Updated protobuf definitions with more content; a better naming scheme and removed redundant java classes

src/main/java/Demo.java

@@ -1,11 +1,7 @@
 import com.google.protobuf.ByteString;
-import meerkat.bulletinboard.BulletinBoard;
+import static meerkat.protobuf.Voting.*;
-import meerkat.comm.BulletinBoardMessageProtos;
-
 import java.io.IOException;
 
-import static meerkat.comm.BulletinBoardMessageProtos.*;
-
 /**
  * Created by talm on 10/26/15.
  */
@@ -15,7 +11,7 @@ public class Demo {
 
         BulletinBoardMessage msg;
 
-        BulletinBoardMessage.Unsigned msgContents = BulletinBoardMessage.Unsigned.newBuilder()
+        UnsignedBulletinBoardMessage msgContents = UnsignedBulletinBoardMessage.newBuilder()
                 .addTags("test")
                 .setData(ByteString.copyFromUtf8("some data"))
                 .build();

src/main/java/meerkat/bulletinboard/BulletinBoard.java

@@ -1,7 +1,7 @@
 package meerkat.bulletinboard;
 
 import meerkat.comm.*;
-import meerkat.crypto.Signature;
+import static meerkat.protobuf.Voting.*;
 
 import java.util.List;
 import java.util.Set;
@@ -13,10 +13,8 @@ public interface BulletinBoard {
     /**
      * Post a message to the bulletin board
      * @param msg
-     * @param sig
      */
-    MessageID postMessage(Message msg, Signature sig) throws CommunicationException;
+    MessageID postMessage(BulletinBoardMessage msg) throws CommunicationException;
-
 
     /**
      * Check how "safe" a given message is
@@ -34,10 +32,10 @@ public interface BulletinBoard {
      * @param max maximum number of messages to return (0=no limit)
      * @return
      */
-    List<Message> readMessages(MessageFilter filter, int max);
+    List<BulletinBoardMessage> readMessages(MessageFilter filter, int max);
 
     interface MessageCallback {
-        void handleNewMessage(Message msg, Signature sig);
+        void handleNewMessage(BulletinBoardMessage msg);
     }
 
     /**

src/main/java/meerkat/comm/Message.java

@@ -1,12 +0,0 @@
-package meerkat.comm;
-
-import java.util.Set;
-
-/**
- * Created by talm on 24/10/15.
- *
- * A structured message
- */
-public interface Message {
-}
-

src/main/java/meerkat/crypto/DigitalSignature.java

@@ -1,8 +1,9 @@
 package meerkat.crypto;
 
-import meerkat.comm.Message;
+import com.google.protobuf.Message;
 
 import java.util.List;
+import static meerkat.protobuf.Crypto.*;
 
 /**
  * Created by talm on 25/10/15.
@@ -10,7 +11,7 @@ import java.util.List;
  * Sign arrays of messages
  */
 public interface DigitalSignature { // Extends SCAPI DigitalSignature
-    public Signature sign(List<Message> msgs);
+    public Signature sign(List<Message> msg);
 
     public boolean verify(Signature sig, List<Message> msgs);
 }

src/main/java/meerkat/crypto/Encryption.java

@@ -0,0 +1,12 @@
+package meerkat.crypto;
+
+import com.google.protobuf.Message;
+import static meerkat.protobuf.Crypto.*;
+
+/**
+ * Created by talm on 11/2/15.
+ */
+public interface Encryption {
+    Message encrypt(Message plaintext, EncryptionRandomness rnd);
+
+}

src/main/java/meerkat/crypto/EncryptionRandomness.java

@@ -1,7 +0,0 @@
-package meerkat.crypto;
-
-/**
- * Created by talm on 10/26/15.
- */
-public interface EncryptionRandomness {
-}

src/main/java/meerkat/crypto/RandomnessGenerationProof.java

@@ -1,7 +0,0 @@
-package meerkat.crypto;
-
-/**
- * Created by talm on 10/26/15.
- */
-public class RandomnessGenerationProof {
-}

src/main/java/meerkat/crypto/Signature.java

@@ -1,9 +0,0 @@
-package meerkat.crypto;
-
-/**
- * Created by talm on 24/10/15.
- *
- * A digital signature
- */
-public interface Signature {
-}

src/main/java/meerkat/crypto/mixnet/Mixer.java

@@ -1,6 +1,6 @@
 package meerkat.crypto.mixnet;
 
