1. Is CA (Certificate Authority) file required?
Please make sure that your CA file is either (1) included in your Certificate File (.crt) section OR (2) listed separately under the Certificate CA File (.ca) section. If your SSL certificate does not contain CA, leave the CA section in blank and proceed the process. However, please keep in mind that invalid or missing CA file may be the cause of your website error.
2. How do I make a bundle .crt file?
This may vary by Certificate Authority and the number of files. In most cases, a bundle .crt file must follow this order.
1. Domain CRT file
2. Intermediate File(s)
3. Root CA File
Please make sure not to add any additional spaces or blanks in between each files.
Copy and paste each certificate file into one or follow the below method on command shell. This will concatenate all files into a bundle file, in which case you don’t have to insert the CA section.
[cat your_domain.crt issuer_commone_name.crt issuer_ca.crt external.crt > sample_ssl.crt]
If you have trouble concatenating SSL files, please refer to the links below.
How to make a Comodo SSL bundle file
How to make a GlobalSign SSL bundle file
How to make a DigiCert SSL bundle file
How to make a GlobalSign SSL bundle file (Korean)