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pe-parse/parser-library/parse.cpp
Wesley Shields ec5c49eaff Make resource parsing more resilient. 
I have a UPX packed sample that corrupted the resource directory. These changes
allow the resources to be properly parsed.

They add an RVA and size to the resource struct. This is the address and size
of the resource as it is declared in the directory. If the address is invalid
create a zero-length buffer for the data. If the size is invalid (ie: it goes
off the end of the .rsrc section) create a zero-length buffer for the data.
Otherwise, return the actual data.

This allows consumers of the rsrc to figure out if the resource is corrupt
or not by comparing the length of the buffer to the size element. If the
size is greater than 0 but buffer is empty then it's invalid.

Also, it should never happen but just to be safe make pepy catch NULL
buffers (in pepy_data_converter) and return an empty bytearray.
2013-12-30 16:45:50 -05:00

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/*
The MIT License (MIT)
Copyright (c) 2013 Andrew Ruef
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
#include <list>
#include "parse.h"
#include "nt-headers.h"
#include "to_string.h"
using namespace std;
using namespace boost;
struct section {
string sectionName;
::uint32_t sectionBase;
bounded_buffer *sectionData;
image_section_header sec;
};
struct importent {
VA addr;
string symbolName;
string moduleName;
};
struct exportent {
VA addr;
string symbolName;
string moduleName;
};
struct reloc {
VA shiftedAddr;
reloc_type type;
};
struct parsed_pe_internal {
list<section> secs;
list<resource> rsrcs;
list<importent> imports;
list<reloc> relocs;
list<exportent> exports;
};
bool getSecForVA(list<section> &secs, VA v, section &sec) {
for(list<section>::iterator it = secs.begin(), e = secs.end();
it != e;
++it)
{
section s = *it;
::uint32_t low = s.sectionBase;
::uint32_t high = low + s.sec.Misc.VirtualSize;
if(v >= low && v < high) {
sec = s;
return true;
}
}
return false;
}
void IterRsrc(parsed_pe *pe, iterRsrc cb, void *cbd) {
parsed_pe_internal *pint = pe->internal;
for(list<resource>::iterator rit = pint->rsrcs.begin(), e = pint->rsrcs.end();
rit != e;
++rit)
{
resource r = *rit;
if(cb(cbd, r) != 0) {
break;
}
}
return;
}
bool parse_resource_id(bounded_buffer *data, ::uint32_t id, string &result) {
::uint8_t c;
::uint16_t len;
if (readWord(data, id, len) == false)
return false;
id += 2;
for (::uint32_t i = 0; i < len * 2; i++) {
if(readByte(data, id + i, c) == false)
return false;
result.push_back((char) c);
}
return true;
}
bool parse_resource_table(bounded_buffer *sectionData, ::uint32_t o, ::uint32_t virtaddr, ::uint32_t depth, resource_dir_entry *dirent, list<resource> &rsrcs) {
::uint32_t i = 0;
resource_dir_table rdt;
if (!sectionData)
return false;
#define READ_WORD(x) \
if(readWord(sectionData, o+_offset(resource_dir_table, x), rdt.x) == false) { \
return false; \
}
#define READ_DWORD(x) \
if(readDword(sectionData, o+_offset(resource_dir_table, x), rdt.x) == false) { \
return false; \
}
READ_DWORD(Characteristics);
READ_DWORD(TimeDateStamp);
READ_WORD(MajorVersion);
READ_WORD(MinorVersion);
READ_WORD(NameEntries);
READ_WORD(IDEntries);
#undef READ_WORD
#undef READ_DWORD
o += sizeof(resource_dir_table);
if (!rdt.NameEntries && !rdt.IDEntries)
return true; // This is not a hard error. It does happen.
