java : vaadin : add U2F support ;)

19 files changed, 1150 insertions, 9 deletions

diff --git a/java/vaadin/build.xml b/java/vaadin/build.xml
index 1090e68..712034f 100644
--- a/java/vaadin/build.xml
+++ b/java/vaadin/build.xml
@@ -2,7 +2,7 @@
 <project xmlns:ivy="antlib:org.apache.ivy.ant"
     name="My Vaadin Hello World"
     basedir="."
-    default="war">
+    default="compile.all">
 
     <target name="configure">
         <property file="${basedir}/src/main/resources/Application.properties"/>
@@ -114,6 +114,11 @@
             <compilerarg value="-Xmaxerrs"/>
             <compilerarg value="10"/>
         </javac>
+        <copy todir="${classes.dir}">
+            <fileset dir="${src.dir}">
+                <include name="**/*.js"/>
+            </fileset>
+        </copy>
     </target>
 
     <target name="compile.all" description="compile everything" depends="compile.app,compile.themes"/>
diff --git a/java/vaadin/ivy.xml b/java/vaadin/ivy.xml
index b1a4b3b..81ca70d 100644
--- a/java/vaadin/ivy.xml
+++ b/java/vaadin/ivy.xml
@@ -22,5 +22,6 @@
         <dependency org="org.codehaus.janino" name="janino" rev="3.0.6"/>
         <dependency org="com.yahoo.platform.yui" name="yuicompressor" rev="2.4.8" conf="themes->default"/>
         <dependency org="org.eclipse.jetty" name="jetty-webapp" rev="9.4.2.v20170220" conf="run->default"/>
+        <dependency org="com.yubico" name="u2flib-server-core" rev="0.16.0"/>
     </dependencies>
 </ivy-module>
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_down.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_down.png
new file mode 100644
index 0000000..7e1709f
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_down.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_up.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_up.png
new file mode 100644
index 0000000..cc442d5
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/thumb_up.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-128.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-128.png
new file mode 100644
index 0000000..52d0761
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-128.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-24.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-24.png
new file mode 100644
index 0000000..bd5594a
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-24.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-32.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-32.png
new file mode 100644
index 0000000..78a15c4
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-32.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-64.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-64.png
new file mode 100644
index 0000000..c89c931
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-64.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-lock.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-lock.png
new file mode 100644
index 0000000..7823ff2
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-lock.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo-48.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo-48.png
new file mode 100644
index 0000000..3641de1
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo-48.png
diff --git a/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo.png b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo.png
new file mode 100644
index 0000000..a18234b
--- /dev/null
+++ b/java/vaadin/src/main/WebContent/VAADIN/themes/mytheme/icons/u2f-logo.png
diff --git a/java/vaadin/src/main/java/ch/asynk/security/U2fConnector.java b/java/vaadin/src/main/java/ch/asynk/security/U2fConnector.java
new file mode 100644
index 0000000..24b406d
--- /dev/null
+++ b/java/vaadin/src/main/java/ch/asynk/security/U2fConnector.java
@@ -0,0 +1,164 @@
+package ch.asynk.security;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.vaadin.annotations.JavaScript;
+import com.vaadin.server.AbstractJavaScriptExtension;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.JavaScriptFunction;
+import com.yubico.u2f.U2F;
+import com.yubico.u2f.data.DeviceRegistration;
+import com.yubico.u2f.data.messages.AuthenticateRequestData;
+import com.yubico.u2f.data.messages.AuthenticateResponse;
+import com.yubico.u2f.data.messages.RegisterRequestData;
+import com.yubico.u2f.data.messages.RegisterResponse;
+import com.yubico.u2f.exceptions.DeviceCompromisedException;
+import com.yubico.u2f.exceptions.NoEligibleDevicesException;
+import elemental.json.JsonArray;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@JavaScript({"u2f-api.js", "u2f_connector.js"})
+public class U2fConnector extends AbstractJavaScriptExtension
+{
+    private static final long serialVersionUID = 1L;
+
+    private static final Logger logger = LoggerFactory.getLogger(U2fConnector.class);
+
+    // appId MUST match the URL  - https://developers.yubico.com/U2F/App_ID.html
+    private final String appId = "https://localhost:8666";
+
+    private final U2F u2f = new U2F();
+    // private final U2F u2f = U2F.withoutAppIdValidation();
+
+    // https://developers.yubico.com/U2F/Libraries/Client_error_codes.html
