Assinatura digital

pessoal, estou tentando assinar um xml mas ta dando erro. To usando o xmlsec 1.4

olha o erro:

org.apache.xml.security.transforms.InvalidTransformException: Unknown transformation. No handler installed for URI http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments at org.apache.xml.security.transforms.Transform.<init>(Unknown Source) at org.apache.xml.security.transforms.Transform.getInstance(Unknown Source) at org.apache.xml.security.transforms.Transform.getInstance(Unknown Source) at org.apache.xml.security.transforms.Transforms.addTransform(Unknown Source)

alguem sabe me dizer porque isso acontece???

[code] XMLSignature signer =
new XMLSignature(doc, baseURI, XMLSignature.ALGO_ID_SIGNATURE_RSA_SHA1);

  element.appendChild(signer.getElement());

  Transforms transforms = new Transforms(doc);
  transforms.addTransform(Transforms.TRANSFORM_ENVELOPED_SIGNATURE); [/code]

A ultima linha que ta acontecendo o erro, ao addTransform…

preciso de ajuda :shock: