C#/.NET基于Topshelf创建Windows服务的守护程序作为服务启动的客户端桌面程序不显示UI界面的问题分析和解决方案

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文章目录

C#/.NET基于Topshelf创建Windows服务的系列文章目录：

1. C#/.NET基于Topshelf创建Windows服务程序及服务的安装和卸载 (1)
2. 在C#/.NET应用程序开发中创建一个基于Topshelf的应用程序守护进程(服务) (2)
3. C#/.NET基于Topshelf创建Windows服务的守护程序作为服务启动的客户端桌面程序不显示UI界面的问题分析和解决方案 (3)

前言

在上一篇文章《在C#/.NET应用程序开发中创建一个基于Topshelf的应用程序守护进程(服务)》的最后，我给大家抛出了一个遗留的问题--在将

TopshelfDemoService

分析问题(Session 0 隔离)

通过查阅资料，这是由于Session 0 隔离作用的结果。那么什么又是Session 0 隔离呢？

在Windows XP、Windows Server 2003 或早期Windows 系统时代，当第一个用户登录系统后服务和应用程序是在同一个Session 中运行的。这就是Session 0 如下图所示：

但是这种运行方式提高了系统安全风险，因为服务是通过提升了用户权限运行的，而应用程序往往是那些不具备管理员身份的普通用户运行的，其中的危险显而易见。

从Vista 开始Session 0 中只包含系统服务，其他应用程序则通过分离的Session 运行，将服务与应用程序隔离提高系统的安全性。如下图所示：

这样使得Session 0 与其他Session 之间无法进行交互，不能通过服务向桌面用户弹出信息窗口、UI 窗口等信息。这也就是为什么刚才我说那个图已经不能通过当前桌面进行截图了。

潜在的问题

解决方案

在了解了Session 0 隔离之后，给出一些有关创建服务程序以及由服务托管的驱动程序的建议：

本文我们的服务程序将通过CreateProcessAsUser创建代理来实现Session 0隔离的穿透。

在项目[TopshelfDemoService]中创建一个静态扩展帮助类

ProcessExtensions.cs

using System;
using System.Runtime.InteropServices;

namespace TopshelfDemoService
{
/// <summary>
/// 进程静态扩展类
/// </summary>
public static class ProcessExtensions
{
#region Win32 Constants

private const int CREATE_UNICODE_ENVIRONMENT = 0x00000400;
private const int CREATE_NO_WINDOW = 0x08000000;

private const int CREATE_NEW_CONSOLE = 0x00000010;

private const uint INVALID_SESSION_ID = 0xFFFFFFFF;
private static readonly IntPtr WTS_CURRENT_SERVER_HANDLE = IntPtr.Zero;

#endregion

#region DllImports

[DllImport("advapi32.dll", EntryPoint = "CreateProcessAsUser", SetLastError = true, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
private static extern bool CreateProcessAsUser(
IntPtr hToken,
String lpApplicationName,
String lpCommandLine,
IntPtr lpProcessAttributes,
IntPtr lpThreadAttributes,
bool bInheritHandle,
uint dwCreationFlags,
IntPtr lpEnvironment,
String lpCurrentDirectory,
ref STARTUPINFO lpStartupInfo,
out PROCESS_INFORMATION lpProcessInformation);

[DllImport("advapi32.dll", EntryPoint = "DuplicateTokenEx")]
private static extern bool DuplicateTokenEx(
IntPtr ExistingTokenHandle,
uint dwDesiredAccess,
IntPtr lpThreadAttributes,
int TokenType,
int ImpersonationLevel,
ref IntPtr DuplicateTokenHandle);

[DllImport("userenv.dll", SetLastError = true)]
private static extern bool CreateEnvironmentBlock(ref IntPtr lpEnvironment, IntPtr hToken, bool bInherit);

[DllImport("userenv.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool DestroyEnvironmentBlock(IntPtr lpEnvironment);

[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool CloseHandle(IntPtr hSnapshot);

[DllImport("kernel32.dll")]
private static extern uint WTSGetActiveConsoleSessionId();

