Restore SEBPatch

SafeExamBrowser.Runtime/Operations/ConfigurationBaseOperation.cs

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * 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)
+		{
+			passwordParams = new PasswordParameters { Password = string.Empty, IsHash = true };
+
+			var status = configuration.TryLoadSettings(uri, out settings, passwordParams);
+
+			if (status == LoadStatus.PasswordNeeded && currentPassword != default)
+			{
+				passwordParams.Password = currentPassword;
+				passwordParams.IsHash = true;
+
+				status = configuration.TryLoadSettings(uri, out settings, passwordParams);
+			}
+
+			for (var 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
+		}
+	}
+}