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
}
    
    SecureString newKeystorePassword() {
        return UUIDs.randomBase64UUIDSecureString();
    }
    /*
     * Detect if the existing yml configuration is incompatible with auto-configuration,
     * in which case auto-configuration is SILENTLY skipped.
     * This assumes the user knows what they are doing when configuring the node.
     */
    void checkExistingConfiguration(Settings settings, boolean inEnrollmentMode, Terminal terminal) throws UserException {
        
        if (XPackSettings.SECURITY_AUTOCONFIGURATION_ENABLED.get(settings) == false) {
            notifyOfFailure(
                inEnrollmentMode,
                terminal,
                Terminal.Verbosity.VERBOSE,
                ExitCodes.NOOP,
                "Skipping security auto configuration because [" + XPackSettings.SECURITY_AUTOCONFIGURATION_ENABLED.getKey() + "] is false"
            );
        }
        
        
        
        if (XPackSettings.SECURITY_ENABLED.exists(settings)) {
            
            
            notifyOfFailure(
                inEnrollmentMode,
                terminal,