SEBWIN-405: Implemented scaffolding for SEB server operation.

SafeExamBrowser.I18n.Contracts/TextKey.cs

@@ -119,6 +119,7 @@ namespace SafeExamBrowser.I18n.Contracts
 		OperationStatus_CloseRuntimeConnection,
 		OperationStatus_EmptyClipboard,
 		OperationStatus_FinalizeApplications,
+		OperationStatus_FinalizeServer,
 		OperationStatus_FinalizeServiceSession,
 		OperationStatus_FinalizeSystemEvents,
 		OperationStatus_InitializeApplications,
@@ -126,6 +127,7 @@ namespace SafeExamBrowser.I18n.Contracts
 		OperationStatus_InitializeConfiguration,
 		OperationStatus_InitializeKioskMode,
 		OperationStatus_InitializeRuntimeConnection,
+		OperationStatus_InitializeServer,
 		OperationStatus_InitializeServiceSession,
 		OperationStatus_InitializeSession,
 		OperationStatus_InitializeShell,

SafeExamBrowser.I18n/Data/de.xml

@@ -315,6 +315,9 @@
     <Entry key="OperationStatus_FinalizeApplications">
         Beende Applikationen
     </Entry>
+    <Entry key="OperationStatus_FinalizeServer">
+        Finalisiere SEB-Server
+    </Entry>
     <Entry key="OperationStatus_FinalizeServiceSession">
         Beende Service-Sitzung
     </Entry>
@@ -336,6 +339,9 @@
     <Entry key="OperationStatus_InitializeRuntimeConnection">
         Initialisiere Verbindung zur Runtime
     </Entry>
+    <Entry key="OperationStatus_InitializeServer">
+        Initialisiere SEB-Server
+    </Entry>
     <Entry key="OperationStatus_InitializeServiceSession">
         Initialisiere Service-Sitzung
     </Entry>

SafeExamBrowser.I18n/Data/en.xml

@@ -315,6 +315,9 @@
     <Entry key="OperationStatus_FinalizeApplications">
         Finalizing applications
     </Entry>
+    <Entry key="OperationStatus_FinalizeServer">
+        Finalizing SEB-Server
+    </Entry>
     <Entry key="OperationStatus_FinalizeServiceSession">
         Finalizing service session
     </Entry>
@@ -336,6 +339,9 @@
     <Entry key="OperationStatus_InitializeRuntimeConnection">
         Initializing runtime connection
     </Entry>
+    <Entry key="OperationStatus_InitializeServer">
+        Initializing SEB-Server
+    </Entry>
     <Entry key="OperationStatus_InitializeServiceSession">
         Initializing service session
     </Entry>

SafeExamBrowser.Runtime/CompositionRoot.cs

@@ -26,6 +26,7 @@ using SafeExamBrowser.Logging;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.Runtime.Communication;
 using SafeExamBrowser.Runtime.Operations;
+using SafeExamBrowser.Server;
 using SafeExamBrowser.Settings.Logging;
 using SafeExamBrowser.SystemComponents;
 using SafeExamBrowser.SystemComponents.Contracts;
@@ -66,6 +67,7 @@ namespace SafeExamBrowser.Runtime
 			var proxyFactory = new ProxyFactory(new ProxyObjectFactory(), ModuleLogger(nameof(ProxyFactory)));
 			var runtimeHost = new RuntimeHost(appConfig.RuntimeAddress, new HostObjectFactory(), ModuleLogger(nameof(RuntimeHost)), FIVE_SECONDS);
 			var runtimeWindow = uiFactory.CreateRuntimeWindow(appConfig);
+			var server = new ServerProxy();
 			var serviceProxy = new ServiceProxy(appConfig.ServiceAddress, new ProxyObjectFactory(), ModuleLogger(nameof(ServiceProxy)), Interlocutor.Runtime);
 			var sessionContext = new SessionContext();
 			var splashScreen = uiFactory.CreateSplashScreen(appConfig);
@@ -80,7 +82,7 @@ namespace SafeExamBrowser.Runtime
 