for (i = 0; i < rdt.NameEntries + rdt.IDEntries; i++) {
resource_dir_entry *rde;
if (!dirent) {
rde = new resource_dir_entry();
if (!rde)
return false;
} else {
rde = dirent;
}
#define READ_DWORD(x) \
if(readDword(sectionData, o+_offset(resource_dir_entry_sz, x), rde->x) == false) { \
return false; \
}
READ_DWORD(ID);
READ_DWORD(RVA);
#undef READ_DWORD
o += sizeof(resource_dir_entry_sz);
if (depth == 0) {
rde->type = rde->ID;
if (i < rdt.NameEntries) {
if (parse_resource_id(sectionData, rde->ID & 0x0FFFFFFF, rde->type_str) == false)
return false;
}
} else if (depth == 1) {
rde->name = rde->ID;
if (i < rdt.NameEntries) {
if (parse_resource_id(sectionData, rde->ID & 0x0FFFFFFF, rde->name_str) == false)
return false;
}
} else if (depth == 2) {
rde->lang = rde->ID;
if (i < rdt.NameEntries) {
if (parse_resource_id(sectionData, rde->ID & 0x0FFFFFFF, rde->lang_str) == false)
return false;
}
}
// High bit 0 = RVA to RDT.
// High bit 1 = RVA to RDE.
if (rde->RVA & 0x80000000) {
if (parse_resource_table(sectionData, rde->RVA & 0x0FFFFFFF, virtaddr, depth + 1, rde, rsrcs) == false)
return false;
} else {
resource_dat_entry rdat;
/*
* This one is using rde->RVA as an offset.
*
* This is because we don't want to set o because we have to keep the
* original value when we are done parsing this resource data entry.
* We could store the original o value and reset it when we are done,
* but meh.
*/
#define READ_DWORD(x) \
if(readDword(sectionData, rde->RVA+_offset(resource_dat_entry, x), rdat.x) == false) { \
return false; \
}
READ_DWORD(RVA);
READ_DWORD(size);
READ_DWORD(codepage);
READ_DWORD(reserved);
#undef READ_DWORD
resource rsrc;
rsrc.type_str = rde->type_str;
rsrc.name_str = rde->name_str;
rsrc.lang_str = rde->lang_str;
rsrc.type = rde->type;
rsrc.name = rde->name;
rsrc.lang = rde->lang;
rsrc.codepage = rdat.codepage;
rsrc.RVA = rdat.RVA;
rsrc.size = rdat.size;
// The start address is (RVA - section virtual address).
uint32_t start = rdat.RVA - virtaddr;
/*
* Some binaries (particularly packed) will have invalid addresses here.
* If those happen, return a zero length buffer.
* If the start is valid, try to get the data and if that fails return
* a zero length buffer.
*/
if (start > rdat.RVA)
rsrc.buf = splitBuffer(sectionData, 0, 0);
else {
rsrc.buf = splitBuffer(sectionData, start, start + rdat.size);
if (!rsrc.buf)
rsrc.buf = splitBuffer(sectionData, 0, 0);
}
/* If we can't get even a zero length buffer, something is very wrong. */
if (!rsrc.buf)
return false;
rsrcs.push_back(rsrc);
}
}
return true;
}
bool getResources(bounded_buffer *b, bounded_buffer *fileBegin, list<section> secs, list<resource> &rsrcs) {
if (!b)
return false;
for (list<section>::iterator sit = secs.begin(), e = secs.end(); sit != e; ++sit) {
section s = *sit;
if (s.sectionName != ".rsrc")
continue;
if (parse_resource_table(s.sectionData, 0, s.sec.VirtualAddress, 0, NULL, rsrcs) == false)
return false;
break; // Because there should only be one .rsrc
}
return true;
}
bool getSections( bounded_buffer *b,
bounded_buffer *fileBegin,
nt_header_32 &nthdr,
list<section> &secs) {
if(b == NULL) {
return false;
}
//get each of the sections...