-import meerkat.comm.Message;
+import meerkat.voting.EncryptedBallot;
 
 import java.util.List;
 
@@ -8,5 +8,5 @@ import java.util.List;
  * Created by talm on 25/10/15.
  */
 public interface Mixer {
-    public List<Message> mix(List<Message> ciphertexts);
+    public List<EncryptedBallot> mix(List<EncryptedBallot> ballots);
 }

src/main/java/meerkat/voting/BallotSecrets.java

@@ -1,14 +0,0 @@
-package meerkat.voting;
-
-import meerkat.crypto.EncryptionRandomness;
-import meerkat.crypto.RandomnessGenerationProof;
-
-/**
- * Created by talm on 10/26/15.
- */
-public class BallotSecrets {
-    PlaintextBallot plaintext;
-
-    EncryptionRandomness encryptionRandomness;
-    RandomnessGenerationProof proof;
-}

src/main/java/meerkat/voting/BoothParams.java

@@ -1,11 +0,0 @@
-package meerkat.voting;
-
-/**
- * Parameters local to the voting booth:
- *  Private and public signature keys
- *  Logging keys,
- *  Randomness generation params
- *  etc.
- */
-public class BoothParams {
-}

src/main/java/meerkat/voting/ElectionParams.java

@@ -1,7 +0,0 @@
-package meerkat.voting;
-
-/**
- * Created by talm on 25/10/15.
- */
-public class ElectionParams {
-}

src/main/java/meerkat/voting/EncryptedBallot.java

@@ -1,6 +1,6 @@
 package meerkat.voting;
 
-import meerkat.comm.Message;
+import com.google.protobuf.Message;
 
 /**
  * Created by talm on 25/10/15.

src/main/java/meerkat/voting/EncryptedBallotWithSecrets.java

@@ -1,12 +0,0 @@
-package meerkat.voting;
-
-/**
- * Created by talm on 10/26/15.
- */
-public interface EncryptedBallotWithSecrets extends EncryptedBallot {
-    /**
-     * Return the secrets required to open and verify an encrypted ballot
-     * @return
-     */
-    BallotSecrets getBallotSecrets();
-}

src/main/java/meerkat/voting/PlaintextBallot.java

@@ -1,19 +0,0 @@
-package meerkat.voting;
-
-import java.util.List;
-
-/**
- * Created by talm on 25/10/15.
- */
-public class PlaintextBallot {
-    /**
-     * Answers to the ballot questions.
-     * Each answer is a list of integers; its parsing depends on the question type.
-     * For example, a multiple choice question would have a length-1 list containing
-     * the single choice's index.
-     */
-    List<List<Integer>> answers;
-
-    long serialNumber;
-
-}

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

@@ -1,5 +1,7 @@
 package meerkat.voting;
 
+import static meerkat.protobuf.Voting.*;
+
 /**
  * Created by talm on 25/10/15.
  */

src/main/proto/meerkat/comm/bulletin_board_message.proto

@@ -1,23 +0,0 @@
-syntax = "proto3";
-
-package meerkat.comm;
-
-import 'meerkat/crypto/signature.proto';
-
-option java_outer_classname = "BulletinBoardMessageProtos";
-
-message BulletinBoardMessage {
-    message  Unsigned {
-        // Optional tags describing message
-        repeated string tags = 1;
-
-        // The actual content of the message
-        bytes data = 2;
-    }
-
-    Unsigned msg = 1;
-
-    // Signature of message (and tags)
-    meerkat.crypto.Signature sig = 2;
-}
-

