kubernetes/staging/src/k8s.io/apiserver/pkg/authentication/request/x509/testdata/intermediate.config.json

{
    "signing": {
        "default": {
            "usages": [
                "digital signature",
                "cert sign",
                "crl sign",
                "signing",
                "key encipherment",
                "client auth"
            ],
            "expiry": "876000h",
            "ca_constraint": {
                "is_ca": true
            }
        }
    }
}