for(::uint32_t i = 0; i < nthdr.FileHeader.NumberOfSections; i++) {
image_section_header curSec;
::uint32_t o = i*sizeof(image_section_header);
for(::uint32_t k = 0; k < NT_SHORT_NAME_LEN; k++) {
if(readByte(b, o+k, curSec.Name[k]) == false) {
return false;
}
}
#define READ_WORD(x) \
if(readWord(b, o+_offset(image_section_header, x), curSec.x) == false) { \
return false; \
}
#define READ_DWORD(x) \
if(readDword(b, o+_offset(image_section_header, x), curSec.x) == false) { \
return false; \
}
READ_DWORD(Misc.VirtualSize);
READ_DWORD(VirtualAddress);
READ_DWORD(SizeOfRawData);
READ_DWORD(PointerToRawData);
READ_DWORD(PointerToRelocations);
READ_DWORD(PointerToLinenumbers);
READ_WORD(NumberOfRelocations);
READ_WORD(NumberOfLinenumbers);
READ_DWORD(Characteristics);
#undef READ_WORD
#undef READ_DWORD
//now we have the section header information, so fill in a section
//object appropriately
section thisSec;
for(::uint32_t i = 0; i < NT_SHORT_NAME_LEN; i++) {
::uint8_t c = curSec.Name[i];
if(c == 0) {
break;
}
thisSec.sectionName.push_back((char)c);
}
thisSec.sectionBase = nthdr.OptionalHeader.ImageBase+curSec.VirtualAddress;
thisSec.sec = curSec;
::uint32_t lowOff = curSec.PointerToRawData;
::uint32_t highOff = lowOff+curSec.SizeOfRawData;
thisSec.sectionData = splitBuffer(fileBegin, lowOff, highOff);
secs.push_back(thisSec);
}
return true;
}
bool readOptionalHeader(bounded_buffer *b, optional_header_32 &header) {
#define READ_WORD(x) \
if(readWord(b, _offset(optional_header_32, x), header.x) == false) { \
return false; \
}
#define READ_DWORD(x) \
if(readDword(b, _offset(optional_header_32, x), header.x) == false) { \
return false; \
}
#define READ_BYTE(x) \
if(readByte(b, _offset(optional_header_32, x), header.x) == false) { \
return false; \
}
READ_WORD(Magic);
if(header.Magic != NT_OPTIONAL_32_MAGIC) {
return false;
}
READ_BYTE(MajorLinkerVersion);
READ_BYTE(MinorLinkerVersion);
READ_DWORD(SizeOfCode);
READ_DWORD(SizeOfInitializedData);
READ_DWORD(SizeOfUninitializedData);
READ_DWORD(AddressOfEntryPoint);
READ_DWORD(BaseOfCode);
READ_DWORD(BaseOfData);
READ_DWORD(ImageBase);
READ_DWORD(SectionAlignment);
READ_DWORD(FileAlignment);
READ_WORD(MajorOperatingSystemVersion);
READ_WORD(MinorOperatingSystemVersion);
READ_WORD(MajorImageVersion);
READ_WORD(MinorImageVersion);
READ_WORD(MajorSubsystemVersion);
READ_WORD(MinorSubsystemVersion);
READ_DWORD(Win32VersionValue);
READ_DWORD(SizeOfImage);
READ_DWORD(SizeOfHeaders);
READ_DWORD(CheckSum);
READ_WORD(Subsystem);
READ_WORD(DllCharacteristics);
READ_DWORD(SizeOfStackReserve);
READ_DWORD(SizeOfStackCommit);
READ_DWORD(SizeOfHeapReserve);
READ_DWORD(SizeOfHeapCommit);
READ_DWORD(LoaderFlags);
READ_DWORD(NumberOfRvaAndSizes);
#undef READ_WORD
#undef READ_DWORD
#undef READ_BYTE
for(::uint32_t i = 0; i < header.NumberOfRvaAndSizes; i++) {
::uint32_t c = (i*sizeof(data_directory));
c+= _offset(optional_header_32, DataDirectory[0]);
::uint32_t o;
o = c + _offset(data_directory, VirtualAddress);
if(readDword(b, o, header.DataDirectory[i].VirtualAddress) == false) {
return false;
}
o = c + _offset(data_directory, Size);
if(readDword(b, o, header.DataDirectory[i].Size) == false) {
return false;
}
}
return true;
}
bool readFileHeader(bounded_buffer *b, file_header &header) {
#define READ_WORD(x) \
