Push notification server settings for iOS

I have developed a push notification module and made all the settings required. In the configuration section of the module it says, The filename for the development certificate should be apns-development-fdd6bfba49.pem, the production certificate should be apns-production-fdd6bfba49.pem. If I generate the certificate with same name only then it works. If i upload .pem file with any other name like apns-production.pem for production certificate it gives this error:- Failed to enable crypto in push_notifications_open_apns(). APNS connection could not be established. Check to make sure you are using a valid certificate file. I am very sure it is not command execution problem. Kindly help as to why am I getting this error. What should I do? Please reply if anyone has an answer for this. I am struggling to get the production certificate.