另類DLL載入方法 —— PEAnalyais

本文詳細介紹了PE檔案解析方法，C++源碼樣本介紹如何解析PE檔案從而打造自己的GetProcAddress，從資源檔中調用dll函數(無需釋放檔案)

轉載請註明出處：http://blog.csdn.net/wangningyu/article/details/8716586

先看圖：

代碼如下：

1、測試DLL

BOOL __stdcall MsgBox(char *pszText,char *pszTitle){return ::MessageBoxA(NULL,pszText,pszTitle,MB_OK | MB_ICONINFORMATION);}BOOL APIENTRY DllMain( HMODULE hModule,                       DWORD  ul_reason_for_call,                       LPVOID lpReserved ){switch (ul_reason_for_call){case DLL_PROCESS_ATTACH:case DLL_THREAD_ATTACH:case DLL_THREAD_DETACH:case DLL_PROCESS_DETACH:break;}return TRUE;}

2、測試工程

      XPEAnalyais.h

//////////////////////////////////////////////////////////////////////////// XPEAnalyais.h// dll loader by Koma// 感謝C++偵探、201724// http://blog.csdn.net/wangningyu#ifndef PEANALYSIS_H#define PEANALYSIS_HPIMAGE_NT_HEADERS AnalyaisImage(HMODULE hModule);FARPROC __stdcall MyGetProcAddress(HMODULE hModule,LPCSTR name);HMODULE LoadLibraryByFile(const char * pszDllPath);HMODULE LoadLibraryByResource(WORD wResID,char *pszFileType);DWORD GetPECodeEnd(HMODULE hModule);DWORD GetPEImageEnd(HMODULE hModule);DWORD GetPEImageSize(HMODULE hModule);DWORD GetCodeSize(HMODULE hModule);#endif