if(readWord(b, _offset(file_header, x), header.x) == false) { \
return false; \
}
#define READ_DWORD(x) \
if(readDword(b, _offset(file_header, x), header.x) == false) { \
return false; \
}
READ_WORD(Machine);
READ_WORD(NumberOfSections);
READ_DWORD(TimeDateStamp);
READ_DWORD(PointerToSymbolTable);
READ_DWORD(NumberOfSymbols);
READ_WORD(SizeOfOptionalHeader);
READ_WORD(Characteristics);
#undef READ_DWORD
#undef READ_WORD
return true;
}
bool readNtHeader(bounded_buffer *b, nt_header_32 &header) {
if(b == NULL) {
return false;
}
::uint32_t pe_magic;
::uint32_t curOffset =0;
if(readDword(b, curOffset, pe_magic) == false || pe_magic != NT_MAGIC) {
return false;
}
header.Signature = pe_magic;
bounded_buffer *fhb =
splitBuffer(b, _offset(nt_header_32, FileHeader), b->bufLen);
if(fhb == NULL) {
return false;
}
if(readFileHeader(fhb, header.FileHeader) == false) {
deleteBuffer(fhb);
return false;
}
bounded_buffer *ohb =
splitBuffer(b, _offset(nt_header_32, OptionalHeader), b->bufLen);
if(ohb == NULL) {
deleteBuffer(fhb);
return false;
}
if(readOptionalHeader(ohb, header.OptionalHeader) == false) {
deleteBuffer(ohb);
deleteBuffer(fhb);
return false;
}
deleteBuffer(ohb);
deleteBuffer(fhb);
return true;
}
bool getHeader(bounded_buffer *file, pe_header &p, bounded_buffer *&rem) {
if(file == NULL) {
return false;
}
//start by reading MZ
::uint16_t tmp = 0;
::uint32_t curOffset = 0;
if(readWord(file, curOffset, tmp) == false) {
return false;
}
if(tmp != MZ_MAGIC) {
return false;
}
//read the offset to the NT headers
::uint32_t offset;
if(readDword(file, _offset(dos_header, e_lfanew), offset) == false) {
return false;
}
curOffset += offset;
//now, we can read out the fields of the NT headers
bounded_buffer *ntBuf = splitBuffer(file, curOffset, file->bufLen);
if(readNtHeader(ntBuf, p.nt) == false) {
return false;
}
//update 'rem' to point to the space after the header
rem = splitBuffer(ntBuf, sizeof(nt_header_32), ntBuf->bufLen);
deleteBuffer(ntBuf);
return true;
}
parsed_pe *ParsePEFromFile(const char *filePath) {
//first, create a new parsed_pe structure
parsed_pe *p = new parsed_pe();
if(p == NULL) {
return NULL;
}
//make a new buffer object to hold just our file data
p->fileBuffer = readFileToFileBuffer(filePath);
if(p->fileBuffer == NULL) {
delete p;
return NULL;
}
p->internal = new parsed_pe_internal();
if(p->internal == NULL) {
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
//get header information
bounded_buffer *remaining = NULL;
if(getHeader(p->fileBuffer, p->peHeader, remaining) == false) {
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
bounded_buffer *file = p->fileBuffer;
if(getSections(remaining, file, p->peHeader.nt, p->internal->secs) == false) {
deleteBuffer(remaining);
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
if(getResources(remaining, file, p->internal->secs, p->internal->rsrcs) == false) {
deleteBuffer(remaining);
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
//get exports
data_directory exportDir =
p->peHeader.nt.OptionalHeader.DataDirectory[DIR_EXPORT];
if(exportDir.Size != 0) {
section s;
::uint32_t addr =
exportDir.VirtualAddress + p->peHeader.nt.OptionalHeader.ImageBase;
if(getSecForVA(p->internal->secs, addr, s) == false) {
return NULL;
}
::uint32_t rvaofft = addr - s.sectionBase;