 			sessionOperations.Enqueue(new SessionInitializationOperation(configuration, logger, runtimeHost, sessionContext));
 			sessionOperations.Enqueue(new ConfigurationOperation(args, configuration, new FileSystem(), new HashAlgorithm(), logger, sessionContext));
-			// TODO: sessionOperations.Enqueue(new ServerOperation());
+			sessionOperations.Enqueue(new ServerOperation(args, configuration, logger, sessionContext, server));
 			sessionOperations.Enqueue(new VirtualMachineOperation(vmDetector, logger, sessionContext));
 			sessionOperations.Enqueue(new ServiceOperation(logger, runtimeHost, serviceProxy, sessionContext, THIRTY_SECONDS, userInfo));
 			sessionOperations.Enqueue(new ClientTerminationOperation(logger, processFactory, proxyFactory, runtimeHost, sessionContext, THIRTY_SECONDS));
@@ -108,7 +110,7 @@ namespace SafeExamBrowser.Runtime
 		}
 
 		internal void LogStartupInformation()
-		{
+		{ 
 			logger.Log($"/* {appConfig.ProgramTitle}, Version {appConfig.ProgramInformationalVersion}, Build {appConfig.ProgramBuildVersion}");
 			logger.Log($"/* {appConfig.ProgramCopyright}");
 			logger.Log($"/* ");

SafeExamBrowser.Runtime/Operations/ConfigurationBaseOperation.cs

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using SafeExamBrowser.Communication.Contracts.Data;
+using SafeExamBrowser.Configuration.Contracts;
+using SafeExamBrowser.Configuration.Contracts.Cryptography;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+using SafeExamBrowser.Runtime.Operations.Events;
+using SafeExamBrowser.Settings;
+
+namespace SafeExamBrowser.Runtime.Operations
+{
+	internal abstract class ConfigurationBaseOperation : SessionOperation
+	{
+		protected string[] commandLineArgs;
+		protected IConfigurationRepository configuration;
+
+		protected string AppDataFilePath => Context.Next.AppConfig.AppDataFilePath;
+		protected string ProgramDataFilePath => Context.Next.AppConfig.ProgramDataFilePath;
+
+		public ConfigurationBaseOperation(string[] commandLineArgs, IConfigurationRepository configuration, SessionContext context) : base(context)
+		{
+			this.commandLineArgs = commandLineArgs;
+			this.configuration = configuration;
+		}
+
+		protected abstract void InvokeActionRequired(ActionRequiredEventArgs args);
+
+		protected LoadStatus? TryLoadSettings(Uri uri, UriSource source, out PasswordParameters passwordParams, out AppSettings settings, string currentPassword = default(string))
+		{
+			passwordParams = new PasswordParameters { Password = string.Empty, IsHash = true };
+
+			var status = configuration.TryLoadSettings(uri, out settings, passwordParams);
+
+			if (status == LoadStatus.PasswordNeeded && currentPassword != default(string))
+			{
+				passwordParams.Password = currentPassword;
+				passwordParams.IsHash = true;
+
+				status = configuration.TryLoadSettings(uri, out settings, passwordParams);
+			}
+
+			for (int attempts = 0; attempts < 5 && status == LoadStatus.PasswordNeeded; attempts++)
+			{
+				var isLocalConfig = source == UriSource.AppData || source == UriSource.ProgramData;
+				var purpose = isLocalConfig ? PasswordRequestPurpose.LocalSettings : PasswordRequestPurpose.Settings;
+				var success = TryGetPassword(purpose, out var password);
+
+				if (success)
+				{
+					passwordParams.Password = password;
+					passwordParams.IsHash = false;
+				}
+				else
+				{
+					return null;
+				}
+
+				status = configuration.TryLoadSettings(uri, out settings, passwordParams);
+			}
+
+			return status;
+		}
+
+		protected bool TryGetPassword(PasswordRequestPurpose purpose, out string password)
+		{
+			var args = new PasswordRequiredEventArgs { Purpose = purpose };
+
+			InvokeActionRequired(args);
+			password = args.Password;
+
+			return args.Success;
+		}
+
+		protected enum UriSource
+		{
+			Undefined,
+			AppData,
+			CommandLine,
+			ProgramData,
+			Reconfiguration,
+			Server
+		}
+	}
+}

SafeExamBrowser.Runtime/Operations/ConfigurationOperation.cs

@@ -21,17 +21,12 @@ using SafeExamBrowser.SystemComponents.Contracts;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class ConfigurationOperation : SessionOperation
+	internal class ConfigurationOperation : ConfigurationBaseOperation
 	{
-		private string[] commandLineArgs;
-		private IConfigurationRepository configuration;
 		private IFileSystem fileSystem;
 		private IHashAlgorithm hashAlgorithm;
 		private ILogger logger;
 
