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Prepare fuzzing engine

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momo5502
2024-09-24 14:18:32 +02:00
parent f5b570351f
commit 10b09b8f51
45 changed files with 598 additions and 101 deletions
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257
src/windows-emulator/module/module_mapping.cpp Normal file
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#include "../std_include.hpp"
#include "module_mapping.hpp"
#include <address_utils.hpp>
#include <utils/io.hpp>
#include <utils/buffer_accessor.hpp>
namespace
{
uint64_t get_first_section_offset(const IMAGE_NT_HEADERS& nt_headers, const uint64_t nt_headers_offset)
{
const auto first_section_absolute = reinterpret_cast<uint64_t>(IMAGE_FIRST_SECTION(&nt_headers));
const auto absolute_base = reinterpret_cast<uint64_t>(&nt_headers);
return nt_headers_offset + (first_section_absolute - absolute_base);
}
std::vector<uint8_t> read_mapped_memory(emulator& emu, const mapped_module& binary)
{
std::vector<uint8_t> memory{};
memory.resize(binary.size_of_image);
emu.read_memory(binary.image_base, memory.data(), memory.size());
return memory;
}
void collect_exports(mapped_module& binary, const utils::safe_buffer_accessor<const uint8_t> buffer,
const IMAGE_OPTIONAL_HEADER& optional_header)
{
auto& export_directory_entry = optional_header.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
if (export_directory_entry.VirtualAddress == 0 || export_directory_entry.Size == 0)
{
return;
}
const auto export_directory = buffer.as<IMAGE_EXPORT_DIRECTORY>(export_directory_entry.
VirtualAddress).get();
//const auto function_count = export_directory->NumberOfFunctions;
const auto names_count = export_directory.NumberOfNames;
const auto names = buffer.as<DWORD>(export_directory.AddressOfNames);
const auto ordinals = buffer.as<WORD>(export_directory.AddressOfNameOrdinals);
const auto functions = buffer.as<DWORD>(export_directory.AddressOfFunctions);
for (DWORD i = 0; i < names_count; i++)
{
exported_symbol symbol{};
symbol.ordinal = ordinals.get(i);
symbol.name = buffer.as_string(names.get(i));
symbol.rva = functions.get(symbol.ordinal);
symbol.address = binary.image_base + symbol.rva;
binary.exports.push_back(std::move(symbol));
}
for (const auto& symbol : binary.exports)
{
binary.address_names.try_emplace(symbol.address, symbol.name);
}
}
template <typename T>
requires(std::is_integral_v<T>)
void apply_relocation(const utils::safe_buffer_accessor<uint8_t> buffer, const uint64_t offset,
const uint64_t delta)
{
const auto obj = buffer.as<T>(offset);
const auto value = obj.get();
const auto new_value = value + static_cast<T>(delta);
obj.set(new_value);
}
void apply_relocations(const mapped_module& binary, const utils::safe_buffer_accessor<uint8_t> buffer,
const IMAGE_OPTIONAL_HEADER& optional_header)
{
const auto delta = binary.image_base - optional_header.ImageBase;
if (delta == 0)
{
return;
}
const auto directory = &optional_header.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC];
if (directory->Size == 0)
{
return;
}
auto relocation_offset = directory->VirtualAddress;
const auto relocation_end = relocation_offset + directory->Size;
while (relocation_offset < relocation_end)
{
const auto relocation = buffer.as<IMAGE_BASE_RELOCATION>(relocation_offset).get();
if (relocation.VirtualAddress <= 0 || relocation.SizeOfBlock <= sizeof(IMAGE_BASE_RELOCATION))
{
break;
}
const auto data_size = relocation.SizeOfBlock - sizeof(IMAGE_BASE_RELOCATION);
const auto entry_count = data_size / sizeof(uint16_t);
const auto entries = buffer.as<uint16_t>(relocation_offset + sizeof(IMAGE_BASE_RELOCATION));
relocation_offset += relocation.SizeOfBlock;
for (size_t i = 0; i < entry_count; ++i)
{
const auto entry = entries.get(i);
const int type = entry >> 12;
const int offset = entry & 0xfff;
const auto total_offset = relocation.VirtualAddress + offset;
switch (type)
{
case IMAGE_REL_BASED_ABSOLUTE:
break;
case IMAGE_REL_BASED_HIGHLOW:
