@Override
    protected void addStageInformation(@Nonnull final SessionData data, Element command) {
        final Locale preferredLocale = SessionManager.getInstance().getLocaleForSession(data.getOwner());

        DataForm form = new DataForm(DataForm.Type.form);
        form.setTitle(LocaleUtils.getLocalizedString("commands.admin.user.authenticateuser.form.title", preferredLocale));
        form.addInstruction(LocaleUtils.getLocalizedString("commands.admin.user.authenticateuser.form.instruction", preferredLocale));

        FormField field = form.addField();
        field.setType(FormField.Type.hidden);
        field.setVariable("FORM_TYPE");
        field.addValue("http://jabber.org/protocol/admin");

        field = form.addField();
        field.setType(FormField.Type.jid_single);
        field.setLabel(LocaleUtils.getLocalizedString("commands.admin.user.authenticateuser.form.field.accountjid.label", preferredLocale));
        field.setVariable("accountjid");
        field.setRequired(true);

        field = form.addField();
        field.setType(FormField.Type.text_private);
        field.setLabel(LocaleUtils.getLocalizedString("commands.admin.user.authenticateuser.form.field.password.label", preferredLocale));
        field.setVariable("password");
        field.setRequired(true);

        // Add the form to the command
        command.add(form.getElement());
    }
Takes a user's username and password to authenticate them against the Openfire authprovider.

@author Alexander Wenckus
xmppserver/src/main/java/org/jivesoftware/openfire/commands/admin/user/AuthenticateUser.java