-		private string AppDataFilePath => Context.Next.AppConfig.AppDataFilePath;
-		private string ProgramDataFilePath => Context.Next.AppConfig.ProgramDataFilePath;
-
 		public override event ActionRequiredEventHandler ActionRequired;
 		public override event StatusChangedEventHandler StatusChanged;
 
@@ -41,10 +36,8 @@ namespace SafeExamBrowser.Runtime.Operations
 			IFileSystem fileSystem,
 			IHashAlgorithm hashAlgorithm,
 			ILogger logger,
-			SessionContext sessionContext) : base(sessionContext)
+			SessionContext sessionContext) : base(commandLineArgs, configuration, sessionContext)
 		{
-			this.commandLineArgs = commandLineArgs;
-			this.configuration = configuration;
 			this.fileSystem = fileSystem;
 			this.hashAlgorithm = hashAlgorithm;
 			this.logger = logger;
@@ -99,6 +92,11 @@ namespace SafeExamBrowser.Runtime.Operations
 			return OperationResult.Success;
 		}
 
+		protected override void InvokeActionRequired(ActionRequiredEventArgs args)
+		{
+			ActionRequired?.Invoke(args);
+		}
+
 		private OperationResult LoadDefaultSettings()
 		{
 			logger.Info("No valid configuration resource specified and no local client configuration found - loading default settings...");
@@ -232,42 +230,6 @@ namespace SafeExamBrowser.Runtime.Operations
 			return result;
 		}
 
-		private LoadStatus? TryLoadSettings(Uri uri, UriSource source, out PasswordParameters passwordParams, out AppSettings settings, string currentPassword = default(string))
-		{
-			passwordParams = new PasswordParameters { Password = string.Empty, IsHash = true };
-
-			var status = configuration.TryLoadSettings(uri, out settings, passwordParams);
-
-			if (status == LoadStatus.PasswordNeeded && currentPassword != default(string))
-			{
-				passwordParams.Password = currentPassword;
-				passwordParams.IsHash = true;
-
-				status = configuration.TryLoadSettings(uri, out settings, passwordParams);
-			}
-
-			for (int attempts = 0; attempts < 5 && status == LoadStatus.PasswordNeeded; attempts++)
-			{
-				var isLocalConfig = source == UriSource.AppData || source == UriSource.ProgramData;
-				var purpose = isLocalConfig ? PasswordRequestPurpose.LocalSettings : PasswordRequestPurpose.Settings;
-				var success = TryGetPassword(purpose, out var password);
-
-				if (success)
-				{
-					passwordParams.Password = password;
-					passwordParams.IsHash = false;
-				}
-				else
-				{
-					return null;
-				}
-
-				status = configuration.TryLoadSettings(uri, out settings, passwordParams);
-			}
-
-			return status;
-		}
-
 		private bool? TryConfigureClient(Uri uri, PasswordParameters passwordParams, string currentPassword = default(string))
 		{
 			var mustAuthenticate = IsRequiredToAuthenticateForClientConfiguration(passwordParams, currentPassword);
@@ -395,16 +357,6 @@ namespace SafeExamBrowser.Runtime.Operations
 			}
 		}
 
-		private bool TryGetPassword(PasswordRequestPurpose purpose, out string password)
-		{
-			var args = new PasswordRequiredEventArgs { Purpose = purpose };
-
-			ActionRequired?.Invoke(args);
-			password = args.Password;
-
-			return args.Success;
-		}
-
 		private bool TryInitializeSettingsUri(out Uri uri, out UriSource source)
 		{
 			var isValidUri = false;
@@ -461,14 +413,5 @@ namespace SafeExamBrowser.Runtime.Operations
 					break;
 			}
 		}
-
-		private enum UriSource
-		{
-			Undefined,
-			AppData,
-			CommandLine,
-			ProgramData,
-			Reconfiguration
-		}
 	}
 }

SafeExamBrowser.Runtime/Operations/Events/ExamSelectionEventArgs.cs

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System.Collections.Generic;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+using SafeExamBrowser.Server.Contracts;
+
+namespace SafeExamBrowser.Runtime.Operations.Events
+{
+	internal class ExamSelectionEventArgs : ActionRequiredEventArgs
+	{
+		internal IEnumerable<Exam> Exams { get; set; }
+		internal Exam SelectedExam { get; set; }
+
+		internal ExamSelectionEventArgs(IEnumerable<Exam> exams)
+		{
+			Exams = exams;
+		}
+	}
+}

