WebBluetoothCG · cmumford · Jul 29, 2021
diff --git a/characteristic_secure_notify/device_code.js b/characteristic_secure_notify/device_code.js
@@ -0,0 +1,115 @@
+/**
+ *  Copyright 2021 Google LLC
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+const data = new Uint32Array([1]);
+const devicePassKey = '141414'; // 6 digit passkey to use.
+let isConnected = false;
+let debug = '?';
+
+function canShowPasskey() {
+  // Without a display this app cannot actually display a passkey, but return
+  // true because this is required in order to pair using passkeys.
+  // http://forum.espruino.com/comments/14922430/
+  return true;
+}
+
+function deviceHasDisplay() {
+  return typeof g !== 'undefined';
+}
+
+function updateScreen() {
+  if (!deviceHasDisplay())
+    return;
+  g.clear();
+  g.setFontBitmap();
+  g.drawString('Current Notify Value:');
+  g.drawString('Connected: ' + isConnected, 0, g.getHeight() - 10);
+  let msg = 'Dbg: ' + debug;
+  g.drawString(msg, g.getWidth() - g.stringWidth(msg), g.getHeight() - 10);
+  g.setFontVector(40);
+  let val = data[0];
+  g.drawString(val, (g.getWidth() - g.stringWidth(val)) / 2, 12);
+
+  g.flip();
+}
+
+function updateValue() {
+  data[0] = data[0] + 1;
+  if (data[0] == 10000) {
+    // Limit to four digits for display on small screens.
+    data[0] = 0;
+  }
+  if (isConnected) {
+    NRF.updateServices({
+      '02fc549a-244c-11eb-adc1-0242ac120002': {
+        '02fc549a-244c-11eb-adc1-0242ac120002':
+            {value: data.buffer, notify: true}
+      }
+    });
+  }
+}
+
+function onInit() {
+  // Put into a known state.
+  digitalWrite(LED, isConnected);
+
+  NRF.setServices({
+    '02fc549a-244c-11eb-adc1-0242ac120002': {
+      '02fc549a-244c-11eb-adc1-0242ac120002': {
+        value: data.buffer,
+        broadcast: false,
+        readable: true,
+        writable: false,
+        notify: true,
+        description: 'Notify characteristic',
+        security: {
+          read: {
+            encrypted: true,  // Encrypt data (default: false).
+            mitm: true        // Man In The Middle (default: false).
+          }
+        }
+      }
+    }
+  });
+
+  NRF.on('disconnect', (reason) => {
+    // Provide feedback that device no longer connected.
+    digitalWrite(LED, 0);
+    isConnected = false;
+    debug = reason;
+    updateScreen();
+  });
+
+  NRF.on('connect', (addr) => {
+    digitalWrite(LED, 1);
+    isConnected = true;
+    debug = addr;
+    updateScreen();
+  });
+
+  NRF.setSecurity({
+    display: canShowPasskey(),  // Can this device display a passkey?
+    keyboard: false,            // Can this device enter a passkey?
+    mitm: true,                 // Man In The Middle protection.
+    passkey: devicePassKey,
+  });
+
+  updateScreen();
+
+  setInterval(updateScreen, 1000);
+  setInterval(updateValue, 40);
+}
+
diff --git a/characteristic_secure_notify/index.html b/characteristic_secure_notify/index.html
@@ -0,0 +1,90 @@
+<!DOCTYPE html>
+<!--
+ Copyright 2021 Google LLC
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+<html>
+
+<head>
+  <meta charset="UTF-8">
+  <title>Bluetooth Secure Characteristic Read w/Notifications</title>
+  <script src="../shared/shared.js"></script>
+  <script src="web_app.js"></script>
+  <link rel="stylesheet" href="../css/main.css">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+</head>
+
+<body onload="init()">
+  <h1>Bluetooth Secure Characteristic Read w/Notifications</h1>
+  <p>This is a simple test to subscribe to secure characteristic value change notifications.
