working on scanner API refactoring (doesn't compile yet)

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

@@ -1,20 +0,0 @@
-syntax = "proto3";
-
-package meerkat;
-
-import "meerkat/voting.proto";
-
-option java_package = "meerkat.protobuf";
-
-// Container for scanned data
-message ScannedData {
-    bytes channel = 1;
-
-    SignedEncryptedBallot signed_encrypted_ballot = 2;
-
-}
-
-// Container for error messages
-message ErrorMsg {
-    string msg = 1;
-}

polling-station/src/main/java/meerkat/pollingstation/PollingStationMainController.java

@@ -1,8 +1,11 @@
 package meerkat.pollingstation;
 
+import com.google.common.util.concurrent.FutureCallback;
 import meerkat.pollingstation.controller.PollingStationControllerInterface;
+import meerkat.pollingstation.controller.callbacks.ScanDataCallback;
 import meerkat.pollingstation.controller.commands.PollingStationCommand;
 import meerkat.pollingstation.controller.commands.ReceivedScanCommand;
+import meerkat.protobuf.PollingStation;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -17,20 +20,31 @@ public class PollingStationMainController implements PollingStationControllerInt
     private LinkedBlockingQueue<PollingStationCommand> queue;
     private volatile boolean shutDownHasBeenCalled;
 
-    private static ReceiverScanHandler server;
-    private static final String ADDRESS = "http://localhost";
-    private static final String SUB_ADDRESS = "";
-    private static final int PORT = 8080;
-
-
     public PollingStationMainController() {
         queue = new LinkedBlockingQueue<PollingStationCommand>();
         shutDownHasBeenCalled = false;
     }
 
     @Override
-    public void init(ReceiverScanHandler server) {
+    public void init(PollingStationScanner.Consumer server) {
-        server.setControllerQueue(queue);
+        server.subscribe(new FutureCallback<PollingStation.ScannedData>() {
+            @Override
+            public void onSuccess(PollingStation.ScannedData result) {
+                if (result.getDataCase().equals(PollingStation.ScannedData.DataCase.BALLOT)) {
+                    // TODO: Set request ID correctly?
+                    int requestID = 1;
+                    long serialNumber = result.getBallot().getSignedEncryptedBallot().getEncryptedBallot().getSerialNumber();
+                    queue.add(new ReceivedScanCommand(requestID, serialNumber));
+                } else if  (result.getDataCase().equals(PollingStation.ScannedData.DataCase.ERROR)) {
+                    // TODO: Deal with scan errors
+                }
+            }
+
+            @Override
+            public void onFailure(Throwable t) {
+                // TODO: deal with this? When is this called?
+            }
+        });
     }
 
     public void run() {

polling-station/src/main/java/meerkat/pollingstation/PollingStationScannerWebApp.java

@@ -6,6 +6,7 @@ package meerkat.pollingstation;
 
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.protobuf.BoolValue;
+import meerkat.protobuf.Crypto;
 import meerkat.protobuf.PollingStation;
 
 import javax.annotation.PostConstruct;
@@ -17,6 +18,7 @@ import javax.ws.rs.Produces;
 import javax.ws.rs.core.Context;
 import java.io.IOException;
 
+import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_CONNECT_PATH;
 import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_ERROR_PATH;
 import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_SCAN_PATH;
 import static meerkat.rest.Constants.MEDIATYPE_PROTOBUF;
@@ -49,6 +51,15 @@ public class PollingStationScannerWebApp implements PollingStationScanner.Produc
 
     }
 
+    @POST
+    @Path(POLLING_STATION_WEB_SCANNER_CONNECT_PATH)
+    @Consumes(MEDIATYPE_PROTOBUF)
+    @Produces(MEDIATYPE_PROTOBUF)
+    @Override
+    public BoolValue connect(PollingStation.ConnectionClientData clientData) {
+        return null;
+    }
+
     @POST
     @Path(POLLING_STATION_WEB_SCANNER_SCAN_PATH)
     @Consumes(MEDIATYPE_PROTOBUF)
@@ -58,6 +69,7 @@ public class PollingStationScannerWebApp implements PollingStationScanner.Produc
 
         boolean handled = false;
 
+        // TODO:
         for (FutureCallback<PollingStation.ScannedData> callback : callbacks){
 
             callback.onSuccess(scannedData);
@@ -71,26 +83,4 @@ public class PollingStationScannerWebApp implements PollingStationScanner.Produc
 
