Defined semi-final versions of the batch interfaces.

Implemented in part extended BB Server interface.
Added Digest support for Batch messages.
Made GlobalCryptoSetup a final singleton.

bulletin-board-client/src/main/java/meerkat/bulletinboard/ThreadedBulletinBoardClient.java

@@ -117,6 +117,11 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
         // TODO: Implement
     }
 
+    @Override
+    public void subscribe(MessageFilterList filterList, MessageHandler messageHandler) {
+        // TODO: Implement
+    }
+
     @Override
     public void close() {
         super.close();

bulletin-board-client/src/main/java/meerkat/bulletinboard/callbacks/ClientFutureCallback.java

@@ -1,14 +1,8 @@
 package meerkat.bulletinboard.callbacks;
 
 import com.google.common.util.concurrent.FutureCallback;
-import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListeningExecutorService;
-import meerkat.bulletinboard.BulletinClientJob;
 import meerkat.bulletinboard.BulletinClientJobResult;
-import meerkat.bulletinboard.BulletinClientWorker;
-import meerkat.protobuf.BulletinBoardAPI;
-
-import java.util.List;
 
 /**
  * This is a future callback used to listen to workers and run on job finish

bulletin-board-client/src/main/java/meerkat/bulletinboard/callbacks/GetRedundancyFutureCallback.java

@@ -1,7 +1,7 @@
 package meerkat.bulletinboard.callbacks;
 
 import com.google.common.util.concurrent.ListeningExecutorService;
-import meerkat.bulletinboard.BulletinBoardClient;
+import meerkat.bulletinboard.AsyncBulletinBoardClient.*;
 import meerkat.bulletinboard.BulletinClientJobResult;
 import meerkat.protobuf.BulletinBoardAPI.*;
 
@@ -13,10 +13,10 @@ import java.util.List;
  */
 public class GetRedundancyFutureCallback extends ClientFutureCallback {
 
-    private BulletinBoardClient.ClientCallback<Float> callback;
+    private ClientCallback<Float> callback;
 
     public GetRedundancyFutureCallback(ListeningExecutorService listeningExecutor,
-                                BulletinBoardClient.ClientCallback<Float> callback) {
+                                ClientCallback<Float> callback) {
         super(listeningExecutor);
         this.callback = callback;
     }

bulletin-board-client/src/main/java/meerkat/bulletinboard/callbacks/PostMessageFutureCallback.java

@@ -2,13 +2,11 @@ package meerkat.bulletinboard.callbacks;
 
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListeningExecutorService;
-import meerkat.bulletinboard.BulletinBoardClient;
+import meerkat.bulletinboard.AsyncBulletinBoardClient.*;
 import meerkat.bulletinboard.BulletinClientJob;
 import meerkat.bulletinboard.BulletinClientJobResult;
 import meerkat.bulletinboard.BulletinClientWorker;
-import meerkat.protobuf.BulletinBoardAPI;
 
-import java.util.List;
 
 /**
  * This is a future callback used to listen to workers and run on job finish
@@ -16,10 +14,10 @@ import java.util.List;
  */
 public class PostMessageFutureCallback extends ClientFutureCallback {
 
-    private BulletinBoardClient.ClientCallback<?> callback;
+    private ClientCallback<?> callback;
 
     public PostMessageFutureCallback(ListeningExecutorService listeningExecutor,
-                              BulletinBoardClient.ClientCallback<?> callback) {
+                              ClientCallback<?> callback) {
         super(listeningExecutor);
         this.callback = callback;
     }

bulletin-board-client/src/main/java/meerkat/bulletinboard/callbacks/ReadMessagesFutureCallback.java

@@ -1,11 +1,8 @@
 package meerkat.bulletinboard.callbacks;
 
-import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListeningExecutorService;
-import meerkat.bulletinboard.BulletinBoardClient;
+import meerkat.bulletinboard.AsyncBulletinBoardClient.*;
-import meerkat.bulletinboard.BulletinClientJob;
 import meerkat.bulletinboard.BulletinClientJobResult;
-import meerkat.bulletinboard.BulletinClientWorker;
 import meerkat.protobuf.BulletinBoardAPI;
 
 import java.util.List;
@@ -16,10 +13,10 @@ import java.util.List;
  */
 public class ReadMessagesFutureCallback extends ClientFutureCallback {
 
-    private BulletinBoardClient.ClientCallback<List<BulletinBoardAPI.BulletinBoardMessage>> callback;
+    private ClientCallback<List<BulletinBoardAPI.BulletinBoardMessage>> callback;
 
     public ReadMessagesFutureCallback(ListeningExecutorService listeningExecutor,
-                                      BulletinBoardClient.ClientCallback<List<BulletinBoardAPI.BulletinBoardMessage>> callback) {
+                                      ClientCallback<List<BulletinBoardAPI.BulletinBoardMessage>> callback) {
         super(listeningExecutor);
         this.callback = callback;
     }

bulletin-board-client/src/test/java/BulletinBoardClientIntegrationTest.java

@@ -1,7 +1,6 @@
 import com.google.protobuf.ByteString;
 import meerkat.bulletinboard.AsyncBulletinBoardClient;
-import meerkat.bulletinboard.BulletinBoardClient;
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
-import meerkat.bulletinboard.BulletinBoardClient.ClientCallback;
 import meerkat.bulletinboard.ThreadedBulletinBoardClient;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Crypto;

bulletin-board-server/src/main/java/meerkat/bulletinboard/sqlserver/BulletinBoardSQLServer.java

@@ -1,20 +1,29 @@
 package meerkat.bulletinboard.sqlserver;
 
+import java.security.InvalidKeyException;
+import java.security.cert.CertificateException;
 import java.sql.*;
 import java.util.*;
 
