block media device enumeration when fingerprinting protection is on

app/extensions/brave/content/scripts/blockCanvasFingerprinting.js

@@ -67,12 +67,10 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     return script_url.replace(/:\d+:\d+$/, '')
   }
 
-  function reportBlock (item) {
+  function reportBlock (type) {
     var script_url = getOriginatingScriptUrl()
     var msg = {
-      type: item.type,
-      obj: item.objName,
-      prop: item.propName,
+      type,
       scriptUrl: stripLineAndColumnNumbers(script_url)
     }
 
@@ -85,7 +83,11 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
    * @param item special item objects
    */
   function trapInstanceMethod (item) {
-    chrome.webFrame.setGlobal(item.objName + ".prototype." + item.propName, reportBlock.bind(null, item))
+    if (!item.methodName) {
+      chrome.webFrame.setGlobal(item.objName + ".prototype." + item.propName, reportBlock.bind(null, item.type))
+    } else {
+      chrome.webFrame.setGlobal(item.methodName, reportBlock.bind(null, item.type))
+    }
   }
 
   var methods = []
@@ -94,8 +96,7 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'Canvas',
       objName: 'CanvasRenderingContext2D',
-      propName: method,
-      obj: CanvasRenderingContext2D
+      propName: method
     }
 
     methods.push(item)
@@ -106,8 +107,7 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'Canvas',
       objName: 'HTMLCanvasElement',
-      propName: method,
-      obj: HTMLCanvasElement
+      propName: method
     }
     methods.push(item)
   })
@@ -118,8 +118,7 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'WebGL',
       objName: 'WebGLRenderingContext',
-      propName: method,
-      obj: WebGLRenderingContext
+      propName: method
     }
     methods.push(item)
   })
@@ -129,8 +128,7 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'AudioContext',
       objName: 'AudioBuffer',
-      propName: method,
-      obj: AudioBuffer
+      propName: method
     }
     methods.push(item)
   })
@@ -141,8 +139,7 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'AudioContext',
       objName: 'AnalyserNode',
-      propName: method,
-      obj: AnalyserNode
+      propName: method
     }
     methods.push(item)
   })
@@ -153,11 +150,16 @@ if (chrome.contentSettings.canvasFingerprinting == 'block') {
     var item = {
       type: 'WebRTC',
       objName: 'webkitRTCPeerConnection',
-      propName: method,
-      obj: webkitRTCPeerConnection
+      propName: method
     }
     methods.push(item)
   })
 
   methods.forEach(trapInstanceMethod)
+
+  // Block WebRTC device enumeration
+  trapInstanceMethod({
+    type: 'WebRTC',
+    methodName: 'navigator.mediaDevices.enumerateDevices'
+  })
 }

test/bravery-components/braveryPanelTest.js

@@ -518,6 +518,31 @@ describe('Bravery Panel', function () {
             .then((stat) => stat === '2' || stat === '3')
         })
     })
+    it('block device enumeration', function * () {
+      const url = Brave.server.url('enumerate_devices.html')
+      yield this.app.client
+        .tabByIndex(0)
+        .loadUrl(url)
+        .waitUntil(function () {
+          return this.getText('body')
+            .then((body) => {
+              return body.includes('default')
+            })
+        })
+        .openBraveMenu(braveMenu, braveryPanel)
+        .click(fpSwitch)
+        .waitUntil(function () {
+          return this.getText(fpStat)
+            .then((stat) => stat === '1')
+        })
+        .tabByUrl(url)
+        .waitUntil(function () {
+          return this.getText('body')
+            .then((body) => {
+              return body === ''
+            })
+        })
+    })
     it('allows fingerprinting when setting is off in private tab', function * () {
       const url = Brave.server.url('fingerprinting.html')
       yield this.app.client

test/fixtures/enumerate_devices.html

@@ -0,0 +1,14 @@
+<body>
+<div id='results'></div>
+<script>
+let results = document.getElementById('results')
+navigator.mediaDevices.enumerateDevices()
+.then(function(devices) {
+  devices.forEach(function(device) {
+    let li = document.createElement('li')
+    li.textContent = [device.label, device.deviceId].join(': ')
+    results.appendChild(li)
+  });
+})
+</script>
+</body>