This article describes how to add a CA as trusted CA on RHEL Based Linux Systems.
This is necessary if you want to use selfsigned certificates.

Copy CA Cert

First copy the CA Cert to your server. For Example with scp.

Add CA Cert to whitelist

Next you need to add the CA Cert to the trusted white list. This is done by moving it into the corresponding directory.

$ mv ca_cert.cer /etc/pki/ca-trust/source/anchors/
# or
$ mv ca_cert.cer /etc/pki/ca-trust/source/whitelist/

Update Whitelist

For your changes to take affect you need to update your whitelist.

$ update-ca-trust

Check you Trust List

You can check the trusted CAs like so:

$ trust list --filter=ca-anchors