+import com.google.protobuf.ByteString;
 import com.google.protobuf.ProtocolStringList;
 
 import meerkat.bulletinboard.BulletinBoardServer;
-import meerkat.bulletinboard.sqlserver.mappers.EntryNumMapper;
+import meerkat.bulletinboard.sqlserver.mappers.*;
-import meerkat.bulletinboard.sqlserver.mappers.MessageMapper;
+
-import meerkat.bulletinboard.sqlserver.mappers.SignatureMapper;
 import meerkat.comm.CommunicationException;
+
+import meerkat.crypto.BatchDigest;
+import meerkat.crypto.DigitalSignature;
+import meerkat.crypto.concrete.ECDSASignature;
+import meerkat.crypto.concrete.SHA256Digest;
+
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Crypto.Signature;
 import meerkat.protobuf.Crypto.SignatureVerificationKey;
-import meerkat.crypto.Digest;
+
-import meerkat.crypto.concrete.SHA256Digest;
+
+import static meerkat.bulletinboard.sqlserver.BulletinBoardSQLServer.SQLQueryProvider.*;
 
 import javax.sql.DataSource;
 
@@ -23,6 +32,8 @@ import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
 import org.springframework.jdbc.support.GeneratedKeyHolder;
 import org.springframework.jdbc.support.KeyHolder;
 
+
+
 /**
  * This is a generic SQL implementation of the BulletinBoardServer API.
  */
@@ -46,7 +57,12 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 			CONNECT_TAG(new String[] {"EntryNum","Tag"}),
 			ADD_SIGNATURE(new String[] {"EntryNum","SignerId","Signature"}),
 			GET_SIGNATURES(new String[] {"EntryNum"}),
-			GET_MESSAGES(new String[] {});
+			GET_MESSAGES(new String[] {}),
+			GET_BATCH_MESSAGE_ENTRY(new String[] {"SignerId", "BatchId"}),
+			CHECK_BATCH_LENGTH(new String[] {"SignerId", "BatchId"}),
+			GET_BATCH_MESSAGE_DATA(new String[] {"SignerId", "BatchId", "StartPosition"}),
+			INSERT_BATCH_DATA(new String[] {"SignerId", "BatchId", "SerialNum", "Data"}),
+			CONNECT_BATCH_TAG(new String[] {"SignerId", "BatchId", "Tag"});
 
 			private String[] paramNames;
 
@@ -58,6 +74,10 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 				return paramNames;
 			}
 
+			public String getParamName(int num) {
+				return paramNames[num];
+			}
+
 		}
 
 		/**
@@ -152,6 +172,11 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 	}
 
+	/**
+	 * This method returns the value of the parameter specified in a message filter
+	 * @param messageFilter is the filter
+	 * @return the object parameter for the SQL query embedded in the filter (this depends on the filter type)
+     */
 	private Object getParam(MessageFilter messageFilter) {
 
 		switch (messageFilter.getType()) {
@@ -170,7 +195,7 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 			case MAX_MESSAGES:
 				return messageFilter.getMaxMessages();
 
-			default:
+			default:	// Unsupported filter type
 				return null;
 		}
 
@@ -193,7 +218,8 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 	protected NamedParameterJdbcTemplate jdbcTemplate;
 	
-	protected Digest digest;
+	protected BatchDigest digest;
+	protected DigitalSignature signer;
 	
 	protected List<SignatureVerificationKey> trusteeSignatureVerificationArray;
 	protected int minTrusteeSignatures;
@@ -232,6 +258,7 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 		// TODO write signature reading part.
 		
 		digest = new SHA256Digest();
+		signer = new ECDSASignature();
 
 		jdbcTemplate = new NamedParameterJdbcTemplate(sqlQueryProvider.getDataSource());
 
@@ -264,12 +291,12 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 		String sql;
 
-		sql = sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.INSERT_NEW_TAG);
+		sql = sqlQueryProvider.getSQLString(QueryType.INSERT_NEW_TAG);
 		Map namedParameters[] = new HashMap[tags.length];
 
 		for (int i = 0 ; i < tags.length ; i++){
 			namedParameters[i] = new HashMap();
-			namedParameters[i].put("Tag", tags[i]);
+			namedParameters[i].put(QueryType.INSERT_NEW_TAG.getParamName(0), tags[i]);
 		}
 
 		jdbcTemplate.batchUpdate(sql, namedParameters);
@@ -316,11 +343,11 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 		// Add message to table if needed and store entry number of message.
 
 			
-		sql = sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.FIND_MSG_ID);
+		sql = sqlQueryProvider.getSQLString(QueryType.FIND_MSG_ID);
 		Map namedParameters = new HashMap();
-		namedParameters.put("MsgId",msgID);
+		namedParameters.put(QueryType.FIND_MSG_ID.getParamName(0),msgID);
 
-		List<Long> entryNums = jdbcTemplate.query(sql, new MapSqlParameterSource(namedParameters), new EntryNumMapper());
+		List<Long> entryNums = jdbcTemplate.query(sql, new MapSqlParameterSource(namedParameters), new LongMapper());
 
 		if (entryNums.size() > 0){
 
@@ -328,8 +355,8 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 		} else{
 
-			sql = sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.INSERT_MSG);
+			sql = sqlQueryProvider.getSQLString(QueryType.INSERT_MSG);
-			namedParameters.put("Msg", msg.getMsg().toByteArray());
+			namedParameters.put(QueryType.INSERT_MSG.getParamName(0), msg.getMsg().toByteArray());
 
 			KeyHolder keyHolder = new GeneratedKeyHolder();
 			jdbcTemplate.update(sql,new MapSqlParameterSource(namedParameters),keyHolder);
@@ -354,14 +381,14 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 		
 		// Connect message to tags.
 
-		sql = sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.CONNECT_TAG);
+		sql = sqlQueryProvider.getSQLString(QueryType.CONNECT_TAG);
 
 		namedParameterArray = new HashMap[tags.length];
 
 		for (int i = 0 ; i < tags.length ; i++) {
 			namedParameterArray[i] = new HashMap();
-			namedParameterArray[i].put("EntryNum", entryNum);
+			namedParameterArray[i].put(QueryType.CONNECT_TAG.getParamName(0), entryNum);
-			namedParameterArray[i].put("Tag", tags[i]);
+			namedParameterArray[i].put(QueryType.CONNECT_TAG.getParamName(1), tags[i]);
 		}
 
 		jdbcTemplate.batchUpdate(sql, namedParameterArray);
@@ -374,15 +401,15 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 		
 		// Connect message to signatures.
 
