The Tor Browser: toolkit/crashreporter/LoadLibraryRemote.cpp@129ffea94266 (annotated)

toolkit/crashreporter/LoadLibraryRemote.cpp@129ffea94266 (annotated)

toolkit/crashreporter/LoadLibraryRemote.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef __GNUC__
 // disable warnings about pointer <-> DWORD conversions
 #pragma warning( disable : 4311 4312 )
 #endif
 #ifdef _WIN64
 #define POINTER_TYPE ULONGLONG
 #else
 #define POINTER_TYPE DWORD
 #endif
 #include <windows.h>
 #include <winnt.h>
 #include <stdlib.h>
 #ifdef DEBUG_OUTPUT
 #include <stdio.h>
 #endif
 #include "nsWindowsHelpers.h"
 typedef const unsigned char* FileView;
 template<>
 class nsAutoRefTraits<FileView>
 {
 public:
   typedef FileView RawRef;
   static FileView Void()
   {
     return nullptr;
   }
   static void Release(RawRef aView)
   {
     if (nullptr != aView)
       UnmapViewOfFile(aView);
   }
 };
 #ifndef IMAGE_SIZEOF_BASE_RELOCATION
 // Vista SDKs no longer define IMAGE_SIZEOF_BASE_RELOCATION!?
 #define IMAGE_SIZEOF_BASE_RELOCATION (sizeof(IMAGE_BASE_RELOCATION))
 #endif
 #include "LoadLibraryRemote.h"
 typedef struct {
   PIMAGE_NT_HEADERS headers;
   unsigned char *localCodeBase;
   unsigned char *remoteCodeBase;
   HMODULE *modules;
   int numModules;
 } MEMORYMODULE, *PMEMORYMODULE;
 typedef BOOL (WINAPI *DllEntryProc)(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved);
 #define GET_HEADER_DICTIONARY(module, idx)  &(module)->headers->OptionalHeader.DataDirectory[idx]
 #ifdef DEBUG_OUTPUT
 static void
 OutputLastError(const char *msg)
 {
   char* tmp;
   char *tmpmsg;
   FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                  nullptr, GetLastError(),
                  MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                  (LPSTR) &tmp, 0, nullptr);
   tmpmsg = (char *)LocalAlloc(LPTR, strlen(msg) + strlen(tmp) + 3);
   sprintf(tmpmsg, "%s: %s", msg, tmp);
   OutputDebugStringA(tmpmsg);
   LocalFree(tmpmsg);
   LocalFree(tmp);
 }
 #endif
 static void
 CopySections(const unsigned char *data, PIMAGE_NT_HEADERS old_headers, PMEMORYMODULE module)
 {
   int i;
   unsigned char *codeBase = module->localCodeBase;
   unsigned char *dest;
   PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
   for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
     dest = codeBase + section->VirtualAddress;
     memset(dest, 0, section->Misc.VirtualSize);
     if (section->SizeOfRawData) {
       memcpy(dest, data + section->PointerToRawData, section->SizeOfRawData);
     }
     //     section->Misc.PhysicalAddress = (POINTER_TYPE) module->remoteCodeBase + section->VirtualAddress;
   }
 }
 // Protection flags for memory pages (Executable, Readable, Writeable)
 static int ProtectionFlags[2][2][2] = {
   {
     // not executable
     {PAGE_NOACCESS, PAGE_WRITECOPY},
     {PAGE_READONLY, PAGE_READWRITE},
   }, {
     // executable
     {PAGE_EXECUTE, PAGE_EXECUTE_WRITECOPY},
     {PAGE_EXECUTE_READ, PAGE_EXECUTE_READWRITE},
   },
 };
 static bool
 FinalizeSections(PMEMORYMODULE module, HANDLE hRemoteProcess)
 {
 #ifdef DEBUG_OUTPUT
   fprintf(stderr, "Finalizing sections: local base %p, remote base %p\n",
           module->localCodeBase, module->remoteCodeBase);
 #endif
   int i;
   PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
   // loop through all sections and change access flags
   for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
