I have used openssl to create a .key and .cer file in pem format (you can read them). Now I want to create .pfx file from them. I have read openssl doumentation it says something like following command I can use
openssl pkcs12 -export -in certificate.cer -inkey privateKey.key -out certificate.pfx -certfile CACert.cer
but I don't know which one is my .cer file (certificate.cer or CACert.cer) what is differences between these two files?
The certificate.cer is your public key and the CACert.cer file (as it names suggest) is the public key of a CA (maybe the one who has signed your certificate).
The -in switch specifies input certificate to embed in output file
The -inkey switch specifies the key file you've generated using OpenSSL
The -out switch tells the openssl your desired name for output file
The -certfile is used to specify additional certificates to add to the output pfx file (it could be ignored)
来源：https://stackoverflow.com/questions/19199293/create-a-pfx-file-from-a-cer-and-a-pem-file