EmbeddingCode.cpp

#include "pch.h"
#include "EmbeddingCode.h"

DWORD align(DWORD size, DWORD align, DWORD addr) {
	if (!(size % align))
		return addr + size;
	return addr + (size / align + 1) * align;
}

std::vector<DWORD> writeNewSection(char*& programData, int& dataSize, DWORD uniqueIdentifyer, const char* nameOfSection, DWORD charicteristecs, std::vector<stringReferenceClass>& stringsToEmbed) {

    PIMAGE_DOS_HEADER pDosHeader_setup = (PIMAGE_DOS_HEADER)programData;
    PIMAGE_OPTIONAL_HEADER OH_setup = (PIMAGE_OPTIONAL_HEADER)(programData + pDosHeader_setup->e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER));

    // get size of new section and extend size appropriately

    int sizeOfNewSection = 20;
    std::vector<DWORD> addressesOfStrings;

    for (auto& string : stringsToEmbed) {
        if (string.changedString == L"")
            continue;

        sizeOfNewSection += (string.changedString.size()+1);
    };

    sizeOfNewSection = align(sizeOfNewSection, OH_setup->FileAlignment, 0);

    char* newProgramData = new char[dataSize+sizeOfNewSection]();
    memcpy(newProgramData,programData, dataSize);

    delete[] programData;
    programData = newProgramData;

    PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)programData;
    PIMAGE_FILE_HEADER FH = (PIMAGE_FILE_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD));
    PIMAGE_OPTIONAL_HEADER OH = (PIMAGE_OPTIONAL_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER));
    PIMAGE_SECTION_HEADER SH = (PIMAGE_SECTION_HEADER)(programData + pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS));

    // write new section's header into data

    ZeroMemory(&SH[FH->NumberOfSections], sizeof(IMAGE_SECTION_HEADER));
    CopyMemory(&SH[FH->NumberOfSections].Name, nameOfSection, 8);

    SH[FH->NumberOfSections].Misc.VirtualSize = align(sizeOfNewSection, OH->SectionAlignment, 0);
    SH[FH->NumberOfSections].VirtualAddress = align(SH[FH->NumberOfSections - 1].Misc.VirtualSize, OH->SectionAlignment, SH[FH->NumberOfSections - 1].VirtualAddress);

    // compiler makes theses section header values all zero later on without warning or reason so have to save the value for use
    DWORD savedRVA = SH[FH->NumberOfSections].VirtualAddress;

    SH[FH->NumberOfSections].SizeOfRawData = align(sizeOfNewSection, OH->FileAlignment, 0);
    SH[FH->NumberOfSections].PointerToRawData = dataSize;
    SH[FH->NumberOfSections].Characteristics = charicteristecs;

    OH->SizeOfImage = SH[FH->NumberOfSections].VirtualAddress + SH[FH->NumberOfSections].Misc.VirtualSize;
    FH->NumberOfSections += 1;

    // write data into new sections data

    for (int i = 0; i < 4; i++) {
        newProgramData[(dataSize)+i] = (uniqueIdentifyer >> (i * 8));
    }

    DWORD currentMemLoc = 10 + dataSize;
    for (auto& string : stringsToEmbed) {

        if (string.changedString == L"")
            continue;

        for (int i = 0; i < string.changedString.size(); i++) {
            if (string.originWasWchar)
                programData[currentMemLoc + (i*2)] = string.changedString[i];
            else
                programData[currentMemLoc + i] = string.changedString[i];
            if (i == 0)
                string.changedStringAddress = getVirtualAddressFromPyisical(currentMemLoc, dataSize, OH->ImageBase, savedRVA);
        }

        currentMemLoc += (string.changedString.size() + 2);
        if (string.originWasWchar)
            currentMemLoc += string.changedString.size();
    };

    dataSize += sizeOfNewSection;

    return addressesOfStrings;
}


void deleateLastSection(char*& programData, int& dataSize) {
	PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)programData;
	PIMAGE_FILE_HEADER FH = (PIMAGE_FILE_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD));
	PIMAGE_OPTIONAL_HEADER OH = (PIMAGE_OPTIONAL_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER));
	PIMAGE_SECTION_HEADER SH = (PIMAGE_SECTION_HEADER)(programData + pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS));

	int lastSecIndex = FH->NumberOfSections - 1;
	OH->SizeOfImage -= SH[lastSecIndex].Misc.VirtualSize;
	FH->NumberOfSections -= 1;

	int sizeOfNewFile = dataSize - SH[lastSecIndex].SizeOfRawData;
	int saved_e_lfanew = pDosHeader->e_lfanew;

	char* newProgData = new char[sizeOfNewFile];
	memcpy(newProgData, programData, sizeOfNewFile);
	delete[] programData;
	programData = newProgData;
	dataSize = sizeOfNewFile;

	void* addressOfLastSectionHeader = (programData + saved_e_lfanew + sizeof(IMAGE_NT_HEADERS)) + (lastSecIndex * sizeof(IMAGE_SECTION_HEADER));

	ZeroMemory(addressOfLastSectionHeader, sizeof(IMAGE_SECTION_HEADER));
}

// function to find position of unique identifyer
std::pair<int,int> findPosOfUniqIdentity(char*& programData,DWORD uniqueIdentifyer){

    PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)programData;
    PIMAGE_FILE_HEADER FH = (PIMAGE_FILE_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD));
   // PIMAGE_OPTIONAL_HEADER OH = (PIMAGE_OPTIONAL_HEADER)(programData + pDosHeader->e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER));
    PIMAGE_SECTION_HEADER SH = (PIMAGE_SECTION_HEADER)(programData + pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS));

    int foundPos = -1;
    int numOfSections = FH->NumberOfSections;

    for (int i = 0; i < numOfSections; i++) {
        int startOfSectionHeader = SH[i].PointerToRawData;
        int numCorrect = 0;
        for (int j = 0; j < 4; j++) {
            if (programData[(startOfSectionHeader)+j] == (char)(uniqueIdentifyer >> (j * 8)))
                numCorrect++;
        }
        if (numCorrect != 4)
            continue;

        foundPos = i;
    }

    return std::make_pair(foundPos,numOfSections);
}

bool openSectionHeader(char*& programData, int& dataSize, DWORD uniqueIdentifyer, const char* nameOfSection, DWORD charicteristecs, std::vector<stringReferenceClass>& stringsToEmbed) {

    std::pair<int,int> posData = findPosOfUniqIdentity(programData,uniqueIdentifyer);

    if(posData.first == posData.second - 1){// if the section with the uniqie id is the last section
		deleateLastSection(programData, dataSize);
		writeNewSection(programData, dataSize, uniqueIdentifyer, nameOfSection, charicteristecs, stringsToEmbed);
    }
    else if (posData.first == -1)
		writeNewSection(programData, dataSize, uniqueIdentifyer, nameOfSection, charicteristecs, stringsToEmbed);

	return 0;
}