[DllImport("Wtsapi32.dll")]
private static extern uint WTSQueryUserToken(uint SessionId, ref IntPtr phToken);

[DllImport("wtsapi32.dll", SetLastError = true)]
private static extern int WTSEnumerateSessions(
IntPtr hServer,
int Reserved,
int Version,
ref IntPtr ppSessionInfo,
ref int pCount);

#endregion

#region Win32 Structs

private enum SW
{
SW_HIDE = 0,
SW_SHOWNORMAL = 1,
SW_NORMAL = 1,
SW_SHOWMINIMIZED = 2,
SW_SHOWMAXIMIZED = 3,
SW_MAXIMIZE = 3,
SW_SHOWNOACTIVATE = 4,
SW_SHOW = 5,
SW_MINIMIZE = 6,
SW_SHOWMINNOACTIVE = 7,
SW_SHOWNA = 8,
SW_RESTORE = 9,
SW_SHOWDEFAULT = 10,
SW_MAX = 10
}

private enum WTS_CONNECTSTATE_CLASS
{
WTSActive,
WTSConnected,
WTSConnectQuery,
WTSShadow,
WTSDisconnected,
WTSIdle,
WTSListen,
WTSReset,
WTSDown,
WTSInit
}

[StructLayout(LayoutKind.Sequential)]
private struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public uint dwProcessId;
public uint dwThreadId;
}

private enum SECURITY_IMPERSONATION_LEVEL
{
SecurityAnonymous = 0,
SecurityIdentification = 1,
SecurityImpersonation = 2,
SecurityDelegation = 3,
}

[StructLayout(LayoutKind.Sequential)]
private struct STARTUPINFO
{
public int cb;
public String lpReserved;
public String lpDesktop;
public String lpTitle;
public uint dwX;
public uint dwY;
public uint dwXSize;
public uint dwYSize;
public uint dwXCountChars;
public uint dwYCountChars;
public uint dwFillAttribute;
public uint dwFlags;
public short wShowWindow;
public short cbReserved2;
public IntPtr lpReserved2;
public IntPtr hStdInput;
public IntPtr hStdOutput;
public IntPtr hStdError;
}

private enum TOKEN_TYPE
{
TokenPrimary = 1,
TokenImpersonation = 2
}

[StructLayout(LayoutKind.Sequential)]
private struct WTS_SESSION_INFO
{
public readonly UInt32 SessionID;

[MarshalAs(UnmanagedType.LPStr)]
public readonly String pWinStationName;

public readonly WTS_CONNECTSTATE_CLASS State;
}

#endregion

// Gets the user token from the currently active session
private static bool GetSessionUserToken(ref IntPtr phUserToken)
{
var bResult = false;
var hImpersonationToken = IntPtr.Zero;
var activeSessionId = INVALID_SESSION_ID;
var pSessionInfo = IntPtr.Zero;
var sessionCount = 0;

// Get a handle to the user access token for the current active session.
if (WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, ref pSessionInfo, ref sessionCount) != 0)
{
var arrayElementSize = Marshal.SizeOf(typeof(WTS_SESSION_INFO));
var current = pSessionInfo;

for (var i = 0; i < sessionCount; i++)
{
var si = (WTS_SESSION_INFO)Marshal.PtrToStructure(current, typeof(WTS_SESSION_INFO));
current += arrayElementSize;

if (si.State == WTS_CONNECTSTATE_CLASS.WTSActive)
{
activeSessionId = si.SessionID;
}
}
}

// If enumerating did not work, fall back to the old method
if (activeSessionId == INVALID_SESSION_ID)
{
activeSessionId = WTSGetActiveConsoleSessionId();
}

if (WTSQueryUserToken(activeSessionId, ref hImpersonationToken) != 0)
{
// Convert the impersonation token to a primary token
bResult = DuplicateTokenEx(hImpersonationToken, 0, IntPtr.Zero,
(int)SECURITY_IMPERSONATION_LEVEL.SecurityImpersonation, (int)TOKEN_TYPE.TokenPrimary,
ref phUserToken);