+    private static String U2F_ERRORS[] = {"","OTHER_ERROR","BAD_REQUEST","CONFIGURATION_UNSUPPORTED","DEVICE_INELIGIBLE","TIMEOUT","DEVICE_COMPROMISED"};
+    public String getErrorMsg(int i) { return U2F_ERRORS[i]; }
+
+    private final U2fService u2fService = new U2fServiceImpl();
+
+    class Request
+    {
+        String userId;
+        String data;
+        U2fListener listener;
+        public Request(String userId, String data, U2fListener listener)
+        {
+            this.userId = userId;
+            this.data = data;
+            this.listener = listener;
+        }
+    }
+
+    private final Map<String, Request> requests = new HashMap<>();
+
+    public enum U2fAction {
+        REGISTRATION_PENDING,
+        REGISTRATION_SUCCESS,
+        REGISTRATION_FAILURE,
+        AUTHENTICATION_PENDING,
+        AUTHENTICATION_FAILURE,
+        AUTHENTICATION_SUCCESS
+    };
+
+    public interface U2fListener
+    {
+        public void u2fCallback(U2fAction action, String msg);
+    }
+
+    public U2fConnector() {
+        extend(UI.getCurrent());
+        addFunction("onRegisterResponse", new JavaScriptFunction() {
+            private static final long serialVersionUID = 1L;
+            @Override
+            public void call(final JsonArray arguments) {
+                onRegisterResponse(arguments);
+            }
+        });
+        addFunction("onAuthenticateResponse", new JavaScriptFunction() {
+            private static final long serialVersionUID = 1L;
+            @Override
+            public void call(final JsonArray arguments) {
+                onAuthenticateResponse(arguments);
+            }
+        });
+    }
+
+    public void sendRegisterRequest(final String userId, final U2fListener listener)
+    {
+        final RegisterRequestData registerRequestData = u2f.startRegistration(appId, u2fService.getDeviceRegistrations(userId));
+        final String registerRequestDataJson = registerRequestData.toJson();
+        final String registerRequestDataId = registerRequestData.getRequestId();
+        requests.put(registerRequestDataId, new Request(userId, registerRequestDataJson, listener));
+        callFunction("register", registerRequestDataJson);
+        listener.u2fCallback(U2fAction.REGISTRATION_PENDING, null);
+        logger.debug(String.format("register[%s] : %s", userId, registerRequestDataJson));
+    }
+
+    public void onRegisterResponse(JsonArray arguments)
+    {
+        if (arguments.get(0) instanceof elemental.json.impl.JreJsonNumber) {
+            int errorCode = (int) arguments.getNumber(0);
+            // FIXME why does it not work ??
+            // final RegisterRequestData registerRequestData = RegisterRequestData.fromJson(arguments.getString(1));
+            final String registerRequestDataJson = arguments.getObject(1).toString();
+            final RegisterRequestData registerRequestData = RegisterRequestData.fromJson(registerRequestDataJson);
+            final Request request = requests.remove(registerRequestData.getRequestId());
+            request.listener.u2fCallback(U2fAction.REGISTRATION_FAILURE, getErrorMsg(errorCode));
+            logger.debug(String.format("failure[%d] : %s", errorCode, registerRequestDataJson));
+        } else {
+            final String registerResponseJson = arguments.getString(0);
+            final RegisterResponse registerResponse = RegisterResponse.fromJson(registerResponseJson);
+            final Request request = requests.remove(registerResponse.getRequestId());
+            final RegisterRequestData registerRequestData = RegisterRequestData.fromJson(request.data);
+            u2fService.addDeviceRegistration(request.userId, u2f.finishRegistration(registerRequestData, registerResponse));
+            request.listener.u2fCallback(U2fAction.REGISTRATION_SUCCESS, null);
+            logger.debug(String.format("success : %s", registerResponseJson));
+        }
+    }
+
+    public void startAuthentication(final String userId, final U2fListener listener)
+    {
+        try {
+            final AuthenticateRequestData authenticateRequestData = u2f.startAuthentication(appId, u2fService.getDeviceRegistrations(userId));
+            final String authenticateRequestDataJson = authenticateRequestData.toJson();
+            final String authenticateRequestDataId = authenticateRequestData.getRequestId();
+            requests.put(authenticateRequestDataId, new Request(userId, authenticateRequestDataJson, listener));
+            callFunction("authenticate", authenticateRequestDataJson, userId);
+            listener.u2fCallback(U2fAction.AUTHENTICATION_PENDING, null);
+            logger.debug(String.format("authenticate[%s] : %s", userId, authenticateRequestDataJson));
+        } catch (NoEligibleDevicesException e) {
+            listener.u2fCallback(U2fAction.AUTHENTICATION_FAILURE, getErrorMsg(4));
+        }
+    }
+
+    public void onAuthenticateResponse(JsonArray arguments)
+    {
+        if (arguments.get(0) instanceof elemental.json.impl.JreJsonNumber) {
+            int errorCode = (int) arguments.getNumber(0);
+            // FIXME why does it not work ??
