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
t.addSuppressed(ex);
            }
            
            
            throw t;
        }
        
        final Path keystoreBackupPath = env.configFile()
            .resolve(
                String.format(Locale.ROOT, KeyStoreWrapper.KEYSTORE_FILENAME + ".%d.orig", autoConfigDate.toInstant().getEpochSecond())
            );
        if (Files.exists(keystorePath)) {
            try {
                Files.copy(keystorePath, keystoreBackupPath, StandardCopyOption.COPY_ATTRIBUTES);
            } catch (Throwable t) {
                try {
                    deleteDirectory(tempGeneratedTlsCertsDir);
                } catch (Exception ex) {
                    t.addSuppressed(ex);
                }
                throw t;
            }
        }
        final SetOnce<SecureString> nodeKeystorePassword = new SetOnce<>();
        try (KeyStoreWrapper nodeKeystore = KeyStoreWrapper.bootstrap(env.configFile(), () -> {
            nodeKeystorePassword.set(new SecureString(terminal.readSecret("")));
            return nodeKeystorePassword.get().clone();
        })) {