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
} catch (Throwable t) {
                throw new UserException(
                    ExitCodes.IO_ERROR,
                    "Aborting enrolling to cluster. Unable to remove existing security configuration.",
                    t
                );
            }
            
            return createEnv(options, processInfo);
        } else {
            throw new UserException(
                ExitCodes.USAGE,
                "Aborting enrolling to cluster. This node doesn't appear to be auto-configured for security. "
                    + "Expected configuration is missing from elasticsearch.yml."
            );
        }
    }
    private void notifyOfFailure(boolean inEnrollmentMode, Terminal terminal, Terminal.Verbosity verbosity, int exitCode, String message)
        throws UserException {
        if (inEnrollmentMode) {
            throw new UserException(exitCode, message);
        } else {
            terminal.println(verbosity, message);
            throw new UserException(exitCode, null);
        }
    }
    @SuppressForbidden(reason = "Commons IO lib uses the File API")
    private void deleteDirectory(Path directory) throws IOException {
        FileUtils.deleteDirectory(directory.toFile());
    }