SEBWIN-405: Fixed and improved LMS session detection.

SafeExamBrowser.Browser.UnitTests/Handlers/RequestHandlerTests.cs

@@ -18,6 +18,7 @@ using SafeExamBrowser.Settings.Browser.Filter;
 using SafeExamBrowser.Settings.Browser.Proxy;
 using BrowserSettings = SafeExamBrowser.Settings.Browser.BrowserSettings;
 using Request = SafeExamBrowser.Browser.Contracts.Filters.Request;
+using ResourceHandler = SafeExamBrowser.Browser.Handlers.ResourceHandler;
 
 namespace SafeExamBrowser.Browser.UnitTests.Handlers
 {
@@ -28,6 +29,7 @@ namespace SafeExamBrowser.Browser.UnitTests.Handlers
 		private Mock<IRequestFilter> filter;
 		private Mock<ILogger> logger;
 		private BrowserSettings settings;
+		private ResourceHandler resourceHandler;
 		private Mock<IText> text;
 		private TestableRequestHandler sut;
 
@@ -39,8 +41,9 @@ namespace SafeExamBrowser.Browser.UnitTests.Handlers
 			logger = new Mock<ILogger>();
 			settings = new BrowserSettings();
 			text = new Mock<IText>();
+			resourceHandler = new ResourceHandler(appConfig, settings, filter.Object, logger.Object, text.Object);
 
-			sut = new TestableRequestHandler(appConfig, filter.Object, logger.Object, settings, text.Object);
+			sut = new TestableRequestHandler(appConfig, filter.Object, logger.Object, settings, resourceHandler, text.Object);
 		}
 
 		[TestMethod]
@@ -194,7 +197,13 @@ namespace SafeExamBrowser.Browser.UnitTests.Handlers
 
 		private class TestableRequestHandler : RequestHandler
 		{
-			internal TestableRequestHandler(AppConfig appConfig, IRequestFilter filter, ILogger logger, BrowserSettings settings, IText text) : base(appConfig, filter, logger, settings, text)
+			internal TestableRequestHandler(
+				AppConfig appConfig,
+				IRequestFilter filter,
+				ILogger logger,
+				BrowserSettings settings,
+				ResourceHandler resourceHandler,
+				IText text) : base(appConfig, filter, logger, settings, resourceHandler, text)
 			{
 			}
 

SafeExamBrowser.Browser/BrowserApplication.cs

@@ -10,8 +10,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Threading.Tasks;
-using System.Timers;
 using CefSharp;
 using CefSharp.WinForms;
 using SafeExamBrowser.Applications.Contracts;
@@ -41,10 +39,8 @@ namespace SafeExamBrowser.Browser
 		private IFileSystemDialog fileSystemDialog;
 		private IMessageBox messageBox;
 		private IModuleLogger logger;
-		private List<string> sessionCookies;
 		private BrowserSettings settings;
 		private IText text;
-		private Timer timer;
 		private IUserInterfaceFactory uiFactory;
 
 		public bool AutoStart { get; private set; }
@@ -72,10 +68,8 @@ namespace SafeExamBrowser.Browser
 			this.instances = new List<BrowserApplicationInstance>();
 			this.logger = logger;
 			this.messageBox = messageBox;
-			this.sessionCookies = new List<string>();
 			this.settings = settings;
 			this.text = text;
-			this.timer = new Timer();
 			this.uiFactory = uiFactory;
 		}
 
@@ -111,15 +105,12 @@ namespace SafeExamBrowser.Browser
 		public void Start()
 		{
 			CreateNewInstance();
-			StartMonitoringCookies();
 		}
 
 		public void Terminate()
 		{
 			logger.Info("Initiating termination...");
 
-			StopMonitoringCookies();
-
 			foreach (var instance in instances)
 			{
 				instance.Terminated -= Instance_Terminated;
@@ -155,6 +146,7 @@ namespace SafeExamBrowser.Browser
 
 			instance.ConfigurationDownloadRequested += (fileName, args) => ConfigurationDownloadRequested?.Invoke(fileName, args);
 			instance.PopupRequested += Instance_PopupRequested;
+			instance.SessionIdentifierDetected += (i) => SessionIdentifierDetected?.Invoke(i);
 			instance.Terminated += Instance_Terminated;
 			instance.TerminationRequested += () => TerminationRequested?.Invoke();
 
