Description of problem: Some tests in org.picketlink.test.identity.federation.api.saml.v2.SignatureValidationUnitTestCase from redhat-picketlink fails on IBM JDK. Version-Release number of selected component (if applicable): 2.5.4.SP8 How reproducible: Run the tests. Steps to Reproduce: mvn -f modules/federation test -Dtest=SignatureValidationUnitTestCase Actual results: javax.xml.crypto.dsig.XMLSignatureException: java.io.IOException: Invalid ASN.1 format of DSA signature at org.apache.jcp.xml.dsig.internal.dom.DOMSignatureMethod.sign(DOMSignatureMethod.java:230) at org.apache.jcp.xml.dsig.internal.dom.DOMXMLSignature.sign(DOMXMLSignature.java:399) at org.picketlink.identity.federation.core.util.XMLSignatureUtil.signImpl(XMLSignatureUtil.java:741) at org.picketlink.identity.federation.core.util.XMLSignatureUtil.sign(XMLSignatureUtil.java:473) at org.picketlink.identity.federation.api.saml.v2.sig.SAML2Signature.sign(SAML2Signature.java:216) at org.picketlink.identity.federation.api.saml.v2.sig.SAML2Signature.sign(SAML2Signature.java:150) at org.picketlink.test.identity.federation.api.saml.v2.SignatureValidationUnitTestCase.testAuthnRequestCreationWithSignature(SignatureValidationUnitTestCase.java:84) ... Expected results: Tests passes. Additional info: In the tests, using RSA instead of DSA works for IBM JDK.