     }
 
-    @POST
-    @Path(POLLING_STATION_WEB_SCANNER_ERROR_PATH)
-    @Consumes(MEDIATYPE_PROTOBUF)
-    @Produces(MEDIATYPE_PROTOBUF)
-    @Override
-    public BoolValue reportScanError(PollingStation.ErrorMsg errorMsg) {
-
-        boolean handled = false;
-
-        for (FutureCallback<PollingStation.ScannedData> callback : callbacks){
-
-            callback.onFailure(new IOException(errorMsg.getMsg()));
-            handled = true;
-
-        }
-
-        return BoolValue.newBuilder()
-                .setValue(handled)
-                .build();
-
-    }
-
 }

polling-station/src/main/java/meerkat/pollingstation/PollingStationToyRun.java

@@ -1,16 +1,20 @@
 package meerkat.pollingstation;
 
+import meerkat.protobuf.PollingStation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * Created by Laura on 3/20/2017.
  */
 public class PollingStationToyRun {
+    final Logger logger = LoggerFactory.getLogger(getClass());
 
     private static PollingStationScanner.Consumer scanner;
-    private static final String ADDRESS = "http://localhost";
+    private static final String CONTEXT_PATH = "/scan";
-    private static final String SUB_ADDRESS = "";
     private static final int PORT = 8080;
 
-    public static void main(String [] args) {
+    public static void main(String [] args) throws Exception {
         System.err.println("Setting up Scanner WebApp!");
 
 //        scanner = new ReceiverScanHandler(PORT, SUB_ADDRESS);
@@ -22,14 +26,17 @@ public class PollingStationToyRun {
 //                System.err.println("Could not start server: " + e.getMessage());
 //        }
 
-        ReceiverScanHandler serverController = new ReceiverScanHandler(PORT, SUB_ADDRESS);
+        scanner = new PollingStationWebScanner(0, CONTEXT_PATH);
+        PollingStation.ConnectionServerData serverData = scanner.start(false);
+
+
         PollingStationMainController controller = new PollingStationMainController();
-        controller.init(serverController);
+        controller.init(scanner);
 
         Thread controllerThread = new Thread(controller);
         controllerThread.setName("Meerkat PS-Controller Thread");
-        Thread serverThread = new Thread(serverController);
+//        Thread serverThread = new Thread(serverController);
-        serverThread.setName("Meerkat PS-ServerScanner Thread");
+//        serverThread.setName("Meerkat PS-ServerScanner Thread");
 
         controllerThread.start();
         serverThread.start();

polling-station/src/main/java/meerkat/pollingstation/PollingStationWebScanner.java

@@ -1,9 +1,11 @@
 package meerkat.pollingstation;
 
+import java.security.SecureRandom;
 import java.util.List;
 import java.util.LinkedList;
 
 import com.google.common.util.concurrent.FutureCallback;
+import meerkat.protobuf.PollingStation;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.servlet.*;
 
@@ -17,20 +19,22 @@ import meerkat.rest.*;
  * Created by Arbel on 05/05/2016.
  */
 
-public class PollingStationWebScanner implements PollingStationScanner.Consumer{
+public class PollingStationWebScanner implements PollingStationScanner.Consumer {
 
     public final static String CALLBACKS_ATTRIBUTE_NAME = "controller";
 
     private final Server server;
     private final List<FutureCallback<ScannedData>> callbacks;
+    boolean verifyScanner;
+    byte nonce[];
 
-    public PollingStationWebScanner(int port, String subAddress) {
+    public PollingStationWebScanner(int port, String contextPath) {
 
         callbacks = new LinkedList<>();
 
         server = new Server(port);
 
-        ServletContextHandler servletContextHandler = new ServletContextHandler(server, subAddress);
+        ServletContextHandler servletContextHandler = new ServletContextHandler(server, contextPath);
         servletContextHandler.setAttribute(CALLBACKS_ATTRIBUTE_NAME, (Iterable<FutureCallback<ScannedData>>) callbacks);
 
         ResourceConfig resourceConfig = new ResourceConfig(PollingStationScannerWebApp.class);
@@ -42,9 +46,17 @@ public class PollingStationWebScanner implements PollingStationScanner.Consumer{
         servletContextHandler.addServlet(servletHolder, "/*");
     }
 
