您如何取消提升子进程的权限

Question

我知道如何使用以下进程启动具有管理员权限的进程：

proc.StartInfo.UseShellExecute = true;
proc.StartInfo.Verb = "runas";

其中 proc 是 System.Diagnostics.Process。但是如何做相反的事情呢？

如果您所在的进程已经提升，您如何在没有管理员权限的情况下启动新进程？更准确地说，我们需要以与Windows资源管理器相同的权限级别启动新进程，因此如果禁用UAC，则不会更改，但是如果启用了UAC，但我们的进程正在运行，我们需要执行某个未提升的操作因为我们正在创建一个虚拟驱动器，如果它是使用提升的权限创建的，并且 Windows 资源管理器未提升运行，它将不会显示。

请随意将标题更改为更好的名称，我想不出一个好的描述。

Answer 1

您的解决方案是使用 EXPLORER.exe 进程。

这个想法是在 UN-ELEVATED 模式下运行该进程，使用 Windows 的文件资源管理器进程 explorer.exe (info)。 假设我们要启动的进程在$TEMP\MyUnElevatedProcess.exe。

所以，对于 NSIS 代码，我只写：（但可以用任何语言运行）

 Exec '"$WINDIR\explorer.exe" "$TEMP\MyUnElevatedProcess.exe"'

示例代码（使用 NSIS 安装程序）

Exec '"$WINDIR\explorer.exe" "$TEMP\MyUnElevatedProcess.exe"'

***代码取自http://mdb-blog.blogspot.com/2013/01/nsis-lunch-program-as-user-from-uac.html

Answer 2

我们最终使用了这篇代码项目文章中的示例：High elevation can be bad for your application: How to start a non-elevated process at the end of the installation

到目前为止它似乎工作，我收集它注入到 RunDll32.exe，我的 C++/Win32 相当弱，所以我没有过多地研究实际的实现，只是它的使用。确认它适用于 x86 和 x64 的 Vista 和 Win7（至少对我们而言，x86 和 x64 需要不同的 dll，在安装时检查并使用正确的）。

Answer 3

Raymond Chen 在他的博客中谈到了这一点：

How can I launch an unelevated process from my elevated process and vice versa?

在 GitHub 中搜索此代码的 C# 版本时，我在 Microsoft 的 Node.js 工具 for Visual Studio 存储库中找到了以下实现：SystemUtilities.cs（ExecuteProcessUnElevated 函数）。

以防文件消失，这是文件的内容：

// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.

using System;
using System.Runtime.InteropServices;

namespace Microsoft.NodejsTools.SharedProject
{
    /// <summary>
    /// Utility for accessing window IShell* interfaces in order to use them to launch a process unelevated
    /// </summary>
    internal class SystemUtility
    {
        /// <summary>
        /// We are elevated and should launch the process unelevated. We can't create the
        /// process directly without it becoming elevated. So to workaround this, we have
        /// explorer do the process creation (explorer is typically running unelevated).
        /// </summary>
        internal static void ExecuteProcessUnElevated(string process, string args, string currentDirectory = "")
        {
            var shellWindows = (IShellWindows)new CShellWindows();

            // Get the desktop window
            object loc = CSIDL_Desktop;
            object unused = new object();
            int hwnd;
            var serviceProvider = (IServiceProvider)shellWindows.FindWindowSW(ref loc, ref unused, SWC_DESKTOP, out hwnd, SWFO_NEEDDISPATCH);

            // Get the shell browser
            var serviceGuid = SID_STopLevelBrowser;
            var interfaceGuid = typeof(IShellBrowser).GUID;
            var shellBrowser = (IShellBrowser)serviceProvider.QueryService(ref serviceGuid, ref interfaceGuid);

            // Get the shell dispatch
            var dispatch = typeof(IDispatch).GUID;
            var folderView = (IShellFolderViewDual)shellBrowser.QueryActiveShellView().GetItemObject(SVGIO_BACKGROUND, ref dispatch);
            var shellDispatch = (IShellDispatch2)folderView.Application;

            // Use the dispatch (which is unelevated) to launch the process for us
            shellDispatch.ShellExecute(process, args, currentDirectory, string.Empty, SW_SHOWNORMAL);
        }