-		sql = sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.ADD_SIGNATURE);
+		sql = sqlQueryProvider.getSQLString(QueryType.ADD_SIGNATURE);
 
 		namedParameterArray = new HashMap[signatures.length];
 
 		for (int i = 0 ; i < signatures.length ; i++) {
 			namedParameterArray[i] = new HashMap();
-			namedParameterArray[i].put("EntryNum", entryNum);
+			namedParameterArray[i].put(QueryType.ADD_SIGNATURE.getParamName(0), entryNum);
-			namedParameterArray[i].put("SignerId", signatures[i].getSignerId().toByteArray());
+			namedParameterArray[i].put(QueryType.ADD_SIGNATURE.getParamName(1), signatures[i].getSignerId().toByteArray());
-			namedParameterArray[i].put("Signature", signatures[i].toByteArray());
+			namedParameterArray[i].put(QueryType.ADD_SIGNATURE.getParamName(2), signatures[i].toByteArray());
 		}
 
 		jdbcTemplate.batchUpdate(sql,namedParameterArray);
@@ -412,7 +439,7 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 		// Check if Tag/Signature tables are required for filtering purposes
 
-		sqlBuilder.append(sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.GET_MESSAGES));
+		sqlBuilder.append(sqlQueryProvider.getSQLString(QueryType.GET_MESSAGES));
 		// Add conditions
 
 		namedParameters = new MapSqlParameterSource();
@@ -434,7 +461,7 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 				sqlBuilder.append(sqlQueryProvider.getCondition(filter.getType(), paramNum));
 
-				SQLQueryProvider.FilterTypeParam filterTypeParam = SQLQueryProvider.FilterTypeParam.getFilterTypeParamName(filter.getType());
+				FilterTypeParam filterTypeParam = FilterTypeParam.getFilterTypeParamName(filter.getType());
 
 				namedParameters.addValue(
 						filterTypeParam.getParamName() + Integer.toString(paramNum),
@@ -457,10 +484,10 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 			// Retrieve signatures
 
 			namedParameters = new MapSqlParameterSource();
-			namedParameters.addValue("EntryNum", msgBuilder.getEntryNum());
+			namedParameters.addValue(QueryType.GET_SIGNATURES.getParamName(0), msgBuilder.getEntryNum());
 
 			List<Signature> signatures = jdbcTemplate.query(
-					sqlQueryProvider.getSQLString(SQLQueryProvider.QueryType.GET_SIGNATURES),
+					sqlQueryProvider.getSQLString(QueryType.GET_SIGNATURES),
 					namedParameters,
 					signatureMapper);
 
@@ -478,6 +505,130 @@ public class BulletinBoardSQLServer implements BulletinBoardServer{
 
 	}
 
+	/**
+	 * This method checks if a specified batch exists and is already closed
+	 * @param signerId is the ID of the publisher of the batch
+	 * @param batchId is the unique (per signer) batch ID
+     * @return TRUE if the batch is closed and FALSE if it is still open or doesn't exist at all
+     */
+	private boolean isBatchClosed(ByteString signerId, int batchId){
+
+		String sql = sqlQueryProvider.getSQLString(QueryType.GET_BATCH_MESSAGE_ENTRY);
+
+		MapSqlParameterSource namedParameters = new MapSqlParameterSource();
+		namedParameters.addValue(QueryType.GET_BATCH_MESSAGE_ENTRY.getParamName(0), signerId);
+		namedParameters.addValue(QueryType.GET_BATCH_MESSAGE_ENTRY.getParamName(1), batchId);
+
+		List<Long> result = jdbcTemplate.query(sql,namedParameters,new LongMapper());
+
+		return (result.size() > 0);
+
+	}
+
+	@Override
+	public BoolMsg beginBatch(BeginBatchMessage message) throws CommunicationException {
+
+		// Check if batch is closed
+		if (isBatchClosed(message.getSignerId(), message.getBatchId())) {
+			return BoolMsg.newBuilder().setValue(false).build();
+		}
+
+		// Add new tags to table
+		ProtocolStringList tagList = message.getTagList();
+		String[] tags = new String[tagList.size()];
+		tags = tagList.toArray(tags);
+		try {
+			insertNewTags(tags);
+		} catch (SQLException e) {
+			throw new CommunicationException(e.getMessage());
+		}
+
+		// Connect tags
+		String sql = sqlQueryProvider.getSQLString(QueryType.CONNECT_BATCH_TAG);
+		MapSqlParameterSource namedParameters[] = new MapSqlParameterSource[tags.length];
+
+		for (int i=0 ; i < tags.length ; i++) {
+			namedParameters[i] = new MapSqlParameterSource();
+			namedParameters[i].addValue(QueryType.CONNECT_BATCH_TAG.getParamName(0),message.getSignerId());
+			namedParameters[i].addValue(QueryType.CONNECT_BATCH_TAG.getParamName(1),message.getBatchId());
+			namedParameters[i].addValue(QueryType.CONNECT_BATCH_TAG.getParamName(2),tags[i]);
+		}
+
+		jdbcTemplate.batchUpdate(sql,namedParameters);
+
+		return BoolMsg.newBuilder().setValue(true).build();
+	}
+
+	@Override
+	public BoolMsg postBatchMessage(BatchMessage batchMessage) {
+
+		// Check if batch is closed
+		if (isBatchClosed(batchMessage.getSignerId(), batchMessage.getBatchId())) {
+			return BoolMsg.newBuilder().setValue(false).build();
+		}
+
+		// Add data
+		String sql = sqlQueryProvider.getSQLString(QueryType.INSERT_BATCH_DATA);
+		MapSqlParameterSource namedParameters = new MapSqlParameterSource();
+
+		namedParameters.addValue(QueryType.INSERT_BATCH_DATA.getParamName(0),batchMessage.getSignerId());
+		namedParameters.addValue(QueryType.INSERT_BATCH_DATA.getParamName(1),batchMessage.getBatchId());
+		namedParameters.addValue(QueryType.INSERT_BATCH_DATA.getParamName(2),batchMessage.getSerialNum());
+		namedParameters.addValue(QueryType.INSERT_BATCH_DATA.getParamName(3),batchMessage.getData());
+
+		jdbcTemplate.update(sql, namedParameters);
+
+		return BoolMsg.newBuilder().setValue(true).build();
+
+	}
+
+	@Override
+	public BoolMsg closeBatchMessage(CloseBatchMessage message) throws CommunicationException {
+
+		// Check batch size
+
+		String sql = sqlQueryProvider.getSQLString(QueryType.CHECK_BATCH_LENGTH);
+		MapSqlParameterSource namedParameters = new MapSqlParameterSource();
+
+		namedParameters.addValue(QueryType.CHECK_BATCH_LENGTH.getParamName(0),message.getSig().getSignerId());
+		namedParameters.addValue(QueryType.CHECK_BATCH_LENGTH.getParamName(1),message.getBatchId());
+
+		List<Long> lengthResult = jdbcTemplate.query(sql, namedParameters, new LongMapper());
+
+		if (lengthResult.get(0) != message.getBatchLength()) {
+			return BoolMsg.newBuilder().setValue(false).build();
+		}
+
+		// Check signature
+
+		sql = sqlQueryProvider.getSQLString(QueryType.GET_BATCH_MESSAGE_DATA);
+		namedParameters = new MapSqlParameterSource();
+
+		namedParameters.addValue(QueryType.GET_BATCH_MESSAGE_DATA.getParamName(0),message.getSig().getSignerId());
+		namedParameters.addValue(QueryType.GET_BATCH_MESSAGE_DATA.getParamName(1),message.getBatchId());
+		namedParameters.addValue(QueryType.GET_BATCH_MESSAGE_DATA.getParamName(2),0); // Read from the beginning
+
+		List<BatchData> batchDataList = jdbcTemplate.query(sql, namedParameters, new BatchDataMapper());
+
+		try {
+			signer.initVerify(message.getSig());
+		} catch (CertificateException | InvalidKeyException e) {
+			return BoolMsg.newBuilder().setValue(false).build();
+		}
+
+		//TODO: FInish this
+
+		//signer.updateContent(msgStream);
+		//assertTrue("Signature did not verify!", signer.verify());
+
+		return null;
+	}
+
+	@Override
+	public List<BatchData> readBatch(BatchSpecificationMessage message) {
+		return null; // TODO: Implement this
+	}
+
 	@Override
 	public void close() {}
 

