[OpenSAML] org.opensaml.xml.XMLRuntimeException: DOM Element node adoption failed thrown when signing the assertion

[Thilina Mahesh Buddhika]

hi all,

I am trying to sign a SAML 2.0 assertion built using OpenSAML2.0 library. In this assertion, I am using holder-of-key subject confirmation method. In subjectConfirmationData element, I am adding a <ds:keyInfo> element to it. I use Axiom to build this keyInfo element. Then I am unmarshelling that keyinfo element to an XMLObject by using the following code snippet.

 ---------------------------------------------------------------------------------
        UnmarshallerFactory unmarshallerFactory = Configuration.getUnmarshallerFactory();
        Unmarshaller unmarshaller = unmarshallerFactory.getUnmarshaller(keyInfoElem);

        // Unmarshall using the document root element, an EntitiesDescriptor in this case
        XMLObject keyInfoElement = null;
        try {
            keyInfoElement = unmarshaller.unmarshall(keyInfoElem);
        } catch (UnmarshallingException e) {
            throw new TrustException("Error unmarshalling KeyInfo Element", e);
        }

----------------------------------------------------------------------

Then I am adding this element into a KeyInfoConfirmationDataType element.

When I am trying to sign the resulting SAML assertion I am hitting with an exception as stated in subject. The StackTrace is as follows.
   
   
    org.opensaml.xml.XMLRuntimeException: DOM Element node adoption failed
    at org.opensaml.xml.util.XMLHelper.adoptElement(XMLHelper.java:482)
    at org.opensaml.xml.util.XMLHelper.appendChildElement(XMLHelper.java:467)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:161)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallChildElements(AbstractXMLObjectMarshaller.java:316)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallInto(AbstractXMLObjectMarshaller.java:224)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:175)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallChildElements(AbstractXMLObjectMarshaller.java:316)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallInto(AbstractXMLObjectMarshaller.java:224)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:175)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallChildElements(AbstractXMLObjectMarshaller.java:316)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallInto(AbstractXMLObjectMarshaller.java:224)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:175)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallChildElements(AbstractXMLObjectMarshaller.java:316)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshallInto(AbstractXMLObjectMarshaller.java:224)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:130)
    at org.opensaml.xml.io.AbstractXMLObjectMarshaller.marshall(AbstractXMLObjectMarshaller.java:86)
    at org.apache.rahas.impl.SAML2TokenIssuer.setSignature(SAML2TokenIssuer.java:461)


When I went through the code of XMLHelper, I found that this error is due to the use of two different dom implementations of adaper and adaptee elements.

 /**
     * Adopts an element into a document if the child is not already in the document.
     *
     * @param adoptee the element to be adopted
     * @param adopter the document into which the element is adopted
     */
    public static void adoptElement(Element adoptee, Document adopter) {
        if (!(adoptee.getOwnerDocument().equals(adopter))) {
            if (adopter.adoptNode(adoptee) == null) {
                // This can happen if the adopter and adoptee were produced by different DOM implementations
                throw new XMLRuntimeException("DOM Element node adoption failed");
            }
        }
    }

I guess this is due to the fact that I am using axiom to build the keyInfo element. Due to some constraints, I am keen on keeping the Axiom involvement as it is.

Is there any workaround for this ?

Thanks in advance.

best regards,
/thilina


E-Mail         : thil...@gmail.com
I blog here : http://thilinamb.com

[Chad La Joie]

About the only way to move between XML libraries with different object
models (and AXIOM is *not* DOM) is to write the XML out to a string from
one model and read it back in to the other model.

--
SWITCH
Serving Swiss Universities
--------------------------
Chad La Joie, Software Engineer, Net Services
Werdstrasse 2, P.O. Box, 8021 Zürich, Switzerland
phone +41 44 268 15 75, fax +41 44 268 15 68
chad....@switch.ch, http://www.switch.ch

[Thilina Mahesh Buddhika]

Thanks Chad. It solved my problem.

best regards,
/thilina

E-Mail         : thil...@gmail.com
I blog here : http://thilinamb.com