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// Checksum Tool
// By Bio (C) 2012
#include "common.h"
// Return codes
#define RESULT_OK 0
#define RESULT_NOTFOUND 10
#define RESULT_READERROR 20
#define RESULT_NOTPE 30
#define RESULT_CORRUPTED 40
#define RESULT_INVALID 50
#define RESULT_NONE 100
#define DEBUG_SECTIONS 1
#define DEBUG_REALLOCS 1
int debug = 0;
struct MFileMapping
{
PBYTE ptr;
HANDLE hMap, hFile;
MFileMapping(const TCHAR* ptszFileName)
{
ptr = NULL;
hMap = NULL;
hFile = CreateFile(ptszFileName, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
if (hFile != INVALID_HANDLE_VALUE)
hMap = CreateFileMapping( hFile, NULL, PAGE_WRITECOPY, 0, 0, NULL);
if (hMap)
ptr = (PBYTE)MapViewOfFile(hMap, FILE_MAP_COPY, 0, 0, 0);
}
~MFileMapping()
{
if (ptr)
UnmapViewOfFile(ptr);
if (hMap)
CloseHandle(hMap);
if (hFile != INVALID_HANDLE_VALUE)
CloseHandle(hFile);
}
};
static void PatchResourcesDirectory(PIMAGE_RESOURCE_DIRECTORY pIRD, BYTE *pBase);
static void PatchResourceEntry(PIMAGE_RESOURCE_DIRECTORY_ENTRY pIRDE, BYTE *pBase)
{
if (pIRDE->DataIsDirectory)
PatchResourcesDirectory( PIMAGE_RESOURCE_DIRECTORY(pBase + pIRDE->OffsetToDirectory), pBase);
}
static void PatchResourcesDirectory(PIMAGE_RESOURCE_DIRECTORY pIRD, PBYTE pBase)
{
UINT i;
pIRD->TimeDateStamp = 0;
PIMAGE_RESOURCE_DIRECTORY_ENTRY pIRDE = PIMAGE_RESOURCE_DIRECTORY_ENTRY(pIRD+1);
for ( i=0; i < pIRD->NumberOfNamedEntries; i++, pIRDE++ )
PatchResourceEntry(pIRDE, pBase);
for ( i=0; i < pIRD->NumberOfIdEntries; i++, pIRDE++ )
PatchResourceEntry(pIRDE, pBase);
}
int CalculateModuleHash(const TCHAR *filename, char *szDest)
{
MFileMapping map(filename);
if (map.hFile == INVALID_HANDLE_VALUE)
return RESULT_NOTFOUND;
if (map.ptr == NULL)
return RESULT_READERROR;
// check minimum and maximum size
DWORD hsize = 0, filesize = GetFileSize(map.hFile, &hsize );
if (!filesize || filesize == INVALID_FILE_SIZE || hsize)
return RESULT_INVALID;
if (filesize < sizeof(IMAGE_DOS_HEADER) + sizeof(IMAGE_NT_HEADERS))
return RESULT_NOTPE;
mir_md5_state_t pms;
mir_md5_init(&pms);
PIMAGE_DOS_HEADER pIDH = (PIMAGE_DOS_HEADER)map.ptr;
if (pIDH->e_magic != IMAGE_DOS_SIGNATURE) {
LBL_NotPE:
mir_md5_append(&pms, map.ptr, filesize);
}
else {
PIMAGE_NT_HEADERS pINTH = (PIMAGE_NT_HEADERS)(map.ptr + pIDH->e_lfanew);
if ((PBYTE)pINTH + sizeof(IMAGE_NT_HEADERS) >= map.ptr + filesize )
return RESULT_CORRUPTED;
if (pINTH->Signature != IMAGE_NT_SIGNATURE)
goto LBL_NotPE;
WORD machine = pINTH->FileHeader.Machine;
DWORD sections = pINTH->FileHeader.NumberOfSections;
if (!sections)
return RESULT_INVALID;
// try to found correct offset independent of architectures
DWORD offset = pIDH->e_lfanew + pINTH->FileHeader.SizeOfOptionalHeader + sizeof(IMAGE_NT_HEADERS) - sizeof(IMAGE_OPTIONAL_HEADER);
