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

--1:000000000000
+:5cd8f580f230
+// 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/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "sandbox/win/src/win_utils.h"
+namespace {
+#pragma pack(push, 1)
+const ULONG kMmovR10EcxMovEax = 0xB8D18B4C;
+const USHORT kSyscall = 0x050F;
+const BYTE kRetNp = 0xC3;
+const ULONG64 kMov1 = 0x54894808244C8948;
+const ULONG64 kMov2 = 0x4C182444894C1024;
+const ULONG kMov3 = 0x20244C89;
+// Service code for 64 bit systems.
+struct ServiceEntry {
+// This struct contains roughly the following code:
+// 00 mov     r10,rcx
+// 03 mov     eax,52h
+// 08 syscall
+// 0a ret
+// 0b xchg    ax,ax
+// 0e xchg    ax,ax
+ULONG mov_r10_rcx_mov_eax;  // = 4C 8B D1 B8
+ULONG service_id;
+USHORT syscall;             // = 0F 05
+BYTE ret;                   // = C3
+BYTE pad;                   // = 66
+USHORT xchg_ax_ax1;         // = 66 90
+USHORT xchg_ax_ax2;         // = 66 90
+};
+// Service code for 64 bit Windows 8.
+struct ServiceEntryW8 {
+// This struct contains the following code:
+// 00 48894c2408      mov     [rsp+8], rcx
+// 05 4889542410      mov     [rsp+10], rdx
+// 0a 4c89442418      mov     [rsp+18], r8
+// 0f 4c894c2420      mov     [rsp+20], r9
+// 14 4c8bd1          mov     r10,rcx
+// 17 b825000000      mov     eax,25h
+// 1c 0f05            syscall
+// 1e c3              ret
+// 1f 90              nop
+ULONG64 mov_1;              // = 48 89 4C 24 08 48 89 54
+ULONG64 mov_2;              // = 24 10 4C 89 44 24 18 4C
+ULONG mov_3;                // = 89 4C 24 20
+ULONG mov_r10_rcx_mov_eax;  // = 4C 8B D1 B8
+ULONG service_id;
+USHORT syscall;             // = 0F 05
+BYTE ret;                   // = C2
+BYTE nop;                   // = 90
+};
+// We don't have an internal thunk for x64.
+struct ServiceFullThunk {
+union {
+ServiceEntry original;
+ServiceEntryW8 original_w8;
+};
+};
+#pragma pack(pop)
+bool IsService(const void* source) {
+const ServiceEntry* service =
+reinterpret_cast<const ServiceEntry*>(source);
+return (kMmovR10EcxMovEax == service->mov_r10_rcx_mov_eax &&
+kSyscall == service->syscall && kRetNp == service->ret);
+}
+};  // 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;
+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))
+return STATUS_UNSUCCESSFUL;
+ret = PerformPatch(thunk, thunk_storage);
+if (NULL != storage_used)
+*storage_used = thunk_bytes;
+return ret;
+}
+size_t ServiceResolverThunk::GetThunkSize() const {
+return sizeof(ServiceFullThunk);
+}
+bool ServiceResolverThunk::IsFunctionAService(void* local_thunk) const {
+ServiceFullThunk 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 (!IsService(&function_code)) {
+// See if it's the Win8 signature.
+ServiceEntryW8* w8_service = &function_code.original_w8;
+if (!IsService(&w8_service->mov_r10_rcx_mov_eax) ||
+w8_service->mov_1 != kMov1 || w8_service->mov_1 != kMov1 ||
+w8_service->mov_1 != kMov1) {
+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) {
+ServiceFullThunk* full_local_thunk = reinterpret_cast<ServiceFullThunk*>(
+local_thunk);
+ServiceFullThunk* full_remote_thunk = reinterpret_cast<ServiceFullThunk*>(
+remote_thunk);
+// Patch the original code.
+ServiceEntry local_service;
+DCHECK_GE(GetInternalThunkSize(), sizeof(local_service));
+if (!SetInternalThunk(&local_service, sizeof(local_service), NULL,
+interceptor_))
+return STATUS_UNSUCCESSFUL;
+// Copy the local thunk buffer to the child.
+SIZE_T actual;
+if (!::WriteProcessMemory(process_, remote_thunk, local_thunk,
+sizeof(ServiceFullThunk), &actual))
+return STATUS_UNSUCCESSFUL;
+if (sizeof(ServiceFullThunk) != actual)
+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_, &local_service,
+sizeof(local_service), &actual))
+return STATUS_UNSUCCESSFUL;
+} else {
+if (!WriteProtectedChildMemory(process_, target_, &local_service,
+sizeof(local_service)))
+return STATUS_UNSUCCESSFUL;
+}
+return STATUS_SUCCESS;
+}
+bool Wow64ResolverThunk::IsFunctionAService(void* local_thunk) const {
+NOTREACHED();
+return false;
+}
+bool Win2kResolverThunk::IsFunctionAService(void* local_thunk) const {
+NOTREACHED();
+return false;
+}
+}  // namespace sandbox

The Tor Browser / file comparison

comparison: security/sandbox/win/src/service_resolver_64.cc

security/sandbox/win/src/service_resolver_64.cc