+
+
     @Override
-    public void start() throws Exception {
+    public PollingStation.ConnectionServerData start(boolean verifyScanner) throws Exception {
+        this.verifyScanner = verifyScanner;
+        nonce = new byte[32];
+        new SecureRandom().nextBytes(nonce);
+
+
         server.start();
+        return null;
     }
 
     @Override

polling-station/src/main/java/meerkat/pollingstation/ReceiverScanHandler.java

@@ -24,7 +24,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 /**
  * Created by Laura on 3/20/2017.
  */
-public class ReceiverScanHandler implements PollingStationScanner.Consumer, Runnable{
+public class ReceiverScanHandler implements PollingStationScanner.Consumer, Runnable {
 
     public final static String CALLBACKS_ATTRIBUTE_NAME = "controller";
 
@@ -78,7 +78,7 @@ public class ReceiverScanHandler implements PollingStationScanner.Consumer, Runn
     }
 
     @Override
-    public void start() throws Exception {
+    public PollingStation.ConnectionServerData start(boolean verifyScanner) throws Exception {
         server.start();
         while (! wasShutDownCalled()) {
             try {

polling-station/src/main/java/meerkat/pollingstation/ReceiverWebAPI.java

@@ -5,6 +5,7 @@ import com.google.protobuf.BoolValue;
 import meerkat.pollingstation.controller.callbacks.ScanCallback;
 import meerkat.pollingstation.controller.callbacks.ScanDataCallback;
 import meerkat.pollingstation.controller.callbacks.ScanErrorCallback;
+import meerkat.protobuf.Crypto;
 import meerkat.protobuf.PollingStation;
 
 import javax.annotation.PostConstruct;
@@ -16,6 +17,7 @@ import javax.ws.rs.Produces;
 import javax.ws.rs.core.Context;
 import java.util.concurrent.LinkedBlockingQueue;
 
+import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_CONNECT_PATH;
 import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_ERROR_PATH;
 import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_SCAN_PATH;
 import static meerkat.rest.Constants.MEDIATYPE_PROTOBUF;
@@ -48,12 +50,37 @@ public class ReceiverWebAPI implements PollingStationScanner.Producer {
 
     }
 
+
+    @POST
+    @Path(POLLING_STATION_WEB_SCANNER_CONNECT_PATH)
+    @Consumes(MEDIATYPE_PROTOBUF)
+    @Produces(MEDIATYPE_PROTOBUF)
+    @Override
+    public BoolValue connect(PollingStation.ConnectionClientData clientData) {
+
+        boolean sent = false;
+
+        try {
+            ScanDataCallback callback = new ScanDataCallback(scannedData);
+
+            callbacks.add(callback);
+            sent = true;
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return BoolValue.newBuilder()
+                .setValue(sent)
+                .build();
+
+    }
+
     @POST
     @Path(POLLING_STATION_WEB_SCANNER_SCAN_PATH)
     @Consumes(MEDIATYPE_PROTOBUF)
     @Produces(MEDIATYPE_PROTOBUF)
     @Override
-    public BoolValue newScan(PollingStation.ScannedData scannedData) {
+    public BoolValue newScan(PollingStation.ScannedData scannedData, Crypto.Signature scannedDataSignature) {
 
         boolean sent = false;
 
@@ -83,7 +110,7 @@ public class ReceiverWebAPI implements PollingStationScanner.Producer {
     @Consumes(MEDIATYPE_PROTOBUF)
     @Produces(MEDIATYPE_PROTOBUF)
     @Override
-    public BoolValue reportScanError(PollingStation.ErrorMsg errorMsg) {
+    public BoolValue reportScanError(PollingStation.ErrorMsg errorMsg, Crypto.Signature errorMsgSignature) {
 
         boolean handled = false;
 
@@ -104,4 +131,5 @@ public class ReceiverWebAPI implements PollingStationScanner.Producer {
 
     }
 
+
 }

polling-station/src/main/java/meerkat/pollingstation/controller/PollingStationControllerInterface.java

@@ -1,6 +1,6 @@
 package meerkat.pollingstation.controller;
 
-import meerkat.pollingstation.ReceiverScanHandler;
+import meerkat.pollingstation.PollingStationScanner;
 
 /**
  * An interface for the controller component of the polling station
@@ -11,12 +11,10 @@ public interface PollingStationControllerInterface extends Runnable {
      * (see VotingBoothController)
      */
     // TODO: 4/16/2017 complete with proper arguments and exceptions
-    public void init(ReceiverScanHandler server);
+    public void init(PollingStationScanner.Consumer server);
 
