- Copy the certificate to a .crt file
- Add the .crt to the trusted store and update the CA certificates
For Ubuntu or Debian:
cp my-custom.crt /usr/local/share/ca-certificates/my-custom.crt update-ca-certificates
For CentOS or Redhat or Fedora:
cp my-custom.crt /etc/pki/ca-trust/source/anchors/ update-ca-trust extract