realign/functions.cpp at master · pezcode/realign · GitHub

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#include"functions.h"

#include<windows.h>
#include<cstddef>// offsetof

boolGetNTHeader(void * pMap, DWORD dwSize, IMAGE_DOS_HEADER ** opDosH, IMAGE_NT_HEADERS ** opNTH, IMAGE_SECTION_HEADER ** opSecs, WORD * onSecs)
{
IMAGE_DOS_HEADER * pDosH;
IMAGE_NT_HEADERS * pNTH;

	pDosH = (IMAGE_DOS_HEADER *)pMap;
if(dwSize > sizeof(IMAGE_DOS_HEADER) && pDosH->e_magic == IMAGE_DOS_SIGNATURE && pDosH->e_lfanew > 0 && pDosH->e_lfanew < 0x10000000)
	{
 pNTH = (IMAGE_NT_HEADERS *)((ULONG_PTR)pMap + pDosH->e_lfanew);
if(dwSize >= (pDosH->e_lfanew + sizeof(IMAGE_NT_HEADERS)) && pNTH->Signature == IMAGE_NT_SIGNATURE)
 {
if(pNTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC ||
 pNTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC)
 {
if(dwSize >= (pDosH->e_lfanew + SizeOfPEHeader(pNTH)))
 {
if(opDosH) *opDosH = pDosH;
if(opNTH) *opNTH = pNTH;
if(opSecs) *opSecs = IMAGE_FIRST_SECTION(pNTH);
if(onSecs) *onSecs = pNTH->FileHeader.NumberOfSections;
returntrue;
 }
 }
 }
	}

returnfalse;
}

IMAGE_NT_HEADERS * GetNTHeader(void * pMap)
{
IMAGE_DOS_HEADER * pDosH;
IMAGE_NT_HEADERS * pNTH;

	pDosH = (IMAGE_DOS_HEADER *)pMap;
if(pDosH->e_magic == IMAGE_DOS_SIGNATURE && pDosH->e_lfanew > 0 && pDosH->e_lfanew < 0x10000000)
	{
 pNTH = (IMAGE_NT_HEADERS *)((ULONG_PTR)pMap + pDosH->e_lfanew);
if(pNTH->Signature == IMAGE_NT_SIGNATURE)
 {
if(pNTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC ||
 pNTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC)
 {
return pNTH;
 }
 }
	}

return0;
}

DWORDSizeOfPEHeader(constIMAGE_NT_HEADERS * pNTH)
{
return (offsetof(IMAGE_NT_HEADERS, OptionalHeader) + pNTH->FileHeader.SizeOfOptionalHeader + (pNTH->FileHeader.NumberOfSections * sizeof(IMAGE_SECTION_HEADER)));
}

boolIsPE64(constIMAGE_NT_HEADERS * pNTH)
{
return (pNTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC);
}

DWORDRVAToOffset(DWORD dwRVA, constvoid * pMap)
{
constIMAGE_NT_HEADERS * pNTH;
constIMAGE_SECTION_HEADER * SectionTable;
DWORD VAddress, VSize, ROffset, RSize, UpperBound;
unsignedint i;

	pNTH = (IMAGE_NT_HEADERS *)((ULONG_PTR)pMap + ((IMAGE_DOS_HEADER *)pMap)->e_lfanew);
	SectionTable = IMAGE_FIRST_SECTION(pNTH);

if(dwRVA < SectionTable[0].VirtualAddress) // RVA points to header
return dwRVA;

for(i=0; i < pNTH->FileHeader.NumberOfSections; i++)
	{
 VAddress = SectionTable[i].VirtualAddress;
 VSize = AlignUp(SectionTable[i].Misc.VirtualSize, pNTH->OptionalHeader.SectionAlignment);
 ROffset = SectionTable[i].PointerToRawData;
 RSize = AlignUp(SectionTable[i].SizeOfRawData, pNTH->OptionalHeader.FileAlignment);

 UpperBound = (RSize < VSize) ? RSize : VSize;

if((dwRVA >= VAddress) && (dwRVA < (VAddress + UpperBound)))
 {
return (dwRVA - VAddress + ROffset);
 }
	}

return0;
}

DWORDStripSection(void * pMap, DWORD dwFsize, DWORD nSection)
{
IMAGE_NT_HEADERS * pNTH;
IMAGE_SECTION_HEADER * pSH, * pSHC;
DWORD dwNewFsize;
DWORD Diff;
unsignedint i;

	pNTH = GetNTHeader(pMap);