     /**
      * an asynchronous call from Admin Console (If there is such one implemented) to shut down the system
      */
     public void callShutDown();
-
-
 }

polling-station/src/main/java/meerkat/pollingstation/controller/callbacks/ScanCallback.java

@@ -3,6 +3,6 @@ package meerkat.pollingstation.controller.callbacks;
 /**
  * Created by Laura on 3/20/2017.
  */
-public abstract class ScanCallback {
+public interface ScanCallback {
 
 }

polling-station/src/main/java/meerkat/pollingstation/controller/callbacks/ScanDataCallback.java

@@ -6,7 +6,7 @@ import meerkat.protobuf.PollingStation;
 /**
  * Created by Laura on 3/20/2017.
  */
-public class ScanDataCallback extends ScanCallback implements FutureCallback<PollingStation.ScannedData> {
+public class ScanDataCallback implements ScanCallback, FutureCallback<PollingStation.ScannedData> {
 
     private final PollingStation.ScannedData expectedData;
     private boolean dataIsAsExpected;
@@ -22,7 +22,8 @@ public class ScanDataCallback extends ScanCallback implements FutureCallback<Pol
 
     @Override
     public void onSuccess(PollingStation.ScannedData result) {
-        dataIsAsExpected = result.getChannel().equals(expectedData.getChannel());
+
+        dataIsAsExpected = result.getBallot().getChannel().equals(expectedData.getBallot().getChannel());
     }
 
     @Override

polling-station/src/test/java/meerkat/pollingstation/Receiver_ClientTest.java

@@ -2,6 +2,7 @@ package meerkat.pollingstation;
 
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.protobuf.ByteString;
+import meerkat.protobuf.PollingStation;
 import meerkat.protobuf.PollingStation.ErrorMsg;
 import meerkat.protobuf.PollingStation.ScannedData;
 import meerkat.rest.Constants;
@@ -10,6 +11,8 @@ import meerkat.rest.ProtobufMessageBodyWriter;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.ws.rs.client.Client;
 import javax.ws.rs.client.ClientBuilder;
@@ -24,18 +27,16 @@ import static org.hamcrest.MatcherAssert.assertThat;
 
 
 public class Receiver_ClientTest {
-
+    final Logger logger = LoggerFactory.getLogger(getClass());
     private PollingStationScanner.Consumer scanner;
-    private static final int PSC_PORT = 8880;
+    private static final String CONTEXT_PATH = "/scan";
-    private static final String PSC_HOST = "localhost";
-    private static final String PSC_SCANNER_PATH = "";
-
-    private static final String PSC_URL = "http://" + PSC_HOST + ":" + PSC_PORT + PSC_SCANNER_PATH;
 
     private Semaphore semaphore;
     private Throwable thrown;
     private boolean dataIsAsExpected;
 
+    PollingStation.ConnectionServerData serverData = null;
+
     private class ScanHandler implements FutureCallback<ScannedData> {
 
         private final ScannedData expectedData;
@@ -58,43 +59,26 @@ public class Receiver_ClientTest {
         }
     }
 
-    private class ErrorHandler implements FutureCallback<ScannedData> {
-
-        private final String expectedErrorMessage;
-
-        public ErrorHandler(String expectedErrorMessage) {
-            this.expectedErrorMessage = expectedErrorMessage;
-        }
-
-        @Override
-        public void onSuccess(ScannedData result) {
-            dataIsAsExpected = false;
-            semaphore.release();
-        }
-
-        @Override
-        public void onFailure(Throwable t) {
-            dataIsAsExpected = t.getMessage().equals(expectedErrorMessage);
-            semaphore.release();
-        }
-    }
 
     @Before
     public void init() {
 
         System.err.println("Setting up Scanner WebApp!");
 
-        scanner = new ReceiverScanHandler(PSC_PORT, PSC_SCANNER_PATH);
+        scanner = new PollingStationWebScanner(0, CONTEXT_PATH);
 
         semaphore = new Semaphore(0);
         thrown = null;
 
+        PollingStation.ConnectionServerData serverData = null;
         try {
-            scanner.start();
+            serverData = scanner.start(false);
         } catch (Exception e) {
             assertThat("Could not start server: " + e.getMessage(), false);
         }
 