bulletin-board-server/src/main/java/meerkat/bulletinboard/sqlserver/MySQLQueryProvider.java

@@ -5,6 +5,7 @@ import meerkat.bulletinboard.sqlserver.BulletinBoardSQLServer.SQLQueryProvider;
 import meerkat.protobuf.BulletinBoardAPI.FilterType;
 
 import javax.sql.DataSource;
+import java.text.MessageFormat;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -32,21 +33,72 @@ public class MySQLQueryProvider implements SQLQueryProvider {
     public String getSQLString(QueryType queryType) throws IllegalArgumentException{
 
         switch(queryType) {
+
             case ADD_SIGNATURE:
-                return "INSERT IGNORE INTO SignatureTable (EntryNum, SignerId, Signature) VALUES (:EntryNum, :SignerId, :Signature)";
+                return MessageFormat.format(
+                        "INSERT IGNORE INTO SignatureTable (EntryNum, SignerId, Signature) VALUES ({0}, {1}, {2})",
+                        QueryType.ADD_SIGNATURE.getParamName(0),
+                        QueryType.ADD_SIGNATURE.getParamName(1),
+                        QueryType.ADD_SIGNATURE.getParamName(2));
+
             case CONNECT_TAG:
-                return "INSERT IGNORE INTO MsgTagTable (TagId, EntryNum)"
+                return MessageFormat.format(
-                    + " SELECT TagTable.TagId, :EntryNum AS EntryNum FROM TagTable WHERE Tag = :Tag";
+                        "INSERT IGNORE INTO MsgTagTable (TagId, EntryNum)"
+                        + " SELECT TagTable.TagId, {0} AS EntryNum FROM TagTable WHERE Tag = {1}",
+                        QueryType.CONNECT_TAG.getParamName(0),
+                        QueryType.CONNECT_TAG.getParamName(1));
+
             case FIND_MSG_ID:
-                return "SELECT EntryNum From MsgTable WHERE MsgId = :MsgId";
+                return MessageFormat.format(
+                        "SELECT EntryNum From MsgTable WHERE MsgId = {0}",
+                        QueryType.FIND_MSG_ID.getParamName(0));
+
             case GET_MESSAGES:
                 return "SELECT MsgTable.EntryNum, MsgTable.Msg FROM MsgTable";
+
             case GET_SIGNATURES:
-                return "SELECT Signature FROM SignatureTable WHERE EntryNum = :EntryNum";
+                return MessageFormat.format(
+                        "SELECT Signature FROM SignatureTable WHERE EntryNum = {0}",
+                        QueryType.GET_SIGNATURES.getParamName(0));
+
             case INSERT_MSG:
-                return "INSERT INTO MsgTable (MsgId, Msg) VALUES(:MsgId, :Msg)";
+                return MessageFormat.format(
+                        "INSERT INTO MsgTable (MsgId, Msg) VALUES({0}, {1})",
+                        QueryType.INSERT_MSG.getParamName(0),
+                        QueryType.INSERT_MSG.getParamName(1));
+
             case INSERT_NEW_TAG:
-                return "INSERT IGNORE INTO TagTable(Tag) VALUES (:Tag)";
+                return MessageFormat.format(
+                        "INSERT IGNORE INTO TagTable(Tag) VALUES ({0})",
+                        QueryType.INSERT_NEW_TAG.getParamName(0));
+
+            case GET_BATCH_MESSAGE_ENTRY:
+                return MessageFormat.format(
+                        "SELECT MsgTable.EntryNum, MsgTable.Msg FROM MsgTable"
+                        + "INNER JOIN SignatureTable ON MsgTable.EntryNum = SignatureTable.EntryNum"
+                        + "INNER JOIN MsgTagTable ON MsgTable.EntryNum = MsgTagTable.EntryNum"
+                        + "INNER JOIN TagTable ON MsgTagTable.TagId = TagTable.TagId"
+                        + "WHERE SignatureTable.SignerId = {0}"
+                        + "AND TagTable.Tag = {1}",
+                        QueryType.GET_BATCH_MESSAGE_ENTRY.getParamName(0),
+                        QueryType.GET_BATCH_MESSAGE_ENTRY.getParamName(1));
+
+            case GET_BATCH_MESSAGE_DATA:
+                return MessageFormat.format(
+                        "SELECT Data FROM BatchTable"
+                        + " WHERE SignerId = {0} AND BatchId = {1} AND SerialNum >= {2}"
+                        + " ORDER BY SerialNum ASC",
+                        QueryType.GET_BATCH_MESSAGE_DATA.getParamName(0),
+                        QueryType.GET_BATCH_MESSAGE_DATA.getParamName(1),
+                        QueryType.GET_BATCH_MESSAGE_DATA.getParamName(2));
+
+            case CHECK_BATCH_LENGTH:
+                return MessageFormat.format(
+                        "SELECT COUNT(Data) AS BatchLength FROM BatchTable"
+                        + " WHERE SignerId = {0} AND BatchId = {1}",
+                        QueryType.GET_BATCH_MESSAGE_DATA.getParamName(0),
+                        QueryType.GET_BATCH_MESSAGE_DATA.getParamName(1));
+
            default:
                throw new IllegalArgumentException("Cannot serve a query of type " + queryType);
         }
@@ -119,7 +171,8 @@ public class MySQLQueryProvider implements SQLQueryProvider {
     public List<String> getSchemaCreationCommands() {
         List<String> list = new LinkedList<String>();
 