SafeExamBrowser.Runtime/Operations/Events/ServerFailureEventArgs.cs

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+
+namespace SafeExamBrowser.Runtime.Operations.Events
+{
+	internal class ServerFailureEventArgs : ActionRequiredEventArgs
+	{
+		public bool Abort { get; set; }
+		public bool Fallback { get; set; }
+		public string Message { get; set; }
+		public bool Retry { get; set; }
+
+		public ServerFailureEventArgs(string message)
+		{
+			Message = message;
+		}
+	}
+}

SafeExamBrowser.Runtime/Operations/ServerOperation.cs

@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using SafeExamBrowser.Configuration.Contracts;
+using SafeExamBrowser.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.Logging.Contracts;
+using SafeExamBrowser.Runtime.Operations.Events;
+using SafeExamBrowser.Server.Contracts;
+using SafeExamBrowser.Settings;
+
+namespace SafeExamBrowser.Runtime.Operations
+{
+	internal class ServerOperation : ConfigurationBaseOperation
+	{
+		private readonly ILogger logger;
+		private readonly IServerProxy server;
+
+		public override event ActionRequiredEventHandler ActionRequired;
+		public override event StatusChangedEventHandler StatusChanged;
+
+		public ServerOperation(
+			string[] commandLineArgs,
+			IConfigurationRepository configuration,
+			ILogger logger,
+			SessionContext context,
+			IServerProxy server) : base(commandLineArgs, configuration, context)
+		{
+			this.logger = logger;
+			this.server = server;
+		}
+
+		public override OperationResult Perform()
+		{
+			var result = OperationResult.Success;
+
+			if (Context.Next.Settings.SessionMode == SessionMode.Server)
+			{
+				logger.Info("Initializing server...");
+				StatusChanged?.Invoke(TextKey.OperationStatus_InitializeServer);
+
+				var (abort, fallback, success) = TryPerformWithFallback(() => server.Connect(Context.Next.Settings.Server));
+
+				if (success)
+				{
+					(abort, fallback, success) = TryPerformWithFallback(() => server.GetAvailableExams(), out var exams);
+
+					if (success)
+					{
+						var exam = SelectExam(exams);
+
+						(abort, fallback, success) = TryPerformWithFallback(() => server.GetConfigurationFor(exam), out var uri);
+
+						if (success)
+						{
+							var status = TryLoadSettings(uri, UriSource.Server, out _, out var settings);
+
+							if (status == LoadStatus.Success)
+							{
+								Context.Next.Settings = settings;
+								result = OperationResult.Success;
+							}
+							else
+							{
+								result = OperationResult.Failed;
+							}
+						}
+					}
+				}
+
+				if (abort)
+				{
+					result = OperationResult.Aborted;
+				}
+
+				if (fallback)
+				{
+					result = OperationResult.Success;
+				}
+			}
+
+			return result;
+		}
+
+		public override OperationResult Repeat()
+		{
+			var result = Revert();
+
+			if (result == OperationResult.Success)
+			{
+				result = Perform();
+			}
+
+			return result;
+		}
+
+		public override OperationResult Revert()
+		{
+			var result = OperationResult.Failed;
+
+			if (Context.Current.Settings.SessionMode == SessionMode.Server)
+			{
+				logger.Info("Finalizing server...");
+				StatusChanged?.Invoke(TextKey.OperationStatus_FinalizeServer);
+
+				var disconnect = server.Disconnect();
+
+				if (disconnect.Success)
+				{
+					result = OperationResult.Success;
+				}
+				else
+				{
+					result = OperationResult.Failed;
+				}
+			}
+			else
+			{
+				result = OperationResult.Success;
+			}
+
+			return result;
+		}
+
+		protected override void InvokeActionRequired(ActionRequiredEventArgs args)
+		{
+			ActionRequired?.Invoke(args);
+		}
+
+		private (bool abort, bool fallback, bool success) TryPerformWithFallback(Func<ServerResponse> request)
+		{
+			var abort = false;
+			var fallback = false;
+			var success = false;
+
+			while (!success)
+			{
+				var response = request();
+
+				success = response.Success;
+
+				if (!success && !Retry(response.Message, out abort, out fallback))
+				{
+					break;
+				}
+			}
+
+			return (abort, fallback, success);
+		}
+
+		private (bool abort, bool fallback, bool success) TryPerformWithFallback<T>(Func<ServerResponse<T>> request, out T value)
+		{
+			var abort = false;
+			var fallback = false;
+			var success = false;
+
+			value = default(T);
+
+			while (!success)
+			{
+				var response = request();
+
+				success = response.Success;
+				value = response.Value;
+
+				if (!success && !Retry(response.Message, out abort, out fallback))
+				{
+					break;
+				}
+			}
+
+			return (abort, fallback, success);
+		}
+
+		private bool Retry(string message, out bool abort, out bool fallback)
+		{
+			var args = new ServerFailureEventArgs(message);
+
+			ActionRequired?.Invoke(args);
+
+			abort = args.Abort;
+			fallback = args.Fallback;
+
+			return args.Retry;
+		}
+
+		private Exam SelectExam(IEnumerable<Exam> exams)
+		{
+			var args = new ExamSelectionEventArgs(exams);
+
+			ActionRequired?.Invoke(args);
+
+			return args.SelectedExam;
+		}
+	}
+}

