First version of Voter Booth

Summary:
Planned some basic interfaces for my revised Voting Booth componenets.
No implementation yet, though...

Test Plan: There are none, yet

Reviewers: arbel.peled

Differential Revision: https://proj-cs.idc.ac.il/D2

meerkat-common/src/main/proto/meerkat/voting.proto

@@ -6,13 +6,38 @@ import 'meerkat/crypto.proto';
 
 option java_package = "meerkat.protobuf";
 
-// A ballot question. This is an opaque
-// data type that is parsed by the UI to display
-// the question.
-message BallotQuestion {
-    bytes data = 1;
+
+
+// Type of the element data to be presented by UI
+enum UIElementDataType {
+	TEXT = 0;
+	IMAGE = 1;
+	VOICE = 2;
 }
 
+// Type of question
+enum QuestionType {
+	MULTIPLE_CHOICE = 0;
+	MULTIPLE_SELECTION = 1;
+	ORDER = 2;
+}
+
+// An element to be presented by UI
+message UIElement {
+	UIElementDataType type = 1;
+	bytes data = 2;
+}
+
+// a new data structure for BallotQuestion. Need to delete the old one
+message BallotQuestion {
+	bool is_mandatory = 1;
+	UIElement question = 2;
+	UIElement description = 3;
+	repeated UIElement answer = 4;
+}
+
+
+
 // An answer to a specific ballot question.
 // The answer is a vector of signed integers,
 // to encompass voting schemes such as ranked voting
@@ -83,7 +108,7 @@ message ElectionParams {
     repeated BallotQuestion questions = 6;
 
     // Translation table between answers and plaintext encoding
-    BallotAnswerTranslationTable answerTranslationTable = 7;
+    //BallotAnswerTranslationTable answerTranslationTable = 7;
 
     // Data required in order to access the Bulletin Board Servers
     BulletinBoardClientParams bulletinBoardClientParams = 8;

voting-booth/src/main/java/meerkat/voting/BallotOutputDevice.java

@@ -0,0 +1,19 @@
+package meerkat.voting;
+
+import meerkat.protobuf.Voting.*;
+
+/**
+ * Created by hai on 15/02/16.
+ */
+public interface BallotOutputDevice {
+
+    void commitToBallot(long sessionId, EncryptedBallot encryptedBallot, VotingBooth.Callback callback);
+
+    void audit(long sessionId, EncryptedBallot encryptedBallot, BallotSecrets ballotSecrets, VotingBooth.Callback callback);
+
+    void castBallot(long sessionId, VotingBooth.Callback callback);
+
+    // probably has no difference than cast. Maybe drop this method
+    void cancelBallot(long sessionId, VotingBooth.Callback callback);
+
+}

voting-booth/src/main/java/meerkat/voting/Encryptor.java

@@ -0,0 +1,13 @@
+package meerkat.voting;
+
+import meerkat.protobuf.Voting.*;
+
+/**
+ * Created by hai on 23/02/16.
+ */
+public interface Encryptor {
+
+    public void encrypt (long sessionId, PlaintextBallot plaintextBallot);
+
+    //TODO: probably needs some key generation methods as well
+}

voting-booth/src/main/java/meerkat/voting/StorageManager.java

@@ -0,0 +1,12 @@
+package meerkat.voting;
+
+/**
+ * Created by hai on 23/02/16.
+ */
+public interface StorageManager {
+
+    // should these methods be synchronous or asynchronous? Can we rely on it being immediate?
+    public void detectAdminHardwareKey();
+
+    public void readElectionParams ();
+}

voting-booth/src/main/java/meerkat/voting/SystemConsoleOutputDevice.java

@@ -0,0 +1,56 @@
+package meerkat.voting;
+
+import com.google.protobuf.ByteString;
+import meerkat.protobuf.Voting.*;
+
+/**
+ * Created by hai on 15/02/16.
+ */
+public class SystemConsoleOutputDevice implements BallotOutputDevice {
+
+    /*
+     * Returns the UTF8 decoding of byte-string data
+     */
+    private static String bytesToString(ByteString data) {
+        return data.toStringUtf8();
+    }
+
+    @Override
+    public void commitToBallot(long sessionId, EncryptedBallot encryptedBallot, VotingBooth.Callback callback) {
+
+        System.out.println("Ballot #" + encryptedBallot.getSerialNumber() + ": "
+                + bytesToString(encryptedBallot.getData().getData()));
+
+        callback.ballotCommitResult(sessionId, true);
+
+    }
+
+    @Override
+    public void audit(long sessionId, EncryptedBallot encryptedBallot, BallotSecrets ballotSecrets, VotingBooth.Callback callback) {
+
+        //TODO: generate standard form for this
+        System.out.println("Ballot #" + encryptedBallot.getSerialNumber() + ": "
+                + bytesToString(encryptedBallot.getData().getData()));
+
+        callback.ballotAuditResult(sessionId, true);
+
+    }
+
+    @Override
+    public void castBallot(long sessionId, VotingBooth.Callback callback) {
+
+        System.out.println("Ballot finalized!");
+
+        callback.ballotCastResult(sessionId, true);
+
+    }
+
+    @Override
+    public void cancelBallot(long sessionId, VotingBooth.Callback callback) {
+
+        System.out.println("Ballot cancelled!");
+
+        callback.ballotCancelResult(sessionId, true);
+
+    }
+}