+            // final AuthenticateRequestData authenticateRequestData = AuthenticateRequestData.fromJson(arguments.getString(1));
+            final String authenticateRequestDataJson = arguments.getObject(1).toString();
+            final AuthenticateRequestData authenticateRequestData = AuthenticateRequestData.fromJson(authenticateRequestDataJson);
+            final Request request = requests.remove(authenticateRequestData.getRequestId());
+            request.listener.u2fCallback(U2fAction.AUTHENTICATION_FAILURE, getErrorMsg(errorCode));
+            logger.debug(String.format("failure[%d] : %s", errorCode, authenticateRequestDataJson));
+        } else {
+            final String authenticateResponseJson = arguments.getString(0);
+            final AuthenticateResponse authenticateResponse = AuthenticateResponse.fromJson(authenticateResponseJson);
+            final Request request = requests.remove(authenticateResponse.getRequestId());
+            final AuthenticateRequestData authenticateRequestData = AuthenticateRequestData.fromJson(request.data);
+            DeviceRegistration registration = null;
+            try {
+                registration = u2f.finishAuthentication(authenticateRequestData, authenticateResponse, u2fService.getDeviceRegistrations(request.userId));
+            } catch (final DeviceCompromisedException e) {
+                request.listener.u2fCallback(U2fAction.AUTHENTICATION_FAILURE, getErrorMsg(6));
+                logger.error(String.format("device compromised: %s", request.data));
+            }
+            request.listener.u2fCallback(U2fAction.AUTHENTICATION_SUCCESS, null);
+            logger.debug(String.format("success : %s", authenticateResponseJson));
+        }
+    }
+}
diff --git a/java/vaadin/src/main/java/ch/asynk/security/U2fService.java b/java/vaadin/src/main/java/ch/asynk/security/U2fService.java
new file mode 100644
index 0000000..9bce94e
--- /dev/null
+++ b/java/vaadin/src/main/java/ch/asynk/security/U2fService.java
@@ -0,0 +1,12 @@
+package ch.asynk.security;
+
+import java.util.List;
+
+import com.yubico.u2f.data.DeviceRegistration;
+
+public interface U2fService
+{
+    public boolean hasDeviceRegistrations(final String userId);
+    public List<DeviceRegistration> getDeviceRegistrations(final String userId);
+    public void addDeviceRegistration(final String userId, final DeviceRegistration deviceRegistration);
+}
diff --git a/java/vaadin/src/main/java/ch/asynk/security/U2fServiceImpl.java b/java/vaadin/src/main/java/ch/asynk/security/U2fServiceImpl.java
new file mode 100644
index 0000000..f8e785f
--- /dev/null
+++ b/java/vaadin/src/main/java/ch/asynk/security/U2fServiceImpl.java
@@ -0,0 +1,43 @@
+package ch.asynk.security;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.yubico.u2f.data.DeviceRegistration;
+
+public class U2fServiceImpl implements U2fService
+{
+    private HashMap<String, List<DeviceRegistration>> store;
+
+    public U2fServiceImpl()
+    {
+        store = new HashMap<String, List<DeviceRegistration>>();
+    }
+
+    public boolean hasDeviceRegistrations(final String userId)
+    {
+        return store.containsKey(userId);
+    }
+
+    public List<DeviceRegistration> getDeviceRegistrations(final String userId)
+    {
+        return get(userId);
+    }
+
+    public void addDeviceRegistration(final String userId, final DeviceRegistration deviceRegistration)
+    {
+        List<DeviceRegistration> registrations = get(userId);
+        registrations.add(deviceRegistration);
+        store.put(userId, registrations);
+    }
+
+    private List<DeviceRegistration> get(final String userId)
+    {
+        List<DeviceRegistration> registrations = store.get(userId);
+        if (registrations == null)
+            registrations = new ArrayList<DeviceRegistration>();
+        return registrations;
+    }
+}
diff --git a/java/vaadin/src/main/java/ch/asynk/security/u2f-api.js b/java/vaadin/src/main/java/ch/asynk/security/u2f-api.js
new file mode 100644
index 0000000..9244d14
--- /dev/null
+++ b/java/vaadin/src/main/java/ch/asynk/security/u2f-api.js
@@ -0,0 +1,748 @@
+//Copyright 2014-2015 Google Inc. All rights reserved.
+
+//Use of this source code is governed by a BSD-style
+//license that can be found in the LICENSE file or at
+//https://developers.google.com/open-source/licenses/bsd
+
+/**
+ * @fileoverview The U2F api.
+ */
+'use strict';
+
+
+/**
+ * Namespace for the U2F api.
+ * @type {Object}
+ */
+var u2f = u2f || {};
+
+/**
+ * FIDO U2F Javascript API Version
+ * @number
+ */
+var js_api_version;
+
+/**
+ * The U2F extension id
+ * @const {string}
+ */
+// The Chrome packaged app extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the package Chrome app and does not require installing the U2F Chrome extension.
+ u2f.EXTENSION_ID = 'kmendfapggjehodndflmmgagdbamhnfd';
+// The U2F Chrome extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the U2F Chrome extension to authenticate.
