To configure mTLS authentication, set the `type` property to the value `tls`.
mTLS uses a TLS certificate to authenticate.

The certificate is specified in the `certificateAndKey` property and is always loaded from a Kubernetes secret.
In the secret, the certificate must be stored in X509 format under two different keys: public and private.

.Example mTLS configuration
[source,yaml,subs=attributes+]
----
authentication:
  type: tls
  certificateAndKey:
    secretName: my-secret
    certificate: my-public-tls-certificate-file.crt
    key: private.key
----

You can use the secrets created by the User Operator,
or you can create your own TLS certificate file, with the keys used for authentication, then create a `Secret` from the file:

[source,shell,subs=+quotes]
kubectl create secret generic <my_tls_secret> \
--from-file=<my_public_tls_certificate>.crt \
--from-file=<my_private_key>.key

.Example secret for mTLS client authentication
[source,yaml,subs="attributes+"]
----
apiVersion: v1
kind: Secret
metadata:
  name: my-tls-secret
type: Opaque
data:
  tls.crt: LS0tLS1CRUdJTiBDRVJ...
  tls.key: LS0tLS1CRUdJTiBQUkl...
----

NOTE: mTLS authentication can only be used with TLS connections.
