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

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

security/sandbox/win/src/process_mitigations.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/process_mitigations.h"
 #include <algorithm>
 #include "base/win/windows_version.h"
 #include "sandbox/win/src/nt_internals.h"
 #include "sandbox/win/src/sandbox_utils.h"
 #include "sandbox/win/src/win_utils.h"
 namespace {
 // Functions for enabling policies.
 typedef BOOL (WINAPI *SetProcessDEPPolicyFunction)(DWORD dwFlags);
 typedef BOOL (WINAPI *SetProcessMitigationPolicyFunction)(
     PROCESS_MITIGATION_POLICY mitigation_policy,
     PVOID buffer,
     SIZE_T length);
 typedef BOOL (WINAPI *SetDefaultDllDirectoriesFunction)(
     DWORD DirectoryFlags);
 }  // namespace
 namespace sandbox {
 bool ApplyProcessMitigationsToCurrentProcess(MitigationFlags flags) {
   if (!CanSetProcessMitigationsPostStartup(flags))
     return false;
   // We can't apply anything before Win XP, so just return cleanly.
   if (!IsXPSP2OrLater())
     return true;
   base::win::Version version = base::win::GetVersion();
   HMODULE module = ::GetModuleHandleA("kernel32.dll");
   if (version >= base::win::VERSION_VISTA &&
       (flags & MITIGATION_DLL_SEARCH_ORDER)) {
     SetDefaultDllDirectoriesFunction set_default_dll_directories =
         reinterpret_cast<SetDefaultDllDirectoriesFunction>(
             ::GetProcAddress(module, "SetDefaultDllDirectories"));
     // Check for SetDefaultDllDirectories since it requires KB2533623.
     if (set_default_dll_directories) {
       if (!set_default_dll_directories(LOAD_LIBRARY_SEARCH_DEFAULT_DIRS) &&
           ERROR_ACCESS_DENIED != ::GetLastError()) {
         return false;
       }
     }
   }
   // Set the heap to terminate on corruption
   if (version >= base::win::VERSION_VISTA &&
       (flags & MITIGATION_HEAP_TERMINATE)) {
     if (!::HeapSetInformation(NULL, HeapEnableTerminationOnCorruption,
                               NULL, 0) &&
         ERROR_ACCESS_DENIED != ::GetLastError()) {
       return false;
     }
   }
 #if !defined(_WIN64)  // DEP is always enabled on 64-bit.
   if (flags & MITIGATION_DEP) {
     DWORD dep_flags = PROCESS_DEP_ENABLE;
     // DEP support is quirky on XP, so don't force a failure in that case.
     const bool return_on_fail = version >= base::win::VERSION_VISTA;
     if (flags & MITIGATION_DEP_NO_ATL_THUNK)
       dep_flags |= PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION;
     SetProcessDEPPolicyFunction set_process_dep_policy =
         reinterpret_cast<SetProcessDEPPolicyFunction>(
             ::GetProcAddress(module, "SetProcessDEPPolicy"));
     if (set_process_dep_policy) {
       if (!set_process_dep_policy(dep_flags) &&
           ERROR_ACCESS_DENIED != ::GetLastError() && return_on_fail) {
         return false;
       }
     } else {
       // We're on XP sp2, so use the less standard approach.
       // For reference: http://www.uninformed.org/?v=2&a=4
       const int MEM_EXECUTE_OPTION_ENABLE = 1;
       const int MEM_EXECUTE_OPTION_DISABLE = 2;
       const int MEM_EXECUTE_OPTION_ATL7_THUNK_EMULATION = 4;
       const int MEM_EXECUTE_OPTION_PERMANENT = 8;
       NtSetInformationProcessFunction set_information_process = NULL;
       ResolveNTFunctionPtr("NtSetInformationProcess",
                            &set_information_process);
       if (!set_information_process)
         return false;
       ULONG dep = MEM_EXECUTE_OPTION_DISABLE | MEM_EXECUTE_OPTION_PERMANENT;
       if (!(dep_flags & PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION))
         dep |= MEM_EXECUTE_OPTION_ATL7_THUNK_EMULATION;
       if (!SUCCEEDED(set_information_process(GetCurrentProcess(),
                                              ProcessExecuteFlags,
                                              &dep, sizeof(dep))) &&
           ERROR_ACCESS_DENIED != ::GetLastError() && return_on_fail) {
         return false;
       }
     }
   }
 #endif
   // This is all we can do in Win7 and below.