@@ -304,20 +296,6 @@ namespace SafeExamBrowser.Browser
 			return userAgent;
 		}
 
-		private void StartMonitoringCookies()
-		{
-			timer.AutoReset = false;
-			timer.Interval = 1000;
-			timer.Elapsed += Timer_Elapsed;
-			timer.Start();
-		}
-
-		private void StopMonitoringCookies()
-		{
-			timer.Stop();
-			timer.Elapsed -= Timer_Elapsed;
-		}
-
 		private string ToScheme(ProxyProtocol protocol)
 		{
 			switch (protocol)
@@ -346,40 +324,5 @@ namespace SafeExamBrowser.Browser
 			instances.Remove(instances.First(i => i.Id == id));
 			WindowsChanged?.Invoke();
 		}
-
-		private void Timer_Elapsed(object sender, ElapsedEventArgs args)
-		{
-			try
-			{
-				var manager = Cef.GetGlobalCookieManager();
-				var task = manager.VisitAllCookiesAsync();
-				var cookies = task.GetAwaiter().GetResult();
-				var edxLogin = cookies.FirstOrDefault(c => c.Name == "edxloggedin");
-				var moodleSession = cookies.FirstOrDefault(c => c.Name == "MoodleSession");
-
-				if (edxLogin != default(Cookie))
-				{
-					var edxSession = cookies.FirstOrDefault(c => c.Domain == edxLogin.Domain && c.Name == "sessionid");
-
-					if (edxSession != default(Cookie) && !sessionCookies.Contains(edxSession.Domain))
-					{
-						sessionCookies.Add(edxSession.Domain);
-						Task.Run(() => SessionIdentifierDetected?.Invoke(edxSession.Value));
-					}
-				}
-
-				if (moodleSession != default(Cookie) && !sessionCookies.Contains(moodleSession.Domain))
-				{
-					sessionCookies.Add(moodleSession.Domain);
-					Task.Run(() => SessionIdentifierDetected?.Invoke(moodleSession.Value));
-				}
-			}
-			catch (Exception e)
-			{
-				logger.Error("Failed to read cookies!", e);
-			}
-
-			timer.Start();
-		}
 	}
 }

SafeExamBrowser.Browser/BrowserApplicationInstance.cs

@@ -30,6 +30,7 @@ using SafeExamBrowser.UserInterface.Contracts.FileSystemDialog;
 using SafeExamBrowser.UserInterface.Contracts.MessageBox;
 using BrowserSettings = SafeExamBrowser.Settings.Browser.BrowserSettings;
 using Request = SafeExamBrowser.Browser.Contracts.Filters.Request;
+using ResourceHandler = SafeExamBrowser.Browser.Handlers.ResourceHandler;
 using TitleChangedEventHandler = SafeExamBrowser.Applications.Contracts.Events.TitleChangedEventHandler;
 
 namespace SafeExamBrowser.Browser
@@ -65,6 +66,7 @@ namespace SafeExamBrowser.Browser
 
 		internal event DownloadRequestedEventHandler ConfigurationDownloadRequested;
 		internal event PopupRequestedEventHandler PopupRequested;
+		internal event SessionIdentifierDetectedEventHandler SessionIdentifierDetected;
 		internal event InstanceTerminatedEventHandler Terminated;
 		internal event TerminationRequestedEventHandler TerminationRequested;
 
@@ -124,7 +126,8 @@ namespace SafeExamBrowser.Browser
 			var lifeSpanHandler = new LifeSpanHandler();
 			var requestFilter = new RequestFilter();
 			var requestLogger = logger.CloneFor($"{nameof(RequestHandler)} #{Id}");
-			var requestHandler = new RequestHandler(appConfig, requestFilter, requestLogger, settings, text);
+			var resourceHandler = new ResourceHandler(appConfig, settings, requestFilter, logger, text);
+			var requestHandler = new RequestHandler(appConfig, requestFilter, requestLogger, settings, resourceHandler, text);
 
 			Icon = new BrowserIconResource();
 
@@ -138,6 +141,7 @@ namespace SafeExamBrowser.Browser
 			keyboardHandler.ZoomOutRequested += ZoomOutRequested;
 			keyboardHandler.ZoomResetRequested += ZoomResetRequested;
 			lifeSpanHandler.PopupRequested += LifeSpanHandler_PopupRequested;
+			resourceHandler.SessionIdentifierDetected += (id) => SessionIdentifierDetected?.Invoke(id);
 			requestHandler.QuitUrlVisited += RequestHandler_QuitUrlVisited;
 			requestHandler.RequestBlocked += RequestHandler_RequestBlocked;
 

