3.6.

$ oc create secret generic cacerts -n istio-system --from-file=<path>/ca-cert.pem \
    --from-file=<path>/ca-key.pem --from-file=<path>/root-cert.pem \
    --from-file=<path>/cert-chain.pem

apiVersion: maistra.io/v1
kind: ServiceMeshControlPlane
spec:
  istio:
    global:
      mtls:
        enabled: true
    security:
      selfSigned: false

$ oc delete secret istio.default

$ RATINGSPOD=`oc get pods -l app=ratings -o jsonpath='{.items[0].metadata.name}'`

$ oc exec -it $RATINGSPOD -c istio-proxy -- /bin/cat /etc/certs/root-cert.pem > /tmp/pod-root-cert.pem

$ oc exec -it $RATINGSPOD -c istio-proxy -- /bin/cat /etc/certs/cert-chain.pem > /tmp/pod-cert-chain.pem

$ openssl x509 -in <path>/root-cert.pem -text -noout > /tmp/root-cert.crt.txt

$ openssl x509 -in /tmp/pod-root-cert.pem -text -noout > /tmp/pod-root-cert.crt.txt

$ diff /tmp/root-cert.crt.txt /tmp/pod-root-cert.crt.txt

$ sed '0,/^-----END CERTIFICATE-----/d' /tmp/pod-cert-chain.pem > /tmp/pod-cert-chain-ca.pem

$ openssl x509 -in <path>/ca-cert.pem -text -noout > /tmp/ca-cert.crt.txt

$ openssl x509 -in /tmp/pod-cert-chain-ca.pem -text -noout > /tmp/pod-cert-chain-ca.crt.txt

$ diff /tmp/ca-cert.crt.txt /tmp/pod-cert-chain-ca.crt.txt

$ head -n 21 /tmp/pod-cert-chain.pem > /tmp/pod-cert-chain-workload.pem

$ openssl verify -CAfile <(cat <path>/ca-cert.pem <path>/root-cert.pem) /tmp/pod-cert-chain-workload.pem

$ oc delete secret cacerts -n istio-system

apiVersion: maistra.io/v1
kind: ServiceMeshControlPlane
spec:
  istio:
    global:
      mtls:
        enabled: true
    security:
      selfSigned: true