voting-booth/src/main/java/meerkat/voting/UI.java

@@ -0,0 +1,32 @@
+package meerkat.voting;
+
+import meerkat.protobuf.Voting.*;
+
+/**
+ * Created by hai on 23/02/16.
+ */
+public interface UI {
+
+
+    // Voter scenario methods
+    void introductionToVoter (long sessionId);
+
+    void chooseChannel (long sessionId, BallotQuestion question);
+
+    void askVoterQuestion (long sessionId, int questionNumber, BallotQuestion question);
+
+    void castOrAudit (long sessionId);
+
+    void showWaitForFinishScreen (long sessionId);
+
+
+    // Admin scenario methods
+    //TODO: the admin scenario still needs some more thinking
+
+
+
+    // bad thing happened scenario
+    void showErrorMessageAndHalt (String errorMessage);
+    void showErrorMessageWithCancelButton (long sessionId, String errorMessage);
+
+}

voting-booth/src/main/java/meerkat/voting/VotingBooth.java

@@ -0,0 +1,82 @@
+package meerkat.voting;
+
+import meerkat.protobuf.Voting;
+import meerkat.protobuf.Voting.*;
+
+/**
+ * Created by hai on 23/02/16.
+ */
+public interface VotingBooth {
+
+    public enum ErrorID {
+        OUTPUT_DEVICE_OUT_OF_PAPER,
+        OUTPUT_DEVICE_OUT_OF_INK,
+        OUTPUT_DEVICE_NO_CONNECTION,
+        OUTPUT_DEVICE_HARDWARE_NOT_FOUND,
+
+        UI_HARDWARE_NOT_FOUND
+    }
+
+
+    // keeps track in which state we are
+    // internal state will also include the number of the current question and the answers we got so far,
+    // later it includes the details of the PlaintextBallot and later the Encryption and the secrets
+    public enum State {
+        INITIALIZED,
+
+        VOTER_INTRODUCTION,
+        VOTER_CHOOSE_CHANNEL,
+        VOTER_VOTING,
+        VOTER_ENCRYPTING,
+        VOTER_CAST_OR_AUDIT,
+        VOTER_CASTING,
+        VOTER_AUDITING
+
+    }
+
+    public interface Callback {
+
+        // callbacks and messages from BallotOutputDevice
+
+        public void ballotCommitResult (long sessionId, boolean result);
+        public void ballotCastResult (long sessionId, boolean result);
+        public void ballotAuditResult (long sessionId, boolean result);
+        public void ballotCancelResult (long sessionId, boolean result);
+        // other error messages, such as Printer turned-off or out-of-paper
+        public void outputDeviceReportProblem (ErrorID errorId);
+
+
+        // callbacks and messages from UI
+
+        public void introductionFinished (long sessionId);
+        public void choiceOfChannel (long sessionId, int channelNumber);
+        public void skipQuestion (long sessionId, int questionNumber);
+        public void backwardsQuestion (long sessionId, int questionNumber);
+        public void cancelVotingSession (long sessionId);
+        public void answer (long sessionId, int questionNumber, String answer);
+        public void cast (long sessionId);
+        public void audit (long sessionId);
+        // other error messages, such as hardware-not-detected
+        public void uiReportProblem (ErrorID errorId);
+
+
+        // callbacks from encryptor
+
+        public void returnEncryption (long sessionId, EncryptedBallot encryptedBallot, BallotSecrets secrets);
+
+
+        // callbacks from StorageManager
+
+        public void adminHardwareKeyDetected (boolean isKeyInserted);
+        public void loadElectionParams (ElectionParams electionParams);
+    }
+
+    // this function is synchronous
+    public void start ();
+
+
+    // messages from Admin Console (If there is such one)
+    // this function is asynchronous
+    public void shutDown();
+
+}