驱动开发：PE导出函数与RVA转换
在笔者上篇文章《驱动开发：内核扫描SSDT挂钩状态》中简单介绍了如何扫描被挂钩的SSDT函数，并简单介绍了如何解析导出表，本章将继续延申PE导出表的解析，实现一系列灵活的解析如通过传入函数名解析出函数的RVA偏移，ID索引，Index下标等参数，并将其封装为可直接使用的函数，以在后期需要时可以被直接引用，同样为了节约篇幅本章中的LoadKernelFile()内存映射函数如需要使用请去前一篇文章中自行摘取。
首先实现GetRvaFromModuleName()函数，当用户传入参数后自动将函数名解析为对应的RVA偏移或Index下标索引值，该函数接收三个参数传递，分别是wzFileName模块名，FunctionName所在模块内的函数名，Flag标志参数，函数输出ULONG64类型的数据。
// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: me@lyshark.com
// 从指定模块中得到特定函数的RVA或相对序号相对偏移
ULONG64 GetRvaFromModuleName(WCHAR *wzFileName, UCHAR *FunctionName, INT Flag)
{
// 加载内核模块
PVOID BaseAddress = LoadKernelFile(wzFileName);
// 取出导出表
PIMAGE_DOS_HEADER pDosHeader;
PIMAGE_NT_HEADERS pNtHeaders;
PIMAGE_SECTION_HEADER pSectionHeader;
ULONGLONG FileOffset;
PIMAGE_EXPORT_DIRECTORY pExportDirectory;
// DLL内存数据转成DOS头结构
pDosHeader = (PIMAGE_DOS_HEADER)BaseAddress;
// 取出PE头结构
pNtHeaders = (PIMAGE_NT_HEADERS)((ULONGLONG)BaseAddress + pDosHeader->e_lfanew);
// 判断PE头导出表是否为空
if (pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress == 0)
{
return 0;
}
// 取出导出表偏移
FileOffset = pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress;
// 取出节头结构
pSectionHeader = (PIMAGE_SECTION_HEADER)((ULONGLONG)pNtHeaders + sizeof(IMAGE_NT_HEADERS));
PIMAGE_SECTION_HEADER pOldSectionHeader = pSectionHeader;
// 遍历节结构进行地址运算
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
// 导出表地址
pExportDirectory = (PIMAGE_EXPORT_DIRECTORY)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数地址
PULONG AddressOfFunctions;
FileOffset = pExportDirectory->AddressOfFunctions;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfFunctions = (PULONG)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数名字
PUSHORT AddressOfNameOrdinals;
FileOffset = pExportDirectory->AddressOfNameOrdinals;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfNameOrdinals = (PUSHORT)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数序号
PULONG AddressOfNames;
FileOffset = pExportDirectory->AddressOfNames;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfNames = (PULONG)((ULONGLONG)BaseAddress + FileOffset);
// 分析导出表
ULONG uOffset;
LPSTR FunName;
ULONG uAddressOfNames;
ULONG TargetOff = 0;
for (ULONG uIndex = 0; uIndex < pExportDirectory->NumberOfNames; uIndex++, AddressOfNames++, AddressOfNameOrdinals++)
{
uAddressOfNames = *AddressOfNames;
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= uAddressOfNames && uAddressOfNames <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
uOffset = uAddressOfNames - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
FunName = (LPSTR)((ULONGLONG)BaseAddress + uOffset);
// 如果找到则返回RVA
if (!_stricmp((const char *)FunctionName, FunName))
{
// 等于1则返回RVA
if (Flag == 1)
{
TargetOff = (ULONG)AddressOfFunctions[*AddressOfNameOrdinals];
// DbgPrint("索引 [ %p ] 函数名 [ %s ] 相对RVA [ %p ] \n", *AddressOfNameOrdinals, FunName, TargetOff);
return TargetOff;
}
// 返回索引
else if (Flag == 0)
{
return *AddressOfNameOrdinals;
}
}
}
// 结束后释放内存
ExFreePoolWithTag(BaseAddress, (ULONG)"LyShark");
return 0;
}
调用该函数很容易，传入模块路径以及该模块内的函数名，解析出RVA地址或Index下标。
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
// 函数分别传入 [模块路径,函数名,标志=1] 返回该导出函数的RVA
ULONG64 get_rva = GetRvaFromModuleName(L"\\SystemRoot\\system32\\ntoskrnl.exe", "NtReadFile", 1);
DbgPrint("NtReadFile RVA = %p \n", get_rva);
// 函数分别传入 [模块路径,函数名,标志=0] 返回该导出函数的ID下标
ULONG64 get_id = GetRvaFromModuleName(L"\\SystemRoot\\system32\\ntoskrnl.exe", "NtReadFile", 0);
DbgPrint("NtReadFile ID = %d \n", get_id);
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
编译并运行程序，分别获取到ntoskrnl.exe模块内NtReadFile函数的RVA,Index索引，调用效果如下；