//get the name of this module
::uint32_t nameRva;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, NameRVA),
nameRva) == false)
{
return NULL;
}
::uint32_t nameVA = nameRva + p->peHeader.nt.OptionalHeader.ImageBase;
section nameSec;
if(getSecForVA(p->internal->secs, nameVA, nameSec) == false) {
return NULL;
}
::uint32_t nameOff = nameVA - nameSec.sectionBase;
string modName;
::uint8_t c;
do {
if(readByte(nameSec.sectionData, nameOff, c) == false) {
return NULL;
}
if(c == 0) {
break;
}
modName.push_back(c);
nameOff++;
}while(true);
//now, get all the named export symbols
::uint32_t numNames;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, NumberOfNamePointers),
numNames) == false)
{
return NULL;
}
if(numNames > 0) {
//get the names section
::uint32_t namesRVA;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, NamePointerRVA),
namesRVA) == false)
{
return NULL;
}
::uint32_t namesVA =
namesRVA + p->peHeader.nt.OptionalHeader.ImageBase;
section namesSec;
if(getSecForVA(p->internal->secs, namesVA, namesSec) == false) {
return NULL;
}
::uint32_t namesOff = namesVA - namesSec.sectionBase;
//get the EAT section
::uint32_t eatRVA;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, ExportAddressTableRVA),
eatRVA) == false)
{
return NULL;
}
::uint32_t eatVA =
eatRVA + p->peHeader.nt.OptionalHeader.ImageBase;
section eatSec;
if(getSecForVA(p->internal->secs, eatVA, eatSec) == false) {
return NULL;
}
::uint32_t eatOff = eatVA - eatSec.sectionBase;
//get the ordinal base
::uint32_t ordinalBase;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, OrdinalBase),
ordinalBase) == false)
{
return NULL;
}
//get the ordinal table
::uint32_t ordinalTableRVA;
if(readDword( s.sectionData,
rvaofft+_offset(export_dir_table, OrdinalTableRVA),
ordinalTableRVA) == false)
{
return NULL;
}
::uint32_t ordinalTableVA =
ordinalTableRVA + p->peHeader.nt.OptionalHeader.ImageBase;
section ordinalTableSec;
if(getSecForVA(p->internal->secs, ordinalTableVA, ordinalTableSec) == false) {
return NULL;
}
::uint32_t ordinalOff = ordinalTableVA - ordinalTableSec.sectionBase;
for(::uint32_t i = 0; i < numNames; i++) {
::uint32_t curNameRVA;
if(readDword( namesSec.sectionData,
namesOff+(i*sizeof(::uint32_t)),
curNameRVA) == false)
{
return NULL;
}
::uint32_t curNameVA =
curNameRVA + p->peHeader.nt.OptionalHeader.ImageBase;
section curNameSec;
if(getSecForVA(p->internal->secs, curNameVA, curNameSec) == false) {
return NULL;
}
::uint32_t curNameOff = curNameVA - curNameSec.sectionBase;
string symName;
::uint8_t d;
do {
if(readByte(curNameSec.sectionData, curNameOff, d) == false) {
return NULL;
}
if(d == 0) {
break;
}
symName.push_back(d);
curNameOff++;
}while(true);
//now, for this i, look it up in the ExportOrdinalTable
::uint16_t ordinal;
if(readWord(ordinalTableSec.sectionData,
ordinalOff+(i*sizeof(uint16_t)),
ordinal) == false)
{
return NULL;
}
//::uint32_t eatIdx = ordinal - ordinalBase;
::uint32_t eatIdx = (ordinal*sizeof(uint32_t));
::uint32_t symRVA;
if(readDword(eatSec.sectionData, eatOff+eatIdx, symRVA) == false) {
return NULL;
}
bool isForwarded =
((symRVA >= exportDir.VirtualAddress) &&
(symRVA < exportDir.VirtualAddress+exportDir.Size));
if(isForwarded == false) {
::uint32_t symVA = symRVA + p->peHeader.nt.OptionalHeader.ImageBase;
exportent a;
