尝试获取客户端进程可执行路径时访问被拒绝错误

Question

我正在处理作为Windows服务托管的WCF服务,该服务使用命名管道 - NamedPipeServerStream(用户权限)在服务器和客户端进程之间建立安全连接.要检查客户端进程的真实性,我需要验证客户端进程可执行文件的数字签名,因此我试图通过使用其进程ID来获取客户端的可执行路径.

我使用Windows 7 Professional SP1(64位)操作系统和Visual Studio 2015 Community Edition进行开发.服务器(Windows服务)和客户端进程(其他exe)都只在Release x64模式下构建.

当一些客户端进程连接到服务器时,我试图获取客户端进程exe路径,但它在以下代码行中抛出"拒绝访问"错误:

return Process.GetProcessById(processId).MainModule.FileName;

因此,为了解决这个问题,我搜索了一下,并尝试了一些其他实验性试验,如下所述,似乎也没有成功.

实验试验

1. 尝试使用查询访问权限获取客户端进程句柄但失败 - >始终返回0并且最后一次Win32错误为5(拒绝访问)

OpenProcess(ProcessAccessFlags.PROCESS_QUERY_INFORMATION, false, processId);

2. 尝试使用有限的查询访问权限获取客户端进程句柄但失败 - >始终返回0并且最后一次Win32错误为5(拒绝访问)

OpenProcess(ProcessAccessFlags.PROCESS_QUERY_LIMITED_INFORMATION, false, processId);

3. 设置SeDebugPrivilege并继续获取具有有限查询权限的客户端进程句柄但失败 - > SeDebugPrivilege已启用但仍为进程句柄返回0,最后一次Win32错误为5(拒绝访问).
4. 尝试使用app.manifest文件(requireAdministrator属性)为Windows服务设置管理员权限但失败 - > 拒绝访问
5. 尝试使用ManagementObject获取进程信息属性但失败 - >对象引用未设置为对象的实例
6. 将"Windows服务"的登录帐户从"本地服务"更改为"本地系统"但失败

但是,我在一个示例Windows控制台应用程序中尝试了所有上述方法,该应用程序工作正常,没有任何错误,并且在Windows服务中也不起作用.此外,我尝试将控制台应用程序转换为dll并在服务器中引用它以获取客户端进程信息但失败 - >再次访问被拒绝

我完全不知道发生了什么以及如何解决它.你的建议真的很有帮助.

编辑:请找到OpenProcess和ProcessAccessFlags的代码片段,如下所示:

public static string GetProcessExecutablePath(int processId)
{
    try
    {
        string exePath = string.Empty;
        //If running on Vista or later use the new function
        if (Environment.OSVersion.Version.Major >= 6)
        {
            return GetProcessExecutablePathAboveVista(processId);
        }
        return Process.GetProcessById(processId).MainModule.FileName;
    }
    catch (Exception ex)
    {
        return "Exception in GetProcessExecutablePath(): " + ex.Message + ": " + ex.InnerException;
    }
}    

private static string GetProcessExecutablePathAboveVista(int processId)
{
    var buffer = new StringBuilder(1024);
    IntPtr hprocess = NativeMethods.OpenProcess(NativeMethods.ProcessAccessFlags.PROCESS_QUERY_LIMITED_INFORMATION,
                                      false, processId);
    if (hprocess != IntPtr.Zero)
    {
        try
        {
            int size = buffer.Capacity;
            if (NativeMethods.QueryFullProcessImageName(hprocess, 0, buffer, out size))
            {
                return buffer.ToString();
            }
            else
            {
                return "Failed in QueryFullProcessImageName(): " + Marshal.GetLastWin32Error();;
            }
        }
        catch (Exception ex)
        {
            return "Exception in: " + ex.Message;
        }
        finally
        {
            NativeMethods.CloseHandle(hprocess);
        }
    }
    else
    {
        return "Handle is Zero: " + Marshal.GetLastWin32Error();
    }
}

NativeMethods.cs

[Flags]
public enum ProcessAccessFlags
{
    PROCESS_TERMINATE = 0x0001,
    PROCESS_CREATE_THREAD = 0x0002,
    PROCESS_VM_OPERATION = 0x0008,
    PROCESS_VM_READ = 0x0010,
    PROCESS_VM_WRITE = 0x0020,
    PROCESS_DUP_HANDLE = 0x0040,
    PROCESS_CREATE_PROCESS = 0x0080,
    PROCESS_SET_QUOTA = 0x0100,
    PROCESS_SET_INFORMATION = 0x0200,
    PROCESS_QUERY_INFORMATION = 0x0400,
    PROCESS_SUSPEND_RESUME = 0x0800,
    PROCESS_QUERY_LIMITED_INFORMATION = 0x1000,
    SYNCHRONIZE = 0x100000,
    DELETE = 0x00010000,
    READ_CONTROL = 0x00020000,
    WRITE_DAC = 0x00040000,
    WRITE_OWNER = 0x00080000,
    STANDARD_RIGHTS_REQUIRED = 0x000F0000,
    PROCESS_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0xFFFF
}

[DllImport("Kernel32.dll", EntryPoint = "OpenProcess", SetLastError = true)]
public static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, bool bInheritHandle, int dwProcessId);

[DllImport("Kernel32.dll", EntryPoint = "QueryFullProcessImageName", SetLastError = true)]
public static extern bool QueryFullProcessImageName(IntPtr hprocess, int dwFlags, StringBuilder lpExeName, out int size);

[DllImport("Kernel32.dll", EntryPoint = "CloseHandle", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool CloseHandle(IntPtr hHandle);

Answer 1

对于从 Vista 开始的 Windows，通过 pid 获取进程映像文件名，您可以使用它NtQuerySystemInformation(SystemProcessInformation, ...)来获取SYSTEM_PROCESS_INFORMATION每个进程的结构数组。此结构必须PVOID UniqueProcessId找到您要查找的 pid 并UNICODE_STRING ImageName获取图像文件名，请参阅 https://msdn.microsoft.com/ru-ru/library/windows/desktop/ms724509(v=vs.85).aspx https ://www.geoffchappell.com/studies/windows/km/ntoskrnl/api/ex/sysinfo/process.htm