-        list.add("CREATE TABLE IF NOT EXISTS MsgTable (EntryNum INT NOT NULL AUTO_INCREMENT PRIMARY KEY, MsgId TINYBLOB, Msg BLOB, UNIQUE(MsgId(50)))");
+        list.add("CREATE TABLE IF NOT EXISTS MsgTable (EntryNum INT NOT NULL AUTO_INCREMENT PRIMARY KEY,"
+                + " MsgId TINYBLOB, Msg BLOB, UNIQUE(MsgId(50)))");
 
         list.add("CREATE TABLE IF NOT EXISTS TagTable (TagId INT NOT NULL AUTO_INCREMENT PRIMARY KEY, Tag VARCHAR(50), UNIQUE(Tag))");
 
@@ -129,7 +182,14 @@ public class MySQLQueryProvider implements SQLQueryProvider {
                 + " CONSTRAINT UNIQUE (EntryNum, TagID))");
 
         list.add("CREATE TABLE IF NOT EXISTS SignatureTable (EntryNum INT, SignerId TINYBLOB, Signature TINYBLOB,"
-                + " INDEX(SignerId(32)), CONSTRAINT Uni UNIQUE(SignerId(32), EntryNum), CONSTRAINT FOREIGN KEY (EntryNum) REFERENCES MsgTable(EntryNum))");
+                + " INDEX(SignerId(32)), CONSTRAINT Unique_Signature UNIQUE(SignerId(32), EntryNum),"
+                + " CONSTRAINT FOREIGN KEY (EntryNum) REFERENCES MsgTable(EntryNum))");
+
+        list.add("CREATE TABLE IF NOT EXISTS BatchTable (SignerId TINYBLOB, BatchId INT, SerialNum INT, Data BLOB,"
+                + " CONSTRAINT Unique_Batch UNIQUE(SignerId(32), BatchId, SerialNum))");
+
+        list.add("CREATE TABLE IF NOT EXISTS BatchTagTable (SignerId TINYBLOB, BatchId INT, TagId INT,"
+                + " INDEX(SignerId, BatchId), CONSTRAINT FOREIGN KEY (TagId) REFERENCES TagTable(TagId))");
 
         return list;
     }
@@ -138,6 +198,8 @@ public class MySQLQueryProvider implements SQLQueryProvider {
     public List<String> getSchemaDeletionCommands() {
         List<String> list = new LinkedList<String>();
 
+        list.add("DROP TABLE IF EXISTS BatchTagTable");
+        list.add("DROP TABLE IF EXISTS BatchTable");
         list.add("DROP TABLE IF EXISTS MsgTagTable");
         list.add("DROP TABLE IF EXISTS SignatureTable");
         list.add("DROP TABLE IF EXISTS TagTable");

bulletin-board-server/src/main/java/meerkat/bulletinboard/sqlserver/mappers/BatchDataMapper.java

@@ -0,0 +1,21 @@
+package meerkat.bulletinboard.sqlserver.mappers;
+
+import com.google.protobuf.ByteString;
+import meerkat.protobuf.BulletinBoardAPI.BatchData;
+import org.springframework.jdbc.core.RowMapper;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by Arbel Deutsch Peled on 19-Dec-15.
+ */
+public class BatchDataMapper implements RowMapper<BatchData> {
+
+    @Override
+    public BatchData mapRow(ResultSet rs, int rowNum) throws SQLException {
+
+        return BatchData.newBuilder().setData(ByteString.copyFrom(rs.getBytes(rowNum))).build();
+
+    }
+}

bulletin-board-server/src/main/java/meerkat/bulletinboard/sqlserver/mappers/LongMapper.java

@@ -9,7 +9,7 @@ import java.sql.SQLException;
 /**
  * Created by Arbel Deutsch Peled on 11-Dec-15.
  */
-public class EntryNumMapper implements RowMapper<Long> {
+public class LongMapper implements RowMapper<Long> {
 
     @Override
     public Long mapRow(ResultSet rs, int rowNum) throws SQLException {

bulletin-board-server/src/main/java/meerkat/bulletinboard/webapp/BulletinBoardWebApp.java

@@ -17,12 +17,11 @@ import meerkat.bulletinboard.sqlserver.H2QueryProvider;
 import meerkat.bulletinboard.sqlserver.MySQLQueryProvider;
 import meerkat.bulletinboard.sqlserver.SQLiteQueryProvider;
 import meerkat.comm.CommunicationException;
-import meerkat.protobuf.BulletinBoardAPI.BoolMsg;
+import meerkat.protobuf.BulletinBoardAPI.*;
-import meerkat.protobuf.BulletinBoardAPI.BulletinBoardMessage;
-import meerkat.protobuf.BulletinBoardAPI.BulletinBoardMessageList;
-import meerkat.protobuf.BulletinBoardAPI.MessageFilterList;
 import meerkat.rest.Constants;
 
+import java.util.List;
+
 @Path(Constants.BULLETIN_BOARD_SERVER_PATH)
 public class BulletinBoardWebApp implements BulletinBoardServer, ServletContextListener{
 		