a.addr = symVA;
a.symbolName = symName;
a.moduleName = modName;
p->internal->exports.push_back(a);
}
}
}
}
//get relocations, if exist
data_directory relocDir =
p->peHeader.nt.OptionalHeader.DataDirectory[DIR_BASERELOC];
if(relocDir.Size != 0) {
section d;
::uint32_t vaAddr =
relocDir.VirtualAddress + p->peHeader.nt.OptionalHeader.ImageBase;
if(getSecForVA(p->internal->secs, vaAddr, d) == false) {
deleteBuffer(remaining);
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
::uint32_t rvaofft = vaAddr - d.sectionBase;
::uint32_t pageRva;
::uint32_t blockSize;
if(readDword( d.sectionData,
rvaofft+_offset(reloc_block, PageRVA),
pageRva) == false)
{
return NULL;
}
if(readDword( d.sectionData,
rvaofft+_offset(reloc_block, BlockSize),
blockSize) == false)
{
return NULL;
}
//iter over all of the blocks
::uint32_t blockCount = blockSize/sizeof(::uint16_t);
rvaofft += sizeof(reloc_block);
while(blockCount != 0) {
::uint16_t block;
::uint8_t type;
::uint16_t offset;
if(readWord(d.sectionData, rvaofft, block) == false) {
return NULL;
}
//mask out the type and assign
type = block >> 12;
//mask out the offset and assign
offset = block & ~0xf000;
//produce the VA of the relocation
::uint32_t relocVA = pageRva + offset +
p->peHeader.nt.OptionalHeader.ImageBase;
//store in our list
reloc r;
r.shiftedAddr = relocVA;
r.type = (reloc_type)type;
p->internal->relocs.push_back(r);
blockCount--;
rvaofft += sizeof(::uint16_t);
}
}
//get imports
data_directory importDir =
p->peHeader.nt.OptionalHeader.DataDirectory[DIR_IMPORT];
if(importDir.Size != 0) {
//get section for the RVA in importDir
section c;
::uint32_t addr =
importDir.VirtualAddress + p->peHeader.nt.OptionalHeader.ImageBase;
if(getSecForVA(p->internal->secs, addr, c) == false) {
deleteBuffer(remaining);
deleteBuffer(p->fileBuffer);
delete p;
return NULL;
}
//get import directory from this section
::uint32_t offt = addr - c.sectionBase;
do {
#define READ_DWORD(x) \
if(readDword(c.sectionData, offt+_offset(import_dir_entry, x), curEnt.x) == false) { \
return NULL; \
}
//read each directory entry out
import_dir_entry curEnt;
READ_DWORD(LookupTableRVA);
READ_DWORD(TimeStamp);
READ_DWORD(ForwarderChain);
READ_DWORD(NameRVA);
READ_DWORD(AddressRVA);
//are all the fields in curEnt null? then we break
if( curEnt.LookupTableRVA == 0 &&
curEnt.NameRVA == 0 &&
curEnt.AddressRVA == 0) {
break;
}
//then, try and get the name of this particular module...
::uint32_t name =
curEnt.NameRVA + p->peHeader.nt.OptionalHeader.ImageBase;
section nameSec;
if(getSecForVA(p->internal->secs, name, nameSec) == false) {
return NULL;
}
::uint32_t nameOff = name - nameSec.sectionBase;
string modName;
::uint8_t c;
do {
if(readByte(nameSec.sectionData, nameOff, c) == false) {
return NULL;
}
if(c == 0) {
break;
}
modName.push_back(toupper(c));
nameOff++;
}while(true);
//then, try and get all of the sub-symbols
::uint32_t lookupVA;
if(curEnt.LookupTableRVA != 0) {
lookupVA =
curEnt.LookupTableRVA + p->peHeader.nt.OptionalHeader.ImageBase;
} else if(curEnt.AddressRVA != 0 ) {
lookupVA =
curEnt.AddressRVA + p->peHeader.nt.OptionalHeader.ImageBase;
}
section lookupSec;
if(getSecForVA(p->internal->secs, lookupVA, lookupSec) == false) {
return NULL;
}
::uint32_t lookupOff = lookupVA - lookupSec.sectionBase;
::uint32_t offInTable = 0;