      XPEAnalyais.cpp

//////////////////////////////////////////////////////////////////////////// XPEAnalyais.cpp// dll loader by Koma// 感謝C++偵探、201724// http://blog.csdn.net/wangningyu#include "stdafx.h"#include "XPEAnalyais.h"#include <stdio.h>#include <assert.h>typedef BOOL (__stdcall * fnDllMain)(HINSTANCE hModule,DWORD dwReason,LPVOID lpvReserved);PIMAGE_NT_HEADERS AnalyaisImage(HMODULE hModule){PBYTE pImage = (PBYTE)hModule;PIMAGE_DOS_HEADER pImageDosHeader;PIMAGE_NT_HEADERS pImageNtHeader;pImageDosHeader = (PIMAGE_DOS_HEADER)pImage;if(pImageDosHeader->e_magic==IMAGE_DOS_SIGNATURE){pImageNtHeader = (PIMAGE_NT_HEADERS)&pImage[pImageDosHeader->e_lfanew];if(pImageNtHeader->Signature==IMAGE_NT_SIGNATURE){return pImageNtHeader;}}return NULL;}FARPROC __stdcall MyGetProcAddress(HMODULE hModule,LPCSTR name){if(!hModule){hModule = GetModuleHandle(0);}PBYTE pDest = (PBYTE)hModule;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest;PIMAGE_DATA_DIRECTORY pDirectory;PIMAGE_EXPORT_DIRECTORY pExport;DWORD i, *nameRef;WORD *ordinal;int idx=-1;pImageDosDest = (PIMAGE_DOS_HEADER)pDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pDest[pImageDosDest->e_lfanew];pDirectory = &pImageNtDest->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];if(pDirectory->Size==0)return NULL;pExport = (PIMAGE_EXPORT_DIRECTORY)((DWORD)pDest + pDirectory->VirtualAddress);if(pExport->NumberOfNames == 0 || pExport->NumberOfFunctions == 0)return NULL;ordinal = (WORD *) ((DWORD)pDest + pExport->AddressOfNameOrdinals);if((DWORD)(name) < 0x10000){if ((DWORD)name >= pExport->NumberOfFunctions+pExport->Base || (DWORD)name < pExport->Base)return NULL;idx = (DWORD)pDest+((DWORD*)((DWORD)pDest+pExport->AddressOfFunctions))[(DWORD)name-pExport->Base];}else{nameRef = (DWORD *) ((DWORD)pDest + pExport->AddressOfNames);for (i=0; i<pExport->NumberOfNames; i++, nameRef++, ordinal++) {if (strcmp(name, (const char *) ((DWORD)pDest + (*nameRef))) == 0) {idx = *ordinal;break;}}}if (idx == -1) {return NULL;}if ((DWORD)idx > pExport->NumberOfFunctions) {return NULL;}return (FARPROC) ((DWORD)hModule + (*(DWORD *) ((DWORD)hModule + pExport->AddressOfFunctions + (idx*4))));}void CopySection(PBYTE pSrc,PBYTE pDest){unsigned int i,size;PIMAGE_DOS_HEADER pImageDosSrc;PIMAGE_NT_HEADERS pImageNtSrc;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest;PIMAGE_SECTION_HEADER pSection;pImageDosSrc = (PIMAGE_DOS_HEADER)pSrc;pImageNtSrc = (PIMAGE_NT_HEADERS)&pSrc[pImageDosSrc->e_lfanew];pImageDosDest = (PIMAGE_DOS_HEADER)pDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pDest[pImageDosDest->e_lfanew];pSection = IMAGE_FIRST_SECTION(pImageNtDest);for(i=0;i<pImageNtDest->FileHeader.NumberOfSections;i++,pSection++){if(pSection->SizeOfRawData == 0){size = pImageNtSrc->OptionalHeader.SectionAlignment;if(size > 0){pSection->Misc.PhysicalAddress = pSection->VirtualAddress + (DWORD)pDest;memset((PVOID)pSection->Misc.PhysicalAddress,0,size);}continue;}pSection->Misc.PhysicalAddress = pSection->VirtualAddress + (DWORD)pDest;memcpy((PVOID)pSection->Misc.PhysicalAddress, (PVOID)((DWORD)pSrc + pSection->PointerToRawData), pSection->SizeOfRawData);}}void GetImportInfo(DWORD imgbase,DWORD impoff){PIMAGE_IMPORT_DESCRIPTOR pImport = (PIMAGE_IMPORT_DESCRIPTOR)(imgbase+impoff);HMODULE hModuleSys;DWORD i,p;PIMAGE_THUNK_DATA32 pimpthunk;PIMAGE_IMPORT_BY_NAME pimpname;FARPROC* pimpwrite;FARPROC pFunc;for(i=0;pImport[i].Characteristics!=0;i++){hModuleSys = LoadLibraryA((LPCSTR)(pImport[i].Name + imgbase));pimpthunk = (PIMAGE_THUNK_DATA32)(pImport[i].OriginalFirstThunk + imgbase);pimpwrite = (FARPROC*)(pImport[i].FirstThunk + imgbase);for(p=0;pimpthunk[p].u1.AddressOfData!=0;p++){pimpname = (PIMAGE_IMPORT_BY_NAME)((DWORD)pimpthunk[p].u1.AddressOfData+imgbase);if(IMAGE_SNAP_BY_ORDINAL32(pimpthunk[p].u1.AddressOfData)){pFunc = GetProcAddress(hModuleSys,(LPCSTR)IMAGE_ORDINAL(pimpthunk[p].u1.AddressOfData));pimpwrite[p] = pFunc;}else{pFunc = GetProcAddress(hModuleSys,(LPCSTR)&pimpname->Name);pimpwrite[p] = pFunc;}}}}void LoadImport(PBYTE pSrc,PBYTE pDest){PIMAGE_DOS_HEADER pImageDosSrc;PIMAGE_NT_HEADERS pImageNtSrc;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest; PIMAGE_DATA_DIRECTORY pDirectory;pImageDosSrc = (PIMAGE_DOS_HEADER)pSrc;pImageNtSrc = (PIMAGE_NT_HEADERS)&pSrc[pImageDosSrc->e_lfanew];pImageDosDest = (PIMAGE_DOS_HEADER)pDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pDest[pImageDosDest->e_lfanew];pDirectory = &pImageNtDest->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];if(!pDirectory->VirtualAddress)return;GetImportInfo((DWORD)pDest,pDirectory->VirtualAddress);}bool check_import(HMODULE hModule){PBYTE pImage = (PBYTE)hModule;PIMAGE_DOS_HEADER pImageDos;PIMAGE_NT_HEADERS pImageNT;PIMAGE_DATA_DIRECTORY pDataDirectory;PIMAGE_IMPORT_DESCRIPTOR pImportDescriptor;pImageDos = (PIMAGE_DOS_HEADER)pImage;pImageNT = (PIMAGE_NT_HEADERS)&pImage[pImageDos->e_lfanew];pDataDirectory = &pImageNT->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];if(!pDataDirectory->VirtualAddress)return false;pImportDescriptor = (PIMAGE_IMPORT_DESCRIPTOR)&pImage[pDataDirectory->VirtualAddress];for(int i=0;pImportDescriptor[i].Characteristics!=0;i++){HMODULE hCurrentModule = LoadLibraryA((LPCSTR)(&pImage[pImportDescriptor[i].Name]));PIMAGE_THUNK_DATA32 pCurrentImportThunk = (PIMAGE_THUNK_DATA32)(&pImage[pImportDescriptor[i].OriginalFirstThunk]);FARPROC* pCurrentImportList = (FARPROC*)(&pImage[pImportDescriptor[i].FirstThunk]);for(int m_imp=0;pCurrentImportThunk[m_imp].u1.AddressOfData!