123 lines
3.4 KiB
C#
123 lines
3.4 KiB
C#
/*
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* Copyright (c) 2023 ETH Zürich, Educational Development and Technology (LET)
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*/
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using System;
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using System.ComponentModel;
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using System.Runtime.InteropServices;
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using SafeExamBrowser.Logging.Contracts;
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using SafeExamBrowser.WindowsApi.Constants;
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using SafeExamBrowser.WindowsApi.Contracts;
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namespace SafeExamBrowser.WindowsApi.Desktops
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{
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public class DesktopFactory : IDesktopFactory
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{
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private readonly ILogger logger;
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private readonly Random random;
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public DesktopFactory(ILogger logger)
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{
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this.logger = logger;
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this.random = new Random();
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}
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public IDesktop CreateNew(string name)
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{
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logger.Debug($"Attempting to create new desktop '{name}'...");
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var handle = User32.CreateDesktop(name, IntPtr.Zero, IntPtr.Zero, 0, (uint) AccessMask.GENERIC_ALL, IntPtr.Zero);
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if (handle == IntPtr.Zero)
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{
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logger.Error($"Failed to create new desktop '{name}'!");
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throw new Win32Exception(Marshal.GetLastWin32Error());
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}
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var desktop = new Desktop(handle, name);
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logger.Debug($"Successfully created desktop {desktop}.");
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return desktop;
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}
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public IDesktop CreateRandom()
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{
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logger.Debug($"Attempting to create random desktop...");
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var name = GenerateRandomDesktopName();
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var handle = User32.CreateDesktop(name, IntPtr.Zero, IntPtr.Zero, 0, (uint) AccessMask.GENERIC_ALL, IntPtr.Zero);
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if (handle == IntPtr.Zero)
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{
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logger.Error($"Failed to create random desktop '{name}'!");
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throw new Win32Exception(Marshal.GetLastWin32Error());
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}
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var obfuscatedHandle = new IntPtr(random.Next(100, 10000));
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var obfuscatedName = GenerateRandomDesktopName();
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var desktop = new ObfuscatedDesktop(handle, name, obfuscatedHandle, obfuscatedName);
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logger.Debug($"Successfully created random desktop {desktop}.");
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return desktop;
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}
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public IDesktop GetCurrent()
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{
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var threadId = Kernel32.GetCurrentThreadId();
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var handle = User32.GetThreadDesktop(threadId);
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var name = string.Empty;
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var nameLength = 0;
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if (handle == IntPtr.Zero)
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{
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logger.Error($"Failed to get desktop handle for thread with ID = {threadId}!");
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throw new Win32Exception(Marshal.GetLastWin32Error());
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}
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logger.Debug($"Found desktop handle for thread with ID = {threadId}. Attempting to get desktop name...");
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User32.GetUserObjectInformation(handle, Constant.UOI_NAME, IntPtr.Zero, 0, ref nameLength);
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var namePointer = Marshal.AllocHGlobal(nameLength);
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var success = User32.GetUserObjectInformation(handle, Constant.UOI_NAME, namePointer, nameLength, ref nameLength);
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if (!success)
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{
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logger.Error($"Failed to retrieve name for desktop with handle = {handle}!");
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throw new Win32Exception(Marshal.GetLastWin32Error());
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}
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name = Marshal.PtrToStringAnsi(namePointer);
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Marshal.FreeHGlobal(namePointer);
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var desktop = new Desktop(handle, name);
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logger.Debug($"Successfully determined current desktop {desktop}.");
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return desktop;
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}
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private string GenerateRandomDesktopName()
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{
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var length = random.Next(5, 20);
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var name = new char[length];
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for (var letter = 0; letter < length; letter++)
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{
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name[letter] = (char) (random.Next(2) == 0 && letter != 0 ? random.Next('a', 'z' + 1) : random.Next('A', 'Z' + 1));
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}
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return new string(name);
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}
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}
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}
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