Files
windows-user-space-emulator/src/windows_emulator/main.cpp
2024-09-05 19:01:55 +02:00

885 lines
23 KiB
C++

#include <gdbstub.h>
#include "std_include.hpp"
#include "emulator_utils.hpp"
#include "process_context.hpp"
#include "syscalls.hpp"
#include "reflect_extension.hpp"
#include <reflect>
#include <address_utils.hpp>
#include <unicorn_x64_emulator.hpp>
#include "gdb_stub.hpp"
#include "module_mapper.hpp"
#include "context_frame.hpp"
#define GS_SEGMENT_ADDR 0x6000000ULL
#define GS_SEGMENT_SIZE (20 << 20) // 20 MB
#define IA32_GS_BASE_MSR 0xC0000101
#define STACK_SIZE 0x40000
#define STACK_ADDRESS (0x80000000000 - STACK_SIZE)
#define KUSD_ADDRESS 0x7ffe0000
#define GDT_ADDR 0x30000
#define GDT_LIMIT 0x1000
#define GDT_ENTRY_SIZE 0x8
bool use_gdb = false;
struct breakpoint_key
{
size_t addr{};
size_t size{};
breakpoint_type type{};
bool operator==(const breakpoint_key& other) const
{
return this->addr == other.addr && this->size == other.size && this->type == other.type;
}
};
template <>
struct std::hash<breakpoint_key>
{
std::size_t operator()(const breakpoint_key& k) const noexcept
{
return ((std::hash<size_t>()(k.addr)
^ (std::hash<size_t>()(k.size) << 1)) >> 1)
^ (std::hash<size_t>()(static_cast<size_t>(k.type)) << 1);
}
};
namespace
{
template <typename T>
class type_info
{
public:
type_info()
{
this->type_name_ = reflect::type_name<T>();
reflect::for_each<T>([this](auto I)
{
const auto member_name = reflect::member_name<I, T>();
const auto member_offset = reflect::offset_of<I, T>();
this->members_[member_offset] = member_name;
});
}
std::string get_member_name(const size_t offset) const
{
size_t last_offset{};
std::string_view last_member{};
for (const auto& member : this->members_)
{
if (offset == member.first)
{
return member.second;
}
if (offset < member.first)
{
const auto diff = offset - last_offset;
return std::string(last_member) + "+" + std::to_string(diff);
}
last_offset = member.first;
last_member = member.second;
}
return "<N/A>";
}
const std::string& get_type_name() const
{
return this->type_name_;
}
private:
std::string type_name_{};
std::map<size_t, std::string> members_{};
};
template <typename T>
void watch_object(x64_emulator& emu, emulator_object<T> object)
{
const type_info<T> info{};
emu.hook_memory_read(object.value(), object.size(),
[i = std::move(info), object](const uint64_t address, size_t)
{
const auto offset = address - object.value();
printf("%s: %llX (%s)\n", i.get_type_name().c_str(), offset,
i.get_member_name(offset).c_str());
});
}
template <typename T>
emulator_object<T> allocate_object_on_stack(x64_emulator& emu)
{
const auto old_sp = emu.reg(x64_register::rsp);
const auto new_sp = align_down(old_sp - sizeof(CONTEXT),
std::max(alignof(CONTEXT), alignof(x64_emulator::pointer_type)));
emu.reg(x64_register::rsp, new_sp);
return {emu, new_sp};
}
void setup_stack(x64_emulator& emu, const uint64_t stack_base, const size_t stack_size)
{
emu.allocate_memory(stack_base, stack_size, memory_permission::read_write);
const uint64_t stack_end = stack_base + stack_size;
emu.reg(x64_register::rsp, stack_end);
}
emulator_allocator setup_gs_segment(x64_emulator& emu, const uint64_t segment_base, const uint64_t size)
{
struct msr_value
{
uint32_t id;
uint64_t value;
};
const msr_value value{
IA32_GS_BASE_MSR,
segment_base
};
emu.write_register(x64_register::msr, &value, sizeof(value));
emu.allocate_memory(segment_base, size, memory_permission::read_write);
return {emu, segment_base, size};
}
emulator_object<KUSER_SHARED_DATA> setup_kusd(x64_emulator& emu)
{
emu.allocate_memory(KUSD_ADDRESS, page_align_up(sizeof(KUSER_SHARED_DATA)), memory_permission::read);
const emulator_object<KUSER_SHARED_DATA> kusd_object{emu, KUSD_ADDRESS};
kusd_object.access([](KUSER_SHARED_DATA& kusd)
{
const auto& real_kusd = *reinterpret_cast<KUSER_SHARED_DATA*>(KUSD_ADDRESS);
memcpy(&kusd, &real_kusd, sizeof(kusd));
kusd.ImageNumberLow = IMAGE_FILE_MACHINE_I386;
kusd.ImageNumberHigh = IMAGE_FILE_MACHINE_AMD64;
memset(&kusd.ProcessorFeatures, 0, sizeof(kusd.ProcessorFeatures));
// ...