=0;m_imp++){if(IMAGE_SNAP_BY_ORDINAL32(pCurrentImportThunk[m_imp].u1.AddressOfData)){if(pCurrentImportList[m_imp] != GetProcAddress(hCurrentModule,(LPCSTR)IMAGE_ORDINAL(pCurrentImportThunk[m_imp].u1.AddressOfData)))return false;}else{if(pCurrentImportList[m_imp] != GetProcAddress(hCurrentModule,(LPCSTR)&((PIMAGE_IMPORT_BY_NAME)&pImage[pCurrentImportThunk[m_imp].u1.AddressOfData])->Name))return false;}}}return true;}void FixupResource(PBYTE pDest){DWORD imagebase;PIMAGE_RESOURCE_DIRECTORY pRes;PIMAGE_RESOURCE_DIRECTORY_ENTRY pEntry;DWORD nEntries;DWORD i;PIMAGE_RESOURCE_DIRECTORY pRes2;PIMAGE_RESOURCE_DIRECTORY_ENTRY pEntry2;DWORD nEntries2;PIMAGE_RESOURCE_DIR_STRING_U pDirStr;PIMAGE_RESOURCE_DIRECTORY pRes3;PIMAGE_RESOURCE_DIRECTORY_ENTRY pEntry3;DWORD nEntries3;DWORD j;DWORD k;PIMAGE_RESOURCE_DATA_ENTRY pData;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest; pImageDosDest = (PIMAGE_DOS_HEADER)pDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pDest[pImageDosDest->e_lfanew];imagebase = pImageNtDest->OptionalHeader.ImageBase;if(!pImageNtDest->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_RESOURCE].VirtualAddress)return;pRes = (PIMAGE_RESOURCE_DIRECTORY)(imagebase + pImageNtDest->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_RESOURCE].VirtualAddress);nEntries = pRes->NumberOfIdEntries + pRes->NumberOfNamedEntries;pEntry = (PIMAGE_RESOURCE_DIRECTORY_ENTRY)((DWORD)pRes + sizeof(IMAGE_RESOURCE_DIRECTORY));for (i = 0; i < nEntries; ++i, ++pEntry) {if (IMAGE_RESOURCE_DATA_IS_DIRECTORY & pEntry->OffsetToData) {pRes2 = (PIMAGE_RESOURCE_DIRECTORY)((DWORD)pRes+ (~IMAGE_RESOURCE_DATA_IS_DIRECTORY & pEntry->OffsetToData));nEntries2 = pRes2->NumberOfIdEntries + pRes2->NumberOfNamedEntries;pEntry2 = (PIMAGE_RESOURCE_DIRECTORY_ENTRY)((DWORD)pRes2 + sizeof(IMAGE_RESOURCE_DIRECTORY));for (j = 0; j < nEntries2; ++j, ++pEntry2) {if (IMAGE_RESOURCE_NAME_IS_STRING & pEntry2->Name) {pDirStr = (PIMAGE_RESOURCE_DIR_STRING_U)((DWORD)pRes+ (~IMAGE_RESOURCE_NAME_IS_STRING & pEntry2->Name));}if (IMAGE_RESOURCE_DATA_IS_DIRECTORY & pEntry2->OffsetToData) {pRes3 = (PIMAGE_RESOURCE_DIRECTORY)((DWORD)pRes+ (~IMAGE_RESOURCE_DATA_IS_DIRECTORY & pEntry2->OffsetToData));nEntries3 = pRes3->NumberOfIdEntries + pRes3->NumberOfNamedEntries;pEntry3 = (PIMAGE_RESOURCE_DIRECTORY_ENTRY)((DWORD)pRes3 + sizeof(IMAGE_RESOURCE_DIRECTORY));for (k = 0; k < nEntries3; ++k) {assert(~IMAGE_RESOURCE_DATA_IS_DIRECTORY & pEntry3->OffsetToData);pData = (PIMAGE_RESOURCE_DATA_ENTRY)((DWORD)pRes + pEntry3->OffsetToData);pData->OffsetToData += (DWORD)imagebase;}}}}}}PVOID ReadData(IN LPCSTR lpFileName,OUT DWORD* ReadSize){PBYTE pLibrarySrc;HANDLE hFile = CreateFileA(lpFileName,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);if(hFile!=INVALID_HANDLE_VALUE){*ReadSize = GetFileSize(hFile,NULL);pLibrarySrc = (PBYTE)VirtualAlloc(0,*ReadSize,MEM_COMMIT,PAGE_EXECUTE_READWRITE);if(!ReadFile(hFile,pLibrarySrc,*ReadSize,ReadSize,NULL)){CloseHandle(hFile);VirtualFree(pLibrarySrc,*ReadSize,MEM_DECOMMIT);return NULL;}CloseHandle(hFile);return (PVOID)pLibrarySrc;}return NULL;}BOOL CheckPEFile(PIMAGE_DOS_HEADER pImageDosDest,PIMAGE_NT_HEADERS* pImageNtDest){PBYTE pImage = (PBYTE)pImageDosDest;if(pImageDosDest->e_magic!=IMAGE_DOS_SIGNATURE)return FALSE;*pImageNtDest = (PIMAGE_NT_HEADERS)&pImage[pImageDosDest->e_lfanew];if((*pImageNtDest)->Signature!