SafeExamBrowser.Runtime/RuntimeController.cs

@@ -384,15 +384,31 @@ namespace SafeExamBrowser.Runtime
 				case ConfigurationCompletedEventArgs a:
 					AskIfConfigurationSufficient(a);
 					break;
+				case ExamSelectionEventArgs a:
+					AskForExamSelection(a);
+					break;
 				case MessageEventArgs m:
 					ShowMessageBox(m);
 					break;
 				case PasswordRequiredEventArgs p:
 					AskForPassword(p);
 					break;
+				case ServerFailureEventArgs a:
+					AskForServerFailureAction(a);
+					break;
 			}
 		}
 
+		private void AskForExamSelection(ExamSelectionEventArgs a)
+		{
+			// TODO: Also implement mechanism to retrieve selection via client!!
+		}
+
+		private void AskForServerFailureAction(ServerFailureEventArgs a)
+		{
+			// TODO: Also implement mechanism to retrieve selection via client!!
+		}
+
 		private void AskIfConfigurationSufficient(ConfigurationCompletedEventArgs args)
 		{
 			var message = TextKey.MessageBox_ClientConfigurationQuestion;

SafeExamBrowser.Runtime/SafeExamBrowser.Runtime.csproj

@@ -90,16 +90,20 @@
     <Compile Include="App.cs" />
     <Compile Include="Operations\ClientOperation.cs" />
     <Compile Include="Operations\ClientTerminationOperation.cs" />
+    <Compile Include="Operations\ConfigurationBaseOperation.cs" />
     <Compile Include="Operations\ConfigurationOperation.cs" />
     <Compile Include="Operations\Events\ClientConfigurationErrorMessageArgs.cs" />
     <Compile Include="Operations\Events\ConfigurationCompletedEventArgs.cs" />
+    <Compile Include="Operations\Events\ExamSelectionEventArgs.cs" />
     <Compile Include="Operations\Events\InvalidDataMessageArgs.cs" />
     <Compile Include="Operations\Events\InvalidPasswordMessageArgs.cs" />
     <Compile Include="Operations\Events\MessageEventArgs.cs" />
     <Compile Include="Operations\Events\NotSupportedMessageArgs.cs" />
     <Compile Include="Operations\Events\PasswordRequiredEventArgs.cs" />
+    <Compile Include="Operations\Events\ServerFailureEventArgs.cs" />
     <Compile Include="Operations\Events\UnexpectedErrorMessageArgs.cs" />
     <Compile Include="Operations\KioskModeOperation.cs" />
+    <Compile Include="Operations\ServerOperation.cs" />
     <Compile Include="Operations\ServiceOperation.cs" />
     <Compile Include="Operations\SessionActivationOperation.cs" />
     <Compile Include="Operations\SessionOperation.cs" />
@@ -177,6 +181,14 @@
       <Project>{e107026c-2011-4552-a7d8-3a0d37881df6}</Project>
       <Name>SafeExamBrowser.Logging</Name>
     </ProjectReference>
+    <ProjectReference Include="..\SafeExamBrowser.Server.Contracts\SafeExamBrowser.Server.Contracts.csproj">
+      <Project>{db701e6f-bddc-4cec-b662-335a9dc11809}</Project>
+      <Name>SafeExamBrowser.Server.Contracts</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\SafeExamBrowser.Server\SafeExamBrowser.Server.csproj">
+      <Project>{46edbde0-58b4-4725-9783-0c55c3d49c0c}</Project>
+      <Name>SafeExamBrowser.Server</Name>
+    </ProjectReference>
     <ProjectReference Include="..\SafeExamBrowser.Settings\SafeExamBrowser.Settings.csproj">
       <Project>{30b2d907-5861-4f39-abad-c4abf1b3470e}</Project>
       <Name>SafeExamBrowser.Settings</Name>

