Seeking advice on serialization of empty string value for SAMLObjects attributes

[Broeder, drs. H.R. den (Hans)]

Hi,

I understand that not setting attribute values on SAMLObjects object instances result in not being serialized. But, what about attributes that take a String and then specifically specifying an empty string value?

Consider the following lines when using OpenSAML 3.4.5 where an AssertionConsumerService object instance is created and an empty string is specified for a (according to the saml specs a required) Location attribute:

        InitializationService.initialize();
        XMLObjectBuilderFactory builderFactory = XMLObjectProviderRegistrySupport.getBuilderFactory();
        XMLObjectBuilder<? extends XMLObject> builder = builderFactory.getBuilder(AssertionConsumerService.DEFAULT_ELEMENT_NAME);

        Object o = builder.buildObject(AssertionConsumerService.DEFAULT_ELEMENT_NAME);
        AssertionConsumerService acs = AssertionConsumerService.class.cast(o);
        acs.setLocation("");
        acs.setBinding(SAMLConstants.SAML2_ARTIFACT_BINDING_URI);
        acs.setIndex(0);

        Marshaller m = XMLObjectProviderRegistrySupport.getMarshallerFactory().getMarshaller(acs);
        Element dom = m.marshall(acs);
        String s = SerializeSupport.nodeToString(dom);
        System.out.println(s);


This results in my case in the following output:
<?xml version="1.0" encoding="UTF-8"?><md:AssertionConsumerService xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Artifact" index="0"/>

At first I thought that it might have anything to do with the LS serializer and I have looked at directing the LS serializer with options like "discard-default-content", as in the next few lines. But it does not have an effect in this case.

Map<String, Object> options = new HashMap<>();
options.put("discard-default-content", Boolean.FALSE);
String s = SerializeSupport.nodeToString(dom, options);


Is this intended behaviour? Is there anyting I can do to achieve the desired result, which is serialization of attributes with empty string values?

Thanks,
Hans




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