+// u2f.EXTENSION_ID = 'pfboblefjcgdjicmnffhdgionmgcdmne';
+
+
+/**
+ * Message types for messsages to/from the extension
+ * @const
+ * @enum {string}
+ */
+u2f.MessageTypes = {
+    'U2F_REGISTER_REQUEST': 'u2f_register_request',
+    'U2F_REGISTER_RESPONSE': 'u2f_register_response',
+    'U2F_SIGN_REQUEST': 'u2f_sign_request',
+    'U2F_SIGN_RESPONSE': 'u2f_sign_response',
+    'U2F_GET_API_VERSION_REQUEST': 'u2f_get_api_version_request',
+    'U2F_GET_API_VERSION_RESPONSE': 'u2f_get_api_version_response'
+};
+
+
+/**
+ * Response status codes
+ * @const
+ * @enum {number}
+ */
+u2f.ErrorCodes = {
+    'OK': 0,
+    'OTHER_ERROR': 1,
+    'BAD_REQUEST': 2,
+    'CONFIGURATION_UNSUPPORTED': 3,
+    'DEVICE_INELIGIBLE': 4,
+    'TIMEOUT': 5
+};
+
+
+/**
+ * A message for registration requests
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   appId: ?string,
+ *   timeoutSeconds: ?number,
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fRequest;
+
+
+/**
+ * A message for registration responses
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   responseData: (u2f.Error | u2f.RegisterResponse | u2f.SignResponse),
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fResponse;
+
+
+/**
+ * An error object for responses
+ * @typedef {{
+ *   errorCode: u2f.ErrorCodes,
+ *   errorMessage: ?string
+ * }}
+ */
+u2f.Error;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {enum {BLUETOOTH_RADIO, BLUETOOTH_LOW_ENERGY, USB, NFC}}
+ */
+u2f.Transport;
+
+
+/**
+ * Data object for a single sign request.
+ * @typedef {Array<u2f.Transport>}
+ */
+u2f.Transports;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string,
+ *   keyHandle: string,
+ *   appId: string
+ * }}
+ */
+u2f.SignRequest;
+
+
+/**
+ * Data object for a sign response.
+ * @typedef {{
+ *   keyHandle: string,
+ *   signatureData: string,
+ *   clientData: string
+ * }}
+ */
+u2f.SignResponse;
+
+
+/**
+ * Data object for a registration request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string
+ * }}
+ */
+u2f.RegisterRequest;
+
+
+/**
+ * Data object for a registration response.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: Transports,
+ *   appId: string
+ * }}
+ */
+u2f.RegisterResponse;
+
+
+/**
+ * Data object for a registered key.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: ?Transports,
+ *   appId: ?string
+ * }}
+ */
+u2f.RegisteredKey;
+
+
+/**
+ * Data object for a get API register response.
+ * @typedef {{
+ *   js_api_version: number
+ * }}
+ */
+u2f.GetJsApiVersionResponse;
+
+
+//Low level MessagePort API support
+
+/**
+ * Sets up a MessagePort to the U2F extension using the
+ * available mechanisms.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ */
+u2f.getMessagePort = function(callback) {
+  if (typeof chrome != 'undefined' && chrome.runtime) {
+    // The actual message here does not matter, but we need to get a reply
+    // for the callback to run. Thus, send an empty signature request
+    // in order to get a failure response.
+    var msg = {
+        type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+        signRequests: []
+    };
+    chrome.runtime.sendMessage(u2f.EXTENSION_ID, msg, function() {
+      if (!chrome.runtime.lastError) {
+        // We are on a whitelisted origin and can talk directly
+        // with the extension.
+        u2f.getChromeRuntimePort_(callback);
+      } else {
+        // chrome.runtime was available, but we couldn't message
+        // the extension directly, use iframe
+        u2f.getIframePort_(callback);
+      }
+    });
+  } else if (u2f.isAndroidChrome_()) {
+    u2f.getAuthenticatorPort_(callback);
+  } else if (u2f.isIosChrome_()) {
+    u2f.getIosPort_(callback);
+  } else {
+    // chrome.runtime was not available at all, which is normal
+    // when this origin doesn't have access to any extensions.
+    u2f.getIframePort_(callback);
+  }
+};
+
+/**
+ * Detect chrome running on android based on the browser's useragent.
+ * @private
+ */
+u2f.isAndroidChrome_ = function() {
+  var userAgent = navigator.userAgent;
+  return userAgent.indexOf('Chrome') != -1 &&
+  userAgent.indexOf('Android') != -1;
+};
+
+/**
+ * Detect chrome running on iOS based on the browser's platform.
+ * @private
+ */
+u2f.isIosChrome_ = function() {
+  return ["iPhone", "iPad", "iPod"].indexOf(navigator.platform) > -1;
+};
+
+/**
+ * Connects directly to the extension via chrome.runtime.connect.
+ * @param {function(u2f.WrappedChromeRuntimePort_)} callback
+ * @private
+ */
+u2f.getChromeRuntimePort_ = function(callback) {
+  var port = chrome.runtime.connect(u2f.EXTENSION_ID,
+      {'includeTlsChannelId': true});
+  setTimeout(function() {
+    callback(new u2f.WrappedChromeRuntimePort_(port));
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the Authenticator app.
+ * @param {function(u2f.WrappedAuthenticatorPort_)} callback
+ * @private
+ */
+u2f.getAuthenticatorPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedAuthenticatorPort_());
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the iOS client app.
+ * @param {function(u2f.WrappedIosPort_)} callback
+ * @private
+ */
+u2f.getIosPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedIosPort_());
+  }, 0);
+};
+
+/**
+ * A wrapper for chrome.runtime.Port that is compatible with MessagePort.
