The Tor Browser: security/sandbox/win/src/service_resolver

security/sandbox/win/src/service_resolver_32.cc@6474c204b198 (annotated)

security/sandbox/win/src/service_resolver_32.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/service_resolver.h"
 #include "base/memory/scoped_ptr.h"
 #include "sandbox/win/src/win_utils.h"
 namespace {
 #pragma pack(push, 1)
 const BYTE kMovEax = 0xB8;
 const BYTE kMovEdx = 0xBA;
 const USHORT kMovEdxEsp = 0xD48B;
 const USHORT kCallPtrEdx = 0x12FF;
 const USHORT kCallEdx = 0xD2FF;
 const BYTE kCallEip = 0xE8;
 const BYTE kRet = 0xC2;
 const BYTE kRet2 = 0xC3;
 const BYTE kNop = 0x90;
 const USHORT kJmpEdx = 0xE2FF;
 const USHORT kXorEcx = 0xC933;
 const ULONG kLeaEdx = 0x0424548D;
 const ULONG kCallFs1 = 0xC015FF64;
 const USHORT kCallFs2 = 0;
 const BYTE kCallFs3 = 0;
 const BYTE kAddEsp1 = 0x83;
 const USHORT kAddEsp2 = 0x4C4;
 const BYTE kJmp32 = 0xE9;
 const USHORT kSysenter = 0x340F;
 const int kMaxService = 1000;
 // Service code for 32 bit systems.
 // NOTE: on win2003 "call dword ptr [edx]" is "call edx".
 struct ServiceEntry {
   // This struct contains roughly the following code:
   // 00 mov     eax,25h
   // 05 mov     edx,offset SharedUserData!SystemCallStub (7ffe0300)
   // 0a call    dword ptr [edx]
   // 0c ret     2Ch
   // 0f nop
   BYTE mov_eax;         // = B8
   ULONG service_id;
   BYTE mov_edx;         // = BA
   ULONG stub;
   USHORT call_ptr_edx;  // = FF 12
   BYTE ret;             // = C2
   USHORT num_params;
   BYTE nop;
 };
 // Service code for 32 bit Windows 8.
 struct ServiceEntryW8 {
   // This struct contains the following code:
   // 00 b825000000      mov     eax,25h
   // 05 e803000000      call    eip+3
   // 0a c22c00          ret     2Ch
   // 0d 8bd4            mov     edx,esp
   // 0f 0f34            sysenter
   // 11 c3              ret
   // 12 8bff            mov     edi,edi
   BYTE mov_eax;         // = B8
   ULONG service_id;
   BYTE call_eip;        // = E8
   ULONG call_offset;
   BYTE ret_p;           // = C2
   USHORT num_params;
   USHORT mov_edx_esp;   // = BD D4
   USHORT sysenter;      // = 0F 34
   BYTE ret;             // = C3
   USHORT nop;
 };
 // Service code for a 32 bit process running on a 64 bit os.
 struct Wow64Entry {
   // This struct may contain one of two versions of code:
   // 1. For XP, Vista and 2K3:
   // 00 b825000000      mov     eax, 25h
   // 05 33c9            xor     ecx, ecx
   // 07 8d542404        lea     edx, [esp + 4]
   // 0b 64ff15c0000000  call    dword ptr fs:[0C0h]
   // 12 c22c00          ret     2Ch
   //
   // 2. For Windows 7:
   // 00 b825000000      mov     eax, 25h
   // 05 33c9            xor     ecx, ecx
   // 07 8d542404        lea     edx, [esp + 4]
   // 0b 64ff15c0000000  call    dword ptr fs:[0C0h]
   // 12 83c404          add     esp, 4
   // 15 c22c00          ret     2Ch
   //
   // So we base the structure on the bigger one:
   BYTE mov_eax;         // = B8
   ULONG service_id;
   USHORT xor_ecx;       // = 33 C9
   ULONG lea_edx;        // = 8D 54 24 04
   ULONG call_fs1;       // = 64 FF 15 C0
   USHORT call_fs2;      // = 00 00
   BYTE call_fs3;        // = 00
   BYTE add_esp1;        // = 83             or ret
   USHORT add_esp2;      // = C4 04          or num_params
   BYTE ret;             // = C2
   USHORT num_params;
 };
 // Service code for a 32 bit process running on 64 bit Windows 8.
 struct Wow64EntryW8 {
   // 00 b825000000      mov     eax, 25h
   // 05 64ff15c0000000  call    dword ptr fs:[0C0h]
   // 0b c22c00          ret     2Ch
   // 0f 90              nop
   BYTE mov_eax;         // = B8
   ULONG service_id;
   ULONG call_fs1;       // = 64 FF 15 C0
   USHORT call_fs2;      // = 00 00
   BYTE call_fs3;        // = 00
   BYTE ret;             // = C2
   USHORT num_params;
   BYTE nop;
 };
 // Make sure that relaxed patching works as expected.
 const size_t kMinServiceSize = offsetof(ServiceEntry, ret);
 COMPILE_ASSERT(sizeof(ServiceEntryW8) >= kMinServiceSize, wrong_service_len);
 COMPILE_ASSERT(sizeof(Wow64Entry) >= kMinServiceSize, wrong_service_len);
 COMPILE_ASSERT(sizeof(Wow64EntryW8) >= kMinServiceSize, wrong_service_len);
 struct ServiceFullThunk {
   union {
     ServiceEntry original;
     ServiceEntryW8 original_w8;