   if (version < base::win::VERSION_WIN8)
     return true;
   SetProcessMitigationPolicyFunction set_process_mitigation_policy =
       reinterpret_cast<SetProcessMitigationPolicyFunction>(
           ::GetProcAddress(module, "SetProcessMitigationPolicy"));
   if (!set_process_mitigation_policy)
     return false;
   // Enable ASLR policies.
   if (flags & MITIGATION_RELOCATE_IMAGE) {
     PROCESS_MITIGATION_ASLR_POLICY policy = { 0 };
     policy.EnableForceRelocateImages = true;
     policy.DisallowStrippedImages = (flags &
         MITIGATION_RELOCATE_IMAGE_REQUIRED) ==
         MITIGATION_RELOCATE_IMAGE_REQUIRED;
     if (!set_process_mitigation_policy(ProcessASLRPolicy, &policy,
                                        sizeof(policy)) &&
         ERROR_ACCESS_DENIED != ::GetLastError()) {
       return false;
     }
   }
   // Enable strict handle policies.
   if (flags & MITIGATION_STRICT_HANDLE_CHECKS) {
     PROCESS_MITIGATION_STRICT_HANDLE_CHECK_POLICY policy = { 0 };
     policy.HandleExceptionsPermanentlyEnabled =
         policy.RaiseExceptionOnInvalidHandleReference = true;
     if (!set_process_mitigation_policy(ProcessStrictHandleCheckPolicy, &policy,
                                        sizeof(policy)) &&
         ERROR_ACCESS_DENIED != ::GetLastError()) {
       return false;
     }
   }
   // Enable system call policies.
   if (flags & MITIGATION_WIN32K_DISABLE) {
     PROCESS_MITIGATION_SYSTEM_CALL_DISABLE_POLICY policy = { 0 };
     policy.DisallowWin32kSystemCalls = true;
     if (!set_process_mitigation_policy(ProcessSystemCallDisablePolicy, &policy,
                                        sizeof(policy)) &&
         ERROR_ACCESS_DENIED != ::GetLastError()) {
       return false;
     }
   }
   // Enable system call policies.
   if (flags & MITIGATION_EXTENSION_DLL_DISABLE) {
     PROCESS_MITIGATION_EXTENSION_POINT_DISABLE_POLICY policy = { 0 };
     policy.DisableExtensionPoints = true;
     if (!set_process_mitigation_policy(ProcessExtensionPointDisablePolicy,
                                        &policy, sizeof(policy)) &&
         ERROR_ACCESS_DENIED != ::GetLastError()) {
       return false;
     }
   }
   return true;
 }
 void ConvertProcessMitigationsToPolicy(MitigationFlags flags,
                                        DWORD64* policy_flags, size_t* size) {
   base::win::Version version = base::win::GetVersion();
   *policy_flags = 0;
 #if defined(_WIN64)
   *size = sizeof(*policy_flags);
 #elif defined(_M_IX86)
   // A 64-bit flags attribute is illegal on 32-bit Win 7 and below.
   if (version < base::win::VERSION_WIN8)
     *size = sizeof(DWORD);
   else
     *size = sizeof(*policy_flags);
 #else
 #error This platform is not supported.
 #endif
   // Nothing for Win XP or Vista.
   if (version <= base::win::VERSION_VISTA)
     return;
   // DEP and SEHOP are not valid for 64-bit Windows
 #if !defined(_WIN64)
   if (flags & MITIGATION_DEP) {
     *policy_flags |= PROCESS_CREATION_MITIGATION_POLICY_DEP_ENABLE;
     if (!(flags & MITIGATION_DEP_NO_ATL_THUNK))
       *policy_flags |= PROCESS_CREATION_MITIGATION_POLICY_DEP_ATL_THUNK_ENABLE;
   }
   if (flags & MITIGATION_SEHOP)
     *policy_flags |= PROCESS_CREATION_MITIGATION_POLICY_SEHOP_ENABLE;
 #endif
   // Win 7
   if (version < base::win::VERSION_WIN8)
     return;
   if (flags & MITIGATION_RELOCATE_IMAGE) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_FORCE_RELOCATE_IMAGES_ALWAYS_ON;
     if (flags & MITIGATION_RELOCATE_IMAGE_REQUIRED) {
       *policy_flags |=
           PROCESS_CREATION_MITIGATION_POLICY_FORCE_RELOCATE_IMAGES_ALWAYS_ON_REQ_RELOCS;
     }
   }
   if (flags & MITIGATION_HEAP_TERMINATE) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_HEAP_TERMINATE_ALWAYS_ON;
   }
   if (flags & MITIGATION_BOTTOM_UP_ASLR) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_BOTTOM_UP_ASLR_ALWAYS_ON;
   }
   if (flags & MITIGATION_HIGH_ENTROPY_ASLR) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_HIGH_ENTROPY_ASLR_ALWAYS_ON;
   }
   if (flags & MITIGATION_STRICT_HANDLE_CHECKS) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_STRICT_HANDLE_CHECKS_ALWAYS_ON;
   }
   if (flags & MITIGATION_WIN32K_DISABLE) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_WIN32K_SYSTEM_CALL_DISABLE_ALWAYS_ON;
   }
   if (flags & MITIGATION_EXTENSION_DLL_DISABLE) {
     *policy_flags |=
         PROCESS_CREATION_MITIGATION_POLICY_EXTENSION_POINT_DISABLE_ALWAYS_ON;
   }
 }
 MitigationFlags FilterPostStartupProcessMitigations(MitigationFlags flags) {
   // Anything prior to XP SP2.
