Error: Can't read the Xero Entrust cert. You need one for partner API applications. http://developer.xero.com/documentation/getting-started/partner-applications/ 

Error: Can't read the self-signed cert key. Check your rsa_private_key config variable. Private and Partner API applications require a self-signed X509 cert http://developer.xero.com/documentation/advanced-docs/public-private-keypair/