Restore SEBPatch

2025-06-01 11:44:20 +02:00
commit 8c656e3137
1297 changed files with 142172 additions and 0 deletions
--- a/SafeExamBrowser.Lockdown/FeatureConfigurationMonitor.cs
+++ b/SafeExamBrowser.Lockdown/FeatureConfigurationMonitor.cs
@@ -0,0 +1,148 @@
+/*
+ * 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 System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using SafeExamBrowser.Lockdown.Contracts;
+using SafeExamBrowser.Logging.Contracts;
+
+namespace SafeExamBrowser.Lockdown
+{
+	public class FeatureConfigurationMonitor : IFeatureConfigurationMonitor
+	{
+		private readonly object @lock = new object();
+
+		private IDictionary<IFeatureConfiguration, FeatureConfigurationStatus> configurations;
+		private ILogger logger;
+		private readonly int timeout_ms;
+		private bool running;
+
+		public FeatureConfigurationMonitor(ILogger logger, int timeout_ms)
+		{
+			if (timeout_ms < 0)
+			{
+				throw new ArgumentException("Must be 0 or greater!", nameof(timeout_ms));
+			}
+
+			this.configurations = new Dictionary<IFeatureConfiguration, FeatureConfigurationStatus>();
+			this.logger = logger;
+			this.timeout_ms = timeout_ms;
+		}
+
+		public void Observe(IFeatureConfiguration configuration, FeatureConfigurationStatus status)
+		{
+			lock (@lock)
+			{
+				configurations.Add(configuration, status);
+			}
+		}
+
+		public void Reset()
+		{
+			lock (@lock)
+			{
+				if (running)
+				{
+					running = false;
+					configurations.Clear();
+					logger.Info("Stopped monitoring.");
+				}
+				else
+				{
+					logger.Info("Monitoring is not running.");
+				}
+			}
+		}
+
+		public void Start()
+		{
+			lock (@lock)
+			{
+				if (!running)
+				{
+					running = true;
+					Task.Run(new Action(Monitor));
+					logger.Info("Started monitoring.");
+				}
+				else
+				{
+					logger.Info("Monitoring is already running.");
+				}
+			}
+		}
+
+		private void Monitor()
+		{
+			if (IsStopped())
+			{
+				return;
+			}
+
+			var configurations = new Dictionary<IFeatureConfiguration, FeatureConfigurationStatus>(this.configurations);
+
+			logger.Debug($"Checking {configurations.Count} configurations...");
+
+			foreach (var item in configurations)
+			{
+				var configuration = item.Key;
+				var status = item.Value;
+
+				Enforce(configuration, status);
+
+				if (IsStopped())
+				{
+					logger.Info("Monitoring was aborted.");
+
+					return;
+				}
+			}
+
+			if (configurations.Any())
+			{
+				Task.Delay(timeout_ms).ContinueWith((_) => Monitor());
+			}
+			else
+			{
+				lock (@lock)
+				{
+					running = false;
+					logger.Info("Nothing to be monitored, stopped monitoring.");
+				}
+			}
+		}
+
+		private void Enforce(IFeatureConfiguration configuration, FeatureConfigurationStatus status)
+		{
+			var currentStatus = configuration.GetStatus();
+
+			if (currentStatus != status)
+			{
+				logger.Warn($"{configuration} is {currentStatus.ToString().ToLower()} instead of {status.ToString().ToLower()}!");
+
+				if (status == FeatureConfigurationStatus.Disabled)
+				{
+					configuration.DisableFeature();
+				}
+				else if (status == FeatureConfigurationStatus.Enabled)
+				{
+					configuration.EnableFeature();
+				}
+			}
+		}
+
+		private bool IsStopped()
+		{
+			lock (@lock)
+			{
+				return !running;
+			}
+		}
+	}
+}