SEBWIN-717: Merged changes & minor code cleanup.

SafeExamBrowser.SystemComponents.Contracts/ISystemInfo.cs

@@ -18,6 +18,11 @@ namespace SafeExamBrowser.SystemComponents.Contracts
 		/// </summary>
 		string BiosInfo { get; }
 
+		/// <summary>
+		/// The name of the CPU.
+		/// </summary>
+		string CpuName { get; }
+
 		/// <summary>
 		/// Reveals whether the computer system contains a battery.
 		/// </summary>

SafeExamBrowser.SystemComponents/Registry/Registry.cs

@@ -229,7 +229,6 @@ namespace SafeExamBrowser.SystemComponents.Registry
 
 			try
 			{
-				logger.Info($"default(RegistryKey) == null: {key == null}");
 				if (TryGetBaseKeyFromKeyName(keyName, out var baseKey, out var subKey))
 				{
 					key = baseKey.OpenSubKey(subKey);

SafeExamBrowser.SystemComponents/SystemInfo.cs

@@ -20,6 +20,7 @@ namespace SafeExamBrowser.SystemComponents
 	public class SystemInfo : ISystemInfo
 	{
 		public string BiosInfo { get; private set; }
+		public string CpuName { get; private set; }
 		public bool HasBattery { get; private set; }
 		public string MacAddress { get; private set; }
 		public string Manufacturer { get; private set; }
@@ -33,6 +34,7 @@ namespace SafeExamBrowser.SystemComponents
 		{
 			InitializeBattery();
 			InitializeBiosInfo();
+			InitializeCpuName();
 			InitializeMacAddress();
 			InitializeMachineInfo();
 			InitializeOperatingSystem();
@@ -79,6 +81,34 @@ namespace SafeExamBrowser.SystemComponents
 			}
 		}
 
+		private void InitializeCpuName()
+		{
+			try
+			{
+				using (var searcher = new ManagementObjectSearcher("SELECT * FROM Win32_Processor"))
+				using (var results = searcher.Get())
+				{
+					foreach (var cpu in results)
+					{
+						using (cpu)
+						{
+							foreach (var property in cpu.Properties)
+							{
+								if (property.Name.Equals("Name"))
+								{
+									CpuName = Convert.ToString(property.Value);
+								}
+							}
+						}
+					}
+				}
+			}
+			catch (Exception)
+			{
+				CpuName = "";
+			}
+		}
+
 		private void InitializeMachineInfo()
 		{
 			var model = default(string);
@@ -192,7 +222,7 @@ namespace SafeExamBrowser.SystemComponents
 				using (var searcher = new ManagementObjectSearcher("SELECT MACAddress FROM Win32_NetworkAdapterConfiguration WHERE DNSDomain IS NOT NULL"))
 				using (var results = searcher.Get())
 				{
-					if (results != null && results.Count > 0)
+					if (results != default && results.Count > 0)
 					{
 						using (var networkAdapter = results.Cast<ManagementObject>().First())
 						{
@@ -226,11 +256,11 @@ namespace SafeExamBrowser.SystemComponents
 				using (var searcher = new ManagementObjectSearcher("root\\CIMV2", "SELECT DeviceID FROM Win32_PnPEntity"))
 				using (var results = searcher.Get())
 				{
-					foreach (ManagementObject queryObj in results)
+					foreach (var device in results.Cast<ManagementObject>())
 					{
-						using (queryObj)
+						using (device)
 						{
-							foreach (var property in queryObj.Properties)
+							foreach (var property in device.Properties)
 							{
 								if (property.Name.Equals("DeviceID"))
 								{

SafeExamBrowser.SystemComponents/VirtualMachineDetector.cs

@@ -7,7 +7,6 @@
  */
 
 using System.Linq;
-using System.Management;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Registry;
@@ -16,6 +15,7 @@ namespace SafeExamBrowser.SystemComponents
 {
 	public class VirtualMachineDetector : IVirtualMachineDetector
 	{
+		private const string MANIPULATED = "000000000000";
 		private const string QEMU_MAC_PREFIX = "525400";
 		private const string VIRTUALBOX_MAC_PREFIX = "080027";
 