});
return kusd_object;
}
uint64_t copy_string(x64_emulator& emu, emulator_allocator& allocator, const void* base_ptr, const uint64_t offset,
const size_t length)
{
if (!length)
{
return 0;
}
const auto length_to_allocate = length + 2;
const auto str_obj = allocator.reserve(length_to_allocate);
emu.write_memory(str_obj, static_cast<const uint8_t*>(base_ptr) + offset, length);
return str_obj;
}
ULONG copy_string_as_relative(x64_emulator& emu, emulator_allocator& allocator, const uint64_t result_base,
const void* base_ptr, const uint64_t offset,
const size_t length)
{
const auto address = copy_string(emu, allocator, base_ptr, offset, length);
if (!address)
{
return 0;
}
assert(address > result_base);
return static_cast<ULONG>(address - result_base);
}
emulator_object<API_SET_NAMESPACE> clone_api_set_map(x64_emulator& emu, emulator_allocator& allocator,
const API_SET_NAMESPACE& orig_api_set_map)
{
const auto api_set_map_obj = allocator.reserve<API_SET_NAMESPACE>();
const auto ns_entries_obj = allocator.reserve<API_SET_NAMESPACE_ENTRY>(orig_api_set_map.Count);
const auto hash_entries_obj = allocator.reserve<API_SET_HASH_ENTRY>(orig_api_set_map.Count);
api_set_map_obj.access([&](API_SET_NAMESPACE& api_set)
{
api_set = orig_api_set_map;
api_set.EntryOffset = static_cast<ULONG>(ns_entries_obj.value() - api_set_map_obj.value());
api_set.HashOffset = static_cast<ULONG>(hash_entries_obj.value() - api_set_map_obj.value());
});
const auto orig_ns_entries = offset_pointer<API_SET_NAMESPACE_ENTRY>(&orig_api_set_map,
orig_api_set_map.EntryOffset);
const auto orig_hash_entries = offset_pointer<API_SET_HASH_ENTRY>(&orig_api_set_map,
orig_api_set_map.HashOffset);
for (ULONG i = 0; i < orig_api_set_map.Count; ++i)
{
auto ns_entry = orig_ns_entries[i];
const auto hash_entry = orig_hash_entries[i];
ns_entry.NameOffset = copy_string_as_relative(emu, allocator, api_set_map_obj.value(), &orig_api_set_map,
ns_entry.NameOffset, ns_entry.NameLength);
if (!ns_entry.ValueCount)
{
continue;
}
const auto values_obj = allocator.reserve<API_SET_VALUE_ENTRY>(ns_entry.ValueCount);
const auto orig_values = offset_pointer<API_SET_VALUE_ENTRY>(&orig_api_set_map,
ns_entry.ValueOffset);
ns_entry.ValueOffset = static_cast<ULONG>(values_obj.value() - api_set_map_obj.value());
for (ULONG j = 0; j < ns_entry.ValueCount; ++j)
{
auto value = orig_values[j];
value.ValueOffset = copy_string_as_relative(emu, allocator, api_set_map_obj.value(), &orig_api_set_map,
value.ValueOffset, value.ValueLength);
if (value.NameLength)
{
value.NameOffset = copy_string_as_relative(emu, allocator, api_set_map_obj.value(),
&orig_api_set_map,
value.NameOffset, value.NameLength);
}
values_obj.write(value, j);
}
ns_entries_obj.write(ns_entry, i);
hash_entries_obj.write(hash_entry, i);
}
//watch_object(emu, api_set_map_obj);
return api_set_map_obj;
}
emulator_object<API_SET_NAMESPACE> build_api_set_map(x64_emulator& emu, emulator_allocator& allocator)
{
const auto& orig_api_set_map = *NtCurrentTeb()->ProcessEnvironmentBlock->ApiSetMap;
return clone_api_set_map(emu, allocator, orig_api_set_map);
}