     DWORD protect, oldProtect, size;
     int executable = (section->Characteristics & IMAGE_SCN_MEM_EXECUTE) != 0;
     int readable =   (section->Characteristics & IMAGE_SCN_MEM_READ) != 0;
     int writeable =  (section->Characteristics & IMAGE_SCN_MEM_WRITE) != 0;
     // determine protection flags based on characteristics
     protect = ProtectionFlags[executable][readable][writeable];
     if (section->Characteristics & IMAGE_SCN_MEM_NOT_CACHED) {
       protect |= PAGE_NOCACHE;
     }
     // determine size of region
     size = section->Misc.VirtualSize;
     if (size > 0) {
       void* remoteAddress = module->remoteCodeBase + section->VirtualAddress;
       void* localAddress = module->localCodeBase + section->VirtualAddress;
 #ifdef DEBUG_OUTPUT
       fprintf(stderr, "Copying section %s to %p, size %x, executable %i readable %i writeable %i\n",
               section->Name, remoteAddress, size, executable, readable, writeable);
 #endif
       // Copy the data from local->remote and set the memory protection
       if (!VirtualAllocEx(hRemoteProcess, remoteAddress, size, MEM_COMMIT, PAGE_READWRITE))
         return false;
       if (!WriteProcessMemory(hRemoteProcess,
                               remoteAddress,
                               localAddress,
                               size,
                               nullptr)) {
 #ifdef DEBUG_OUTPUT
         OutputLastError("Error writing remote memory.\n");
 #endif
         return false;
       }
       if (VirtualProtectEx(hRemoteProcess, remoteAddress, size, protect, &oldProtect) == 0) {
 #ifdef DEBUG_OUTPUT
         OutputLastError("Error protecting memory page");
 #endif
         return false;
       }
     }
   }
   return true;
 }
 static void
 PerformBaseRelocation(PMEMORYMODULE module, SIZE_T delta)
 {
   DWORD i;
   unsigned char *codeBase = module->localCodeBase;
   PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_BASERELOC);
   if (directory->Size > 0) {
     PIMAGE_BASE_RELOCATION relocation = (PIMAGE_BASE_RELOCATION) (codeBase + directory->VirtualAddress);
     for (; relocation->VirtualAddress > 0; ) {
       unsigned char *dest = codeBase + relocation->VirtualAddress;
       unsigned short *relInfo = (unsigned short *)((unsigned char *)relocation + IMAGE_SIZEOF_BASE_RELOCATION);
       for (i=0; i<((relocation->SizeOfBlock-IMAGE_SIZEOF_BASE_RELOCATION) / 2); i++, relInfo++) {
         DWORD *patchAddrHL;
 #ifdef _WIN64
         ULONGLONG *patchAddr64;
 #endif
         int type, offset;
         // the upper 4 bits define the type of relocation
         type = *relInfo >> 12;
         // the lower 12 bits define the offset
         offset = *relInfo & 0xfff;
         switch (type)
         {
         case IMAGE_REL_BASED_ABSOLUTE:
           // skip relocation
           break;
         case IMAGE_REL_BASED_HIGHLOW:
           // change complete 32 bit address
           patchAddrHL = (DWORD *) (dest + offset);
           *patchAddrHL += delta;
           break;
 #ifdef _WIN64
         case IMAGE_REL_BASED_DIR64:
           patchAddr64 = (ULONGLONG *) (dest + offset);
           *patchAddr64 += delta;
           break;
 #endif
         default:
           //printf("Unknown relocation: %d\n", type);
           break;
         }
       }
       // advance to next relocation block
       relocation = (PIMAGE_BASE_RELOCATION) (((char *) relocation) + relocation->SizeOfBlock);
     }
   }
