Hi Dominic,
I did as you instructed. I created a .pem file from the three certificates generated by openssl. However the device could not take a document above 4kb. This was 6kb. I got this feedback from vendor:
Your format may be a certificate issued by an intermediate authority, I am not sure if the certificate issued by the Root CA authority is the same
1. It may be the reason of openssl parameters, you can try to modify the parameters
2. The test only keeps a set of content from “BEGIN CERTIFICATE” to “END CERTIFICATE” to see if it can be connected
3. Generally speaking, each “certificate” should be less than 4KB; this is also the reason why “Invalid File” appears when burning the software and importing server.pem (6KB).
Any comment to this? Do I need all 3 certificates in the file?