apply_relocation<DWORD>(buffer, total_offset, delta);
break;
case IMAGE_REL_BASED_DIR64:
apply_relocation<ULONGLONG>(buffer, total_offset, delta);
break;
default:
throw std::runtime_error("Unknown relocation type: " + std::to_string(type));
}
}
}
}
void map_sections(emulator& emu, const mapped_module& binary,
const utils::safe_buffer_accessor<const uint8_t> buffer,
const IMAGE_NT_HEADERS& nt_headers, const uint64_t nt_headers_offset)
{
const auto first_section_offset = get_first_section_offset(nt_headers, nt_headers_offset);
const auto sections = buffer.as<IMAGE_SECTION_HEADER>(first_section_offset);
for (size_t i = 0; i < nt_headers.FileHeader.NumberOfSections; ++i)
{
const auto section = sections.get(i);
const auto target_ptr = binary.image_base + section.VirtualAddress;
if (section.SizeOfRawData > 0)
{
const auto size_of_data = std::min(section.SizeOfRawData, section.Misc.VirtualSize);
const auto* source_ptr = buffer.get_pointer_for_range(section.PointerToRawData, size_of_data);
emu.write_memory(target_ptr, source_ptr, size_of_data);
}
auto permissions = memory_permission::none;
if (section.Characteristics & IMAGE_SCN_MEM_EXECUTE)
{
permissions |= memory_permission::exec;
}
if (section.Characteristics & IMAGE_SCN_MEM_READ)
{
permissions |= memory_permission::read;
}
if (section.Characteristics & IMAGE_SCN_MEM_WRITE)
{
permissions |= memory_permission::write;
}
const auto size_of_section = page_align_up(std::max(section.SizeOfRawData, section.Misc.VirtualSize));
emu.protect_memory(target_ptr, size_of_section, permissions, nullptr);
}
}
std::optional<mapped_module> map_module(emulator& emu, const std::span<const uint8_t> data,
std::filesystem::path file)
{
mapped_module binary{};
binary.path = std::move(file);
binary.name = binary.path.filename().string();
utils::safe_buffer_accessor buffer{data};
const auto dos_header = buffer.as<IMAGE_DOS_HEADER>(0).get();
const auto nt_headers_offset = dos_header.e_lfanew;
const auto nt_headers = buffer.as<IMAGE_NT_HEADERS>(nt_headers_offset).get();
auto& optional_header = nt_headers.OptionalHeader;
binary.image_base = optional_header.ImageBase;
binary.size_of_image = optional_header.SizeOfImage; // TODO: Sanitize
if (!emu.allocate_memory(binary.image_base, binary.size_of_image, memory_permission::read))
{
binary.image_base = emu.find_free_allocation_base(binary.size_of_image);
const auto is_dll = nt_headers.FileHeader.Characteristics & IMAGE_FILE_DLL;
const auto has_dynamic_base =
optional_header.DllCharacteristics & IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE;
const auto is_relocatable = is_dll || has_dynamic_base;
if (!is_relocatable || !emu.allocate_memory(binary.image_base, binary.size_of_image,
memory_permission::read))
{
return {};
}
}
binary.entry_point = binary.image_base + optional_header.AddressOfEntryPoint;
const auto* header_buffer = buffer.get_pointer_for_range(0, optional_header.SizeOfHeaders);
emu.write_memory(binary.image_base, header_buffer,
optional_header.SizeOfHeaders);
map_sections(emu, binary, buffer, nt_headers, nt_headers_offset);
auto mapped_memory = read_mapped_memory(emu, binary);
utils::safe_buffer_accessor<uint8_t> mapped_buffer{mapped_memory};
apply_relocations(binary, mapped_buffer, optional_header);
collect_exports(binary, mapped_buffer, optional_header);
emu.write_memory(binary.image_base, mapped_memory.data(), mapped_memory.size());
return binary;
}
}
std::optional<mapped_module> map_module_from_data(emulator& emu, const std::span<const uint8_t> data,
std::filesystem::path file)
{
try
{
return map_module(emu, data, std::move(file));
}
catch (...)
{
return {};
}
}
std::optional<mapped_module> map_module_from_file(emulator& emu, std::filesystem::path file)
{
const auto data = utils::io::read_file(file);
if (data.empty())
{
return {};
}
return map_module_from_data(emu, data, std::move(file));
}
bool unmap_module(emulator& emu, const mapped_module& mod)
{
return emu.release_memory(mod.image_base, mod.size_of_image);
}