移动重定位表到新增节

一、为什么要移动重定位表

数据目录中的表是分散在各个节里的，如果对节进行加密，操作系统找不到表，就无法加载程序。因此加密前要先把表移动到新的节里。

二、怎么移动

计算重定位表的大小，首先要遍历重定位表，累加 SizeOfBlock，然后新增一个节，大小是表的大小文件对齐。最后把表复制到新增节的开头，然后更新数据目录的VirtualAddress指向新的重定位表。

三、代码

// 移动重定位表到新增节，返回新缓冲区的大小
DWORD MoveRelocationTableToNewSection(LPVOID pFileBuffer, LPVOID *pNewFileBuffer, DWORD dwFileBufferSize)
{
	PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)pFileBuffer;
	PIMAGE_FILE_HEADER pPEHeader = (PIMAGE_FILE_HEADER)(pDosHeader->e_lfanew + (DWORD)pDosHeader + 4);
	PIMAGE_OPTIONAL_HEADER32 pOptionHeader = (PIMAGE_OPTIONAL_HEADER32)((DWORD)pPEHeader + sizeof(IMAGE_FILE_HEADER));
	PIMAGE_SECTION_HEADER pSectionHeader = \
		(PIMAGE_SECTION_HEADER)((DWORD)pOptionHeader + pPEHeader->SizeOfOptionalHeader);
	
	PIMAGE_BASE_RELOCATION pRelocationTable = (PIMAGE_BASE_RELOCATION)((DWORD)pFileBuffer + \
		RvaToFoa(pFileBuffer, pOptionHeader->DataDirectory[5].VirtualAddress));

	size_t i = 0;
	DWORD dwRelocationTableSize = 0;
	while (pRelocationTable->VirtualAddress || pRelocationTable->SizeOfBlock)
	{
		dwRelocationTableSize += pRelocationTable->SizeOfBlock;
		//printf("%x\n", (pRelocationTable->SizeOfBlock - 8) / 2 );
		pRelocationTable = (PIMAGE_BASE_RELOCATION)((DWORD)pRelocationTable + pRelocationTable->SizeOfBlock);
	}
	
	DWORD dwNewBufferSize = AddSection(pFileBuffer, pNewFileBuffer, dwFileBufferSize, \
		Align(dwRelocationTableSize, pOptionHeader->FileAlignment));
	
	pDosHeader = (PIMAGE_DOS_HEADER)*pNewFileBuffer;
	pPEHeader = (PIMAGE_FILE_HEADER)(pDosHeader->e_lfanew + (DWORD)pDosHeader + 4);
	pOptionHeader = (PIMAGE_OPTIONAL_HEADER32)((DWORD)pPEHeader + sizeof(IMAGE_FILE_HEADER));
	pSectionHeader = (PIMAGE_SECTION_HEADER)((DWORD)pOptionHeader + pPEHeader->SizeOfOptionalHeader);
	
	// 修改新增节属性为可读、含已初始化数据
	pSectionHeader[pPEHeader->NumberOfSections - 1].Characteristics = 0x40000040;
	// 指针指向重定位表
	pRelocationTable = (PIMAGE_BASE_RELOCATION)((DWORD)*pNewFileBuffer + \
		RvaToFoa(*pNewFileBuffer, pOptionHeader->DataDirectory[5].VirtualAddress));
	// 定义插入点为新增节的起始地址
	LPVOID pInsert = (LPVOID)((DWORD)*pNewFileBuffer + pSectionHeader[pPEHeader->NumberOfSections - 1].PointerToRawData);
	// 拷贝重定位表
	memcpy(pInsert, (LPVOID)pRelocationTable, dwRelocationTableSize);
	// 更新目录项，指向新的重定位表
	pOptionHeader->DataDirectory[5].VirtualAddress = FoaToRva(*pNewFileBuffer, \
		(DWORD)pInsert - (DWORD)*pNewFileBuffer);
	
	return dwNewBufferSize;
}

四、运行结果

修改前和修改后对比

五、完整代码

https://blog.csdn.net/Kwansy/article/details/106234264