The package "org.jcp.xml.dsig.internal" was included in both JDK 7 and JDK 8, but it is not added as a system package in jboss-module.

So, if we do this:

String providerName = System.getProperty("jsr105Provider", "org.jcp.xml.dsig.internal.dom.XMLDSigRI");
XMLSignatureFactory fac =
XMLSignatureFactory.getInstance("DOM", (Provider) Class.forName(providerName).newInstance());

We cannot find this "org.jcp.xml.dsig.internal.dom.XMLDSigRI" at runtime.

The current workaround is to hack "standalone.conf" file, added "org.jcp.xml.dsig.internal" package after package "org.jboss.byteman".

if [ "x$JBOSS_MODULES_SYSTEM_PKGS" = "x" ]; then
JBOSS_MODULES_SYSTEM_PKGS="org.jboss.byteman,org.jcp.xml.dsig.internal"
fi