DWORD* CIATHook::IATHook( /*HMODULE hDllWhichImports,*/ char *DllImportsFrom, char *OldFunctionName ){
if (!this->loaded) return 0;
DWORD dwIndex;
DWORD dwOffset;
HMODULE hDllWhichImports = this->moduleimporting;
PIMAGE_DATA_DIRECTORY pDataDirectory;
PIMAGE_DOS_HEADER pDosHeader;
PDWORD pdwIAT;
PDWORD pdwINT;
PIMAGE_IMPORT_DESCRIPTOR pImportDescriptor;
PIMAGE_IMPORT_BY_NAME pImportName;
PIMAGE_OPTIONAL_HEADER pOptionalHeader;
PIMAGE_NT_HEADERS pPeHeader;
PSTR strCurrent;
//hDllWhichImports = GetModuleHandleA(DllWhichImports);
if(!hDllWhichImports) return NULL;
pDosHeader = PIMAGE_DOS_HEADER(hDllWhichImports);
dwOffset = pDosHeader->e_lfanew;
pPeHeader = PIMAGE_NT_HEADERS(long(hDllWhichImports) + dwOffset);
pOptionalHeader = &pPeHeader->OptionalHeader;
pDataDirectory = pOptionalHeader->DataDirectory;
dwOffset = pDataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress;
pImportDescriptor = PIMAGE_IMPORT_DESCRIPTOR(long(hDllWhichImports) + dwOffset);
for(dwIndex = 0; true; dwIndex++)
{
dwOffset = pImportDescriptor[dwIndex].Name;
if (!dwOffset) return NULL;
strCurrent = PSTR(long(hDllWhichImports) + dwOffset);
if(_stricmp( strCurrent, DllImportsFrom) == 0 )
{
break;
}
}
dwOffset = pImportDescriptor[dwIndex].FirstThunk;
pdwIAT = PDWORD(long(hDllWhichImports) + dwOffset);
dwOffset = pImportDescriptor[dwIndex].OriginalFirstThunk;
pdwINT = PDWORD(long(hDllWhichImports) + dwOffset);
for(dwIndex = 0; true; dwIndex++)
{
dwOffset = pdwINT[dwIndex];
if (!dwOffset) return NULL;
pImportName = PIMAGE_IMPORT_BY_NAME(long(hDllWhichImports) + dwOffset);
strCurrent = PSTR(pImportName->Name);
if(_stricmp(strCurrent, OldFunctionName) == 0)
{
return &pdwIAT[dwIndex];
}
}
return NULL;
}
PIMAGE_IMPORT_BY_NAME IATHookInjector::ReadRemoteImportByName(HANDLE hProcess, LPCVOID lpImageBaseAddress, PIMAGE_THUNK_DATA32 pImageThunk) const
{
auto lpImportNameBuffer = new BYTE[BUFFER_SIZE];
auto bSuccess = ReadProcessMemory(hProcess, LPCVOID(DWORD(lpImageBaseAddress) + pImageThunk->u1.AddressOfData), lpImportNameBuffer,BUFFER_SIZE, nullptr);
if (!bSuccess)
{
return nullptr;
}
return PIMAGE_IMPORT_BY_NAME(lpImportNameBuffer);
}