=IMAGE_NT_SIGNATURE)return FALSE;return TRUE;}void LoadRelocation(PBYTE pSrc,PBYTE pDest){PIMAGE_DOS_HEADER pImageDosSrc;PIMAGE_NT_HEADERS pImageNtSrc;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest;PIMAGE_DATA_DIRECTORY pDirectory;PIMAGE_BASE_RELOCATION pRelocation;DWORD dwOriginAddress;DWORD dwBaseDelta;PWORD pData;int i,size;DWORD* dwRelocationPointer;int iType;pImageDosSrc = (PIMAGE_DOS_HEADER)pSrc;pImageNtSrc = (PIMAGE_NT_HEADERS)&pSrc[pImageDosSrc->e_lfanew];pImageDosDest = (PIMAGE_DOS_HEADER)pDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pDest[pImageDosDest->e_lfanew];pDirectory = (PIMAGE_DATA_DIRECTORY)&pImageNtDest->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC];if(!pDirectory->VirtualAddress)return;pRelocation = (PIMAGE_BASE_RELOCATION)(pDirectory->VirtualAddress + (DWORD)pDest);dwOriginAddress = pImageNtSrc->OptionalHeader.ImageBase;dwBaseDelta = (DWORD)pDest - dwOriginAddress;while(pRelocation->VirtualAddress!=0){size = (pRelocation->SizeOfBlock-sizeof(IMAGE_DATA_DIRECTORY))/2;pData = (PWORD)((DWORD)pRelocation + 8);for (i=0;i<size;i++){iType = pData[i] >> 12;dwRelocationPointer =  (DWORD*)((DWORD)pDest + ((pData[i] & 0x0fff) + pRelocation->VirtualAddress));switch(iType){case IMAGE_REL_BASED_ABSOLUTE:break;case IMAGE_REL_BASED_HIGH:*(PWORD)dwRelocationPointer = (WORD)(((dwBaseDelta + *(PWORD)dwRelocationPointer) >> 16) & 0xFFFF);break;case IMAGE_REL_BASED_LOW:*(PWORD)dwRelocationPointer = (WORD)((dwBaseDelta + *(PWORD)dwRelocationPointer) & 0xFFFF);break;case IMAGE_REL_BASED_HIGHLOW:*dwRelocationPointer = *dwRelocationPointer + dwBaseDelta;break;default:break;}}pRelocation = (PIMAGE_BASE_RELOCATION)((DWORD)pRelocation + pRelocation->SizeOfBlock);}}HMODULE LoadLibraryByResource(WORD wResID,char *pszFileType){DWORD dwReadSize;PBYTE pLibrarySrc;PBYTE pLibraryDest;PIMAGE_DOS_HEADER pImageDosSrc;PIMAGE_NT_HEADERS pImageNtSrc;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest;HRSRChrsc =  FindResourceA(NULL, MAKEINTRESOURCEA(wResID),pszFileType);HGLOBAL hG   = LoadResource(NULL, hrsc);dwReadSize   = SizeofResource( NULL,  hrsc);pLibrarySrc  = (PBYTE)hG;if(pLibrarySrc!=NULL){pImageDosSrc = (PIMAGE_DOS_HEADER)pLibrarySrc;if(!CheckPEFile(pImageDosSrc,&pImageNtSrc))return NULL;pLibraryDest = (PBYTE)VirtualAlloc(NULL,pImageNtSrc->OptionalHeader.SizeOfImage,MEM_COMMIT,PAGE_EXECUTE_READWRITE);//copy headermemcpy(pLibraryDest, pImageDosSrc, pImageDosSrc->e_lfanew + pImageNtSrc->OptionalHeader.SizeOfHeaders);pImageDosDest = (PIMAGE_DOS_HEADER)pLibraryDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pLibraryDest[pImageDosDest->e_lfanew];pImageNtDest->OptionalHeader.ImageBase = (DWORD)pLibraryDest;CopySection(pLibrarySrc,pLibraryDest);LoadRelocation(pLibrarySrc,pLibraryDest);//FixupResource(pLibraryDest);LoadImport(pLibrarySrc,pLibraryDest);if(pImageNtDest->OptionalHeader.AddressOfEntryPoint)((fnDllMain)(pImageNtDest->OptionalHeader.AddressOfEntryPoint + (DWORD)pLibraryDest))((HINSTANCE)pLibraryDest,DLL_PROCESS_ATTACH,NULL);//pImageDosDest->e_magic = 0;//pImageNtDest->Signature = 0;return (HMODULE)pLibraryDest;}return NULL;}HMODULE LoadLibraryByFile(const char * pszDllPath){DWORD dwReadSize;PBYTE pLibrarySrc;PBYTE pLibraryDest;PIMAGE_DOS_HEADER pImageDosSrc;PIMAGE_NT_HEADERS pImageNtSrc;PIMAGE_DOS_HEADER pImageDosDest;PIMAGE_NT_HEADERS pImageNtDest;pLibrarySrc  = (PBYTE)ReadData(pszDllPath,&dwReadSize);if(pLibrarySrc!=NULL){pImageDosSrc = (PIMAGE_DOS_HEADER)pLibrarySrc;if(!CheckPEFile(pImageDosSrc,&pImageNtSrc)){VirtualFree(pLibrarySrc,dwReadSize,MEM_COMMIT);return NULL;}pLibraryDest = (PBYTE)VirtualAlloc(NULL,pImageNtSrc->OptionalHeader.SizeOfImage,MEM_COMMIT,PAGE_EXECUTE_READWRITE);//copy headermemcpy(pLibraryDest, pImageDosSrc, pImageDosSrc->e_lfanew + pImageNtSrc->OptionalHeader.SizeOfHeaders);pImageDosDest = (PIMAGE_DOS_HEADER)pLibraryDest;pImageNtDest = (PIMAGE_NT_HEADERS)&pLibraryDest[pImageDosDest->e_lfanew];pImageNtDest->OptionalHeader.ImageBase = (DWORD)pLibraryDest;CopySection(pLibrarySrc,pLibraryDest);LoadRelocation(pLibrarySrc,pLibraryDest);//FixupResource(pLibraryDest);LoadImport(pLibrarySrc,pLibraryDest);VirtualFree(pLibrarySrc,dwReadSize,MEM_DECOMMIT);if(pImageNtDest->OptionalHeader.AddressOfEntryPoint)((fnDllMain)(pImageNtDest->OptionalHeader.AddressOfEntryPoint + (DWORD)pLibraryDest))((HINSTANCE)pLibraryDest,DLL_PROCESS_ATTACH,NULL);//pImageDosDest->e_magic = 0;//pImageNtDest->Signature = 0;return (HMODULE)pLibraryDest;}return NULL;}DWORD GetCodeSize(HMODULE hModule){PBYTE pInfo = (PBYTE)hModule;PIMAGE_DOS_HEADER pImgDos = (PIMAGE_DOS_HEADER)pInfo;PIMAGE_NT_HEADERS pImgNt;if(pImgDos->e_magic==IMAGE_DOS_SIGNATURE){pImgNt = (PIMAGE_NT_HEADERS)&pInfo[pImgDos->e_lfanew];if(pImgNt){if(pImgNt->Signature==IMAGE_NT_SIGNATURE){return pImgNt->OptionalHeader.SizeOfCode;}}}return NULL;}DWORD GetPEImageSize(HMODULE hModule){PBYTE pInfo = (PBYTE)hModule;PIMAGE_DOS_HEADER pImgDos = (PIMAGE_DOS_HEADER)pInfo;PIMAGE_NT_HEADERS pImgNt;if(pImgDos->e_magic==IMAGE_DOS_SIGNATURE){pImgNt = (PIMAGE_NT_HEADERS)&pInfo[pImgDos->e_lfanew];if(pImgNt){if(pImgNt->Signature==IMAGE_NT_SIGNATURE){return pImgNt->OptionalHeader.SizeOfImage;}}}return NULL;}DWORD GetPEImageEnd(HMODULE hModule){return ((DWORD)hModule + GetPEImageSize(hModule));}DWORD GetPECodeEnd(HMODULE hModule){return ((DWORD)hModule + GetCodeSize(hModule));}

      Main.cpp

// 定義函數指標typedef BOOL (__stdcall *MSGBOX)(char *,char *);void Test(HMODULE hModule){if(hModule){MSGBOX pMsgBox = (MSGBOX)MyGetProcAddress(hModule,"MsgBox");if(pMsgBox){pMsgBox("Hello World","Hi");}FreeLibrary(hModule);}}// 從檔案載入擷取函數地址void CPEAnalyaisDlg::OnBnClickedButton1(){Test(LoadLibraryByFile("MsgBox.dll"));}// 從資源檔載入擷取函數地址void CPEAnalyaisDlg::OnBnClickedButton2(){Test(LoadLibraryByResource(IDR_DLL_MSGBOX,"EXE"));}

完整工程下載：

http://download.csdn.net/detail/wangningyu/5178695