emulator_allocator create_allocator(emulator& emu, const size_t size)
{
const auto base = emu.find_free_allocation_base(size);
emu.allocate_memory(base, size, memory_permission::read_write);
return emulator_allocator{emu, base, size};
}
void setup_gdt(x64_emulator& emu)
{
constexpr uint64_t gdtr[4] = {0, GDT_ADDR, GDT_LIMIT, 0};
emu.write_register(x64_register::gdtr, &gdtr, sizeof(gdtr));
emu.allocate_memory(GDT_ADDR, GDT_LIMIT, memory_permission::read);
emu.write_memory<uint64_t>(GDT_ADDR + 6 * (sizeof(uint64_t)), 0xEFFE000000FFFF);
emu.reg<uint16_t>(x64_register::cs, 0x33);
emu.write_memory<uint64_t>(GDT_ADDR + 5 * (sizeof(uint64_t)), 0xEFF6000000FFFF);
emu.reg<uint16_t>(x64_register::ss, 0x2B);
}
process_context setup_context(x64_emulator& emu)
{
process_context context{};
setup_stack(emu, STACK_ADDRESS, STACK_SIZE);
setup_gdt(emu);
context.kusd = setup_kusd(emu);
context.gs_segment = setup_gs_segment(emu, GS_SEGMENT_ADDR, GS_SEGMENT_SIZE);
auto allocator = create_allocator(emu, 1 << 20);
auto& gs = context.gs_segment;
context.teb = gs.reserve<TEB>();
context.peb = gs.reserve<PEB>();
context.process_params = gs.reserve<RTL_USER_PROCESS_PARAMETERS>();
context.teb.access([&](TEB& teb)
{
teb.ClientId.UniqueProcess = reinterpret_cast<HANDLE>(1);
teb.ClientId.UniqueThread = reinterpret_cast<HANDLE>(2);
teb.NtTib.StackLimit = reinterpret_cast<void*>(STACK_ADDRESS);
teb.NtTib.StackBase = reinterpret_cast<void*>((STACK_ADDRESS + STACK_SIZE));
teb.NtTib.Self = &context.teb.ptr()->NtTib;
teb.ProcessEnvironmentBlock = context.peb.ptr();
});
context.process_params.access([&](RTL_USER_PROCESS_PARAMETERS& proc_params)
{
proc_params.Length = sizeof(proc_params);
proc_params.Flags = 0x6001 | 0x80000000; // Prevent CsrClientConnectToServer
proc_params.ConsoleHandle = reinterpret_cast<HANDLE>(CONSOLE_HANDLE);
proc_params.StandardOutput = reinterpret_cast<HANDLE>(STDOUT_HANDLE);
proc_params.StandardInput = reinterpret_cast<HANDLE>(STDIN_HANDLE);
proc_params.StandardError = proc_params.StandardOutput;
gs.make_unicode_string(proc_params.CurrentDirectory.DosPath, L"C:\\Users\\mauri\\Desktop");
gs.make_unicode_string(proc_params.ImagePathName, L"C:\\Users\\mauri\\Desktop\\ConsoleApplication6.exe");
gs.make_unicode_string(proc_params.CommandLine, L"C:\\Users\\mauri\\Desktop\\ConsoleApplication6.exe");
});
context.peb.access([&](PEB& peb)
{
peb.ImageBaseAddress = nullptr;
peb.ProcessHeap = nullptr;
peb.ProcessHeaps = nullptr;
peb.ProcessParameters = context.process_params.ptr();
peb.ApiSetMap = build_api_set_map(emu, allocator).ptr();
});
return context;
}
std::vector gdb_registers{
x64_register::rax,
x64_register::rbx,
x64_register::rcx,
x64_register::rdx,
x64_register::rsi,
x64_register::rdi,
x64_register::rbp,
x64_register::rsp,
x64_register::r8,
x64_register::r9,
x64_register::r10,
x64_register::r11,
x64_register::r12,
x64_register::r13,
x64_register::r14,
x64_register::r15,
x64_register::rip,
x64_register::rflags,
/*x64_register::cs,
x64_register::ss,
x64_register::ds,
x64_register::es,
x64_register::fs,
x64_register::gs,*/
};
memory_operation map_breakpoint_type(const breakpoint_type type)