@@ -52,176 +52,161 @@ namespace SafeExamBrowser.SystemComponents
 
 		public bool IsVirtualMachine()
 		{
-			var biosInfo = systemInfo.BiosInfo;
-			var devices = systemInfo.PlugAndPlayDeviceIds;
 			var isVirtualMachine = false;
-			var macAddress = systemInfo.MacAddress;
-			var manufacturer = systemInfo.Manufacturer;
-			var model = systemInfo.Model;
 
+			isVirtualMachine |= HasVirtualDevice();
+			isVirtualMachine |= HasVirtualMacAddress();
+			isVirtualMachine |= IsVirtualCpu();
 			isVirtualMachine |= IsVirtualRegistry();
-			isVirtualMachine |= IsVirtualSystemInfo(biosInfo, manufacturer, model);
+			isVirtualMachine |= IsVirtualSystem(systemInfo.BiosInfo, systemInfo.Manufacturer, systemInfo.Model);
-			isVirtualMachine |= IsVirtualWmi();
-
-			if (macAddress != null && macAddress.Count() > 2)
-			{
-				isVirtualMachine |= macAddress.StartsWith(QEMU_MAC_PREFIX);
-				isVirtualMachine |= macAddress.StartsWith(VIRTUALBOX_MAC_PREFIX);
-				isVirtualMachine |= macAddress.StartsWith("000000000000");
-			}
-
-			foreach (var device in devices)
-			{
-				isVirtualMachine |= DeviceBlacklist.Any(d => device.ToLower().Contains(d.ToLower())) && DeviceWhitelist.All(d => !device.ToLower().Contains(d.ToLower()));
-			}
 
 			logger.Debug($"Computer '{systemInfo.Name}' appears {(isVirtualMachine ? "" : "not ")}to be a virtual machine.");
 
 			return isVirtualMachine;
 		}
 
-		private bool IsVirtualSystemInfo(string biosInfo, string manufacturer, string model)
+		private bool HasVirtualDevice()
 		{
-			var isVirtualMachine = false;
+			var hasVirtualDevice = false;
+
+			foreach (var device in systemInfo.PlugAndPlayDeviceIds)
+			{
+				hasVirtualDevice |= DeviceBlacklist.Any(d => device.ToLower().Contains(d.ToLower())) && DeviceWhitelist.All(d => !device.ToLower().Contains(d.ToLower()));
+			}
+
+			return hasVirtualDevice;
+		}
+
+		private bool HasVirtualMacAddress()
+		{
+			var hasVirtualMacAddress = false;
+			var macAddress = systemInfo.MacAddress;
+
+			if (macAddress != null && macAddress.Length > 2)
+			{
+				hasVirtualMacAddress |= macAddress.StartsWith(MANIPULATED);
+				hasVirtualMacAddress |= macAddress.StartsWith(QEMU_MAC_PREFIX);
+				hasVirtualMacAddress |= macAddress.StartsWith(VIRTUALBOX_MAC_PREFIX);
+			}
+
+			return hasVirtualMacAddress;
+		}
+
+		private bool IsVirtualCpu()
+		{
+			var isVirtualCpu = false;
+
+			isVirtualCpu |= systemInfo.CpuName.ToLower().Contains(" kvm ");
+
+			return isVirtualCpu;
+		}
+
+		private bool IsVirtualRegistry()
+		{
+			var isVirtualRegistry = false;
+
+			isVirtualRegistry |= HasHistoricVirtualMachineHardwareConfiguration();
+			isVirtualRegistry |= HasLocalVirtualMachineDeviceCache();
+
+			return isVirtualRegistry;
+		}
+
+		private bool IsVirtualSystem(string biosInfo, string manufacturer, string model)
+		{
+			var isVirtualSystem = false;
 
 			biosInfo = biosInfo.ToLower();
 			manufacturer = manufacturer.ToLower();
 			model = model.ToLower();
 