@@ -99,6 +98,58 @@ public class BulletinBoardWebApp implements BulletinBoardServer, ServletContextL
 		return bulletinBoard.readMessages(filterList);
 	}
 
+	@Path(Constants.BEGIN_BATCH_PATH)
+	@POST
+	@Consumes(Constants.MEDIATYPE_PROTOBUF)
+	@Produces(Constants.MEDIATYPE_PROTOBUF)
+	@Override
+	public BoolMsg beginBatch(BeginBatchMessage message) {
+		try {
+			return bulletinBoard.beginBatch(message);
+		} catch (CommunicationException e) {
+			System.err.println(e.getMessage());
+			return null;
+		}
+	}
+
+	@Path(Constants.POST_BATCH_PATH)
+	@POST
+	@Consumes(Constants.MEDIATYPE_PROTOBUF)
+	@Produces(Constants.MEDIATYPE_PROTOBUF)
+	@Override
+	public BoolMsg postBatchMessage(BatchMessage batchMessage) {
+		try {
+			return bulletinBoard.postBatchMessage(batchMessage);
+		} catch (CommunicationException e) {
+			System.err.println(e.getMessage());
+			return null;
+		}
+	}
+
+	@Path(Constants.CLOSE_BATCH_PATH)
+	@POST
+	@Consumes(Constants.MEDIATYPE_PROTOBUF)
+	@Produces(Constants.MEDIATYPE_PROTOBUF)
+	@Override
+	public BoolMsg closeBatchMessage(CloseBatchMessage message) {
+		try {
+			return bulletinBoard.closeBatchMessage(message);
+		} catch (CommunicationException e) {
+			System.err.println(e.getMessage());
+			return null;
+		}
+	}
+
+	@Override
+	public List<BatchData> readBatch(BatchSpecificationMessage message) {
+		try {
+			return bulletinBoard.readBatch(message);
+		} catch (CommunicationException | IllegalArgumentException e) {
+			System.err.println(e.getMessage());
+			return null;
+		}
+	}
+
 	@Override
 	public void close(){
 		try {

meerkat-common/src/main/java/meerkat/bulletinboard/AsyncBulletinBoardClient.java

@@ -9,13 +9,22 @@ import java.util.List;
  */
 public interface AsyncBulletinBoardClient extends BulletinBoardClient {
 
+    public interface ClientCallback<T> {
+        void handleCallback(T msg);
+        void handleFailure(Throwable t);
+    }
+
+    public interface MessageHandler {
+        void handleNewMessages(List<BulletinBoardMessage> messageList);
+    }
+
     /**
      * Post a message to the bulletin board in an asynchronous manner
      * @param msg is the message to be posted
      * @param callback is a class containing methods to handle the result of the operation
      * @return a unique message ID for the message, that can be later used to retrieve the batch
      */
-    MessageID postMessage(BulletinBoardMessage msg, ClientCallback<?> callback);
+    public MessageID postMessage(BulletinBoardMessage msg, ClientCallback<?> callback);
 
     /**
      * This method allows for sending large messages as a batch to the bulletin board
@@ -26,12 +35,12 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
      * @param callback is a callback function class for handling results of the operation
      * @return a unique message ID for the entire message, that can be later used to retrieve the batch
      */
-    MessageID postBatch(byte[] signerId, int batchId, List<BatchData> batchDataList, int startPosition, ClientCallback<?> callback);
+    public MessageID postBatch(byte[] signerId, int batchId, List<BatchData> batchDataList, int startPosition, ClientCallback<?> callback);
 
     /**
      * Overloading of the postBatch method in which startPosition is set to the default value 0
      */
-    MessageID postBatch(byte[] signerId, int batchId, List<BatchData> batchDataList, ClientCallback<?> callback);
+    public MessageID postBatch(byte[] signerId, int batchId, List<BatchData> batchDataList, ClientCallback<?> callback);
 
     /**
      * Check how "safe" a given message is in an asynchronous manner
@@ -39,7 +48,7 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
      * @param id is the unique message identifier for retrieval
      * @param callback is a callback function class for handling results of the operation
      */
-    void getRedundancy(MessageID id, ClientCallback<Float> callback);
+    public void getRedundancy(MessageID id, ClientCallback<Float> callback);
 
     /**
      * Read all messages posted matching the given filter in an asynchronous manner
@@ -49,7 +58,7 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
      * @param filterList return only messages that match the filters (null means no filtering).
      * @param callback is a callback function class for handling results of the operation
      */
-    void readMessages(MessageFilterList filterList, ClientCallback<List<BulletinBoardMessage>> callback);
+    public void readMessages(MessageFilterList filterList, ClientCallback<List<BulletinBoardMessage>> callback);
 
     /**
      * Read a given batch message from the bulletin board
@@ -57,6 +66,13 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
      * @param batchId is the unique (per signer) ID of the batch
      * @param callback is a callback class for handling the result of the operation
      */
-    void readBatch(byte[] signerId, int batchId, ClientCallback<SignedBatch> callback);
+    public void readBatch(byte[] signerId, int batchId, ClientCallback<SignedBatch> callback);
+
+    /**
+     * Subscribes to a notifier that will return any new messages on the server that match the given filters
+     * @param filterList defines the set of filters for message retrieval
+     * @param messageHandler defines the handler for new messages received
+     */
+    public void subscribe(MessageFilterList filterList, MessageHandler messageHandler);
 
 }

meerkat-common/src/main/java/meerkat/bulletinboard/BulletinBoardClient.java

@@ -12,11 +12,6 @@ import java.util.List;
  */
 public interface BulletinBoardClient {
 
-    interface ClientCallback<T> {
-        void handleCallback(T msg);
-        void handleFailure(Throwable t);
-    }
-
     /**
      * Initialize the client to use some specified servers
      * @param clientParams contains the parameters required for the client setup

meerkat-common/src/main/java/meerkat/bulletinboard/BulletinBoardServer.java

@@ -3,40 +3,83 @@ package meerkat.bulletinboard;
 import meerkat.comm.CommunicationException;
 import meerkat.protobuf.BulletinBoardAPI.*;
 