 }
 static int
 BuildImportTable(PMEMORYMODULE module)
 {
   int result=1;
   unsigned char *codeBase = module->localCodeBase;
   PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_IMPORT);
   if (directory->Size > 0) {
     PIMAGE_IMPORT_DESCRIPTOR importDesc = (PIMAGE_IMPORT_DESCRIPTOR) (codeBase + directory->VirtualAddress);
     PIMAGE_IMPORT_DESCRIPTOR importEnd = (PIMAGE_IMPORT_DESCRIPTOR) (codeBase + directory->VirtualAddress + directory->Size);
     for (; importDesc < importEnd && importDesc->Name; importDesc++) {
       POINTER_TYPE *thunkRef;
       FARPROC *funcRef;
       HMODULE handle = GetModuleHandleA((LPCSTR) (codeBase + importDesc->Name));
       if (handle == nullptr) {
 #if DEBUG_OUTPUT
         OutputLastError("Can't load library");
 #endif
         result = 0;
         break;
       }
       module->modules = (HMODULE *)realloc(module->modules, (module->numModules+1)*(sizeof(HMODULE)));
       if (module->modules == nullptr) {
         result = 0;
         break;
       }
       module->modules[module->numModules++] = handle;
       if (importDesc->OriginalFirstThunk) {
         thunkRef = (POINTER_TYPE *) (codeBase + importDesc->OriginalFirstThunk);
         funcRef = (FARPROC *) (codeBase + importDesc->FirstThunk);
       } else {
         // no hint table
         thunkRef = (POINTER_TYPE *) (codeBase + importDesc->FirstThunk);
         funcRef = (FARPROC *) (codeBase + importDesc->FirstThunk);
       }
       for (; *thunkRef; thunkRef++, funcRef++) {
         if (IMAGE_SNAP_BY_ORDINAL(*thunkRef)) {
           *funcRef = (FARPROC)GetProcAddress(handle, (LPCSTR)IMAGE_ORDINAL(*thunkRef));
         } else {
           PIMAGE_IMPORT_BY_NAME thunkData = (PIMAGE_IMPORT_BY_NAME) (codeBase + (*thunkRef));
           *funcRef = (FARPROC)GetProcAddress(handle, (LPCSTR)&thunkData->Name);
         }
         if (*funcRef == 0) {
           result = 0;
           break;
         }
       }
       if (!result) {
         break;
       }
     }
   }
   return result;
 }
 static void* MemoryGetProcAddress(PMEMORYMODULE module, const char *name);
 void* LoadRemoteLibraryAndGetAddress(HANDLE hRemoteProcess,
                                      const WCHAR* library,
                                      const char* symbol)
 {
   // Map the DLL into memory
   nsAutoHandle hLibrary(
     CreateFile(library, GENERIC_READ, FILE_SHARE_READ, nullptr, OPEN_EXISTING,
                FILE_ATTRIBUTE_NORMAL, nullptr));
   if (INVALID_HANDLE_VALUE == hLibrary) {
 #if DEBUG_OUTPUT
     OutputLastError("Couldn't CreateFile the library.\n");
 #endif
     return nullptr;
   }
   nsAutoHandle hMapping(
     CreateFileMapping(hLibrary, nullptr, PAGE_READONLY, 0, 0, nullptr));
   if (!hMapping) {
 #if DEBUG_OUTPUT
     OutputLastError("Couldn't CreateFileMapping.\n");
 #endif
     return nullptr;
   }
   nsAutoRef<FileView> data(
     (const unsigned char*) MapViewOfFile(hMapping, FILE_MAP_READ, 0, 0, 0));
   if (!data) {
 #if DEBUG_OUTPUT
     OutputLastError("Couldn't MapViewOfFile.\n");
 #endif
     return nullptr;
   }
   SIZE_T locationDelta;
   PIMAGE_DOS_HEADER dos_header = (PIMAGE_DOS_HEADER)data.get();
   if (dos_header->e_magic != IMAGE_DOS_SIGNATURE) {
 #if DEBUG_OUTPUT
     OutputDebugStringA("Not a valid executable file.\n");
 #endif
     return nullptr;
   }
   PIMAGE_NT_HEADERS old_header = (PIMAGE_NT_HEADERS)(data + dos_header->e_lfanew);
