We have been using apple pay to get a payment token for future payment processing. This has been working fine until our merchant identity and payment processing certs expired. We have renewed the certs but are still having problems. We are using the contents of a file called privateKey.der to decrypt the returned token. I am assuming this is the private key for the merchant identity cert. However, I don't seem to be able to recreate this file from the current merchant identity cert. How do I extract the private key from the pfx file? Nothing I have done seems to work. Thanks for any help.