+import java.util.List;
+
 /**
  * Created by Arbel on 07/11/15.
  * 
- * This interface refers to a single instance of a Bulletin Board.
+ * This interface refers to a single instance of a Bulletin Board
  * An implementation of this interface may use any DB and be hosted on any machine.
  */
 
 public interface BulletinBoardServer{
 	
 	/**
-	 * This method initializes the server by reading the signature data and storing it.
+	 * This method initializes the server by reading the signature data and storing it
-	 * It also establishes the connection to the DB.
+	 * It also establishes the connection to the DB
-	 * @throws CommunicationException on DB connection error.
+	 * @throws CommunicationException on DB connection error
 	 */
 	public void init(String meerkatDB) throws CommunicationException;
 	
 	/**
      * Post a message to bulletin board.
      * @param msg is the actual (signed) message
-	 * @return TRUE if the message has been authenticated and FALSE otherwise (in ProtoBuf form).
+	 * @return TRUE if the message has been authenticated and FALSE otherwise (in ProtoBuf form)
-	 * @throws CommunicationException on DB connection error.
+	 * @throws CommunicationException on DB connection error
      */
-	 public BoolMsg postMessage(BulletinBoardMessage msg) throws CommunicationException;
+	public BoolMsg postMessage(BulletinBoardMessage msg) throws CommunicationException;
 	 
 	 /**
-	  * Read all messages posted matching the given filter.
+	  * Read all messages posted matching the given filter
-	  * @param filter return only messages that match the filter (empty list means no filtering).
+	  * @param filterList return only messages that match the filters (empty list or null means no filtering)
 	  * @return
+	  * @throws CommunicationException on DB connection error
 	  */
-	 BulletinBoardMessageList readMessages(MessageFilterList filterList) throws CommunicationException;
+	public BulletinBoardMessageList readMessages(MessageFilterList filterList) throws CommunicationException;
+
+	/**
+	 * Informs server about a new batch message
+	 * @param message contains the required data about the new batch
+	 * @return TRUE if the batch request is accepted amd FALSE otherwise
+	 * 		Specifically, if such a batch already exists and is not yet closed: the value returned will be TRUE
+	 * 		However, if such a batch exists and is already closed: the value returned will be FALSE
+	 * @throws CommunicationException on DB connection error
+     */
+	public BoolMsg beginBatch(BeginBatchMessage message) throws CommunicationException;
+
+	/**
+	 * Posts a (part of a) batch message to the bulletin board
+	 * Note that the existence and contents of a batch message are not available for reading before the batch is finalized
+	 * @param batchMessage contains the (partial) data this message carries as well as meta-data required in order to place the data
+	 *                     in the correct position inside the correct batch
+	 * @return TRUE if the message is accepted and successfully saved and FALSE otherwise
+	 * 		Specifically, if the batch is already closed: the value returned will be FALSE
+	 * 		However, requiring to open a batch before insertion of messages is implementation-dependent
+	 * @throws CommunicationException on DB connection error
+     */
+	public BoolMsg postBatchMessage(BatchMessage batchMessage) throws CommunicationException;
+
+	/**
+	 * Attempts to close and finalize a batch message
+	 * @param message contains the data necessary to close the batch; in particular: the signature for the batch
+	 * @return TRUE if the batch was successfully closed, FALSE otherwise
+	 * 		Specifically, if the signature is invalid or if some of the batch parts have not yet been submitted: the value returned will be FALSE
+	 * @throws CommunicationException on DB connection error
+     */
+	public BoolMsg closeBatchMessage(CloseBatchMessage message) throws CommunicationException;
+
+	/**
+	 * Reads a batch message from the server (starting with the supplied position)
+	 * @param message specifies the signer ID and the batch ID to read as well as an (optional) start position
+	 * @return an ordered list of batch messages starting from the specified start position (if given) or from the beginning (if omitted)
+	 * @throws CommunicationException on DB connection error
+	 * @throws IllegalArgumentException if message does not specify a batch
+     */
+	public List<BatchData> readBatch(BatchSpecificationMessage message) throws CommunicationException, IllegalArgumentException;
 
 	 /**
-	 * This method closes the connection to the DB.
+	 * This method closes the connection to the DB
-	 * @throws CommunicationException on DB connection error.
+	 * @throws CommunicationException on DB connection error
 	 */
-	 public void close() throws CommunicationException;
+	public void close() throws CommunicationException;
 }

meerkat-common/src/main/java/meerkat/crypto/BatchDigest.java

@@ -0,0 +1,20 @@
+package meerkat.crypto;
+
+import meerkat.protobuf.BulletinBoardAPI.*;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 18-Dec-15.
+ * Extends the Digest interface with a method for digesting Batch messages
+ */
+public interface BatchDigest extends Digest{
+
+    /**
+     * Update the digest with the
+     * @param beginBatchMessage is the message that starts the batch
+     * @param batchDataList is the (ordered) list of data in the batch
+     */
+    public void update(BeginBatchMessage beginBatchMessage, List<BatchData> batchDataList);
+
+}

meerkat-common/src/main/java/meerkat/crypto/Digest.java

@@ -13,7 +13,7 @@ public interface Digest {
      * (copied from {@link MessageDigest#digest()})
      * @return
      */
-    byte[] digest();
+    public byte[] digest();
 
     /**
      * Updates the digest using the specified message (in serialized wire form)
@@ -22,12 +22,12 @@ public interface Digest {
      * @param msg
      * @return
      */
-    void update(Message msg);
+    public void update(Message msg);
 
     /**
      * Resets the digest for further use.
      */
-    void reset();
+    public void reset();
 