+ * @param {Port} port
+ * @constructor
+ * @private
+ */
+u2f.WrappedChromeRuntimePort_ = function(port) {
+  this.port_ = port;
+};
+
+/**
+ * Format and return a sign request compliant with the JS API version supported by the extension.
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatSignRequest_ =
+  function(appId, challenge, registeredKeys, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: challenge,
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+      signRequests: signRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+    appId: appId,
+    challenge: challenge,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+/**
+ * Format and return a register request compliant with the JS API version supported by the extension..
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {Array<u2f.RegisterRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatRegisterRequest_ =
+  function(appId, registeredKeys, registerRequests, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    for (var i = 0; i < registerRequests.length; i++) {
+      registerRequests[i].appId = appId;
+    }
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: registerRequests[0],
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+      signRequests: signRequests,
+      registerRequests: registerRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+    appId: appId,
+    registerRequests: registerRequests,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+
+/**
+ * Posts a message on the underlying channel.
+ * @param {Object} message
+ */
+u2f.WrappedChromeRuntimePort_.prototype.postMessage = function(message) {
+  this.port_.postMessage(message);
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface. Works only for the
+ * onmessage event, which is hooked up to the chrome.runtime.Port.onMessage.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedChromeRuntimePort_.prototype.addEventListener =
+    function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message' || name == 'onmessage') {
+    this.port_.onMessage.addListener(function(message) {
+      // Emulate a minimal MessageEvent object
+      handler({'data': message});
+    });
+  } else {
+    console.error('WrappedChromeRuntimePort only supports onMessage');
+  }
+};
+
+/**
+ * Wrap the Authenticator app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_ = function() {
+  this.requestId_ = -1;
+  this.requestObject_ = null;
+}
+
+/**
+ * Launch the Authenticator intent.
+ * @param {Object} message
+ */
+u2f.WrappedAuthenticatorPort_.prototype.postMessage = function(message) {
+  var intentUrl =
+    u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ +
+    ';S.request=' + encodeURIComponent(JSON.stringify(message)) +
+    ';end';
+  document.location = intentUrl;
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedAuthenticatorPort_.prototype.getPortType = function() {
+  return "WrappedAuthenticatorPort_";
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedAuthenticatorPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message') {
+    var self = this;
+    /* Register a callback to that executes when
+     * chrome injects the response. */
+    window.addEventListener(
+        'message', self.onRequestUpdate_.bind(self, handler), false);
+  } else {
+    console.error('WrappedAuthenticatorPort only supports message');
+  }
+};
+
+/**
+ * Callback invoked  when a response is received from the Authenticator.
+ * @param function({data: Object}) callback
+ * @param {Object} message message Object
+ */
+u2f.WrappedAuthenticatorPort_.prototype.onRequestUpdate_ =
+    function(callback, message) {
+  var messageObject = JSON.parse(message.data);
+  var intentUrl = messageObject['intentURL'];
+
+  var errorCode = messageObject['errorCode'];
+  var responseObject = null;
+  if (messageObject.hasOwnProperty('data')) {
+    responseObject = /** @type {Object} */ (
+        JSON.parse(messageObject['data']));
+  }
+
+  callback({'data': responseObject});
+};
+
+/**
+ * Base URL for intents to Authenticator.
+ * @const
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ =
+  'intent:#Intent;action=com.google.android.apps.authenticator.AUTHENTICATE';
+
+/**
+ * Wrap the iOS client app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedIosPort_ = function() {};
+
+/**
+ * Launch the iOS client app request
+ * @param {Object} message
+ */
+u2f.WrappedIosPort_.prototype.postMessage = function(message) {
+  var str = JSON.stringify(message);
+  var url = "u2f://auth?" + encodeURI(str);
+  location.replace(url);
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedIosPort_.prototype.getPortType = function() {
+  return "WrappedIosPort_";
+};
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedIosPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name !== 'message') {
+    console.error('WrappedIosPort only supports message');
+  }
+};
+
+/**
+ * Sets up an embedded trampoline iframe, sourced from the extension.
+ * @param {function(MessagePort)} callback
+ * @private
+ */
+u2f.getIframePort_ = function(callback) {
+  // Create the iframe
+  var iframeOrigin = 'chrome-extension://' + u2f.EXTENSION_ID;
+  var iframe = document.createElement('iframe');
+  iframe.src = iframeOrigin + '/u2f-comms.html';
+  iframe.setAttribute('style', 'display:none');
+  document.body.appendChild(iframe);
+
+  var channel = new MessageChannel();
+  var ready = function(message) {
+    if (message.data == 'ready') {
+      channel.port1.removeEventListener('message', ready);
+      callback(channel.port1);
+    } else {
+      console.error('First event on iframe port was not "ready"');
+    }
+  };
+  channel.port1.addEventListener('message', ready);
+  channel.port1.start();
+
+  iframe.addEventListener('load', function() {
+    // Deliver the port to the iframe and initialize
+    iframe.contentWindow.postMessage('init', iframeOrigin, [channel.port2]);
+  });
+};
+
+
+//High-level JS API
+
+/**
+ * Default extension response timeout in seconds.
