Add timeout for SAML webcam logins

chrome/browser/resources/chromeos/login/screen_gaia_signin.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Oobe signin screen implementation.
  */
 
 login.createScreen('GaiaSigninScreen', 'gaia-signin', function() {
   // GAIA animation guard timer. Started when GAIA page is loaded
   // (Authenticator 'ready' event) and is intended to guard against edge cases
   // when 'showView' message is not generated/received.
   /** @const */ var GAIA_ANIMATION_GUARD_MILLISEC = 300;
 
   // Maximum Gaia loading time in seconds.
   /** @const */ var MAX_GAIA_LOADING_TIME_SEC = 60;
 
   // The help topic regarding user not being in the whitelist.
   /** @const */ var HELP_CANT_ACCESS_ACCOUNT = 188036;
 
   // Amount of time the user has to be idle for before showing the online login
   // page.
   /** @const */ var IDLE_TIME_UNTIL_EXIT_OFFLINE_IN_MILLISECONDS = 180 * 1000;
 
   // Approximate amount of time between checks to see if we should go to the
   // online login page when we're in the offline login page and the device is
   // online.
   /** @const */ var IDLE_TIME_CHECK_FREQUENCY = 5 * 1000;
 
+  // Amount of time allowed for video based SAML logins, to prevent a site
+  // from keeping the camera on indefinitely.  This is a hard deadline and
+  // it will not be extended by user activity.
+  /** @const */ var VIDEO_LOGIN_TIMEOUT = 60 * 1000;

[emaxx, 2016/05/18 01:14:53]

According to http://crbug.com/606979#c8, the timeout should be 180 seconds.

[Kevin Cernekee, 2016/05/18 20:38:09]

Done.

+
   /**
    * The modes this screen can be in.
    * @enum {integer}
    */
   var ScreenMode = {
     DEFAULT: 0,           // Default GAIA login flow.
     OFFLINE: 1,           // GAIA offline login.
     SAML_INTERSTITIAL: 2  // Interstitial page before SAML redirection.
   };
 
@@ skipping 35 matching lines @@
 
     /**
      * Timer id of a guard timer that is fired in case 'showView' message
      * is not received from GAIA.
      * @type {number}
      * @private
      */
     loadAnimationGuardTimer_: undefined,
 
     /**
+     * Timer id of the video login timer.
+     * @type {number}
+     * @private
+     */
+    videoTimer_: undefined,
+
+    /**
      * Whether we've processed 'showView' message - either from GAIA or from
      * guard timer.
      * @type {boolean}
      * @private
      */
     showViewProcessed_: false,
 
     /**
      * Whether we've processed 'authCompleted' message.
      * @type {boolean}
@@ skipping 533 matching lines @@
      */
     onAuthDomainChange_: function() {
       this.updateSamlNotice_();
     },
 
     /**
      * Invoked when the videoEnabled property is changed on the GAIA host.
      */
     onVideoEnabledChange_: function() {
       this.updateSamlNotice_();
+      if (this.gaiaAuthHost_.videoEnabled && this.videoTimer_ === undefined) {
+        this.videoTimer_ = setTimeout(this.cancel.bind(this),
+            VIDEO_LOGIN_TIMEOUT);
+      }

[emaxx, 2016/05/18 01:14:53]

I guess that, as an effect of the Authenticator.resetStates_ method, the
videoEnabled flag may change back from true to false here. The cancel method
below may cover all such possible cases, but it's quite difficult to track down
all possible execution flows.
So I would suggest, being on the safe side, to add here a branch with clearing
the timeout when the video is not enabled (and +1 to separating the timer
stopping operation into another method).

[Kevin Cernekee, 2016/05/18 20:38:09]

Done.

     },
 
     /**
      * Invoked when the authFlow property is changed on the GAIA host.
      */
     onAuthFlowChange_: function() {
       var isSAML = this.isSAML();
 
       this.classList.toggle('full-width', isSAML);
       $('saml-notice-container').hidden = !isSAML;
@@ skipping 200 matching lines @@
                      credentials.usingSAML]);
       }
 
       this.loading = true;
 
       // Now that we're in logged in state header should be hidden.
       Oobe.getInstance().headerHidden = true;
       // Clear any error messages that were shown before login.
       Oobe.clearErrors();
 
+      if (this.videoTimer_ !== undefined) {

[achuithb, 2016/05/17 23:38:38]

Maybe add a method like clearVideoTimer()?

[Kevin Cernekee, 2016/05/18 20:38:09]

Done.

+        clearTimeout(this.videoTimer_);
+        this.videoTimer_ = undefined;
+      }
+
       this.authCompleted_ = true;
       this.updateControlsState();
     },
 
     /**
      * Invoked when onAuthCompleted message received.
      * @param {!Object} e Payload of the received HTML5 message.
      * @private
      */
     onAuthCompletedMessage_: function(e) {
@@ skipping 76 matching lines @@
       }
     },
 
     /**
      * Called when user canceled signin.
      */
     cancel: function() {
       if (!this.navigation_.refreshVisible && !this.navigation_.closeVisible)
         return;
 
+      if (this.videoTimer_ !== undefined) {

[emaxx, 2016/05/18 01:30:17]

Shouldn't this be moved to the top of the function?
Because currently it may happen that the video timer fires, but its id stored in
the videoTimer_ member is not cleared here because of the above code; this would
result in ignoring all new attempts to set up a video timer.

[Kevin Cernekee, 2016/05/18 20:38:09]

Done.

+        clearTimeout(this.videoTimer_);
+        this.videoTimer_ = undefined;
+      }
+
       if (this.closable)
         Oobe.showUserPods();
       else
         Oobe.resetSigninUI(true);
     },
 
     /**
      * Handler for webview error handling.
      * @param {!Object} data Additional information about error event like:
      * {string} error Error code such as "ERR_INTERNET_DISCONNECTED".
@@ skipping 46 matching lines @@
       this.classList.toggle('whitelist-error', show);
       this.loading = !show;
 
       if (!show)
         Oobe.showSigninUI();
 
       this.updateControlsState();
     }
   };
 });