PBYTE pRealloc = 0;
PIMAGE_DEBUG_DIRECTORY pDBG = 0;
PIMAGE_DATA_DIRECTORY pIDD;
ULONGLONG base;
if ((machine == IMAGE_FILE_MACHINE_I386) &&
(pINTH->FileHeader.SizeOfOptionalHeader >= sizeof(IMAGE_OPTIONAL_HEADER32)) &&
(pINTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC))
{
pIDD = (PIMAGE_DATA_DIRECTORY)((PBYTE)pINTH + offsetof(IMAGE_NT_HEADERS32, OptionalHeader.DataDirectory));
base = *(DWORD*)((PBYTE)pINTH + offsetof( IMAGE_NT_HEADERS32, OptionalHeader.ImageBase ));
}
else if ((machine == IMAGE_FILE_MACHINE_AMD64) &&
(pINTH->FileHeader.SizeOfOptionalHeader >= sizeof(IMAGE_OPTIONAL_HEADER64)) &&
(pINTH->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC))
{
pIDD = (PIMAGE_DATA_DIRECTORY)((PBYTE)pINTH + offsetof(IMAGE_NT_HEADERS64, OptionalHeader.DataDirectory));
base = *(ULONGLONG*)((PBYTE)pINTH + offsetof( IMAGE_NT_HEADERS64, OptionalHeader.ImageBase ));
}
else return RESULT_CORRUPTED;
// Debugging information entry
DWORD dbgAddr = pIDD[IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress;
DWORD dbgSize = pIDD[IMAGE_DIRECTORY_ENTRY_DEBUG].Size;
// Export information entry
DWORD expAddr = pIDD[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress;
DWORD expSize = pIDD[IMAGE_DIRECTORY_ENTRY_EXPORT].Size;
// Resource directory
DWORD resAddr = pIDD[IMAGE_DIRECTORY_ENTRY_RESOURCE].VirtualAddress;
DWORD resSize = pIDD[IMAGE_DIRECTORY_ENTRY_RESOURCE].Size;
// Reallocation information entry
DWORD relocAddr = pIDD[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress;
DWORD relocSize = pIDD[IMAGE_DIRECTORY_ENTRY_BASERELOC].Size;
// verify image integrity
for (DWORD idx=0; idx < sections; idx++) {
PIMAGE_SECTION_HEADER pISH = (PIMAGE_SECTION_HEADER)(map.ptr + offset + idx * sizeof(IMAGE_SECTION_HEADER));
if (((PBYTE)pISH + sizeof(IMAGE_SECTION_HEADER) > map.ptr + filesize) || (pISH->PointerToRawData + pISH->SizeOfRawData > filesize))
return RESULT_CORRUPTED;
// erase timestamp
if (( dbgSize >= sizeof(IMAGE_DEBUG_DIRECTORY)) &&
(dbgAddr >= pISH->VirtualAddress) &&
(dbgAddr + dbgSize <= pISH->VirtualAddress + pISH->SizeOfRawData))
{
DWORD shift = dbgAddr - pISH->VirtualAddress;
pDBG = (PIMAGE_DEBUG_DIRECTORY)(map.ptr + shift + pISH->PointerToRawData);
pDBG->TimeDateStamp = 0;
}
// erase export timestamp
if ((expSize >= sizeof(IMAGE_EXPORT_DIRECTORY)) &&
(expAddr >= pISH->VirtualAddress) &&
(expAddr + expSize <= pISH->VirtualAddress + pISH->SizeOfRawData))
{
DWORD shift = expAddr - pISH->VirtualAddress;
PIMAGE_EXPORT_DIRECTORY pEXP = (PIMAGE_EXPORT_DIRECTORY)(map.ptr + shift + pISH->PointerToRawData);
pEXP->TimeDateStamp = 0;
}
// find realocation table
if ((relocSize >= sizeof(IMAGE_BASE_RELOCATION)) &&
(relocAddr >= pISH->VirtualAddress) &&
