The Tor Browser: security/sandbox/win/src/Wow64.cc@6474c204b198 (annotated)

security/sandbox/win/src/Wow64.cc@6474c204b198 (annotated)

security/sandbox/win/src/Wow64.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 #include "sandbox/win/src/wow64.h"
 #include <sstream>
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/win/scoped_process_information.h"
 #include "base/win/windows_version.h"
 #include "sandbox/win/src/target_process.h"
 namespace {
 // Holds the information needed for the interception of NtMapViewOfSection on
 // 64 bits.
 // Warning: do not modify this definition without changing also the code on the
 // 64 bit helper process.
 struct PatchInfo32 {
   HANDLE dll_load;  // Event to signal the broker.
   ULONG pad1;
   HANDLE continue_load;  // Event to wait for the broker.
   ULONG pad2;
   HANDLE section;  // First argument of the call.
   ULONG pad3;
   void* orig_MapViewOfSection;
   ULONG original_high;
   void* signal_and_wait;
   ULONG pad4;
   void* patch_location;
   ULONG patch_high;
 };
 // Size of the 64 bit service entry.
 const SIZE_T kServiceEntry64Size = 0x10;
 // Removes the interception of ntdll64.
 bool Restore64Code(HANDLE child, PatchInfo32* patch_info) {
   PatchInfo32 local_patch_info;
   SIZE_T actual;
   if (!::ReadProcessMemory(child, patch_info, &local_patch_info,
                            sizeof(local_patch_info), &actual))
     return false;
   if (sizeof(local_patch_info) != actual)
     return false;
   if (local_patch_info.original_high)
     return false;
   if (local_patch_info.patch_high)
     return false;
   char buffer[kServiceEntry64Size];
   if (!::ReadProcessMemory(child, local_patch_info.orig_MapViewOfSection,
                            &buffer, kServiceEntry64Size, &actual))
     return false;
   if (kServiceEntry64Size != actual)
     return false;
   if (!::WriteProcessMemory(child, local_patch_info.patch_location, &buffer,
                             kServiceEntry64Size, &actual))
     return false;
   if (kServiceEntry64Size != actual)
     return false;
   return true;
 }
 typedef BOOL (WINAPI* IsWow64ProcessFunction)(HANDLE process, BOOL* wow64);
 }  // namespace
 namespace sandbox {
 Wow64::~Wow64() {
   if (dll_load_)
     ::CloseHandle(dll_load_);
   if (continue_load_)
     ::CloseHandle(continue_load_);
 }
 // The basic idea is to allocate one page of memory on the child, and initialize
 // the first part of it with our version of PatchInfo32. Then launch the helper
 // process passing it that address on the child. The helper process will patch
 // the 64 bit version of NtMapViewOfFile, and the interception will signal the
 // first event on the buffer. We'll be waiting on that event and after the 32
 // bit version of ntdll is loaded, we'll remove the interception and return to
 // our caller.
 bool Wow64::WaitForNtdll() {
   if (base::win::OSInfo::GetInstance()->wow64_status() !=
       base::win::OSInfo::WOW64_ENABLED)
     return true;
   const size_t page_size = 4096;
   // Create some default manual reset un-named events, not signaled.
   dll_load_ = ::CreateEvent(NULL, TRUE, FALSE, NULL);
   continue_load_ = ::CreateEvent(NULL, TRUE, FALSE, NULL);
   HANDLE current_process = ::GetCurrentProcess();
   HANDLE remote_load, remote_continue;
   DWORD access = EVENT_MODIFY_STATE | SYNCHRONIZE;
   if (!::DuplicateHandle(current_process, dll_load_, child_->Process(),
                          &remote_load, access, FALSE, 0))
     return false;
   if (!::DuplicateHandle(current_process, continue_load_, child_->Process(),
                          &remote_continue, access, FALSE, 0))
     return false;
   void* buffer = ::VirtualAllocEx(child_->Process(), NULL, page_size,
                                   MEM_COMMIT, PAGE_EXECUTE_READWRITE);
   DCHECK(buffer);
   if (!buffer)
     return false;
   PatchInfo32* patch_info = reinterpret_cast<PatchInfo32*>(buffer);
   PatchInfo32 local_patch_info = {0};
   local_patch_info.dll_load = remote_load;
   local_patch_info.continue_load = remote_continue;
   SIZE_T written;
   if (!::WriteProcessMemory(child_->Process(), patch_info, &local_patch_info,
                             offsetof(PatchInfo32, section), &written))
     return false;
   if (offsetof(PatchInfo32, section) != written)
     return false;
   if (!RunWowHelper(buffer))
     return false;
   // The child is intercepted on 64 bit, go on and wait for our event.
   if (!DllMapped())
     return false;
   // The 32 bit version is available, cleanup the child.
   return Restore64Code(child_->Process(), patch_info);
 }
 bool Wow64::RunWowHelper(void* buffer) {
   COMPILE_ASSERT(sizeof(buffer) <= sizeof(DWORD), unsupported_64_bits);
   // Get the path to the helper (beside the exe).
   wchar_t prog_name[MAX_PATH];
   GetModuleFileNameW(NULL, prog_name, MAX_PATH);
   std::wstring path(prog_name);
   size_t name_pos = path.find_last_of(L"\\");
   if (std::wstring::npos == name_pos)
     return false;
   path.resize(name_pos + 1);
   std::wstringstream command;
   command << std::hex << std::showbase << L"\"" << path <<
                L"wow_helper.exe\" " << child_->ProcessId() << " " <<
                bit_cast<ULONG>(buffer);
   scoped_ptr_malloc<wchar_t> writable_command(_wcsdup(command.str().c_str()));
   STARTUPINFO startup_info = {0};
   startup_info.cb = sizeof(startup_info);
   base::win::ScopedProcessInformation process_info;
   if (!::CreateProcess(NULL, writable_command.get(), NULL, NULL, FALSE, 0, NULL,
                        NULL, &startup_info, process_info.Receive()))
     return false;
   DWORD reason = ::WaitForSingleObject(process_info.process_handle(), INFINITE);
   DWORD code;
   bool ok =
       ::GetExitCodeProcess(process_info.process_handle(), &code) ? true : false;
   if (WAIT_TIMEOUT == reason)
     return false;
   return ok && (0 == code);
 }
 // First we must wake up the child, then wait for dll loads on the child until
 // the one we care is loaded; at that point we must suspend the child again.
 bool Wow64::DllMapped() {
   if (1 != ::ResumeThread(child_->MainThread())) {
     NOTREACHED();
     return false;
   }
   for (;;) {
     DWORD reason = ::WaitForSingleObject(dll_load_, INFINITE);
     if (WAIT_TIMEOUT == reason || WAIT_ABANDONED == reason)
       return false;
     if (!::ResetEvent(dll_load_))
       return false;
     bool found = NtdllPresent();
     if (found) {
       if (::SuspendThread(child_->MainThread()))
         return false;
     }
     if (!::SetEvent(continue_load_))
       return false;
     if (found)
       return true;
   }
 }
 bool Wow64::NtdllPresent() {
   const size_t kBufferSize = 512;
   char buffer[kBufferSize];
   SIZE_T read;
   if (!::ReadProcessMemory(child_->Process(), ntdll_, &buffer, kBufferSize,
                            &read))
     return false;
   if (kBufferSize != read)
     return false;
   return true;
 }
 }  // namespace sandbox

The Tor Browser / annotate

security/sandbox/win/src/Wow64.cc@6474c204b198 (annotated)

security/sandbox/win/src/Wow64.cc