        /// <summary>
        /// Interop definitions
        /// </summary>
        private const int CSIDL_Desktop = 0;
        private const int SWC_DESKTOP = 8;
        private const int SWFO_NEEDDISPATCH = 1;
        private const int SW_SHOWNORMAL = 1;
        private const int SVGIO_BACKGROUND = 0;
        private readonly static Guid SID_STopLevelBrowser = new Guid("4C96BE40-915C-11CF-99D3-00AA004AE837");

        [ComImport]
        [Guid("9BA05972-F6A8-11CF-A442-00A0C90A8F39")]
        [ClassInterfaceAttribute(ClassInterfaceType.None)]
        private class CShellWindows
        {
        }

        [ComImport]
        [Guid("85CB6900-4D95-11CF-960C-0080C7F4EE85")]
        [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
        private interface IShellWindows
        {
            [return: MarshalAs(UnmanagedType.IDispatch)]
            object FindWindowSW([MarshalAs(UnmanagedType.Struct)] ref object pvarloc, [MarshalAs(UnmanagedType.Struct)] ref object pvarlocRoot, int swClass, out int pHWND, int swfwOptions);
        }

        [ComImport]
        [Guid("6d5140c1-7436-11ce-8034-00aa006009fa")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        private interface IServiceProvider
        {
            [return: MarshalAs(UnmanagedType.Interface)]
            object QueryService(ref Guid guidService, ref Guid riid);
        }

        [ComImport]
        [Guid("000214E2-0000-0000-C000-000000000046")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        private interface IShellBrowser
        {
            void VTableGap01(); // GetWindow
            void VTableGap02(); // ContextSensitiveHelp
            void VTableGap03(); // InsertMenusSB
            void VTableGap04(); // SetMenuSB
            void VTableGap05(); // RemoveMenusSB
            void VTableGap06(); // SetStatusTextSB
            void VTableGap07(); // EnableModelessSB
            void VTableGap08(); // TranslateAcceleratorSB
            void VTableGap09(); // BrowseObject
            void VTableGap10(); // GetViewStateStream
            void VTableGap11(); // GetControlWindow
            void VTableGap12(); // SendControlMsg
            IShellView QueryActiveShellView();
        }

        [ComImport]
        [Guid("000214E3-0000-0000-C000-000000000046")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        private interface IShellView
        {
            void VTableGap01(); // GetWindow
            void VTableGap02(); // ContextSensitiveHelp
            void VTableGap03(); // TranslateAcceleratorA
            void VTableGap04(); // EnableModeless
            void VTableGap05(); // UIActivate
            void VTableGap06(); // Refresh
            void VTableGap07(); // CreateViewWindow
            void VTableGap08(); // DestroyViewWindow
            void VTableGap09(); // GetCurrentInfo
            void VTableGap10(); // AddPropertySheetPages
            void VTableGap11(); // SaveViewState
            void VTableGap12(); // SelectItem

            [return: MarshalAs(UnmanagedType.Interface)]
            object GetItemObject(UInt32 aspectOfView, ref Guid riid);
        }

        [ComImport]
        [Guid("00020400-0000-0000-C000-000000000046")]
        [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
        private interface IDispatch
        {
        }

        [ComImport]
        [Guid("E7A1AF80-4D96-11CF-960C-0080C7F4EE85")]
        [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
        private interface IShellFolderViewDual
        {
            object Application { [return: MarshalAs(UnmanagedType.IDispatch)] get; }
        }

        [ComImport]
        [Guid("A4C6892C-3BA9-11D2-9DEA-00C04FB16162")]
        [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
        public interface IShellDispatch2
        {
            void ShellExecute([MarshalAs(UnmanagedType.BStr)] string File, [MarshalAs(UnmanagedType.Struct)] object vArgs, [MarshalAs(UnmanagedType.Struct)] object vDir, [MarshalAs(UnmanagedType.Struct)] object vOperation, [MarshalAs(UnmanagedType.Struct)] object vShow);
        }
    }
}

Answer 4

如果您想从提升的进程启动未提升的进程，您可以复制 shell 进程的访问令牌并使用它来启动新进程。

public static class UnelevatedProcessStarter
{
    public static void Start(string cmdArgs)
    {
        // 1. Get the shell
        var shell = NativeMethods.GetShellWindow();
        if (shell == IntPtr.Zero)
        {
            throw new Exception("Could not find shell window");
        }