(relocAddr + relocSize <= pISH->VirtualAddress + pISH->SizeOfRawData))
{
DWORD shift = relocAddr - pISH->VirtualAddress;
pRealloc = map.ptr + shift + pISH->PointerToRawData;
}
}
for (size_t idx=0; idx < sections; idx++) {
PIMAGE_SECTION_HEADER pISH = (PIMAGE_SECTION_HEADER)(map.ptr + offset + idx * sizeof(IMAGE_SECTION_HEADER));
if (((PBYTE)pISH + sizeof(IMAGE_SECTION_HEADER) > map.ptr + filesize) || ( pISH->PointerToRawData + pISH->SizeOfRawData > filesize))
return RESULT_CORRUPTED;
// erase debug information
if (pDBG && pDBG->SizeOfData > 0 &&
pDBG->PointerToRawData >= pISH->PointerToRawData &&
pDBG->PointerToRawData + pDBG->SizeOfData <= pISH->PointerToRawData + pISH->SizeOfRawData)
{
ZeroMemory(map.ptr + pDBG->PointerToRawData, pDBG->SizeOfData);
}
// patch resources
if (resSize > 0 && resAddr >= pISH->VirtualAddress && resAddr + resSize <= pISH->VirtualAddress + pISH->SizeOfRawData) {
DWORD shift = resAddr - pISH->VirtualAddress + pISH->PointerToRawData;
IMAGE_RESOURCE_DIRECTORY *pIRD = (IMAGE_RESOURCE_DIRECTORY*)(map.ptr + shift);
PatchResourcesDirectory(pIRD, map.ptr + shift);
}
// rebase to zero address
if (pRealloc) {
DWORD blocklen = relocSize;
PIMAGE_BASE_RELOCATION pIBR = (PIMAGE_BASE_RELOCATION)pRealloc;
while(pIBR) {
if ((pIBR->VirtualAddress >= pISH->VirtualAddress) &&
(pIBR->VirtualAddress < pISH->VirtualAddress + pISH->SizeOfRawData) &&
(pIBR->SizeOfBlock <= blocklen))
{
DWORD shift = pIBR->VirtualAddress - pISH->VirtualAddress + pISH->PointerToRawData;
int len = pIBR->SizeOfBlock - sizeof(IMAGE_BASE_RELOCATION);
PWORD pw = (PWORD)((PBYTE)pIBR + sizeof(IMAGE_BASE_RELOCATION));
while(len > 0) {
DWORD type = *pw >> 12;
DWORD addr = (*pw & 0x0FFF);
PBYTE pAddr = map.ptr + shift + addr;
switch(type) {
case IMAGE_REL_BASED_HIGHLOW:
if (addr + pIBR->VirtualAddress + sizeof(DWORD) >= pISH->VirtualAddress + pISH->SizeOfRawData) {
len = 0;
break;
}
*(PDWORD)pAddr = (DWORD)((*(PDWORD)pAddr) - (DWORD)base );
break;
case IMAGE_REL_BASED_DIR64:
if (addr + pIBR->VirtualAddress + sizeof(ULONGLONG) >= pISH->VirtualAddress + pISH->SizeOfRawData) {
len = 0;
break;
}
*(ULONGLONG*)pAddr = (ULONGLONG)((*(ULONGLONG*)pAddr) - base );
break;
case IMAGE_REL_BASED_ABSOLUTE:
// stop processing
len = 0;
break;
case IMAGE_REL_BASED_HIGH:
case IMAGE_REL_BASED_LOW:
case IMAGE_REL_BASED_HIGHADJ:
break;
}
len -= sizeof(WORD);
pw++;
}
}
blocklen -= pIBR->SizeOfBlock;
if (blocklen <= sizeof(IMAGE_BASE_RELOCATION))
break;
pIBR = (PIMAGE_BASE_RELOCATION)((PBYTE)pIBR + pIBR->SizeOfBlock);
}
}
mir_md5_append(&pms, map.ptr + pISH->PointerToRawData, pISH->SizeOfRawData);
}
}
BYTE digest[16];
mir_md5_finish(&pms, digest);
bin2hex(digest, sizeof(digest), szDest);
return RESULT_OK;
}
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