-			isVirtualMachine |= biosInfo.Contains("hyper-v");
+			isVirtualSystem |= biosInfo.Contains("hyper-v");
-			isVirtualMachine |= biosInfo.Contains("virtualbox");
+			isVirtualSystem |= biosInfo.Contains("virtualbox");
-			isVirtualMachine |= biosInfo.Contains("vmware");
+			isVirtualSystem |= biosInfo.Contains("vmware");
-			isVirtualMachine |= biosInfo.Contains("ovmf");
+			isVirtualSystem |= biosInfo.Contains("ovmf");
-			isVirtualMachine |= biosInfo.Contains("edk ii unknown");
+			isVirtualSystem |= biosInfo.Contains("edk ii unknown");
-			isVirtualMachine |= manufacturer.Contains("microsoft corporation") && !model.Contains("surface");
+			isVirtualSystem |= manufacturer.Contains("microsoft corporation") && !model.Contains("surface");
-			isVirtualMachine |= manufacturer.Contains("parallels software");
+			isVirtualSystem |= manufacturer.Contains("parallels software");
-			isVirtualMachine |= manufacturer.Contains("qemu");
+			isVirtualSystem |= manufacturer.Contains("qemu");
-			isVirtualMachine |= manufacturer.Contains("vmware");
+			isVirtualSystem |= manufacturer.Contains("vmware");
-			isVirtualMachine |= model.Contains("virtualbox");
+			isVirtualSystem |= model.Contains("virtualbox");
-			isVirtualMachine |= model.Contains("Q35 +");
+			isVirtualSystem |= model.Contains("Q35 +");
 
-			return isVirtualMachine;
+			return isVirtualSystem;
-		}
-
-		private bool IsVirtualRegistry()
-		{
-			var isVirtualMachine = false;
-
-			isVirtualMachine |= HasHistoricVirtualMachineHardwareConfiguration();
-			isVirtualMachine |= HasLocalVirtualMachineDeviceCache();
-
-			return isVirtualMachine;
 		}
 
 		private bool HasHistoricVirtualMachineHardwareConfiguration()
 		{
-			/** 
+			const string HARDWARE_ROOT_KEY = @"HKEY_LOCAL_MACHINE\SYSTEM\HardwareConfig";
-			 * scanned registry format:
-			 * 
-			 * HKLM\SYSTEM\HardwareConfig\{configId=uuid}
-			 *	 - BIOSVendor
-			 *	 - SystemManufacturer
-			 *	 - ...
-			 *	 \ComputerIds
-			 *	   - {computerId=uuid}: {computerSummary=hardwareInfo}
-			 * 
-			 */
-			const string HARDWARE_ROOT_KEY = "HKEY_LOCAL_MACHINE\\SYSTEM\\HardwareConfig";
 
-			var isVirtualMachine = false;
+			var hasHistoricConfiguration = false;
 
-			if (!registry.TryGetSubKeys(HARDWARE_ROOT_KEY, out var hardwareConfigSubkeys))
+			if (registry.TryGetSubKeys(HARDWARE_ROOT_KEY, out var hardwareConfigSubkeys))
 			{
-				return false;
+				foreach (var configId in hardwareConfigSubkeys)
-			}
-
-			foreach (var configId in hardwareConfigSubkeys)
-			{
-				var hardwareConfigKey = $"{HARDWARE_ROOT_KEY}\\{configId}";
-				var didReadKeys = true;
-
-				didReadKeys &= registry.TryRead(hardwareConfigKey, "BIOSVendor", out var biosVendor);
-				didReadKeys &= registry.TryRead(hardwareConfigKey, "BIOSVersion", out var biosVersion);
-				didReadKeys &= registry.TryRead(hardwareConfigKey, "SystemManufacturer", out var systemManufacturer);
-				didReadKeys &= registry.TryRead(hardwareConfigKey, "SystemProductName", out var systemProductName);
-
-				if (!didReadKeys)
 				{
-					continue;
+					var hardwareConfigKey = $"{HARDWARE_ROOT_KEY}\\{configId}";
-				}
+					var computerIdsKey = $"{hardwareConfigKey}\\ComputerIds";
+					var success = true;
 
-				var biosInfo = $"{(string) biosVendor} {(string) biosVersion}";
+					success &= registry.TryRead(hardwareConfigKey, "BIOSVendor", out var biosVendor);
+					success &= registry.TryRead(hardwareConfigKey, "BIOSVersion", out var biosVersion);
+					success &= registry.TryRead(hardwareConfigKey, "SystemManufacturer", out var systemManufacturer);
+					success &= registry.TryRead(hardwareConfigKey, "SystemProductName", out var systemProductName);
 
