"Cannot resolve element with ID" Error

[Phillip Duba]

Hopefully someone can point me in the right direction to solve this
problem. I have a SAML 1.1 Assertion being verified, however, it fails
verification as I receive a "Cannot resolve element with ID ." error.
The issue arises, from what I can tell doing a Google search, is that
the SAML Assertion 1.1 schema has the AssertionID of type ID but no ID
attribute so the Reference lookup fails. Below is my logic for
verification:
 
    public boolean VerifySignature(String token, String certPath) throws
Exception {
      //Initialize the library
      org.apache.xml.security.Init.init();
      
      DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
      dbf.newInstance();
      dbf.setNamespaceAware(true);
      dbf.setAttribute("http://xml.org/sax/features/namespaces";,
Boolean.TRUE);
      DocumentBuilder db = dbf.newDocumentBuilder();
      db.setErrorHandler(new
org.apache.xml.security.utils.IgnoreAllErrorHandler());
            
      byte inputBytes[] = token.getBytes();
      Document doc = db.parse(new ByteArrayInputStream(inputBytes));
      // Set up required ID attribute using DOM3 support
      String uriRef =
doc.getDocumentElement().getAttribute("AssertionID");
          
      Element sigElement = null;
      NodeList nodes =
doc.getElementsByTagNameNS(org.apache.xml.security.utils.Constants.Signa
tureSpecNS,"Signature");
      String password = "mypass";
          
if(nodes.getLength() !=0 ){
         // Found Nodes for Signature element
            sigElement = (Element)nodes.item(0);
            XMLSignature signature = new
XMLSignature(sigElement,uriRef);
            KeyStore ks = KeyStore.getInstance("JKS");
            ks.load(new FileInputStream(new
File(certPath)),password.toCharArray());
            PublicKey pubkey =
ks.getCertificate("SamlTest").getPublicKey();
            return signature.checkSignatureValue(pubkey);
      }
      return false;
    }
 
A sample of the XML being submitted is:
 
<saml:Assertion xmlns:saml="urn:oasis:names:tc:SAML:1.0:assertion"
AssertionID="B9B97DFA-188B-10AF-6C7D03F0B072070E"
IssueInstance="2007-05-23T16:16:20Z" Issuer="http://samltest.dev/";
MajorVersion="1" MinorVersion="1">
  <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#";> 
    <ds:SignedInfo> 
      <ds:CanonicalizationMethod
Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315";></ds:Canonic
alizationMethod> 
      <ds:SignatureMethod
Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1";></ds:SignatureMet
hod> 
      <ds:Reference URI="#B9B97DFA-188B-10AF-6C7D03F0B072070E"> 
        <ds:Transforms> 
          <ds:Transform
Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature";></ds:T
ransform> 
          <ds:Transform
Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#";></ds:Transform> 
        </ds:Transforms> 
        <ds:DigestMethod
Algorithm="http://www.w3.org/2000/09/xmldsig#sha1";></ds:DigestMethod> 
        <ds:DigestValue>JF/Dh0v786ttB38KYCq1w+X+gtk=</ds:DigestValue> 
      </ds:Reference> 
...
 
The system configuration versioning is limited by an application server
and is:
 
JDK 1.4.11
XML Apache Security Library 1.2.0 with xmlsec-1.2.96.jar
 
Most of the solutions I have found have focused on DOM3 capabilities
which I do not have access to or using an IdResolver with which I have
had no luck. Any help would be appreciated. Thanks,
 
Phil