We generate certificates that are intended to be used for server authentication in a couple of places:

- `bin/elasticsearch-certutil http` command  ( See `CertGenUtils.generateSignedCertificate` in `HttpCertificateCommand` )
- TLS auto-configuraion for node startup ( see [`AutoConfigureNode`](https://github.com/elastic/elasticsearch/blob/814f7f9f52cb8c05db6465b9bfc818ea5d76c575/x-pack/plugin/security/cli/src/main/java/org/elasticsearch/xpack/security/cli/AutoConfigureNode.java#L454) )

In these cases we know that the certificate is meant to be used for server authentication, so we can set Extended Key Usage extension to `1.3.6.1.5.5.7.3.1`
x-pack/plugin/security/cli/src/test/java/org/elasticsearch/xpack/security/cli/HttpCertificateCommandTests.java
verifyCertificate(certAndKey.v1(), certNames[i], certYears, List.of(hostNames[i]), List.of());
            verifyChain(certAndKey.v1(), caCertKey.v1());
            assertThat(getRSAKeySize(certAndKey.v1().getPublicKey()), is(HttpCertificateCommand.DEFAULT_CERT_KEY_SIZE));
            assertThat(getRSAKeySize(certAndKey.v2()), is(HttpCertificateCommand.DEFAULT_CERT_KEY_SIZE));
            
            assertThat(readme, containsString(p12Path.getFileName().toString()));
            assertThat(readme, containsString(ymlPath.getFileName().toString()));
            if ("".equals(password) == false) {
                assertThat(readme, not(containsString(password)));
            }
            if ("".equals(caPassword) == false) {
                assertThat(readme, not(containsString(caPassword)));
            }
            
            assertThat(yml, containsString(p12Path.getFileName().toString()));
            if ("".equals(password) == false) {
                assertThat(yml, not(containsString(password)));
            }
            if ("".equals(caPassword) == false) {
                assertThat(yml, not(containsString(caPassword)));
            }
        }
        verifyKibanaDirectory(
            zipRoot,
            true,
            List.of("2. elasticsearch-ca.pem"),
            Stream.of(password, caPassword, caPath.getFileName().toString()).filter(s -> "".equals(s) == false).collect(Collectors.toList())
        );
    }
    public void testParsingValidityPeriod() throws Exception {