iniwf

以下的代码描述了如何利用NTDLL.DLL中的上述几个API，实现对物理内存的读取。需要指出的是，只有system拥有读写权限，administrator只有读权限，而user连读权限都没有。这一点，是不能与专用驱动程序方法向相比的。

在VC/.NET中，由于没有相应的原型说明和库文件，我们用GetProcAddress()进行DLL显式调用。前面大段的代码，用于说明必需的类型和结构。读取物理内存的主要步骤为：打开内核对象 → 映射虚拟地址空间 → 读取(复制)内存 → 取消地址空间映射。

typedef LONG    NTSTATUS;
typedef struct _UNICODE_STRING
{
USHORT Length;
USHORT MaximumLength;
PWSTR Buffer;
} UNICODE_STRING, *PUNICODE_STRING;
typedef enum _SECTION_INHERIT
{
ViewShare = 1,
ViewUnmap = 2
} SECTION_INHERIT, *PSECTION_INHERIT;
typedef struct _OBJECT_ATTRIBUTES
{
ULONG Length;
HANDLE RootDirectory;
PUNICODE_STRING ObjectName;
ULONG Attributes;
PVOID SecurityDescriptor;
PVOID SecurityQualityOfService;
} OBJECT_ATTRIBUTES, *POBJECT_ATTRIBUTES;
#define InitializeObjectAttributes( p, n, a, r, s ) { \
(p)->Length = sizeof( OBJECT_ATTRIBUTES ); \
(p)->RootDirectory = r; \
(p)->Attributes = a; \
(p)->ObjectName = n; \
(p)->SecurityDescriptor = s; \
(p)->SecurityQualityOfService = NULL; \
}
// Interesting functions in NTDLL
typedef NTSTATUS (WINAPI *ZwOpenSectionProc)
(
PHANDLE SectionHandle,
DWORD DesiredAccess,
POBJECT_ATTRIBUTES ObjectAttributes
);
typedef NTSTATUS (WINAPI *ZwMapViewOfSectionProc)
(
HANDLE SectionHandle,
HANDLE ProcessHandle,
PVOID *BaseAddress,
ULONG ZeroBits,
ULONG CommitSize,
PLARGE_INTEGER SectionOffset,
PULONG ViewSize,
SECTION_INHERIT InheritDisposition,
ULONG AllocationType,
ULONG Protect
);
typedef NTSTATUS (WINAPI *ZwUnmapViewOfSectionProc)
(
HANDLE ProcessHandle,
PVOID BaseAddress
);
typedef VOID (WINAPI *RtlInitUnicodeStringProc)
(
IN OUT PUNICODE_STRING DestinationString,
IN PCWSTR SourceString
);
// Global variables
static HMODULE hModule = NULL;
static HANDLE hPhysicalMemory = NULL;
static ZwOpenSectionProc ZwOpenSection;
static ZwMapViewOfSectionProc ZwMapViewOfSection;
static ZwUnmapViewOfSectionProc ZwUnmapViewOfSection;
static RtlInitUnicodeStringProc RtlInitUnicodeString;
// initialize
BOOL InitPhysicalMemory()
{
if (!(hModule = LoadLibrary("ntdll.dll")))
{
return FALSE;
}
// 以下从NTDLL获取我们需要的几个函数指针
if (!(ZwOpenSection = (ZwOpenSectionProc)GetProcAddress(hModule, "ZwOpenSection")))
{
return FALSE;
}
if (!(ZwMapViewOfSection = (ZwMapViewOfSectionProc)GetProcAddress(hModule, "ZwMapViewOfSection")))
{
return FALSE;
}
if (!(ZwUnmapViewOfSection = (ZwUnmapViewOfSectionProc)GetProcAddress(hModule, "ZwUnmapViewOfSection")))
{
return FALSE;
}
if (!(RtlInitUnicodeString = (RtlInitUnicodeStringProc)GetProcAddress(hModule, "RtlInitUnicodeString")))
{
return FALSE;
}
// 以下打开内核对象
WCHAR PhysicalMemoryName[] = L"\\Device\\PhysicalMemory";
UNICODE_STRING PhysicalMemoryString;
OBJECT_ATTRIBUTES attributes;
RtlInitUnicodeString(&PhysicalMemoryString, PhysicalMemoryName);
InitializeObjectAttributes(&attributes, &PhysicalMemoryString, 0, NULL, NULL);
NTSTATUS status = ZwOpenSection(&hPhysicalMemory, SECTION_MAP_READ, &attributes );
return (status >= 0);
}
// terminate -- free handles
void ExitPhysicalMemory()
{
if (hPhysicalMemory != NULL)
{
CloseHandle(hPhysicalMemory);
}
if (hModule != NULL)
{
FreeLibrary(hModule);
}
}
BOOL ReadPhysicalMemory(PVOID buffer, DWORD address, DWORD length)
{
DWORD outlen;            // 输出长度，根据内存分页大小可能大于要求的长度
PVOID vaddress;          // 映射的虚地址
NTSTATUS status;         // NTDLL函数返回的状态
LARGE_INTEGER base;      // 物理内存地址
vaddress = 0;
outlen = length;
base.QuadPart = (ULONGLONG)(address);
// 映射物理内存地址到当前进程的虚地址空间
status = ZwMapViewOfSection(hPhysicalMemory,
(HANDLE) -1,
(PVOID *)&vaddress,
0,
length,
&base,
&outlen,
ViewShare,
0,
PAGE_READONLY);
if (status < 0)
{
return FALSE;
}
// 当前进程的虚地址空间中，复制数据到输出缓冲区
memmove(buffer, vaddress, length);
// 完成访问，取消地址映射
status = ZwUnmapViewOfSection((HANDLE)-1, (PVOID)vaddress);
return (status >= 0);
}
// 一个测试函数，从物理地址0xfe000开始，读取4096个字节
// 对于Award BIOS，可以从这段数据找到序列号等信息
BOOL test()
{
UCHAR buf[4096];
if (!InitPhysicalMemory())
{
return FALSE;
}
if (!ReadPhysicalMemory(buf, 0xfe000, 4096))
{
// ... 成功读取了指定数据
ExitPhysicalMemory();
return FALSE;
}
ExitPhysicalMemory();
return TRUE;
}

补充说明一点，由于Windows虚拟内存页面大小默认是4KB，NtMapViewOfSection()返回的虚拟空间基址是按照4KB对齐的，返回的长度也是4KB的整数倍。在上面的ReadPhysicalMemory()中，认为输入的物理地址也是4KB对齐的，如果不是，需要更加全面地考虑。

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