private void sendRejectAnswer(
Agent ag,
Desire desire,
CensorComponent cexec,
SpeechAct action,
Secret s,
String answerValue) {
Answer answer = null;
String act = null;
if (action instanceof Update) {
Update update = (Update) action;
answer = new Answer(ag, update.getSenderId(), update.getProposition(), AnswerValue.AV_REJECT);
act = "update";
} else if (action instanceof Revision) {
Revision revision = (Revision) action;
answer =
new Answer(ag, revision.getSenderId(), revision.getProposition(), AnswerValue.AV_REJECT);
act = "revision";
} else if (action instanceof Query) {
Query query = (Query) action;
answer = new Answer(ag, query.getSenderId(), query.getQuestion(), AnswerValue.AV_REJECT);
act = "query";
}
Subgoal answerGoal = new Subgoal(ag, desire);
answerGoal.newStack(answer);
ag.getPlanComponent().addPlan(answerGoal);
cexec.report(
"The reaction '"
+ answerValue
+ "' would reveal secret "
+ s
+ ". Reject the "
+ act
+ ".");
cexec.report(
"Add the new action '" + Answer.class.getSimpleName() + "' to the plan",
ag.getPlanComponent());
}
/**
* Process an incoming revision request from an attacking agent. Using the censor component, this
* method first checks if a secret might be revealed by the actual revision handling. Based on
* this preprocessing, it either generates a Refusal-SpeechAct or runs the actual revision on the
* belief base and generates a notification action.
*
* @param desire
* @param pp
* @param ag
*/
public boolean processRevision(Desire desire, PlanParameter pp, Agent ag) {
pp.report("Generate new subgoal to process revision request");
CensorComponent cexec = ag.getComponent(CensorComponent.class);
Revision revision = (Revision) desire.getPerception();
View view = (View) ag.getComponent(ViewDataComponent.class).getView(revision.getSenderId());
SecrecyKnowledge conf = ag.getComponent(SecrecyKnowledge.class);
pp.report("Invoke censor to check all possible answers for meta inferences");
// check if revision would reveal a secret
View refinedView = view.RefineViewByRevision(revision.getProposition(), AnswerValue.AV_TRUE);
if (cexec.poss(refinedView)) {
for (Secret s : conf.getSecrets()) {
if (cexec.scepticalInference(refinedView, s.getInformation())) {
this.sendRejectAnswer(ag, desire, cexec, revision, s, "success");
return true;
}
}
}
// check if the failure of the revision would reveal a secret
refinedView = view.RefineViewByRevision(revision.getProposition(), AnswerValue.AV_FALSE);
if (cexec.poss(refinedView)) {
for (Secret s : conf.getSecrets()) {
if (cexec.scepticalInference(refinedView, s.getInformation())) {
this.sendRejectAnswer(ag, desire, cexec, revision, s, "failure");
return true;
}
}
}
// revision would not breach confidentiality, continue revising beliefbase
BaseBeliefbase bbase = ag.getBeliefs().getWorldKnowledge();
// slightly hacked: we need to get the revision result from the revision operator
OperatorCallWrapper changeOp = bbase.getChangeOperator();
boolean success = false;
if (changeOp.getImplementation() instanceof ConditionalRevision) {
ConditionalRevision revisionOp = (ConditionalRevision) changeOp.getImplementation();
OperatorCallWrapper translator = bbase.getTranslator();
Set<FolFormula> revisionFormulas = new HashSet<FolFormula>();
revisionFormulas.add(revision.getProposition());
ConditionalBeliefbase newK =
(ConditionalBeliefbase)
translator.process(new TranslatorParameter(bbase, revisionFormulas));
success = revisionOp.simulateRevision((ConditionalBeliefbase) bbase, newK);
}
AnswerValue answerValue = AnswerValue.AV_FALSE;
if (success) {
pp.report(
"Revision will be successful. Send answer 'true' and add '"
+ revision.getProposition().toString()
+ "' to belief base");
answerValue = AnswerValue.AV_TRUE;
} else {
pp.report("Revision will be not be successful. Send answer 'false'.");
answerValue = AnswerValue.AV_FALSE;
}
// send answer
RevisionAnswer answer =
new RevisionAnswer(ag, revision.getSenderId(), revision.getProposition(), answerValue);
Subgoal answerGoal = new Subgoal(ag, desire);
answerGoal.newStack(answer);
ag.getPlanComponent().addPlan(answerGoal);
pp.report(
"Add the new action '" + RevisionAnswer.class.getSimpleName() + "' to the plan",
ag.getPlanComponent());
return true;
}
