How make Spring Security use the generated KeyStore ?

[wimdeblauwe-swmu]

I am trying to use mock-oauth2-server with the Okta library for my integration tests. I have gotten to a point where I now get:

org.springframework.web.client.ResourceAccessException: I/O error on GET request for "https://localhost:55978/issuer1/oauth2/v1/keys": PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

The documentation states:

This will generate a SSL certificate for localhost and can be added to your client's truststore by getting the ssl config: ssl.sslKeystore.keyStore

Is there anybody that has some more explanation how I can use that KeyStore object I get from ssl.getSslKeystore().getKeyStore() and make Spring Security use it?