+        logger.info("Started scanner web service. API endpoint: {}", serverData.getServerUrl());
+
     }
 
     @Test
@@ -103,13 +87,17 @@ public class Receiver_ClientTest {
         byte[] data = {(byte) 1, (byte) 2};
 
         ScannedData scannedData = ScannedData.newBuilder()
-                .setChannel(ByteString.copyFrom(data))
+                .setBallot(PollingStation.ScannedBallot.newBuilder()
+                    .setChannel(ByteString.copyFrom(data))
+                )
                 .build();
 
         scanner.subscribe(new ScanHandler(scannedData));
 
-        ScannerClientAPI scannerClient = new ScannerClientAPI(PSC_URL + POLLING_STATION_WEB_SCANNER_SCAN_PATH);
+        PollingStationScanner.Producer scannerClient = new ScannerClientAPI()
-        scannerClient.sendScan(scannedData);
+
+                ScannerClientAPI(PSC_URL + POLLING_STATION_WEB_SCANNER_SCAN_PATH);
+        scannerClient.newScan(scannedData, null);
 
         semaphore.acquire();
         assertThat("Scanner has thrown an error", thrown == null);
@@ -126,7 +114,10 @@ public class Receiver_ClientTest {
 
         scanner.subscribe(new ErrorHandler(errorMsg.getMsg()));
 
-        ScannerClientAPI scannerClient = new ScannerClientAPI(PSC_URL + POLLING_STATION_WEB_SCANNER_ERROR_PATH);
+        ScannerClientAPI scannerClient = new ScannerClientAPI();
+
+
+        PSC_URL + POLLING_STATION_WEB_SCANNER_ERROR_PATH);
         scannerClient.sendError(errorMsg);
 
         semaphore.acquire();

scanner-api-common/build.gradle

@@ -106,7 +106,6 @@ idea {
 
             def srcDir = "${protobuf.generatedFilesBaseDir}/$sourceSet.name/java"
 
-            println "Adding $srcDir"
             // add protobuf generated sources to generated source dir.
             if ("test".equals(sourceSet.name)) {
                 testSourceDirs += file(srcDir)

scanner-api-common/src/main/java/meerkat/pollingstation/PollingStationConstants.java

@@ -9,5 +9,6 @@ public interface PollingStationConstants {
 
     public static final String POLLING_STATION_WEB_SCANNER_SCAN_PATH = "/scan";
     public static final String POLLING_STATION_WEB_SCANNER_ERROR_PATH = "/error";
+    public static final String POLLING_STATION_WEB_SCANNER_CONNECT_PATH = "/connect";
 
 }

scanner-api-common/src/main/java/meerkat/pollingstation/PollingStationScanner.java

@@ -2,6 +2,7 @@ package meerkat.pollingstation;
 
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.protobuf.BoolValue;
+import meerkat.protobuf.Crypto;
 import meerkat.protobuf.PollingStation.*;
 /**
  * Created by Arbel on 05/05/2016.
@@ -17,10 +18,13 @@ public interface PollingStationScanner {
     public interface Consumer {
 
         /**
-         * Sets up the connection to the scanner and begins receiving scans
+         * Sets up the connection to the scanner and begins receiving scans.
+         * Returns the data the scanner client will need to connect
+         * If verifyScanner is true, will verify that scanner has the correct nonce before
+         * allowing connection, and verify signatures on scanned data.
          * @throws Exception when the operation fails
          */
-        public void start() throws Exception;
+        public ConnectionServerData start(boolean verifyScanner) throws Exception;
 
         /**
          * Closes the connection to the scanner
@@ -34,7 +38,6 @@ public interface PollingStationScanner {
          * @param scanCallback is the handler for scanned data
          */
         public void subscribe(FutureCallback<ScannedData> scanCallback);
-
     }
 
     /**
@@ -42,6 +45,13 @@ public interface PollingStationScanner {
      */
     public interface Producer {
 
+        /**
+         * Connect to the polling station server.
+         * The client data contains the scanner ID and optional verification data.
+         * @return
+         */
+        public BoolValue connect(ConnectionClientData clientData);
+
         /**
          * Sends a scan to all subscribers
          * @param scannedData contains the scanned data
@@ -49,13 +59,6 @@ public interface PollingStationScanner {
          */
         public BoolValue newScan(ScannedData scannedData);
 