-				isVirtualMachine |= IsVirtualSystemInfo(biosInfo, (string) systemManufacturer, (string) systemProductName);
+					if (success)
-
-				var computerIdsKey = $"{hardwareConfigKey}\\ComputerIds";
-				if (!registry.TryGetNames(computerIdsKey, out var computerIdNames))
-				{
-					continue;
-				}
-
-				foreach (var computerIdName in computerIdNames)
-				{
-					if (!registry.TryRead(computerIdsKey, computerIdName, out var computerSummary))
 					{
-						continue;
+						var biosInfo = $"{(string) biosVendor} {(string) biosVersion}";
-					}
 
-					isVirtualMachine |= IsVirtualSystemInfo((string) computerSummary, (string) systemManufacturer, (string) systemProductName);
+						hasHistoricConfiguration |= IsVirtualSystem(biosInfo, (string) systemManufacturer, (string) systemProductName);
+
+						if (registry.TryGetNames(computerIdsKey, out var computerIdNames))
+						{
+							foreach (var computerIdName in computerIdNames)
+							{
+								if (registry.TryRead(computerIdsKey, computerIdName, out var computerSummary))
+								{
+									hasHistoricConfiguration |= IsVirtualSystem((string) computerSummary, (string) systemManufacturer, (string) systemProductName);
+								}
+							}
+						}
+					}
 				}
 			}
 
-			return isVirtualMachine;
+			return hasHistoricConfiguration;
 		}
 
 		private bool HasLocalVirtualMachineDeviceCache()
 		{
-			const string DEVICE_CACHE_PARENT_KEY = "HKEY_CURRENT_USER\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\TaskFlow\\DeviceCache";
+			const string DEVICE_CACHE_PARENT_KEY = @"HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\TaskFlow\DeviceCache";
 
-			var isVirtualMachine = false;
 			var deviceName = System.Environment.GetEnvironmentVariable("COMPUTERNAME");
+			var hasDeviceCache = false;
 			var hasDeviceCacheKeys = registry.TryGetSubKeys(DEVICE_CACHE_PARENT_KEY, out var deviceCacheKeys);
 
-			if (deviceName != null && hasDeviceCacheKeys)
+			if (deviceName != default && hasDeviceCacheKeys)
 			{
 				foreach (var cacheId in deviceCacheKeys)
 				{
-					var cacheIdKey = $"{DEVICE_CACHE_PARENT_KEY}\\{cacheId}";
+					var cacheIdKey = $@"{DEVICE_CACHE_PARENT_KEY}\{cacheId}";
 					var didReadKeys = true;
 
 					didReadKeys &= registry.TryRead(cacheIdKey, "DeviceName", out var cacheDeviceName);
 
-					if (!didReadKeys || deviceName.ToLower() != ((string) cacheDeviceName).ToLower())
+					if (didReadKeys && deviceName.ToLower() == ((string) cacheDeviceName).ToLower())
 					{
-						continue;
+						didReadKeys &= registry.TryRead(cacheIdKey, "DeviceMake", out var cacheDeviceManufacturer);
+						didReadKeys &= registry.TryRead(cacheIdKey, "DeviceModel", out var cacheDeviceModel);
+
+						if (didReadKeys)
+						{
+							hasDeviceCache |= IsVirtualSystem("", (string) cacheDeviceManufacturer, (string) cacheDeviceModel);
+						}
 					}
-
-					didReadKeys &= registry.TryRead(cacheIdKey, "DeviceMake", out var cacheDeviceManufacturer);
-					didReadKeys &= registry.TryRead(cacheIdKey, "DeviceModel", out var cacheDeviceModel);
-
-					if (!didReadKeys)
-					{
-						continue;
-					}
-
-					isVirtualMachine |= IsVirtualSystemInfo("", (string) cacheDeviceManufacturer, (string) cacheDeviceModel);
 				}
 			}
 
-			return isVirtualMachine;
+			return hasDeviceCache;
-		}
-
-		private bool IsVirtualWmi()
-		{
-			var isVirtualMachine = false;
-			var cpuObjSearcher = new ManagementObjectSearcher("SELECT * FROM Win32_Processor");
-
-			foreach (var cpuObj in cpuObjSearcher.Get())
-			{
-				isVirtualMachine |= ((string) cpuObj["Name"]).ToLower().Contains(" kvm ");
-			}
-
-			return isVirtualMachine;
 		}
 	}
 }