do {
::uint32_t val;
if(readDword(lookupSec.sectionData, lookupOff, val) == false) {
return NULL;
}
if(val == 0) {
break;
}
//check and see if high bit is set
if(val >> 31 == 0) {
//import by name
string symName;
section symNameSec;
::uint32_t valVA = val + p->peHeader.nt.OptionalHeader.ImageBase;
if(getSecForVA(p->internal->secs, valVA, symNameSec) == false) {
return NULL;
}
::uint32_t nameOff = valVA - symNameSec.sectionBase;
nameOff += sizeof(::uint16_t);
do {
::uint8_t d;
if(readByte(symNameSec.sectionData, nameOff, d) == false) {
return NULL;
}
if(d == 0) {
break;
}
symName.push_back(d);
nameOff++;
} while(true);
//okay now we know the pair... add it
importent ent;
ent.addr = offInTable +
curEnt.AddressRVA + p->peHeader.nt.OptionalHeader.ImageBase;
ent.symbolName = symName;
ent.moduleName = modName;
p->internal->imports.push_back(ent);
} else {
//import by ordinal
//mask out 'val' so that oval is the low 16 bits of 'val'
::uint16_t oval = (val & ~0xFFFF0000);
string symName =
"ORDINAL_" + modName + "_" + to_string<uint32_t>(oval, dec);
importent ent;
ent.addr = offInTable +
curEnt.AddressRVA + p->peHeader.nt.OptionalHeader.ImageBase;
ent.symbolName = symName;
ent.moduleName = modName;
p->internal->imports.push_back(ent);
}
lookupOff += sizeof(::uint32_t);
offInTable += sizeof(::uint32_t);
} while(true);
offt += sizeof(import_dir_entry);
} while(true);
}
deleteBuffer(remaining);
#undef READ_DWORD
return p;
}
void DestructParsedPE(parsed_pe *p) {
if(p == NULL) {
return;
}
delete p->internal;
delete p;
return;
}
//iterate over the imports by VA and string
void IterImpVAString(parsed_pe *pe, iterVAStr cb, void *cbd) {
list<importent> &l = pe->internal->imports;
for(list<importent>::iterator it = l.begin(), e = l.end(); it != e; ++it) {
importent i = *it;
if(cb(cbd, i.addr, i.moduleName, i.symbolName) != 0) {
break;
}
}
return;
}
//iterate over relocations in the PE file
void IterRelocs(parsed_pe *pe, iterReloc cb, void *cbd) {
list<reloc> &l = pe->internal->relocs;
for(list<reloc>::iterator it = l.begin(), e = l.end(); it != e; ++it) {
reloc r = *it;
if(cb(cbd, r.shiftedAddr, r.type) != 0) {
break;
}
}
return;
}
//iterate over the exports by VA
void IterExpVA(parsed_pe *pe, iterExp cb, void *cbd) {
list<exportent> &l = pe->internal->exports;
for(list<exportent>::iterator it = l.begin(), e = l.end(); it != e; ++it) {
exportent i = *it;
if(cb(cbd, i.addr, i.moduleName, i.symbolName)) {
break;
}
}
return;
}
//iterate over sections
void IterSec(parsed_pe *pe, iterSec cb, void *cbd) {
parsed_pe_internal *pint = pe->internal;
for(list<section>::iterator sit = pint->secs.begin(), e = pint->secs.end();
sit != e;
++sit)
{
section s = *sit;
if(cb(cbd, s.sectionBase, s.sectionName, s.sec, s.sectionData) != 0) {
break;
}
}
return;
}
bool ReadByteAtVA(parsed_pe *pe, VA v, ::uint8_t &b) {
//find this VA in a section
section s;
if(getSecForVA(pe->internal->secs, v, s) == false) {
return false;
}
::uint32_t off = v - s.sectionBase;
return readByte(s.sectionData, off, b);
}
bool GetEntryPoint(parsed_pe *pe, VA &v) {
if(pe != NULL) {
nt_header_32 *nthdr = &pe->peHeader.nt;
v = nthdr->OptionalHeader.AddressOfEntryPoint + nthdr->OptionalHeader.ImageBase;
return true;
}
return false;
}
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