I want to use apache xml security suite (xmlsec) to work with signature.
The first thing to do is to initialize :
java.lang.IllegalAccessError: tried to access field org.apache.xpath.compiler.FunctionTable.m_functions from class org.apache.xml.security.Init
Its not jboss doing this. There was a change in the xml classes bundled with the 1.4.2_05 jdk that changed the signature of the org.apache.xpath.compiler.FunctionTable which broken the xmlsec library. Get a newer xmlsec build which has fixed the problem.