{
switch (type)
{
case breakpoint_type::software:
case breakpoint_type::hardware_exec:
return memory_operation::exec;
case breakpoint_type::hardware_read:
return memory_permission::read;
case breakpoint_type::hardware_write:
return memory_permission::write;
case breakpoint_type::hardware_read_write:
return memory_permission::read_write;
default:
throw std::runtime_error("Bad bp type");
}
}
class scoped_emulator_hook
{
public:
scoped_emulator_hook() = default;
scoped_emulator_hook(emulator& emu, emulator_hook* hook)
: emu_(&emu)
, hook_(hook)
{
}
~scoped_emulator_hook()
{
this->remove();
}
scoped_emulator_hook(const scoped_emulator_hook&) = delete;
scoped_emulator_hook& operator=(const scoped_emulator_hook&) = delete;
scoped_emulator_hook(scoped_emulator_hook&& obj) noexcept
{
this->operator=(std::move(obj));
}
scoped_emulator_hook& operator=(scoped_emulator_hook&& obj) noexcept
{
if (this != &obj)
{
this->remove();
this->emu_ = obj.emu_;
this->hook_ = obj.hook_;
obj.hook_ = {};
}
return *this;
}
void remove()
{
if (this->hook_)
{
this->emu_->delete_hook(this->hook_);
this->hook_ = {};
}
}
private:
emulator* emu_{};
emulator_hook* hook_{};
};
class x64_gdb_stub_handler : public gdb_stub_handler
{
public:
x64_gdb_stub_handler(x64_emulator& emu)
: emu_(&emu)
{
}
~x64_gdb_stub_handler() override = default;
gdb_action cont() override
{
try
{
this->emu_->start_from_ip();
}
catch (const std::exception& e)
{
puts(e.what());
}
return gdb_action::resume;
}
gdb_action stepi() override
{
try
{
this->emu_->start_from_ip({}, 1);
}
catch (const std::exception& e)
{
puts(e.what());
}
return gdb_action::resume;
}
bool read_reg(const int regno, size_t* value) override
{
*value = 0;
try
{
if (static_cast<size_t>(regno) >= gdb_registers.size())
{
return true;
}
this->emu_->read_register(gdb_registers[regno], value, sizeof(*value));
return true;
}
catch (...)
{
return true;
}
}
bool write_reg(const int regno, const size_t value) override
{
try
{
if (static_cast<size_t>(regno) >= gdb_registers.size())
{
return true;
}
this->emu_->write_register(gdb_registers[regno], &value, sizeof(value));
return true;
}
catch (...)
{
return false;
}
}
bool read_mem(const size_t addr, const size_t len, void* val) override
{
return this->emu_->try_read_memory(addr, val, len);
}
bool write_mem(const size_t addr, const size_t len, void* val) override
{
try
{
this->emu_->write_memory(addr, val, len);
return true;
}
catch (...)
{
return false;
}
}
bool set_bp(const breakpoint_type type, const size_t addr, const size_t size) override
{
try
{
this->hooks_[{addr, size, type}] = scoped_emulator_hook(*this->emu_, this->emu_->hook_memory_access(
addr, size, map_breakpoint_type(type),
[this](uint64_t, size_t, memory_operation)
{
this->on_interrupt();
}));
return true;
}
catch (...)
{
return false;
}
}
bool del_bp(const breakpoint_type type, const size_t addr, const size_t size) override
{
try
{
const auto entry = this->hooks_.find({addr, size, type});
if (entry == this->hooks_.end())
{
return false;
}
this->hooks_.erase(entry);
return true;
}
catch (...)
