usually when you get SSL Certificate, you will get multiple cert files which can be confusing.
they mostly contains a
- CA (Certificate Authority)
- Trusted Cgain
- domain cer (your main certificate file with your domain name on it)
- domain private key (your private key which you created when you where requesting for SSL
if you want to combine all of these certificate and create a so called certificate bundle or store, you should first concatenate ROOT certificate authority or CA file with chain 1 (Trusted Chain) and Chain 2 (Organizer).
$ cat chain1 chain2 root > bundle.cer
then you can verify it with
$ openssl verify -verbose -purpose sslserver -cafile bundle.cer domain.cer
now create a key store (PKCS12) from the bundle and private key
$ openssl PKCS12 -export -out domain.pfx -inkey private.key -in domain.cer -cert bundle.cer