+ * @const
+ */
+u2f.EXTENSION_TIMEOUT_SEC = 30;
+
+/**
+ * A singleton instance for a MessagePort to the extension.
+ * @type {MessagePort|u2f.WrappedChromeRuntimePort_}
+ * @private
+ */
+u2f.port_ = null;
+
+/**
+ * Callbacks waiting for a port
+ * @type {Array<function((MessagePort|u2f.WrappedChromeRuntimePort_))>}
+ * @private
+ */
+u2f.waitingForPort_ = [];
+
+/**
+ * A counter for requestIds.
+ * @type {number}
+ * @private
+ */
+u2f.reqCounter_ = 0;
+
+/**
+ * A map from requestIds to client callbacks
+ * @type {Object.<number,(function((u2f.Error|u2f.RegisterResponse))
+ *                       |function((u2f.Error|u2f.SignResponse)))>}
+ * @private
+ */
+u2f.callbackMap_ = {};
+
+/**
+ * Creates or retrieves the MessagePort singleton to use.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ * @private
+ */
+u2f.getPortSingleton_ = function(callback) {
+  if (u2f.port_) {
+    callback(u2f.port_);
+  } else {
+    if (u2f.waitingForPort_.length == 0) {
+      u2f.getMessagePort(function(port) {
+        u2f.port_ = port;
+        u2f.port_.addEventListener('message',
+            /** @type {function(Event)} */ (u2f.responseHandler_));
+
+        // Careful, here be async callbacks. Maybe.
+        while (u2f.waitingForPort_.length)
+          u2f.waitingForPort_.shift()(u2f.port_);
+      });
+    }
+    u2f.waitingForPort_.push(callback);
+  }
+};
+
+/**
+ * Handles response messages from the extension.
+ * @param {MessageEvent.<u2f.Response>} message
+ * @private
+ */
+u2f.responseHandler_ = function(message) {
+  var response = message.data;
+  var reqId = response['requestId'];
+  if (!reqId || !u2f.callbackMap_[reqId]) {
+    console.error('Unknown or missing requestId in response.');
+    return;
+  }
+  var cb = u2f.callbackMap_[reqId];
+  delete u2f.callbackMap_[reqId];
+  cb(response['responseData']);
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the sign request.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sign = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual sign request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0 : response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual sign request in the supported API version.
+    u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendSignRequest = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatSignRequest_(appId, challenge, registeredKeys, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the register request.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.register = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual register request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0: response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+              callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual register request in the supported API version.
+    u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+        callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendRegisterRequest = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatRegisterRequest_(
+        appId, registeredKeys, registerRequests, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+
+/**
+ * Dispatches a message to the extension to find out the supported
+ * JS API version.
+ * If the user is on a mobile phone and is thus using Google Authenticator instead
+ * of the Chrome extension, don't send the request and simply return 0.
+ * @param {function((u2f.Error|u2f.GetJsApiVersionResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.getApiVersion = function(callback, opt_timeoutSeconds) {
+ u2f.getPortSingleton_(function(port) {
+   // If we are using Android Google Authenticator or iOS client app,
+   // do not fire an intent to ask which JS API version to use.
+   if (port.getPortType) {
+     var apiVersion;
+     switch (port.getPortType()) {
+       case 'WrappedIosPort_':
+       case 'WrappedAuthenticatorPort_':
+         apiVersion = 1.1;
+         break;
+
+       default:
+         apiVersion = 0;
+         break;
+     }
+     callback({ 'js_api_version': apiVersion });
+     return;
+   }
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var req = {
+      type: u2f.MessageTypes.U2F_GET_API_VERSION_REQUEST,
+      timeoutSeconds: (typeof opt_timeoutSeconds !== 'undefined' ?
