Winapi 使用EasyHook（c#）从ntdll.dll挂接NtCreateFile API

这是我第一次尝试钩住windows API。我的目标是监视进程将要创建/打开/读取/写入的所有文件。 为了尽可能详细，我决定钩住ntdll.dll API，如NtCreateFile（）和NtOpenFile（）。所以，为了实现这个目标，我选择了EasyHook，它看起来简单而健壮。 我一直遵循FileMon示例，更改了我真正想要的：Hooked函数。 当我尝试读取有关将要打开的文件的信息时，我尝试从对象属性结构中读取信息，例如 对象名。这些是整数指针，因此我希望使用函数Marshal.PtrToStringAuto（attributes.objectName）来获取字符串值。然而，结果是我只能有坏字符串，没有任何意义。此外，文件访问似乎不起作用。我想这有点不对劲 代码，可能在DllImport签名中。我不得不用IntPtr替换SafeHandle，因为EasyHook正在抱怨对它们进行编组。 有人能帮我吗

以下是我的注入DLL的特定代码：

下面是Run方法代码

public void Run(RemoteHooking.IContext InContext, String inChannelName) 
        {
            // First of all, install all the hooks
            try
            {
                // NtCreateFile
                fileCreationHook = LocalHook.Create(
                    LocalHook.GetProcAddress("ntdll.dll", "NtCreateFile"),
                    new CreateFileDelegate(CreateFile_Hooked),
                    this
                    );

                fileCreationHook = LocalHook.Create(
                    LocalHook.GetProcAddress("ntdll.dll", "NtOpenFile"),
                    new OpenFileDelegate(OpenFile_Hooked),
                    this
                    );

                fileCreationHook.ThreadACL.SetExclusiveACL(new Int32[] { 0 });
                remoteIf.Log("File creation Hook correctly installed on pid "+RemoteHooking.GetCurrentProcessId());


            }
            catch (Exception e)
            {
                remoteIf.Log(e.Message);
                remoteIf.Log(e.StackTrace);
                return;
            }

            // Wake up the process
            remoteIf.Log("Waiking up process...");
            RemoteHooking.WakeUpProcess();

            while (true)
            {
                Thread.Sleep(500);

                if (queue.Count > 0)
                {
                    String[] package = null;

                    lock (queue)
                    {
                        package = queue.ToArray();
                        queue.Clear();
                    }

                    remoteIf.OnCreateFile(RemoteHooking.GetCurrentProcessId(), package);
                }
                else
                    remoteIf.Ping();
            }

        }

以下是承包商代码：

public InjectedDLL(RemoteHooking.IContext InContext, String inChannelName)
        {
            // Create the structure which will contain all the messages
            queue = new Stack<string>();
            // Initiate the connection to the Injector process, getting back its interface
            remoteIf = RemoteHooking.IpcConnectClient<IPCInterface>(inChannelName);
            // Try invocating a method to test the connection.
            remoteIf.Ping();
        }

以下是NtDll.Dll本机函数：

[DllImport("ntdll.dll", ExactSpelling = true, SetLastError = true)]
        public static extern int NtCreateFile(
            out  IntPtr handle,
            System.IO.FileAccess access,
            ref OBJECT_ATTRIBUTES objectAttributes,
            out IO_STATUS_BLOCK ioStatus,
            ref long allocSize,
            uint fileAttributes,
            System.IO.FileShare share,
            uint createDisposition,
            uint createOptions,
            IntPtr eaBuffer,
            uint eaLength);

        [DllImport("ntdll.dll", ExactSpelling = true, SetLastError = true)]
        public static extern int NtOpenFile(
            out  IntPtr handle,
            System.IO.FileAccess access,
            ref OBJECT_ATTRIBUTES objectAttributes,
            out IO_STATUS_BLOCK ioStatus,
            System.IO.FileShare share,
            uint openOptions
            );

        [StructLayout(LayoutKind.Sequential, Pack = 0)]
        public struct OBJECT_ATTRIBUTES
        {
            public Int32 Length;
            public IntPtr RootDirectory;
            public IntPtr ObjectName;
            public uint Attributes;
            public IntPtr SecurityDescriptor;
            public IntPtr SecurityQualityOfService;

        }

        [StructLayout(LayoutKind.Sequential, Pack = 0)]
        public struct IO_STATUS_BLOCK
        {
            public uint status;
            public IntPtr information;
        }

---

ObjectName是指向UNICODE_字符串结构的指针。托管等效项如下所示：

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct UNICODE_STRING
{
    public ushort Length;
    public ushort MaximumLength;
    [MarshalAs(UnmanagedType.LPWStr)]
    public String Buffer;
}

您需要使用封送处理来获取结构的托管副本

var us = Marshal.PtrToStructure<UNICODE_STRING>(objectAttributes.ObjectName);

var us=Marshal.PtrToStructure（objectAttributes.ObjectName）；

---

拥有托管结构后，可以访问缓冲区字段以获取对象的名称。

ObjectName是指向UNICODE字符串结构的指针。托管等效项如下所示：

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct UNICODE_STRING
{
    public ushort Length;
    public ushort MaximumLength;
    [MarshalAs(UnmanagedType.LPWStr)]
    public String Buffer;
}

您需要使用封送处理来获取结构的托管副本

var us = Marshal.PtrToStructure<UNICODE_STRING>(objectAttributes.ObjectName);

var us=Marshal.PtrToStructure（objectAttributes.ObjectName）；

---

一旦您拥有托管结构，您就可以访问缓冲区字段以获取对象的名称。

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