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
|| localFinalEnv.settings().hasValue(TransportSettings.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 other nodes to join the cluster from anywhere");
                        bw.newLine();
                        bw.write("# Connections are encrypted and mutually authenticated");
                        bw.newLine();
                        if (false == inEnrollmentMode
                            || false == anyRemoteHostNodeAddress(transportAddresses, NetworkUtils.getAllAddresses())) {
                            bw.write("#");
                        }
                        bw.write(TransportSettings.HOST.getKey() + ": 0.0.0.0");
                        bw.newLine();
                    }
                    bw.newLine();
                    bw.write(AUTO_CONFIGURATION_END_MARKER);
                    bw.newLine();
                }
            });
        } catch (Throwable t) {
            try {
                if (Files.exists(keystoreBackupPath)) {
                    Files.move(keystoreBackupPath, keystorePath, StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.ATOMIC_MOVE);
                } else {
                    
                    Files.deleteIfExists(keystorePath);
                }
            } catch (Exception ex) {