CloseHandle(hImpersonationToken);
}

return bResult;
}

public static bool StartProcessAsCurrentUser(string appPath, string cmdLine = null, string workDir = null, bool visible = true)
{
var hUserToken = IntPtr.Zero;
var startInfo = new STARTUPINFO();
var procInfo = new PROCESS_INFORMATION();
var pEnv = IntPtr.Zero;
int iResultOfCreateProcessAsUser;

startInfo.cb = Marshal.SizeOf(typeof(STARTUPINFO));

try
{
if (!GetSessionUserToken(ref hUserToken))
{
throw new Exception("StartProcessAsCurrentUser: GetSessionUserToken failed.");
}

uint dwCreationFlags = CREATE_UNICODE_ENVIRONMENT | (uint)(visible ? CREATE_NEW_CONSOLE : CREATE_NO_WINDOW);
startInfo.wShowWindow = (short)(visible ? SW.SW_SHOW : SW.SW_HIDE);
startInfo.lpDesktop = "winsta0\\default";

if (!CreateEnvironmentBlock(ref pEnv, hUserToken, false))
{
throw new Exception("StartProcessAsCurrentUser: CreateEnvironmentBlock failed.");
}

if (!CreateProcessAsUser(hUserToken,
appPath, // Application Name
cmdLine, // Command Line
IntPtr.Zero,
IntPtr.Zero,
false,
dwCreationFlags,
pEnv,
workDir, // Working directory
ref startInfo,
out procInfo))
{
iResultOfCreateProcessAsUser = Marshal.GetLastWin32Error();
throw new Exception("StartProcessAsCurrentUser: CreateProcessAsUser failed.  Error Code -" + iResultOfCreateProcessAsUser);
}

iResultOfCreateProcessAsUser = Marshal.GetLastWin32Error();
}
finally
{
CloseHandle(hUserToken);
if (pEnv != IntPtr.Zero)
{
DestroyEnvironmentBlock(pEnv);
}
CloseHandle(procInfo.hThread);
CloseHandle(procInfo.hProcess);
}

return true;
}

}
}

修改

ProcessHelper.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace TopshelfDemoService
{
/// <summary>
/// 进程处理帮助类
/// </summary>
internal class ProcessorHelper
{
/// <summary>
/// 获取当前计算机所有的进程列表(集合)
/// </summary>
/// <returns></returns>
public static List<Process> GetProcessList()
{
return GetProcesses().ToList();
}

/// <summary>
/// 获取当前计算机所有的进程列表(数组)
/// </summary>
/// <returns></returns>
public static Process[] GetProcesses()
{
var processList = Process.GetProcesses();
return processList;
}

/// <summary>
/// 判断指定的进程是否存在
/// </summary>
/// <param name="processName"></param>
/// <returns></returns>
public static bool IsProcessExists(string processName)
{
return Process.GetProcessesByName(processName).Length > 0;
}

/// <summary>
/// 启动一个指定路径的应用程序
/// </summary>
/// <param name="applicationPath"></param>
/// <param name="args"></param>
public static void RunProcess(string applicationPath, string args = "")
{
try
{
ProcessExtensions.StartProcessAsCurrentUser(applicationPath, args);
}
catch (Exception e)
{
var psi = new ProcessStartInfo
{
FileName = applicationPath,
WindowStyle = ProcessWindowStyle.Normal,
Arguments = args
};
Process.Start(psi);
}
}
}
}

RunProcess()

重新编译服务程序项目[TopshelfDemoService]，并将它作为Windows服务安装，最后启动服务。守护进程服务将启动一个带UI界面的客户端程序。大功告成！！！

我是Rector，希望本文的关于Topshelf服务和守护程序设计对需要的朋友有所帮助。

感谢花你宝贵的时间阅读！！！

参考资料

穿透Session 0 隔离（一）
Windows中Session 0隔离对服务程序和驱动程序的影响
CreateProcessAsUser

源代码下载

本示例代码托管地址可以在原出处找到：示例代码下载地址