src/main/proto/meerkat/crypto.proto

@@ -0,0 +1,40 @@
+syntax = "proto3";
+
+package meerkat;
+
+option java_package = "meerkat.protobuf";
+
+enum SignatureType {
+    ECDSA = 0;
+    DSA = 1;
+}
+
+// A digital signature
+message Signature {
+    SignatureType type = 1;
+
+    // Data encoding depends on type; default is x509 BER-encoded
+    bytes data = 2;
+}
+
+// Public key used to verify signatures
+message SignatureVerificationKey {
+    SignatureType type = 1;
+
+    bytes data = 2;
+}
+
+// A public encryption key
+message EncryptionPublicKey {
+    bytes data = 1;
+}
+
+// Randomness used for encryption
+message EncryptionRandomness {
+    bytes data = 1;
+}
+
+// A proof that randomness is correctly generated
+message RandomnessGenerationProof {
+    bytes data = 1;
+}

src/main/proto/meerkat/crypto/signature.proto

@@ -1,15 +0,0 @@
-syntax = "proto3";
-
-package meerkat.crypto;
-
-option java_outer_classname = "SignatureProtos";
-
-message Signature {
-    enum Type {
-        ECDSA = 0;
-        DSA = 1;
-    }
-    Type type = 1;
-    
-    bytes data = 2;
-}

src/main/proto/meerkat/voting.proto

@@ -0,0 +1,89 @@
+syntax = "proto3";
+
+package meerkat;
+
+import 'meerkat/crypto.proto';
+
+option java_package = "meerkat.protobuf";
+
+
+message  UnsignedBulletinBoardMessage {
+    // Optional tags describing message
+    repeated string tags = 1;
+
+    // The actual content of the message
+    bytes data = 2;
+}
+
+message BulletinBoardMessage {
+
+    UnsignedBulletinBoardMessage msg = 1;
+
+    // Signature of message (and tags)
+    meerkat.Signature sig = 2;
+}
+
+// A ballot question. This is an opaque
+// data type that is parsed by the UI to display
+// the question.
+message BallotQuestion {
+    bytes data = 1;
+}
+
+// An answer to a specific ballot question.
+// The answer is a vector of signed integers,
+// to encompass voting schemes such as ranked voting
+// and STV.
+message BallotAnswer {
+    repeated sint64 answer = 1 [packed=true];
+}
+
+message PlaintextBallot {
+    uint64 serialNumber = 1; // Ballot serial number
+
+    repeated BallotAnswer answers = 2;
+}
+
+message BallotSecrets {
+    PlaintextBallot plaintext_ballot = 1;
+
+    EncryptionRandomness encryption_randomness = 2;
+    RandomnessGenerationProof proof = 3;
+}
+
+message BoothParams {
+    repeated SignatureVerificationKey pscVerificationKeys = 1;
+
+}
+
+// A table to translate to and from compactly encoded answers
+// and their human-understandable counterparts.
+// This should be parsable by the UI
+message BallotAnswerTranslationTable {
+    bytes data = 1;
+}
+
+message ElectionParams {
+    // TODO: different sets of keys for different roles?
+    repeated SignatureVerificationKey trusteeVerificationKeys = 1;
+
+    // How many trustees must participate in a signature for it to be considered valid.
+    uint32 trusteeSignatureThreshold = 2;
+
+    // The key used to encrypt ballots. The corresponding private key
+    // is shared between the trustees.
+    EncryptionPublicKey ballotEncryptionKey = 3;
+
+    // Verification keys for valid mixers.
+    repeated SignatureVerificationKey mixerVerificationKeys = 4;
+
+    // How many mixers must participate for the mixing to be considered valid
+    uint32 mixerThreshold = 5;
+
+    // Candidate list (or other question format)
+    repeated BallotQuestion questions = 6;
+
+    // Translation table between answers and plaintext encoding
+    BallotAnswerTranslationTable answerTranslationTable = 7;
+
+}