{
return false;
}
}
void on_interrupt() override
{
this->emu_->stop();
}
private:
x64_emulator* emu_{};
std::unordered_map<breakpoint_key, scoped_emulator_hook> hooks_{};
};
uint64_t find_exported_function(const std::vector<exported_symbol>& exports, const std::string_view name)
{
for (auto& symbol : exports)
{
if (symbol.name == name)
{
return symbol.address;
}
}
return 0;
}
emulator_object<CONTEXT> save_context_on_stack(x64_emulator& emu)
{
CONTEXT ctx{};
ctx.ContextFlags = CONTEXT_ALL;
context_frame::save(emu, ctx);
const auto ctx_obj = allocate_object_on_stack<CONTEXT>(emu);
ctx_obj.write(ctx);
return ctx_obj;
}
using exception_record_map = std::unordered_map<const EXCEPTION_RECORD*, emulator_object<EXCEPTION_RECORD>>;
emulator_object<EXCEPTION_RECORD> save_exception_record_on_stack(x64_emulator& emu, const EXCEPTION_RECORD& record,
exception_record_map& record_mapping)
{
const auto record_obj = allocate_object_on_stack<EXCEPTION_RECORD>(emu);
record_obj.write(record);
if (record.ExceptionRecord)
{
record_mapping[&record] = record_obj;
emulator_object<EXCEPTION_RECORD> nested_record_obj{};
const auto nested_record = record_mapping.find(record.ExceptionRecord);
if (nested_record != record_mapping.end())
{
nested_record_obj = nested_record->second;
}
else
{
nested_record_obj = save_exception_record_on_stack(emu, *record.ExceptionRecord, record_mapping);
}
record_obj.access([&](EXCEPTION_RECORD& r)
{
r.ExceptionRecord = nested_record_obj.ptr();
});
}
return record_obj;
}
emulator_object<EXCEPTION_RECORD> save_exception_record_on_stack(x64_emulator& emu, const EXCEPTION_RECORD& record)
{
exception_record_map record_mapping{};
return save_exception_record_on_stack(emu, record, record_mapping);
}
uint32_t map_violation_operation_to_parameter(const memory_operation operation)
{
switch (operation)
{
default:
case memory_operation::read:
return 0;
case memory_operation::write:
return 1;
case memory_operation::exec:
return 1;
}
}
EXCEPTION_POINTERS create_access_violation_exception_pointers(x64_emulator& emu, const uint64_t address,
const memory_operation operation)
{
EXCEPTION_RECORD record{};
memset(&record, 0, sizeof(record));
record.ExceptionCode = STATUS_ACCESS_VIOLATION;
record.ExceptionFlags = 0;
record.ExceptionRecord = nullptr;
record.ExceptionAddress = reinterpret_cast<void*>(address);
record.NumberParameters = 2;
record.ExceptionInformation[0] = map_violation_operation_to_parameter(operation);
record.ExceptionInformation[1] = address;
EXCEPTION_POINTERS pointers{};
pointers.ContextRecord = save_context_on_stack(emu).ptr();
pointers.ExceptionRecord = save_exception_record_on_stack(emu, record).ptr();
return pointers;
}
void dispatch_exception_pointers(x64_emulator& emu, uint64_t dispatcher, const EXCEPTION_POINTERS pointers)
{
emu.reg(x64_register::rcx, reinterpret_cast<uint64_t>(pointers.ExceptionRecord));
emu.reg(x64_register::rdx, reinterpret_cast<uint64_t>(pointers.ContextRecord));
emu.reg(x64_register::rip, dispatcher);
}
void dispatch_access_violation(x64_emulator& emu, uint64_t dispatcher, const uint64_t address,
const memory_operation operation)
{
const auto pointers = create_access_violation_exception_pointers(emu, address, operation);
dispatch_exception_pointers(emu, dispatcher, pointers);
}
void run()
{
const auto emu = unicorn::create_x64_emulator();
auto context = setup_context(*emu);
context.executable = *map_file(*emu, R"(C:\Users\mauri\Desktop\ConsoleApplication6.exe)");
context.peb.access([&](PEB& peb)
{
peb.ImageBaseAddress = reinterpret_cast<void*>(context.executable.image_base);
});
context.ntdll = *map_file(*emu, R"(C:\Windows\System32\ntdll.dll)");