SafeExamBrowser.Server.Contracts/Exam.cs

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+namespace SafeExamBrowser.Server.Contracts
+{
+	/// <summary>
+	/// 
+	/// </summary>
+	public class Exam
+	{
+
+	}
+}

SafeExamBrowser.Server.Contracts/IServerProxy.cs

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using SafeExamBrowser.Settings.Server;
+
+namespace SafeExamBrowser.Server.Contracts
+{
+	/// <summary>
+	/// 
+	/// </summary>
+	public interface IServerProxy
+	{
+		/// <summary>
+		/// 
+		/// </summary>
+		ServerResponse Connect(ServerSettings settings);
+
+		/// <summary>
+		/// 
+		/// </summary>
+		ServerResponse Disconnect();
+
+		/// <summary>
+		/// 
+		/// </summary>
+		ServerResponse<IEnumerable<Exam>> GetAvailableExams();
+
+		/// <summary>
+		/// 
+		/// </summary>
+		ServerResponse<Uri> GetConfigurationFor(Exam exam);
+
+		/// <summary>
+		/// 
+		/// </summary>
+		ServerResponse SendSessionInfo(string sessionId);
+	}
+}

SafeExamBrowser.Server.Contracts/SafeExamBrowser.Server.Contracts.csproj

@@ -54,7 +54,16 @@
     <Reference Include="Microsoft.CSharp" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Exam.cs" />
+    <Compile Include="IServerProxy.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="ServerResponse.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\SafeExamBrowser.Settings\SafeExamBrowser.Settings.csproj">
+      <Project>{30b2d907-5861-4f39-abad-c4abf1b3470e}</Project>
+      <Name>SafeExamBrowser.Settings</Name>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

SafeExamBrowser.Server.Contracts/ServerResponse.cs

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+namespace SafeExamBrowser.Server.Contracts
+{
+	/// <summary>
+	/// Defines the result of a communication with a SEB server.
+	/// </summary>
+	public class ServerResponse
+	{
+		/// <summary>
+		/// The message retrieved by the server in case the communication failed.
+		/// </summary>
+		public string Message { get; }
+
+		/// <summary>
+		/// Defines whether the communication was successful or not.
+		/// </summary>
+		public bool Success { get; }
+
+		public ServerResponse(bool success, string message = default(string))
+		{
+			Message = message;
+			Success = success;
+		}
+	}
+
+	/// <summary>
+	/// Defines the result of a communication with a SEB server.
+	/// </summary>
+	/// <typeparam name="T">The type of the expected response value.</typeparam>
+	public class ServerResponse<T> : ServerResponse
+	{
+		/// <summary>
+		/// The response value. Can be <c>null</c> or <c>default(T)</c> in case the communication failed!
+		/// </summary>
+		public T Value { get; }
+
+		public ServerResponse(bool success, T value, string message = default(string)) : base(success, message)
+		{
+			Value = value;
+		}
+	}
+}

SafeExamBrowser.Server/SafeExamBrowser.Server.csproj

@@ -55,6 +55,17 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="ServerProxy.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\SafeExamBrowser.Server.Contracts\SafeExamBrowser.Server.Contracts.csproj">
+      <Project>{db701e6f-bddc-4cec-b662-335a9dc11809}</Project>
+      <Name>SafeExamBrowser.Server.Contracts</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\SafeExamBrowser.Settings\SafeExamBrowser.Settings.csproj">
+      <Project>{30b2d907-5861-4f39-abad-c4abf1b3470e}</Project>
+      <Name>SafeExamBrowser.Settings</Name>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

SafeExamBrowser.Server/ServerProxy.cs

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using SafeExamBrowser.Server.Contracts;
+using SafeExamBrowser.Settings.Server;
+
+namespace SafeExamBrowser.Server
+{
+	public class ServerProxy : IServerProxy
+	{
+		public ServerResponse Connect(ServerSettings settings)
+		{
+			throw new NotImplementedException();
+		}
+
+		public ServerResponse Disconnect()
+		{
+			throw new NotImplementedException();
+		}
+
+		public ServerResponse<IEnumerable<Exam>> GetAvailableExams()
+		{
+			throw new NotImplementedException();
+		}
+
+		public ServerResponse<Uri> GetConfigurationFor(Exam exam)
+		{
+			throw new NotImplementedException();
+		}
+
+		public ServerResponse SendSessionInfo(string sessionId)
+		{
+			throw new NotImplementedException();
+		}
+	}
+}