第二个函数GetModuleNameFromRVA()则实现传入RVA或者函数Index序号，解析出函数名，具体实现方法与如上函数基本一致，仅仅只是在过滤时做了调整。
// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: me@lyshark.com
// 根据传入的函数RVA或Index下标，获取该函数的函数名
PCHAR GetModuleNameFromRVA(WCHAR *wzFileName, ULONG64 uRVA, INT Flag)
{
// 加载内核模块
PVOID BaseAddress = LoadKernelFile(wzFileName);
// 取出导出表
PIMAGE_DOS_HEADER pDosHeader;
PIMAGE_NT_HEADERS pNtHeaders;
PIMAGE_SECTION_HEADER pSectionHeader;
ULONGLONG FileOffset;
PIMAGE_EXPORT_DIRECTORY pExportDirectory;
// DLL内存数据转成DOS头结构
pDosHeader = (PIMAGE_DOS_HEADER)BaseAddress;
// 取出PE头结构
pNtHeaders = (PIMAGE_NT_HEADERS)((ULONGLONG)BaseAddress + pDosHeader->e_lfanew);
// 判断PE头导出表是否为空
if (pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress == 0)
{
return 0;
}
// 取出导出表偏移
FileOffset = pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress;
// 取出节头结构
pSectionHeader = (PIMAGE_SECTION_HEADER)((ULONGLONG)pNtHeaders + sizeof(IMAGE_NT_HEADERS));
PIMAGE_SECTION_HEADER pOldSectionHeader = pSectionHeader;
// 遍历节结构进行地址运算
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
// 导出表地址
pExportDirectory = (PIMAGE_EXPORT_DIRECTORY)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数地址
PULONG AddressOfFunctions;
FileOffset = pExportDirectory->AddressOfFunctions;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfFunctions = (PULONG)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数名字
PUSHORT AddressOfNameOrdinals;
FileOffset = pExportDirectory->AddressOfNameOrdinals;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfNameOrdinals = (PUSHORT)((ULONGLONG)BaseAddress + FileOffset);
// 取出导出表函数序号
PULONG AddressOfNames;
FileOffset = pExportDirectory->AddressOfNames;
// 遍历节结构进行地址运算
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= FileOffset && FileOffset <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
FileOffset = FileOffset - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
AddressOfNames = (PULONG)((ULONGLONG)BaseAddress + FileOffset);
// 分析导出表
ULONG uOffset;
LPSTR FunName;
ULONG uAddressOfNames;
ULONG TargetOff = 0;
for (ULONG uIndex = 0; uIndex < pExportDirectory->NumberOfNames; uIndex++, AddressOfNames++, AddressOfNameOrdinals++)
{
uAddressOfNames = *AddressOfNames;
pSectionHeader = pOldSectionHeader;
for (UINT16 Index = 0; Index < pNtHeaders->FileHeader.NumberOfSections; Index++, pSectionHeader++)
{
if (pSectionHeader->VirtualAddress <= uAddressOfNames && uAddressOfNames <= pSectionHeader->VirtualAddress + pSectionHeader->SizeOfRawData)
{
uOffset = uAddressOfNames - pSectionHeader->VirtualAddress + pSectionHeader->PointerToRawData;
}
}
FunName = (LPSTR)((ULONGLONG)BaseAddress + uOffset);
TargetOff = (ULONG)AddressOfFunctions[*AddressOfNameOrdinals];
// 等于1则通过RVA返回函数名
if (Flag == 1)
{
if (uRVA == TargetOff)
{
return FunName;
}
}
// 返回索引
else if (Flag == 0)
{
if (uRVA == *AddressOfNameOrdinals)
{
return FunName;
}
}
}
// 结束后释放内存
ExFreePoolWithTag(BaseAddress, (ULONG)"LyShark");
return "None";
}
调用GetModuleNameFromRVA()并传入相应的RVA偏移或Index下标。
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark.com \n");
PCHAR function_name;
// 传入函数RVA得到函数名
function_name = GetModuleNameFromRVA(L"\\SystemRoot\\system32\\ntoskrnl.exe", 0x5e5220, 1);
DbgPrint("根据RVA得到函数名 = %s \n", function_name);
// 传入函数下标得到函数名
function_name = GetModuleNameFromRVA(L"\\SystemRoot\\system32\\ntoskrnl.exe", 1472, 0);
DbgPrint("根据Index得到函数名 = %s \n", function_name);
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
编译并运行程序，调用后分别获取到RVA=0x5e5220或Index=1472的函数名；
文章出处：https://www.cnblogs.com/LyShark/p/17154175.html
本博客所有文章除特别声明外，均采用 BY-NC-SA 许可协议。转载请注明出处！
本博客所有文章除特别声明外，均采用 BY-NC-SA 许可协议。转载请注明出处！