     /**
      * Clone the current digest state

meerkat-common/src/main/java/meerkat/crypto/concrete/ECDSASignature.java

@@ -30,7 +30,10 @@ import javax.security.auth.callback.UnsupportedCallbackException;
  *
  * This class is not thread-safe (each thread should have its own instance).
  */
-public class ECDSASignature extends GlobalCryptoSetup implements DigitalSignature {
+public class ECDSASignature implements DigitalSignature {
+
+    private static GlobalCryptoSetup globalCryptoSetup = GlobalCryptoSetup.getInstance();
+
     final Logger logger = LoggerFactory.getLogger(getClass());
 
     final public static String KEYSTORE_TYPE = "PKCS12";

meerkat-common/src/main/java/meerkat/crypto/concrete/ECElGamalEncryption.java

@@ -31,7 +31,10 @@ import java.util.Random;
 /**
  * Created by talm on 17/11/15.
  */
-public class ECElGamalEncryption extends GlobalCryptoSetup implements Encryption {
+public class ECElGamalEncryption implements Encryption {
+
+    private static GlobalCryptoSetup globalCryptoSetup = GlobalCryptoSetup.getInstance();
+
     final Logger logger = LoggerFactory.getLogger(getClass());
 
     public final static String KEY_ALGORITHM = "ECDH";

meerkat-common/src/main/java/meerkat/crypto/concrete/GenericBatchDigest.java

@@ -0,0 +1,27 @@
+package meerkat.crypto.concrete;
+
+import com.google.protobuf.Message;
+import meerkat.crypto.BatchDigest;
+import meerkat.protobuf.BulletinBoardAPI.*;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 19-Dec-15.
+ */
+public abstract class GenericBatchDigest implements BatchDigest{
+
+
+    @Override
+    public void update(BeginBatchMessage beginBatchMessage, List<BatchData> batchDataList) {
+        update(beginBatchMessage);
+        for (BatchData batchData : batchDataList) {
+            update(batchData);
+        }
+    }
+
+    @Override
+    // Repeated here to circumvent compiler error
+    public abstract BatchDigest clone() throws CloneNotSupportedException;
+
+}

meerkat-common/src/main/java/meerkat/crypto/concrete/GlobalCryptoSetup.java

@@ -10,13 +10,26 @@ import java.security.Security;
 /**
  * A class that performs required crypto setup
  */
-public class GlobalCryptoSetup {
+public final class GlobalCryptoSetup {
+
+    private static GlobalCryptoSetup globalCryptoSetup;
+
     final static Logger logger = LoggerFactory.getLogger(GlobalCryptoSetup.class);
 
-    static boolean loadedBouncyCastle = false;
+    private boolean loadedBouncyCastle = false;
-    static Provider bouncyCastleProvider;
+    private Provider bouncyCastleProvider;
 
-    public static boolean hasSecp256k1Curve() {
+    private GlobalCryptoSetup() { doSetup(); }
+
+    public static GlobalCryptoSetup getInstance() {
+        if (globalCryptoSetup == null) {
+            globalCryptoSetup = new GlobalCryptoSetup();
+        }
+
+        return globalCryptoSetup;
+    }
+
+    public boolean hasSecp256k1Curve() {
         // For now we just check if the java version is at least 8
         String[] version = System.getProperty("java.version").split("\\.");
         int major = Integer.parseInt(version[0]);
@@ -24,9 +37,11 @@ public class GlobalCryptoSetup {
         return ((major > 1) || ((major > 0) && (minor > 7)));
     }
 
-    public static  Provider getBouncyCastleProvider() { doSetup(); return bouncyCastleProvider; }
+    public Provider getBouncyCastleProvider() {
+        return bouncyCastleProvider;
+    }
 
-    public static synchronized void doSetup() {
+    public void doSetup() {
         if (bouncyCastleProvider == null) {
             bouncyCastleProvider = new BouncyCastleProvider();
             // Make bouncycastle our default provider if we're running on a JVM version < 8
@@ -39,5 +54,4 @@ public class GlobalCryptoSetup {
         }
     }
 
-    public GlobalCryptoSetup() { doSetup(); }
 }

meerkat-common/src/main/java/meerkat/crypto/concrete/SHA256Digest.java

@@ -2,6 +2,7 @@ package meerkat.crypto.concrete;
 
 import com.google.protobuf.ByteString;
 import com.google.protobuf.Message;
+import meerkat.crypto.BatchDigest;
 import meerkat.crypto.Digest;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -13,7 +14,7 @@ import java.security.NoSuchAlgorithmException;
 /**
  * Created by talm on 11/9/15.
  */
-public class SHA256Digest extends GlobalCryptoSetup implements Digest {
+public class SHA256Digest extends GenericBatchDigest {
     final Logger logger = LoggerFactory.getLogger(getClass());
     public static final String SHA256 = "SHA-256";
 

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

@@ -105,3 +105,10 @@ message BatchMessage {
     int32 serialNum = 3;            // Location of the message in the batch: starting from 0
     BatchData data = 4;             // Actual data
 }
+
+// This message defines which batch to read and from which location to start reading
+message BatchSpecificationMessage {
+    bytes signerId = 1;             // Unique signer identifier
+    int32 batchId = 2;              // Unique identifier for the batch (unique per signer)
+    int32 startPosition = 3;        // Position in batch to start reading from
+}

meerkat-common/src/test/java/meerkat/crypto/concrete/ECElGamalUtils.java

@@ -26,6 +26,9 @@ import java.security.spec.InvalidKeySpecException;
  * utilities for ECElgamal
  */
 public class ECElGamalUtils {
+
+    private static GlobalCryptoSetup globalCryptoSetup = GlobalCryptoSetup.getInstance();
+
     final static Logger logger = LoggerFactory.getLogger(ECElGamalUtils.class);
 
     public final static String ENCRYPTION_KEY_ALGORITHM = "ECDH";
@@ -43,7 +46,7 @@ public class ECElGamalUtils {
 
         try {
             KeyFactory fact = KeyFactory.getInstance(ENCRYPTION_KEY_ALGORITHM,
-                    GlobalCryptoSetup.getBouncyCastleProvider());
+                    globalCryptoSetup.getBouncyCastleProvider());
             PublicKey javaPk = fact.generatePublic(pubKeySpec);
             ConcreteCrypto.ElGamalPublicKey serializedPk = ConcreteCrypto.ElGamalPublicKey.newBuilder()
                 .setSubjectPublicKeyInfo(ByteString.copyFrom(javaPk.getEncoded())).build();

restful-api-common/src/main/java/meerkat/rest/Constants.java

@@ -9,4 +9,8 @@ public interface Constants {
     public static final String BULLETIN_BOARD_SERVER_PATH = "/bbserver";
     public static final String READ_MESSAGES_PATH = "/readmessages";
     public static final String POST_MESSAGE_PATH = "/postmessage";
+    public static final String BEGIN_BATCH_PATH = "/beginbatch";
+    public static final String POST_BATCH_PATH = "/postbatch";
+    public static final String CLOSE_BATCH_PATH = "/closebatch";
+
 }