// section doesn't exist / only one section
if(nSection >= pNTH->FileHeader.NumberOfSections || pNTH->FileHeader.NumberOfSections == 1)
return0;

	pSHC = IMAGE_FIRST_SECTION(pNTH); // used in loop
	pSH = &pSHC[nSection]; // section to delete

	pNTH->FileHeader.NumberOfSections--;

if(nSection == pNTH->FileHeader.NumberOfSections)
	{	// last section -> truncate at section start
 dwNewFsize = pSH->PointerToRawData; // ????

 pSH--;
if(IsPE64(pNTH)){
if(pSH->Misc.PhysicalAddress)
 ((IMAGE_NT_HEADERS64 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->Misc.VirtualSize;
else// WATCOM is always a bit special >:-)
 ((IMAGE_NT_HEADERS64 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->SizeOfRawData;
 }
else{
if(pSH->Misc.PhysicalAddress)
 ((IMAGE_NT_HEADERS32 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->Misc.VirtualSize;
else
 ((IMAGE_NT_HEADERS32 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->SizeOfRawData;
 }
	}
else// not the last section
	{
if(pSH->SizeOfRawData != 0)
 {
 Diff = AlignUp(pSH->SizeOfRawData, HDR3264(pNTH, OptionalHeader.FileAlignment));

 dwNewFsize = dwFsize - Diff;

// copy section(s) after this section to the start of this section
memcpy((void *)((ULONG_PTR)pMap + pSH->PointerToRawData), (void *)((ULONG_PTR)pMap + pSH->PointerToRawData + Diff), dwFsize - pSH->PointerToRawData - Diff);

for(i=0; i <= pNTH->FileHeader.NumberOfSections; i++)
 {
if(pSHC->PointerToRawData >= (pSH->PointerToRawData + Diff))
 pSHC->PointerToRawData -= Diff;
 pSHC++;
 }
 }

// fix section header
if(nSection == 0)
 {
 pSH->SizeOfRawData = 0;
 pNTH->FileHeader.NumberOfSections++;
 }
else
 {
 (pSH-1)->Misc.VirtualSize += pSH->Misc.VirtualSize;
memcpy(pSH, (pSH+1), sizeof(IMAGE_SECTION_HEADER) * (pNTH->FileHeader.NumberOfSections-nSection));
 }
	}

if(nSection != 0)
	{ // Zerofill last section header
 pSH = IMAGE_FIRST_SECTION(pNTH);
memset(&pSH[pNTH->FileHeader.NumberOfSections], 0, sizeof(IMAGE_SECTION_HEADER));
	}

return dwNewFsize;
}

voidFixVSizes(IMAGE_NT_HEADERS * pNTH)
{
IMAGE_SECTION_HEADER * pSH;

// fix virtual parts of the PE Header (a must for win2k)
	pSH = IMAGE_FIRST_SECTION(pNTH);
for(WORD i=0; i < pNTH->FileHeader.NumberOfSections-1; i++)
	{
 pSH->Misc.VirtualSize = (pSH+1)->VirtualAddress - pSH->VirtualAddress;
 pSH++;
	}
// (pSH -> pointer to last section)

// align last section VSize to Sectionalignment
	pSH->Misc.VirtualSize = AlignUp(pSH->Misc.VirtualSize, HDR3264(pNTH, OptionalHeader.SectionAlignment));

if(IsPE64(pNTH)){
if(pSH->Misc.PhysicalAddress)
 ((IMAGE_NT_HEADERS64 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->Misc.VirtualSize;
else
 ((IMAGE_NT_HEADERS64 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->SizeOfRawData;
	}
else{
if(pSH->Misc.PhysicalAddress)
 ((IMAGE_NT_HEADERS32 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->Misc.VirtualSize;
else
 ((IMAGE_NT_HEADERS32 *)pNTH)->OptionalHeader.SizeOfImage = pSH->VirtualAddress + pSH->SizeOfRawData;
	}
}

DWORDAlignUp(DWORD dwBadSize, DWORD dwAlignment)
{
	dwAlignment--;
return ((dwBadSize+dwAlignment) & ~dwAlignment);
}

DWORDAlignDown(DWORD dwBadSize, DWORD dwAlignment)
{
	dwAlignment--;
return (dwBadSize & ~dwAlignment);
}

boolValidFileAlignment(DWORD dwAlign)
{
// lower and upper limits (pecoff spec)
constDWORDMIN_ALIGN = 0x200;
constDWORDMAX_ALIGN = 0x10000;

if((dwAlign & (dwAlign-1)) != 0) // power of 2 ?
returnfalse;

if(dwAlign < MIN_ALIGN || dwAlign > 0x10000)
returnfalse;

returntrue;
}