+  </p>
+  <div id="bluetooth_available" style="visibility: visible;">
+    <h2>Step 1</h2>
+    <div class="container">
+      <div class="flex">
+        <div class="inRow">
+          Press the button to load the code to the Espruino IDE.
+          From there flash any Bluetooth capable Espruino device.
+          <br>
+          <br>
+          View <a href="device_code.js" title="Device source code">source</a>.
+        </div>
+        <div class="inRow">
+          <button id="btn_load_code" type="button" onclick="loadEspruinoDeviceCode()">Load Device Code</button>
+        </div>
+      </div>
+    </div>
+
+    <h2>Step 2</h2>
+    <div>
+      <div class="flex">
+        <div class="inRow">
+          Once running, start the test. When prompted for the passcode enter
+          "141414".
+        </div>
+        <div class="inRow">
+          <button id="btn_start_test" type="button" onclick="startTest()">Start Test</button>
+        </div>
+      </div>
+      <div class="flex">
+        <div class="inNote"><b>NOTE:</b></div>
+        <div class="inNote">
+          When re-running this test, this device will likely
+          <b>not</b> prompt for the passcode a second time, as the device is
+          now paired with this host. To force re-prompting for the passcode,
+          access the Bluetooth preferences on this host and forget/unpair
+          the test device.
+        </div>
+      </div>
+    </div>
+
+    <p>Status: <span id='test_result'></span></p>
+    <pre id='status'></pre>
+  </div>
+  <!-- Only one of the three below will be visible. -->
+  <div id="bluetooth_none" class="no-bluetooth" style="visibility: hidden;">
+    Web Bluetooth is not supported by this browser.
+  </div>
+  <div id="bluetooth_insecure" class="no-bluetooth" style="visibility: hidden;">
+    Bluetooth requires a secure context (HTTPS). For development purposes it
+    does support HTTP, but only the on the loopback adapter (i.e. "localhost").
+  </div>
+  <div id="bluetooth_unavailable" class="no-bluetooth" style="visibility: hidden;">
+    Web Bluetooth is supported by this browser but this device does not have
+    Bluetooth capabilities.
+  </div>
+</body>
+
+</html>
diff --git a/characteristic_secure_notify/web_app.js b/characteristic_secure_notify/web_app.js
@@ -0,0 +1,153 @@
+/**
+ *  Copyright 2021 Google LLC
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+// The test service defined in device_code.js
+const testService = '02fc549a-244c-11eb-adc1-0242ac120002';
+// The test characteristic defined in device_code.js
+const testCharacteristic = '02fc549a-244c-11eb-adc1-0242ac120002';
+const requiredNumUpdates = 100;
+
+let gattServer = undefined;
+
+/**
+ * Load the device code to the Espruino IDE.
+ */
+function loadEspruinoDeviceCode() {
+  fetch('device_code.js').then(response => response.text()).then(data => {
+    let url = 'http://www.espruino.com/webide?code=' + encodeURIComponent(data);
+    window.open(url, '_window');
+  });
+}
+
+function onGattDisconnected(evt) {
+  const device = evt.target;
+  logInfo(`Disconnected from GATT on device ${device.name}.`);
+  assertFalse(gattServer.connected, 'Server connected');
+}
+
+async function startTest() {
+  clearStatus();
+  logInfo('Starting test');
+
+  $('btn_start_test').disabled = true;
+  $('btn_load_code').disabled = true;
+  let notifyCharacteristic = undefined;
+  let updateNum = 0;
+  let lastValue = null;
+
+  const resetTest = async () => {
+    if (notifyCharacteristic) {
+      await notifyCharacteristic.stopNotifications();
+    }
+    if (gattServer && gattServer.connected) {
+      logInfo('Disconnecting from GATT.');
+      gattServer.disconnect();
+    }
+    $('btn_start_test').disabled = false;
+    $('btn_load_code').disabled = false;
+  }
+
+  const checkCharacteristicValue = (value) => {
+    if (value > 9999) {
+      throw `Invalid characteristic value ${value}. Should be val <= 9999.`;
+    }
+    if (!lastValue) {
+      return;
+    }
+    if (lastValue === 9999) {
+      assertEquals(0, value);
+    }
+    assertEquals(lastValue + 1, value, 'Skipped value');
+  }
+
+  const onCharacteristicChanged = (evt) => {
+    updateNum += 1;
+    try {
+      const characteristic = evt.target;
+      const dataView = characteristic.value;
+      const val = dataView.getUint32(0, /*littleEndian=*/true);
+      checkCharacteristicValue(val);
+      lastValue = val;
+      if (updateNum == requiredNumUpdates) {
+        logInfo('Test success.');
+      }
+    } catch (error) {
+      logError(`Unexpected failure: ${error}`);
+      updateNum = requiredNumUpdates;  // Force test to stop.