SafeExamBrowser.Browser/Handlers/RequestHandler.cs

@@ -31,12 +31,18 @@ namespace SafeExamBrowser.Browser.Handlers
 		internal event UrlEventHandler QuitUrlVisited;
 		internal event UrlEventHandler RequestBlocked;
 
-		internal RequestHandler(AppConfig appConfig, IRequestFilter filter, ILogger logger, BrowserSettings settings, IText text)
+		internal RequestHandler(
+			AppConfig appConfig,
+			IRequestFilter filter,
+			ILogger logger,
+			BrowserSettings settings,
+			ResourceHandler resourceHandler,
+			IText text)
 		{
 			this.filter = filter;
 			this.logger = logger;
 			this.settings = settings;
-			this.resourceHandler = new ResourceHandler(appConfig, settings, filter, logger, text);
+			this.resourceHandler = resourceHandler;
 		}
 
 		protected override bool GetAuthCredentials(IWebBrowser webBrowser, IBrowser browser, string originUrl, bool isProxy, string host, int port, string realm, string scheme, IAuthCallback callback)

SafeExamBrowser.Browser/Handlers/ResourceHandler.cs

@@ -8,10 +8,15 @@
 
 using System;
 using System.Collections.Specialized;
+using System.Linq;
 using System.Net.Mime;
 using System.Security.Cryptography;
 using System.Text;
+using System.Threading.Tasks;
 using CefSharp;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using SafeExamBrowser.Browser.Contracts.Events;
 using SafeExamBrowser.Browser.Contracts.Filters;
 using SafeExamBrowser.Browser.Pages;
 using SafeExamBrowser.Configuration.Contracts;
@@ -36,6 +41,8 @@ namespace SafeExamBrowser.Browser.Handlers
 		private BrowserSettings settings;
 		private IText text;
 
+		internal event SessionIdentifierDetectedEventHandler SessionIdentifierDetected;
+
 		internal ResourceHandler(AppConfig appConfig, BrowserSettings settings, IRequestFilter filter, ILogger logger, IText text)
 		{
 			this.appConfig = appConfig;
@@ -70,6 +77,13 @@ namespace SafeExamBrowser.Browser.Handlers
 			return base.OnBeforeResourceLoad(webBrowser, browser, frame, request, callback);
 		}
 
+		protected override void OnResourceRedirect(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IResponse response, ref string newUrl)
+		{
+			SearchSessionIdentifiers(response);
+
+			base.OnResourceRedirect(chromiumWebBrowser, browser, frame, request, response, ref newUrl);
+		}
+
 		protected override bool OnResourceResponse(IWebBrowser webBrowser, IBrowser browser, IFrame frame, IRequest request, IResponse response)
 		{
 			if (RedirectToDisablePdfToolbar(request, response, out var url))
@@ -79,6 +93,8 @@ namespace SafeExamBrowser.Browser.Handlers
 				return true;
 			}
 
+			SearchSessionIdentifiers(response);
+
 			return base.OnResourceResponse(webBrowser, browser, frame, request, response);
 		}
 
@@ -206,5 +222,64 @@ namespace SafeExamBrowser.Browser.Handlers
 					return contentHandler;
 			}
 		}
+
+		private void SearchSessionIdentifiers(IResponse response)
+		{
+			SearchEdxIdentifier(response);
+			SearchMoodleIdentifier(response);
+		}
+
+		private void SearchEdxIdentifier(IResponse response)
+		{
+			var cookies = response.Headers.GetValues("Set-Cookie");
+
+			if (cookies != default(string[]))
+			{
+				try
+				{
+					var userInfo = cookies.FirstOrDefault(c => c.Contains("edx-user-info"));
+
+					if (userInfo != default(string))
+					{
+						var start = userInfo.IndexOf("=") + 1;
+						var end = userInfo.IndexOf("; expires");
+						var cookie = userInfo.Substring(start, end - start);
+						var sanitized = cookie.Replace("\\\"", "\"").Replace("\\054", ",").Trim('"');
+						var json = JsonConvert.DeserializeObject(sanitized) as JObject;
+						var userName = json["username"].Value<string>();
+
+						Task.Run(() => SessionIdentifierDetected?.Invoke(userName));
+					}
+				}
+				catch (Exception e)
+				{
+					logger.Error("Failed to parse edX session identifier!", e);
+				}
+			}
+		}
+
+		private void SearchMoodleIdentifier(IResponse response)
+		{
+			var locations = response.Headers.GetValues("Location");
+
+			if (locations != default(string[]))
+			{
+				try
+				{
+					var location = locations.FirstOrDefault(l => l.Contains("moodle/login/index.php?testsession"));
+
+					if (location != default(string))
+					{
+						var userId = location.Substring(location.IndexOf("=") + 1);
+
+						Task.Run(() => SessionIdentifierDetected?.Invoke(userId));
+					}
+				}
+				catch (Exception e)
+				{
+					logger.Error("Failed to parse Moodle session identifier!", e);
+				}
+			}
+		}
 	}
 }

SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj

@@ -54,6 +54,9 @@
     <ErrorReport>prompt</ErrorReport>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
+      <HintPath>..\packages\Newtonsoft.Json.12.0.3\lib\net45\Newtonsoft.Json.dll</HintPath>
+    </Reference>
     <Reference Include="Syroot.KnownFolders, Version=1.2.3.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>..\packages\Syroot.Windows.IO.KnownFolders.1.2.3\lib\netstandard2.0\Syroot.KnownFolders.dll</HintPath>
     </Reference>

SafeExamBrowser.Browser/packages.config

@@ -4,6 +4,7 @@
   <package id="cef.redist.x86" version="81.3.10" targetFramework="net472" />
   <package id="CefSharp.Common" version="81.3.100" targetFramework="net472" />
   <package id="CefSharp.WinForms" version="81.3.100" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="12.0.3" targetFramework="net472" />
   <package id="Syroot.Windows.IO.KnownFolders" version="1.2.3" targetFramework="net472" />
   <package id="System.Security.Principal.Windows" version="4.7.0" targetFramework="net472" />
 </packages>

SafeExamBrowser.Runtime/Operations/ServerOperation.cs

@@ -77,7 +77,6 @@ namespace SafeExamBrowser.Runtime.Operations
 
 								if (status == LoadStatus.Success)
 								{
-									// TODO: Why aren't the server settings and SEB mode correctly set in the exam configuration?
 									var serverSettings = Context.Next.Settings.Server;
 
 									Context.Next.AppConfig.ServerApi = info.Api;

SafeExamBrowser.Server/ServerProxy.cs

@@ -256,20 +256,28 @@ namespace SafeExamBrowser.Server
 			task = new Task(SendLog, cancellationTokenSource.Token);
 			task.Start();
 
+			logger.Info("Started sending log items.");
+
 			timer.AutoReset = false;
 			timer.Elapsed += Timer_Elapsed;
 			timer.Interval = 1000;
 			timer.Start();
+
+			logger.Info("Starting sending pings.");
 		}
 
 		public void StopConnectivity()
 		{
 			logger.Unsubscribe(this);
 			cancellationTokenSource.Cancel();
-			task.Wait();
+			task?.Wait();
+
+			logger.Info("Stopped sending log items.");
 
 			timer.Stop();
 			timer.Elapsed -= Timer_Elapsed;
+
+			logger.Info("Stopped sending pings.");
 		}
 
 		private void SendLog()
@@ -278,8 +286,6 @@ namespace SafeExamBrowser.Server
 			var contentType = "application/json;charset=UTF-8";
 			var token = ("SEBConnectionToken", connectionToken);
 
-			logger.Info("Starting to send log items...");
-
 			while (!cancellationTokenSource.IsCancellationRequested)
 			{
 				try
@@ -293,7 +299,6 @@ namespace SafeExamBrowser.Server
 							["text"] = message.Message
 						};
 						var content = json.ToString();
-						// TODO: Why can't we send multiple log messages in one request?
 						var success = TryExecute(HttpMethod.Post, api.LogEndpoint, out var response, content, contentType, authorization, token);
 					}
 				}
@@ -302,8 +307,6 @@ namespace SafeExamBrowser.Server
 					logger.Error("Failed to send log!", e);
 				}
 			}
-
-			logger.Info("Stopped sending log items.");
 		}
 
 		private void Timer_Elapsed(object sender, ElapsedEventArgs args)