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/main/java/org/elasticsearch/xpack/security/cli/AutoConfigureNode.java
bw.write("# Create a new cluster with the current node only");
                            bw.newLine();
                            bw.write("# Additional nodes can still join the cluster later");
                            bw.newLine();
                            bw.write(
                                ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING.getKey()
                                    + ": "
                                    + initialMasterNodesSettingValue(localFinalEnv)
                            );
                            bw.newLine();
                        }
                    }
                    
                    
                    if (false == (localFinalEnv.settings().hasValue(HttpTransportSettings.SETTING_HTTP_HOST.getKey())
                        || localFinalEnv.settings().hasValue(HttpTransportSettings.SETTING_HTTP_BIND_HOST.getKey())
                        || localFinalEnv.settings().hasValue(HttpTransportSettings.SETTING_HTTP_PUBLISH_HOST.getKey())
                        || localFinalEnv.settings().hasValue(NetworkService.GLOBAL_NETWORK_HOST_SETTING.getKey())
                        || localFinalEnv.settings().hasValue(NetworkService.GLOBAL_NETWORK_BIND_HOST_SETTING.getKey())
                        || localFinalEnv.settings().hasValue(NetworkService.GLOBAL_NETWORK_PUBLISH_HOST_SETTING.getKey()))) {
                        bw.newLine();
                        bw.write("# Allow HTTP API connections from anywhere");
                        bw.newLine();
                        bw.write("# Connections are encrypted and require user authentication");
                        bw.newLine();
                        bw.write(HttpTransportSettings.SETTING_HTTP_HOST.getKey() + ": 0.0.0.0");
                        bw.newLine();
                    }
                    if (false == (localFinalEnv.settings().hasValue(TransportSettings.HOST.getKey())
                        || localFinalEnv.settings().hasValue(TransportSettings.BIND_HOST.getKey())