   if (!IsXPSP2OrLater())
     return 0;
   base::win::Version version = base::win::GetVersion();
   // Windows XP SP2+.
   if (version < base::win::VERSION_VISTA) {
     return flags & (MITIGATION_DEP |
                     MITIGATION_DEP_NO_ATL_THUNK);
   // Windows Vista
   if (version < base::win::VERSION_WIN7) {
     return flags & (MITIGATION_DEP |
                     MITIGATION_DEP_NO_ATL_THUNK |
                     MITIGATION_BOTTOM_UP_ASLR |
                     MITIGATION_DLL_SEARCH_ORDER |
                     MITIGATION_HEAP_TERMINATE);
   }
   // Windows 7 and Vista.
   } else if (version < base::win::VERSION_WIN8) {
     return flags & (MITIGATION_BOTTOM_UP_ASLR |
                     MITIGATION_DLL_SEARCH_ORDER |
                     MITIGATION_HEAP_TERMINATE);
   }
   // Windows 8 and above.
   return flags & (MITIGATION_BOTTOM_UP_ASLR |
                   MITIGATION_DLL_SEARCH_ORDER);
 }
 bool ApplyProcessMitigationsToSuspendedProcess(HANDLE process,
                                                MitigationFlags flags) {
 // This is a hack to fake a weak bottom-up ASLR on 32-bit Windows.
 #if !defined(_WIN64)
   if (flags & MITIGATION_BOTTOM_UP_ASLR) {
     unsigned int limit;
     rand_s(&limit);
     char* ptr = 0;
     const size_t kMask64k = 0xFFFF;
     // Random range (512k-16.5mb) in 64k steps.
     const char* end = ptr + ((((limit % 16384) + 512) * 1024) & ~kMask64k);
     while (ptr < end) {
       MEMORY_BASIC_INFORMATION memory_info;
       if (!::VirtualQueryEx(process, ptr, &memory_info, sizeof(memory_info)))
         break;
       size_t size = std::min((memory_info.RegionSize + kMask64k) & ~kMask64k,
                              static_cast<SIZE_T>(end - ptr));
       if (ptr && memory_info.State == MEM_FREE)
         ::VirtualAllocEx(process, ptr, size, MEM_RESERVE, PAGE_NOACCESS);
       ptr += size;
     }
   }
 #endif
   return true;
 }
 bool CanSetProcessMitigationsPostStartup(MitigationFlags flags) {
   // All of these mitigations can be enabled after startup.
   return !(flags & ~(MITIGATION_HEAP_TERMINATE |
                      MITIGATION_DEP |
                      MITIGATION_DEP_NO_ATL_THUNK |
                      MITIGATION_RELOCATE_IMAGE |
                      MITIGATION_RELOCATE_IMAGE_REQUIRED |
                      MITIGATION_BOTTOM_UP_ASLR |
                      MITIGATION_STRICT_HANDLE_CHECKS |
                      MITIGATION_WIN32K_DISABLE |
                      MITIGATION_EXTENSION_DLL_DISABLE |
                      MITIGATION_DLL_SEARCH_ORDER));
 }
 bool CanSetProcessMitigationsPreStartup(MitigationFlags flags) {
   // These mitigations cannot be enabled prior to startup.
   return !(flags & (MITIGATION_STRICT_HANDLE_CHECKS |
                     MITIGATION_WIN32K_DISABLE |
                     MITIGATION_DLL_SEARCH_ORDER));
 }
 }  // namespace sandbox

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

security/sandbox/win/src/process_mitigations.cc