on the "Load" button.
3. Select the private key file that you want to put a passphrase on.
4. Enter the new desired passphrase in the "Key passphrase" and "Confirm Passphrase" fields.
5. Click on the "Save private key" button. Overwrite the existing copy of your key.