Certificates for LwM2M Carrier library

[DevinCallahan]

Hi!

I'm updating to SDK v1.7.1 and I am looking at the changes in LwM2M Carrier Library v0.20.1.  I was previously using LwM2M Carrier LIbrary v0.10.2

The big change is the application now needs to build in the CA certificates used to authenticate the FOTA package.  The samples show how to do this and include certificates from nrf/samples/nrf9160/lwm2m_carrier/certs

My question then is which certificates do I need to build into my application?

We are using iBasis SIM cards, though if Nordic is signing the modem FOTA package then I wouldn't expect that to matter.

Thank you!

[Charlie]

Hi Devin,

If I understand correctly, you only need to run  LwM2M carrier library in an application in order to connect to the operator LwM2M network when a specific operator like Verizon requests and provides this LwM2M backend. You would be able to find CA information from their LwM2M carrier library documentation.

I am not sure if iBasis in your local region also require it. Have you checked with our local FAE about your condition?

Best regards,

Charlie

[DevinCallahan]

Thank you for the response Charlie!

Could you help me understand then what the certificates are for so I can be more knowledgeable when discussing this with the carriers?

In particular:

1. At /nrf/samples/nrf9160/lwm2m_carrier/certs there is DigiCertGlobalRootCA.pem, DigiCertGlobalRootG2.pem, and DSTRootCA-X3.pem.  How were these certificates selected to be included for that sample?

2. How are those certificates used in the library?  Are they used to authenticate the download URL for the FOTA package when it is received from the Carriers LwM2M server, or are they used to authenticate something else?

3. LwM2M Carrier Library v0.10.2 had a CA certificate built into by default.  Where did that certificate come from?

Thank you!