+          opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC),
+      requestId: reqId
+    };
+    port.postMessage(req);
+  });
+};
diff --git a/java/vaadin/src/main/java/ch/asynk/security/u2f_connector.js b/java/vaadin/src/main/java/ch/asynk/security/u2f_connector.js
new file mode 100644
index 0000000..8723cb3
--- /dev/null
+++ b/java/vaadin/src/main/java/ch/asynk/security/u2f_connector.js
@@ -0,0 +1,30 @@
+window.ch_asynk_security_U2fConnector = function() {
+
+    var connector = this;
+
+    this.register = function(requestJson) {
+        var request = JSON.parse(requestJson);
+        // alert(JSON.stringify(request));
+        setTimeout(function() {
+            u2f.register(request.registerRequests, request.authenticateRequests, function(data) {
+                if(data.errorCode)
+                    connector.onRegisterResponse(data.errorCode, request);
+                else
+                    connector.onRegisterResponse(JSON.stringify(data));
+            });
+        }, 500);
+    }
+
+    this.authenticate = function(requestJson) {
+        var request = JSON.parse(requestJson);
+        //alert(JSON.stringify(request));
+        setTimeout(function() {
+            u2f.sign(request.authenticateRequests, function(data) {
+                if(data.errorCode)
+                    connector.onAuthenticateResponse(data.errorCode, request);
+                else
+                    connector.onAuthenticateResponse(JSON.stringify(data));
+            });
+        }, 500);
+    }
+}
diff --git a/java/vaadin/src/main/java/ch/asynk/ui/Icons.java b/java/vaadin/src/main/java/ch/asynk/ui/Icons.java
index 98bfb5f..3cc96bc 100644
--- a/java/vaadin/src/main/java/ch/asynk/ui/Icons.java
+++ b/java/vaadin/src/main/java/ch/asynk/ui/Icons.java
@@ -6,4 +6,13 @@ public class Icons
 {
     public static final ThemeResource help = new ThemeResource("icons/help.png");
     public static final ThemeResource home = new ThemeResource("icons/home.png");
+    public static final ThemeResource u2f128 = new ThemeResource("icons/u2f-128.png");
+    public static final ThemeResource u2f64 = new ThemeResource("icons/u2f-64.png");
+    public static final ThemeResource u2f32 = new ThemeResource("icons/u2f-32.png");
+    public static final ThemeResource u2f24 = new ThemeResource("icons/u2f-24.png");
+    public static final ThemeResource u2flogo = new ThemeResource("icons/u2f-logo.png");
+    public static final ThemeResource u2flogo48 = new ThemeResource("icons/u2f-logo-48.png");
+    public static final ThemeResource u2flock = new ThemeResource("icons/u2f-lock.png");
+    public static final ThemeResource thumbUp = new ThemeResource("icons/thumb_up.png");
+    public static final ThemeResource thumbDown = new ThemeResource("icons/thumb_down.png");
 }
diff --git a/java/vaadin/src/main/java/ch/asynk/ui/ViewMain.java b/java/vaadin/src/main/java/ch/asynk/ui/ViewMain.java
index 489e328..66ef64f 100644
--- a/java/vaadin/src/main/java/ch/asynk/ui/ViewMain.java
+++ b/java/vaadin/src/main/java/ch/asynk/ui/ViewMain.java
@@ -1,20 +1,43 @@
 package ch.asynk.ui;
 
+import com.vaadin.data.validator.RegexpValidator;
 import com.vaadin.navigator.View;
 import com.vaadin.navigator.ViewChangeListener.ViewChangeEvent;
+import com.vaadin.server.Page;
+import com.vaadin.ui.Alignment;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.Image;
 import com.vaadin.ui.Label;
+import com.vaadin.ui.Notification;
+import com.vaadin.ui.Panel;
 import com.vaadin.ui.TabSheet;
+import com.vaadin.ui.TextField;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.GridLayout;
 import com.vaadin.ui.VerticalLayout;
+import com.vaadin.ui.Window;
 
-public class ViewMain extends TabSheet implements View
+import ch.asynk.security.U2fConnector;
+
+public class ViewMain extends TabSheet implements View, U2fConnector.U2fListener
 {
     private static final long serialVersionUID = 1L;
 
+    private static final String U2F_TITLE = "FIDO U2F (Universal 2nd factor)";
+
+    private final Window u2fWindow;
+    private final U2fConnector u2fConnector;
+
+    private enum Action { U2F_REGISTER, U2F_AUTHENTICATE }
+
     public ViewMain()
     {
+        u2fWindow = u2fWindow();
+        u2fConnector = new U2fConnector();
         addStyleName("framed");
-        addTab(content("0"), "Tab 0", Icons.home, 0);
-        addTab(content("1"), "Tab 1");
+        addTab(u2fComponent("register", Action.U2F_REGISTER), "Register", Icons.u2flogo48);
+        addTab(u2fComponent("authenticate", Action.U2F_AUTHENTICATE), "Authenticate", Icons.u2f32);
         setSelectedTab(2);
     }
 
@@ -29,4 +52,110 @@ public class ViewMain extends TabSheet implements View
         ly.addComponent(new Label(" Hi, this is " + s));
         return ly;
     }
+
+    private Component u2fComponent(final String title, Action action)
+    {
+        final TextField tf = new TextField();
+        tf.setRequired(true);
+        tf.setInputPrompt("username");
+        tf.addValidator(new RegexpValidator("^(?=.{6,20}$)[a-zA-Z][a-zA-Z0-9#@.]+[a-zA-Z]$", "invalid username"));
+
+        final ViewMain instance = this;
+        final Button bt = new Button(title.toLowerCase());
+        bt.addClickListener(new Button.ClickListener() {
+            private static final long serialVersionUID = 1L;
