UNICODE_STRING（用户模式 内核模式）

UNICODE_STRING结构：

typedef struct  _UNICODE_STRING {

USHORT Length;                                   //字节长度，不包括终止符“NULL”
    USHORT MaximumLength;                  //字符串所能占的最大字节数字符串的指针
    PWCH   Buffer;                                       //字符串的地址，也即指针
} UNICODE_STRING;

一.用户模式初始化，拷贝操作

// UnicodeString(User).cpp : 定义控制台应用程序的入口点。
//

#include <windows.h>
#include <iostream>
using namespace std;
#define BUFFER_SIZE 0x400
typedef struct _UNICODE_STRING
{
	USHORT Length;
	USHORT MaximumLength;
    PWCHAR Buffer;
}UNICODE_STRING,*PUNICODE_STRING;

/************************************************************************/
/* 初始化                                                               */
/************************************************************************/
void InitUNICODESTRING_1();
VOID
SeRtlInitUnicodeString(
	OUT PUNICODE_STRING DestinationString,
	IN PCWSTR SourceString OPTIONAL);

void InitUNICODESTRING_2();
void InitUNICODESTRING_3();

void InitUNICODESTRING_4();
VOID
SeRtlCopyUnicodeString(
	OUT PUNICODE_STRING DestinationString,
	IN PUNICODE_STRING SourceString OPTIONAL);
VOID
SeRtlFreeUnicodeString(
	IN OUT PUNICODE_STRING UnicodeString);

/*
typedef struct _UNICODE_STRING {
USHORT  Length;     //UNICODE占用的内存字节数，个数*2；
USHORT  MaximumLength;
PWSTR  Buffer;
} UNICODE_STRING ,*PUNICODE_STRING;
*/

int main()
{
	InitUNICODESTRING_1();
	InitUNICODESTRING_2();
	InitUNICODESTRING_3();
	InitUNICODESTRING_4();
	printf("Input AnyKey To Exit\r\n");
	getchar();

    return 0;
}

void InitUNICODESTRING_1()
{

	UNICODE_STRING v1;

	SeRtlInitUnicodeString(&v1, L"HelloWorld");

	printf("%wZ\r\n", &v1); //ASCI_STRING   %Z       UNICODE_STRING   %wZ

}

VOID
SeRtlInitUnicodeString(
	OUT PUNICODE_STRING DestinationString,
	IN PCWSTR SourceString OPTIONAL)
{
	USHORT Length = 0;
	DestinationString->Length = 0;
	DestinationString->Buffer = (PWSTR)SourceString;
	if (SourceString!=NULL)
	{
		while (*SourceString++)
		{
			Length += sizeof(*SourceString);
		}
		DestinationString->Length = Length;
		DestinationString->MaximumLength = Length + (USHORT)sizeof(UNICODE_NULL);
	}
	else {
		DestinationString->MaximumLength = 0;
	}
}

void InitUNICODESTRING_2()
{
	UNICODE_STRING v1;
	WCHAR BufferData[] = L"HelloWorld";
	v1.Buffer = BufferData;
	v1.Length = wcslen(BufferData) * sizeof(WCHAR);
	v1.MaximumLength = (wcslen(BufferData) + 1) * sizeof(WCHAR);
	printf("%wZ\r\n", &v1);
}
void InitUNICODESTRING_3()
{
	UNICODE_STRING v1;
	WCHAR BufferData[] = L"HelloWorld";

	v1.Length = wcslen(BufferData) * sizeof(WCHAR);
	v1.MaximumLength = (wcslen(BufferData) + 1) * sizeof(WCHAR);
	v1.Buffer = (WCHAR*)malloc(v1.MaximumLength);
	RtlZeroMemory(v1.Buffer, v1.MaximumLength);
	RtlCopyMemory(v1.Buffer, BufferData, v1.Length);

	printf("%wZ\r\n", &v1);
	if (v1.Buffer != NULL)
	{
		free(v1.Buffer);
		v1.Buffer = NULL;
		v1.Length = v1.MaximumLength = 0;
	}
}

void InitUNICODESTRING_4()
{

	UNICODE_STRING SourceString;
	SeRtlInitUnicodeString(&SourceString, L"HelloWorld");
	UNICODE_STRING DestinationString = { 0 };
	DestinationString.Buffer = (PWSTR)malloc(BUFFER_SIZE);
	DestinationString.MaximumLength = BUFFER_SIZE;
	SeRtlCopyUnicodeString(&DestinationString, &SourceString);
	printf("SourceString:%wZ\n", &SourceString);
	printf("DestinationString:%wZ\n", &DestinationString);
	SeRtlFreeUnicodeString(&DestinationString);
}