     Wow64Entry wow_64;
     Wow64EntryW8 wow_64_w8;
   };
   int internal_thunk;  // Dummy member to the beginning of the internal thunk.
 };
 #pragma pack(pop)
 };  // namespace
 namespace sandbox {
 NTSTATUS ServiceResolverThunk::Setup(const void* target_module,
                                      const void* interceptor_module,
                                      const char* target_name,
                                      const char* interceptor_name,
                                      const void* interceptor_entry_point,
                                      void* thunk_storage,
                                      size_t storage_bytes,
                                      size_t* storage_used) {
   NTSTATUS ret = Init(target_module, interceptor_module, target_name,
                       interceptor_name, interceptor_entry_point,
                       thunk_storage, storage_bytes);
   if (!NT_SUCCESS(ret))
     return ret;
   relative_jump_ = 0;
   size_t thunk_bytes = GetThunkSize();
   scoped_ptr<char[]> thunk_buffer(new char[thunk_bytes]);
   ServiceFullThunk* thunk = reinterpret_cast<ServiceFullThunk*>(
                                 thunk_buffer.get());
   if (!IsFunctionAService(&thunk->original) &&
       (!relaxed_ || !SaveOriginalFunction(&thunk->original, thunk_storage)))
     return STATUS_UNSUCCESSFUL;
   ret = PerformPatch(thunk, thunk_storage);
   if (NULL != storage_used)
     *storage_used = thunk_bytes;
   return ret;
 }
 size_t ServiceResolverThunk::GetThunkSize() const {
   return offsetof(ServiceFullThunk, internal_thunk) + GetInternalThunkSize();
 }
 bool ServiceResolverThunk::IsFunctionAService(void* local_thunk) const {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kMovEax != function_code.mov_eax ||
       kMovEdx != function_code.mov_edx ||
       (kCallPtrEdx != function_code.call_ptr_edx &&
        kCallEdx != function_code.call_ptr_edx) ||
       kRet != function_code.ret)
     return false;
   // Find the system call pointer if we don't already have it.
   if (kCallEdx != function_code.call_ptr_edx) {
     DWORD ki_system_call;
     if (!::ReadProcessMemory(process_,
                              bit_cast<const void*>(function_code.stub),
                              &ki_system_call, sizeof(ki_system_call), &read))
       return false;
     if (sizeof(ki_system_call) != read)
       return false;
     HMODULE module_1, module_2;
     // last check, call_stub should point to a KiXXSystemCall function on ntdll
     if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
                                GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
                            bit_cast<const wchar_t*>(ki_system_call), &module_1))
       return false;
     if (NULL != ntdll_base_) {
       // This path is only taken when running the unit tests. We want to be
       // able to patch a buffer in memory, so target_ is not inside ntdll.
       module_2 = ntdll_base_;
     } else {
       if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
                                  GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
                              reinterpret_cast<const wchar_t*>(target_),
                              &module_2))
         return false;
     }
     if (module_1 != module_2)
       return false;
   }
   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));
   return true;
 }
 NTSTATUS ServiceResolverThunk::PerformPatch(void* local_thunk,
                                             void* remote_thunk) {
   ServiceEntry intercepted_code;
   size_t bytes_to_write = sizeof(intercepted_code);
   ServiceFullThunk *full_local_thunk = reinterpret_cast<ServiceFullThunk*>(
       local_thunk);
   ServiceFullThunk *full_remote_thunk = reinterpret_cast<ServiceFullThunk*>(
       remote_thunk);
   // patch the original code
   memcpy(&intercepted_code, &full_local_thunk->original,
          sizeof(intercepted_code));
   intercepted_code.mov_eax = kMovEax;
   intercepted_code.service_id = full_local_thunk->original.service_id;
   intercepted_code.mov_edx = kMovEdx;
   intercepted_code.stub = bit_cast<ULONG>(&full_remote_thunk->internal_thunk);
   intercepted_code.call_ptr_edx = kJmpEdx;
   bytes_to_write = kMinServiceSize;
