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/test/java/org/elasticsearch/xpack/security/cli/HttpCertificateCommandTests.java
}
            hostNames.add(host);
        }
        return hostNames;
    }
    private String randomPassword(boolean longPassword) {
        
        
        return randomFrom(
            "",
            randomAlphaOfLengthBetween(4, 8) + randomFrom('~', '*', '%', '$', '|') + randomAlphaOfLength(longPassword ? 100 : 4)
        );
    }
    private void verifyCertificationRequest(
        PKCS10CertificationRequest csr,
        String certificateName,
        List<String> hostNames,
        List<String> ipAddresses
    ) throws IOException {
        
        assertThat(new X500Principal(csr.getSubject().getEncoded()).toString(), is("CN=" + certificateName.replaceAll("\\.", ", DC=")));
        final Attribute[] extensionAttributes = csr.getAttributes(PKCSObjectIdentifiers.pkcs_9_at_extensionRequest);
        assertThat(extensionAttributes, arrayWithSize(1));
        assertThat(extensionAttributes[0].getAttributeValues(), arrayWithSize(1));
        assertThat(extensionAttributes[0].getAttributeValues()[0], instanceOf(DLSequence.class));
        
        final Extensions extensions = Extensions.getInstance(extensionAttributes[0].getAttributeValues()[0]);
        assertThat(extensions, notNullValue());
        final GeneralNames names = GeneralNames.fromExtensions(extensions, Extension.subjectAlternativeName);
        assertThat(names.getNames(), arrayWithSize(hostNames.size() + ipAddresses.size()));