+            @Override
+            public void buttonClick(Button.ClickEvent event) {
+                try {
+                    tf.validate();
+                    String userId = tf.getValue();
+                    tf.setValue("");
+                    if (action == Action.U2F_REGISTER)
+                        u2fConnector.sendRegisterRequest(userId, instance);
+                    else if (action == Action.U2F_AUTHENTICATE)
+                        u2fConnector.startAuthentication(userId, instance);
+                } catch (com.yubico.u2f.exceptions.U2fBadConfigurationException e) {
+                    Notification.show(U2F_TITLE, e.getMessage(), Notification.Type.ERROR_MESSAGE);
+                } catch (Exception e) {
+                    Notification.show("invalid user name");
+                }
+            }
+        });
+
+        Panel panel = new Panel(title);
+        panel.setWidth("450px");
+        final GridLayout ly = new GridLayout(2,2);
+        ly.setMargin(true);
+        ly.setSpacing(true);
+        panel.setContent(ly);
+        ly.addComponent(new Image(null, Icons.u2flock), 0, 0, 0, 1);
+        ly.addComponent(tf, 1, 0);
+        ly.addComponent(bt,1,1);
+        ly.setComponentAlignment(bt, Alignment.MIDDLE_CENTER);
+
+        VerticalLayout vl = new VerticalLayout();
+        vl.setMargin(true);
+        vl.setSizeFull();
+        vl.addComponent(panel);
+        vl.setComponentAlignment(panel, Alignment.MIDDLE_CENTER);
+        return vl;
+    }
+
+    public void u2fCallback(U2fConnector.U2fAction action, String msg)
+    {
+        Notification n = null;
+        switch (action) {
+            case REGISTRATION_PENDING:
+            case AUTHENTICATION_PENDING:
+                UI.getCurrent().addWindow(u2fWindow);
+                break;
+            case REGISTRATION_SUCCESS:
+                msg = "Your token has been successfully registred.";
+                break;
+            case REGISTRATION_FAILURE:
+                msg = "Registration failed with error : " + msg;
+                break;
+            case AUTHENTICATION_SUCCESS:
+                msg = "You have been successfully authenticated.";
+                break;
+            case AUTHENTICATION_FAILURE:
+                msg = "Authentication failed with error : " + msg;
+                break;
+        }
+        switch (action) {
+            case REGISTRATION_SUCCESS:
+            case AUTHENTICATION_SUCCESS:
+                n = new Notification(U2F_TITLE, msg, Notification.Type.HUMANIZED_MESSAGE);
+                n.setIcon(Icons.thumbUp);
+                break;
+            case REGISTRATION_FAILURE:
+            case AUTHENTICATION_FAILURE:
+                n = new Notification(U2F_TITLE, msg, Notification.Type.ERROR_MESSAGE);
+                n.setIcon(Icons.thumbDown);
+                break;
+        }
+        if (n != null) {
+            n.setDelayMsec(5000);
+            u2fWindow.close();
+            n.show(Page.getCurrent());
+        }
+    }
+
+    private Window u2fWindow()
+    {
+        Window w = new Window(U2F_TITLE);
+        final VerticalLayout vy = new VerticalLayout();
+        vy.setMargin(true);
+        vy.setSpacing(true);
+        vy.addComponent(new Label("Insert your u2f token and click on it."));
+        vy.addComponent(new Image(null, Icons.u2flock));
+        w.setModal(true);
+        w.setClosable(false);
+        w.setContent(vy);
+        w.setResizable(false);
+        w.setWidth("280px");
+        w.setHeight("220px");
+        w.center();
+        return w;
+    }
 }
diff --git a/java/vaadin/src/run/java/ch/asynk/Main.java b/java/vaadin/src/run/java/ch/asynk/Main.java
index 222fccb..005ac9c 100644
--- a/java/vaadin/src/run/java/ch/asynk/Main.java
+++ b/java/vaadin/src/run/java/ch/asynk/Main.java
@@ -84,7 +84,7 @@ class HttpVaadinJettyServer extends VaadinJettyServer
     @Override
     protected void configure(int port)
     {
-        System.out.println("http://127.0.0.1:" + port + "/hello");
+        System.out.println("http://localhost:" + port + "/hello");
         addConnector(httpConnector(port));
     }
 }
@@ -96,7 +96,7 @@ class HttpsVaadinJettyServer extends VaadinJettyServer
     @Override
     protected void configure(int port)
     {
-        System.out.println("https://127.0.0.1:" + port + "/hello");
+        System.out.println("https://localhost:" + port + "/hello");
         addConnector(httpsConnector(port));
     }
 }
@@ -107,8 +107,8 @@ class HttpHttpsVaadinJettyServer extends HttpsVaadinJettyServer
     @Override
     protected void configure(int port)
     {
-        System.out.println("http://127.0.0.1:" + port + "/hello");
-        System.out.println("https://127.0.0.1:" + (port + 1) + "/hello");
+        System.out.println("http://localhost:" + port + "/hello");
+        System.out.println("https://localhost:" + (port + 1) + "/hello");
         this.setConnectors(new Connector[] { httpConnector(port), httpsConnector(port + 1) });
     }
 }
@@ -121,6 +121,6 @@ public class Main
         String webRoot = System.getProperty("WEBROOT");
         if (webRoot == null) webRoot = "./src/main/WebContent";
 
-        new HttpVaadinJettyServer(port, webRoot).start();
+        new HttpsVaadinJettyServer(port, webRoot).start();
     }
 }