const auto ldr_initialize_thunk = find_exported_function(context.ntdll.exports, "LdrInitializeThunk");
const auto rtl_user_thread_start = find_exported_function(context.ntdll.exports, "RtlUserThreadStart");
const auto ki_user_exception_dispatcher = find_exported_function(
context.ntdll.exports, "KiUserExceptionDispatcher");
syscall_dispatcher dispatcher{context.ntdll.exports};
emu->hook_instruction(x64_hookable_instructions::syscall, [&]
{
dispatcher.dispatch(*emu, context);
return instruction_hook_continuation::skip_instruction;
});
emu->hook_instruction(x64_hookable_instructions::rdtsc, [&]
{
emu->reg(x64_register::rax, 0x0011223344556677);
return instruction_hook_continuation::skip_instruction;
});
emu->hook_instruction(x64_hookable_instructions::invalid, [&]
{
const auto ip = emu->read_instruction_pointer();
printf("Invalid instruction at: %llX\n", ip);
return instruction_hook_continuation::skip_instruction;
});
emu->hook_interrupt([&](int interrupt)
{
printf("Interrupt: %i\n", interrupt);
});
bool continue_execution = true;
emu->hook_memory_violation([&](const uint64_t address, const size_t size, const memory_operation operation,
const memory_violation_type type)
{
const auto permission = get_permission_string(operation);
const auto ip = emu->read_instruction_pointer();
if (type == memory_violation_type::protection)
{
printf("Protection violation: %llX (%zX) - %s at %llX\n", address, size, permission.c_str(), ip);
}
else if (type == memory_violation_type::unmapped)
{
printf("Mapping violation: %llX (%zX) - %s at %llX\n", address, size, permission.c_str(), ip);
}
dispatch_access_violation(*emu, ki_user_exception_dispatcher, address, operation);
continue_execution = true;
return memory_violation_continuation::stop;
});
/*
watch_object(*emu, context.teb);
watch_object(*emu, context.peb);
watch_object(*emu, context.process_params);
watch_object(*emu, context.kusd);
*/
/*emu->hook_memory_execution(0, std::numeric_limits<size_t>::max(), [&](const uint64_t address, const size_t)
{
if (address == 0x1800D52F4)
{
//emu->stop();
}
printf(
"Inst: %16llX - RAX: %16llX - RBX: %16llX - RCX: %16llX - RDX: %16llX - R8: %16llX - R9: %16llX - RDI: %16llX - RSI: %16llX\n",
address,
emu->reg(x64_register::rax), emu->reg(x64_register::rbx), emu->reg(x64_register::rcx),
emu->reg(x64_register::rdx), emu->reg(x64_register::r8), emu->reg(x64_register::r9),
emu->reg(x64_register::rdi), emu->reg(x64_register::rsi));
});*/
CONTEXT ctx{};
ctx.ContextFlags = CONTEXT_ALL;
context_frame::save(*emu, ctx);
ctx.Rip = rtl_user_thread_start;
ctx.Rcx = context.executable.entry_point;
const auto ctx_obj = allocate_object_on_stack<CONTEXT>(*emu);
ctx_obj.write(ctx);
emu->reg(x64_register::rcx, ctx_obj.value());
emu->reg(x64_register::rdx, context.ntdll.image_base);
emu->reg(x64_register::rip, ldr_initialize_thunk);
try
{
if (use_gdb)
{
puts("Launching gdb stub...");
x64_gdb_stub_handler handler{*emu};
run_gdb_stub(handler, "i386:x86-64", gdb_registers.size(), "0.0.0.0:28960");
}
else
{
while (continue_execution)
{
continue_execution = false;
try
{
emu->start_from_ip();
}
catch (...)
{
if (!continue_execution)
{
throw;
}
}
}
}
}
catch (...)
{
printf("Emulation failed at: %llX\n", emu->reg(x64_register::rip));
throw;
}
printf("Emulation done.\n");
}
}
int main(int /*argc*/, char** /*argv*/)
{
try
{
do
{
run();
}
while (use_gdb);
return 0;
}
catch (std::exception& e)
{
puts(e.what());
#ifdef _WIN32
//MessageBoxA(nullptr, e.what(), "ERROR", MB_ICONERROR);
#endif
}
return 1;
}
#ifdef _WIN32
int WINAPI WinMain(HINSTANCE, HINSTANCE, PSTR, int)
{
return main(__argc, __argv);
}
#endif