+    }
+    if (updateNum >= requiredNumUpdates) {
+      resetTest();
+      testDone();
+    }
+  }
+
+  try {
+    const options = {
+      filters: [{ services: [getEspruinoPrimaryService()] }],
+      optionalServices: [testService]
+    };
+    logInfo(`Requesting Bluetooth device with service ${testService}`);
+    const device = await navigator.bluetooth.requestDevice(options);
+
+    device.addEventListener('gattserverdisconnected', onGattDisconnected);
+    logInfo(`Connecting to GATT server for device \"${device.name}\"...`);
+    gattServer = await device.gatt.connect();
+    assertEquals(gattServer.device, device, 'Server device mismatch');
+    assertTrue(gattServer.connected, 'server.connected should be true');
+
+    logInfo(`Connected to GATT, requesting service: ${testService}...`);
+    const service = await gattServer.getPrimaryService(testService);
+    assertEquals(service.device, device, 'service device mismatch');
+
+    logInfo(`Connected to service uuid:${service.uuid}, primary:${service.isPrimary}`);
+    logInfo(`Requesting characteristic ${testCharacteristic}...`);
+    const characteristic = await service.getCharacteristic(testCharacteristic);
+    assertEquals(characteristic.service, service,
+      'characteristic service mismatch');
+
+    logInfo(`Got characteristic, reading value...`);
+    let dataView = await characteristic.readValue();
+    let val = dataView.getUint32(0, /*littleEndian=*/true);
+    checkCharacteristicValue(val);
+
+    notifyCharacteristic = await characteristic.startNotifications();
+    notifyCharacteristic.addEventListener(
+      'characteristicvaluechanged', onCharacteristicChanged);
+  } catch (error) {
+    logError(`Unexpected failure: ${error}`);
+    resetTest();
+    testDone();
+  }
+}
+
+async function init() {
+  if (!isBluetoothSupported()) {
+    console.log('Bluetooth not supported.');
+    $('bluetooth_available').style.display = 'none';
+    if (window.isSecureContext == 'https') {
+      $('bluetooth_none').style.visibility = 'visible';
+    } else {
+      $('bluetooth_insecure').style.visibility = 'visible';
+    }
+    return;
+  }
+
+  const available = await navigator.bluetooth.getAvailability();
+  if (!available) {
+    $('bluetooth_available').style.display = 'none';
+    $('bluetooth_unavailable').style.visibility = 'visible';
+  }
+}
diff --git a/index.html b/index.html
@@ -38,6 +38,7 @@ <h2>Tests</h2>
     <li><a href="characteristic_readwrite">Read and write to a characteristic</a></li>
     <li><a href="characteristic_notify">Subscribe to characteristic value changes</a></li>
     <li><a href="characteristic_secure">Read and write to a secure characteristic</a></li>
+    <li><a href="characteristic_secure_notify">Subscribe to secure characteristic value changes</a></li>
     <li><a href="get_primary_services">Test getPrimaryServices()</a></li>
     <li><a href="descriptors">Descriptors</a></li>
   </ol>