-        /**
-         * Notifies subscribers about an error that occurred during scan
-         * @param errorMsg is the error that occurred
-         * @return a BoolValue containing TRUE iff the error has been sent to at least one subscriber
-         */
-        public BoolValue reportScanError(ErrorMsg errorMsg);
-
     }
     
 }

scanner-api-common/src/main/java/meerkat/pollingstation/ScannerClientAPI.java

@@ -1,7 +1,7 @@
 package meerkat.pollingstation;
 
 import com.google.protobuf.BoolValue;
-import meerkat.protobuf.BulletinBoardAPI;
+import meerkat.protobuf.Crypto;
 import meerkat.protobuf.PollingStation;
 import meerkat.rest.Constants;
 import meerkat.rest.ProtobufMessageBodyReader;
@@ -13,13 +13,10 @@ import javax.ws.rs.client.Entity;
 import javax.ws.rs.client.WebTarget;
 import javax.ws.rs.core.Response;
 
-import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_ERROR_PATH;
-import static meerkat.pollingstation.PollingStationConstants.POLLING_STATION_WEB_SCANNER_SCAN_PATH;
-
 /**
  * Created by Laura on 3/20/2017.
  */
-public class ScannerClientAPI {
+public class ScannerClientAPI implements PollingStationScanner.Producer {
     private Client client;
     private WebTarget webTarget;
 
@@ -30,27 +27,38 @@ public class ScannerClientAPI {
         webTarget = client.target(url);
     }
 
+
     /**
      * Sends the scanned data to the polling station server
      * @param scannedData
      * @return boolean value: true if the data was sent successfully, false otherwise
      */
-    public boolean sendScan(PollingStation.ScannedData scannedData) {
+    @Override
-        Response response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(Entity.entity(scannedData, Constants.MEDIATYPE_PROTOBUF));
+    public BoolValue newScan(PollingStation.ScannedData scannedData) {
+
+        Response response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(Entity.entity(scannedData, Constants.MEDIATYPE_PROTOBUF),
+                );
         BoolValue res = response.readEntity(BoolValue.class);
         response.close();
         return res.getValue();
     }
 
-    /**
+
-     * Sends the error message to the polling station server
+    public void close() {
-     * @param errorMsg
+        client.close();
-     * @return boolean value: true if the error message was sent successfully, false otherwise
+
-     */
+    }
-    public boolean sendError(PollingStation.ErrorMsg errorMsg) {
+
-        Response response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(Entity.entity(errorMsg, Constants.MEDIATYPE_PROTOBUF));
+    @Override
-        BoolValue res = response.readEntity(BoolValue.class);
+    public BoolValue connect(PollingStation.ConnectionClientData clientData) {
-        response.close();
+        return null;
-        return res.getValue();
+    }
+
+        return null;
+    }
+
+    @Override
+    public BoolValue reportScanError(PollingStation.ErrorMsg errorMsg, Crypto.Signature errorMsgSignature) {
+        return null;
     }
 }

scanner-api-common/src/main/proto/meerkat/PollingStation.proto

@@ -0,0 +1,54 @@
+syntax = "proto3";
+
+package meerkat;
+
+option java_package = "meerkat.protobuf";
+
+import "meerkat/crypto.proto";
+import "meerkat/voting.proto";
+
+
+
+
+// Data sent (out-of-band) by the server that the client will require to set up a connection
+message ConnectionServerData {
+    // Web-API URL for the server
+    string server_url = 1;
+
+    // random nonce used for verification of the client.
+    bytes nonce = 2;
+}
+
+// Data sent by the client in order to set up a connection
+message ConnectionClientData {
+    // Key used to identify the client
+    SignatureVerificationKey scannerPK = 1;
+
+    // Nonce sent by connection-server
+    bytes nonce = 2;
+}
+
+
+message ScannedBallot {
+    bytes channel = 1;
+
+    SignedEncryptedBallot signed_encrypted_ballot = 2;
+
+}
+
+// Container for error messages
+message ScanError {
+    string msg = 1;
+}
+
+// Container for scanned data
+message ScannedData {
+    oneof data {
+        ScannedBallot ballot = 2;
+        ScanError error = 3;
+    }
+    uint64 serial = 4; // Serial number of the message
+    bytes scannerId = 5; // hash of the scannerPK
+    Signature scannerSig = 6; // signature on the serialzed form of data.
+}
+