VOID
SeRtlCopyUnicodeString(
    OUT PUNICODE_STRING DestinationString,
    IN PUNICODE_STRING SourceString OPTIONAL
    )
{
    WCHAR *v1, *v2;
    ULONG SourceStringLength = 0;

    if (SourceString!=NULL)
	{
        v2 = DestinationString->Buffer;
        v1 = SourceString->Buffer;
        SourceStringLength = SourceString->Length;
        if ((USHORT)SourceStringLength > DestinationString->MaximumLength) {
            SourceStringLength = DestinationString->MaximumLength;
        }

        DestinationString->Length = (USHORT)SourceStringLength;
        RtlCopyMemory(v2, v1, SourceStringLength);
        if (DestinationString->Length < DestinationString->MaximumLength)
		{
            v2[SourceStringLength / sizeof(WCHAR)] = UNICODE_NULL;
        }

    } else {
        DestinationString->Length = 0;
    }

    return;
}
VOID
SeRtlFreeUnicodeString(
    IN OUT PUNICODE_STRING UnicodeString
    )
{

    if (UnicodeString->Buffer)
	{
        free(UnicodeString->Buffer);
        memset( UnicodeString, 0, sizeof( *UnicodeString ) );

	}
}

　　

二.内核模式初始化，拷贝操作

　　初始化UNICODE_STRING：

　　1.常量内存，RtlInitUnicodeString 函数Buffer指针指向字符串的首地址，然后对Length和 MaximumLength成员赋值为字符串的字节数。

　　2.动态内存，ExAllocatePool函数动态分配。

3.栈区内存，局部变量手动赋值。

#include <ntifs.h>
#define  MAX_PATH 260
#define  BUFFER_SIZE 0x400

/************************************************************************/
/* 初始化                                                               */
/************************************************************************/
void Sub_1(); //常量内存
void Sub_2(); //栈区内存
void Sub_3(); //动态内存
/************************************************************************/
/* 拷贝操作                                                             */
/************************************************************************/
void Sub_4();

VOID DriverUnload(PDRIVER_OBJECT DriverObject);
//bp UnicodeString(Kernel)!DriverEntry

NTSTATUS DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegisterPath)
{
	NTSTATUS Status = STATUS_SUCCESS;
	PDEVICE_OBJECT  DeviceObject = NULL;
	DriverObject->DriverUnload = DriverUnload;

	Sub_1();
	return Status;
}

//初始操作
void Sub_1()
{
	UNICODE_STRING v1;
	RtlInitUnicodeString(&v1, L"HelloWorld");   

	DbgPrint("%wZ\r\n", &v1);
}
void Sub_2()
{
	UNICODE_STRING v1;
	WCHAR BufferData[] = L"HelloWorld";
	v1.Buffer = BufferData;
	v1.Length = wcslen(BufferData)*sizeof(WCHAR);
	v1.MaximumLength = (wcslen(BufferData)+1)*sizeof(WCHAR);
	DbgPrint("%wZ\r\n", &v1);

}
void Sub_3()
{
	UNICODE_STRING v1;
	WCHAR BufferData[] = L"HelloWorld";

	v1.Length = wcslen(BufferData) * sizeof(WCHAR);
	v1.MaximumLength = (wcslen(BufferData) + 1) * sizeof(WCHAR);
	v1.Buffer = ExAllocatePool(PagedPool, v1.MaximumLength);
	RtlZeroMemory(v1.Buffer, v1.MaximumLength);
	RtlCopyMemory(v1.Buffer,BufferData,v1.Length);

	DbgPrint("%wZ\r\n", &v1);
	if (v1.Buffer!=NULL)
	{
		ExFreePool(v1.Buffer);
		v1.Buffer = NULL;
		v1.Length = v1.MaximumLength = 0;
	}

}
//拷贝操作
void Sub_4()
{

	UNICODE_STRING SourceString;
	RtlInitUnicodeString(&SourceString, L"HelloWorld");

	UNICODE_STRING DestinationString = { 0 };
	DestinationString.Buffer = (PWSTR)ExAllocatePool(PagedPool, BUFFER_SIZE);
	DestinationString.MaximumLength = BUFFER_SIZE;

	RtlCopyUnicodeString(&DestinationString, &SourceString);

	KdPrint(("SourceString:%wZ\n", &SourceString));
	KdPrint(("DestinationString:%wZ\n", &DestinationString));
	RtlFreeUnicodeString(&DestinationString);
}

VOID DriverUnload(PDRIVER_OBJECT DriverObject)
{
	DbgPrint("DriverUnload()\r\n");
}