Recently I ran into an issue with key based authentication between Netbeans and an sFTP server. It was returning an error saying I had an invalid private key.
The key worked for other tools, so I was slightly confused why it wouldn't for Netbeans.
After some digging I uncovered that Netbeans doesn't like PPK files, it needs OpenSSH key files in order to connect with key based authentication
The fix is pretty simple;
- Download PuTTY Key Generator.
- Open your PPK file. (File > Load Private Key)
- Convert your file. (Conversions > Export OpenSSH Key)
- Load this as your key file in Netbeans.