        // 2. Copy the access token of the process
        NativeMethods.GetWindowThreadProcessId(shell, out uint shellProcessId);
        var hShellProcess = NativeMethods.OpenProcess(0x00000400 /* QueryInformation */, false, (int)shellProcessId);
        if (!NativeMethods.OpenProcessToken(hShellProcess, 2 /* TOKEN_DUPLICATE */, out IntPtr hShellToken))
        {
            throw new Win32Exception();
        }

        // 3. Dublicate the acess token
        uint tokenAccess = 8 /*TOKEN_QUERY*/ | 1 /*TOKEN_ASSIGN_PRIMARY*/ | 2 /*TOKEN_DUPLICATE*/ | 0x80 /*TOKEN_ADJUST_DEFAULT*/ | 0x100 /*TOKEN_ADJUST_SESSIONID*/;
        var securityAttributes = new SecurityAttributes();

        NativeMethods.DuplicateTokenEx(
            hShellToken,
            tokenAccess,
            ref securityAttributes,
            2 /* SecurityImpersonation */,
            1 /* TokenPrimary */,
            out IntPtr hToken);

        // 4. Create a new process with the copied token
        var si = new Startupinfo();
        si.cb = Marshal.SizeOf(si);

        if (!NativeMethods.CreateProcessWithTokenW(
            hToken,
            0x00000002 /* LogonNetcredentialsOnly */,
            null,
            cmdArgs,
            0x00000010 /* CreateNewConsole */,
            IntPtr.Zero,
            null,
            ref si,
            out ProcessInformation _))
        {
            throw new Win32Exception();
        }
    }

    public class NativeMethods
    {

        [DllImport("user32.dll")]
        public static extern IntPtr GetShellWindow();
        [DllImport("user32.dll", SetLastError = true)]
        public static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern IntPtr OpenProcess(int processAccess, bool bInheritHandle, int processId);
        [DllImport("advapi32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool OpenProcessToken(IntPtr processHandle, UInt32 desiredAccess, out IntPtr tokenHandle);
        [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        public static extern bool DuplicateTokenEx(IntPtr hExistingToken, uint dwDesiredAccess,
            ref SecurityAttributes lpTokenAttributes,
            int impersonationLevel,
            int tokenType,
            out IntPtr phNewToken);
        [DllImport("advapi32", SetLastError = true, CharSet = CharSet.Unicode)]
        public static extern bool CreateProcessWithTokenW(
            IntPtr hToken, int dwLogonFlags,
            string lpApplicationName, string lpCommandLine,
            int dwCreationFlags, IntPtr lpEnvironment,
            string lpCurrentDirectory, [In] ref Startupinfo lpStartupInfo, out ProcessInformation lpProcessInformation);
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct ProcessInformation
    {
        public IntPtr hProcess;
        public IntPtr hThread;
        public int dwProcessId;
        public int dwThreadId;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SecurityAttributes
    {
        public int nLength;
        public IntPtr lpSecurityDescriptor;
        public int bInheritHandle;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct Startupinfo
    {
        public Int32 cb;
        public string lpReserved;
        public string lpDesktop;
        public string lpTitle;
        public Int32 dwX;
        public Int32 dwY;
        public Int32 dwXSize;
        public Int32 dwYSize;
        public Int32 dwXCountChars;
        public Int32 dwYCountChars;
        public Int32 dwFillAttribute;
        public Int32 dwFlags;
        public Int16 wShowWindow;
        public Int16 cbReserved2;
        public IntPtr lpReserved2;
        public IntPtr hStdInput;
        public IntPtr hStdOutput;
        public IntPtr hStdError;
    }
}

Answer 5

您可以使用ProcessStartInfo.UserName 和ProcessStartInfo.Password 指定您希望进程在其下运行的帐户。

class Program
{
    static void Main(string[] args)
    {
        var psi = new ProcessStartInfo(@"c:\windows\system32\whoami.exe");
        var password = new SecureString();
        password.AppendChar('s');
        password.AppendChar('e');
        password.AppendChar('c');
        password.AppendChar('r');
        password.AppendChar('e');
        password.AppendChar('t');
        psi.Password = password;
        psi.UserName = "username";
        psi.UseShellExecute = false;
        psi.RedirectStandardOutput = true;

        var p = new Process();
        p.StartInfo = psi;
        p.Start();
        p.WaitForExit();

        Console.WriteLine(p.StandardOutput.ReadToEnd());
    }
}