   if (old_header->Signature != IMAGE_NT_SIGNATURE) {
 #if DEBUG_OUTPUT
     OutputDebugStringA("No PE header found.\n");
 #endif
     return nullptr;
   }
   // reserve memory for image of library in this process and the target process
   unsigned char* localCode = (unsigned char*) VirtualAlloc(nullptr,
     old_header->OptionalHeader.SizeOfImage,
     MEM_RESERVE | MEM_COMMIT,
     PAGE_READWRITE);
   if (!localCode) {
 #if DEBUG_OUTPUT
     OutputLastError("Can't reserve local memory.");
 #endif
   }
   unsigned char* remoteCode = (unsigned char*) VirtualAllocEx(hRemoteProcess, nullptr,
     old_header->OptionalHeader.SizeOfImage,
     MEM_RESERVE,
     PAGE_EXECUTE_READ);
   if (!remoteCode) {
 #if DEBUG_OUTPUT
     OutputLastError("Can't reserve remote memory.");
 #endif
   }
   MEMORYMODULE result;
   result.localCodeBase = localCode;
   result.remoteCodeBase = remoteCode;
   result.numModules = 0;
   result.modules = nullptr;
   // copy PE header to code
   memcpy(localCode, dos_header, dos_header->e_lfanew + old_header->OptionalHeader.SizeOfHeaders);
   result.headers = reinterpret_cast<PIMAGE_NT_HEADERS>(localCode + dos_header->e_lfanew);
   // update position
   result.headers->OptionalHeader.ImageBase = (POINTER_TYPE)remoteCode;
   // copy sections from DLL file block to new memory location
   CopySections(data, old_header, &result);
   // adjust base address of imported data
   locationDelta = (SIZE_T)(remoteCode - old_header->OptionalHeader.ImageBase);
   if (locationDelta != 0) {
     PerformBaseRelocation(&result, locationDelta);
   }
   // load required dlls and adjust function table of imports
   if (!BuildImportTable(&result)) {
     return nullptr;
   }
   // mark memory pages depending on section headers and release
   // sections that are marked as "discardable"
   if (!FinalizeSections(&result, hRemoteProcess)) {
     return nullptr;
   }
   return MemoryGetProcAddress(&result, symbol);
 }
 static void* MemoryGetProcAddress(PMEMORYMODULE module, const char *name)
 {
   unsigned char *localCodeBase = module->localCodeBase;
   int idx=-1;
   DWORD i, *nameRef;
   WORD *ordinal;
   PIMAGE_EXPORT_DIRECTORY exports;
   PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_EXPORT);
   if (directory->Size == 0) {
     // no export table found
     return nullptr;
   }
   exports = (PIMAGE_EXPORT_DIRECTORY) (localCodeBase + directory->VirtualAddress);
   if (exports->NumberOfNames == 0 || exports->NumberOfFunctions == 0) {
     // DLL doesn't export anything
     return nullptr;
   }
   // search function name in list of exported names
   nameRef = (DWORD *) (localCodeBase + exports->AddressOfNames);
   ordinal = (WORD *) (localCodeBase + exports->AddressOfNameOrdinals);
   for (i=0; i<exports->NumberOfNames; i++, nameRef++, ordinal++) {
     if (stricmp(name, (const char *) (localCodeBase + (*nameRef))) == 0) {
       idx = *ordinal;
       break;
     }
   }
   if (idx == -1) {
     // exported symbol not found
     return nullptr;
   }
   if ((DWORD)idx > exports->NumberOfFunctions) {
     // name <-> ordinal number don't match
     return nullptr;
   }
   // AddressOfFunctions contains the RVAs to the "real" functions
   return module->remoteCodeBase + (*(DWORD *) (localCodeBase + exports->AddressOfFunctions + (idx*4)));
 }

The Tor Browser / annotate

toolkit/crashreporter/LoadLibraryRemote.cpp@129ffea94266 (annotated)

toolkit/crashreporter/LoadLibraryRemote.cpp