   if (relative_jump_) {
     intercepted_code.mov_eax = kJmp32;
     intercepted_code.service_id = relative_jump_;
     bytes_to_write = offsetof(ServiceEntry, mov_edx);
   }
   // setup the thunk
   SetInternalThunk(&full_local_thunk->internal_thunk, GetInternalThunkSize(),
                    remote_thunk, interceptor_);
   size_t thunk_size = GetThunkSize();
   // copy the local thunk buffer to the child
   SIZE_T written;
   if (!::WriteProcessMemory(process_, remote_thunk, local_thunk,
                             thunk_size, &written))
     return STATUS_UNSUCCESSFUL;
   if (thunk_size != written)
     return STATUS_UNSUCCESSFUL;
   // and now change the function to intercept, on the child
   if (NULL != ntdll_base_) {
     // running a unit test
     if (!::WriteProcessMemory(process_, target_, &intercepted_code,
                               bytes_to_write, &written))
       return STATUS_UNSUCCESSFUL;
   } else {
     if (!WriteProtectedChildMemory(process_, target_, &intercepted_code,
                                    bytes_to_write))
       return STATUS_UNSUCCESSFUL;
   }
   return STATUS_SUCCESS;
 }
 bool ServiceResolverThunk::SaveOriginalFunction(void* local_thunk,
                                                 void* remote_thunk) {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kJmp32 == function_code.mov_eax) {
     // Plain old entry point patch. The relative jump address follows it.
     ULONG relative = function_code.service_id;
     // First, fix our copy of their patch.
     relative += bit_cast<ULONG>(target_) - bit_cast<ULONG>(remote_thunk);
     function_code.service_id = relative;
     // And now, remember how to re-patch it.
     ServiceFullThunk *full_thunk =
         reinterpret_cast<ServiceFullThunk*>(remote_thunk);
     const ULONG kJmp32Size = 5;
     relative_jump_ = bit_cast<ULONG>(&full_thunk->internal_thunk) -
                      bit_cast<ULONG>(target_) - kJmp32Size;
   }
   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));
   return true;
 }
 bool Wow64ResolverThunk::IsFunctionAService(void* local_thunk) const {
   Wow64Entry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kMovEax != function_code.mov_eax || kXorEcx != function_code.xor_ecx ||
       kLeaEdx != function_code.lea_edx || kCallFs1 != function_code.call_fs1 ||
       kCallFs2 != function_code.call_fs2 || kCallFs3 != function_code.call_fs3)
     return false;
   if ((kAddEsp1 == function_code.add_esp1 &&
        kAddEsp2 == function_code.add_esp2 &&
        kRet == function_code.ret) || kRet == function_code.add_esp1) {
     // Save the verified code
     memcpy(local_thunk, &function_code, sizeof(function_code));
     return true;
   }
   return false;
 }
 bool Wow64W8ResolverThunk::IsFunctionAService(void* local_thunk) const {
   Wow64EntryW8 function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kMovEax != function_code.mov_eax || kCallFs1 != function_code.call_fs1 ||
       kCallFs2 != function_code.call_fs2 ||
       kCallFs3 != function_code.call_fs3 || kRet != function_code.ret) {
     return false;
   }
   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));
   return true;
 }
 bool Win2kResolverThunk::IsFunctionAService(void* local_thunk) const {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kMovEax != function_code.mov_eax ||
       function_code.service_id > kMaxService)
     return false;
   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));
   return true;
 }
 bool Win8ResolverThunk::IsFunctionAService(void* local_thunk) const {
   ServiceEntryW8 function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;
   if (sizeof(function_code) != read)
     return false;
   if (kMovEax != function_code.mov_eax || kCallEip != function_code.call_eip ||
       function_code.call_offset != 3 || kRet != function_code.ret_p ||
       kMovEdxEsp != function_code.mov_edx_esp ||
       kSysenter != function_code.sysenter || kRet2 != function_code.ret) {
     return false;
   }
   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));
   return true;
 }
 }  // namespace sandbox

The Tor Browser / annotate

security/sandbox/win/src/service_resolver_32.cc@6474c204b198 (annotated)

security/sandbox/win/src/service_resolver_32.cc