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Bump vendored LIEF 0.13.0 -> 0.17.6 and migrate to its API #108

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Bump vendored LIEF 0.13.0 -> 0.17.6 and migrate to its API #108

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42 changes: 28 additions & 14 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
@@ -1,25 +1,39 @@
cmake_minimum_required(VERSION 3.9)
set(CMAKE_CXX_STANDARD 11)
cmake_minimum_required(VERSION 3.24)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

project(postject)

# Disable unnecessary LIEF options
option(LIEF_DOC "Build LIEF docs" OFF)
option(LIEF_C_API "C API" OFF)
option(LIEF_PYTHON_API "Build LIEF Python API" OFF)
option(LIEF_ENABLE_JSON "Enable JSON-related APIs" OFF)
option(LIEF_EXAMPLES "Build LIEF examples" OFF)
option(LIEF_TESTS "Build LIEF tests" OFF)
option(LIEF_ART "Build LIEF with ART module" OFF)
option(LIEF_DEX "Build LIEF with DEX module" OFF)
option(LIEF_VDEX "Build LIEF with VDEX module" OFF)
option(LIEF_OAT "Build LIEF with OAT module" OFF)
# LIEF bundles fmt/spdlog, whose memory_buffer calls global `free` from a template
# whose definition point (under Emscripten's libc++ headers) doesn't yet have
# <cstdlib> visible -- ADL can't find it, so the build errors. Force-include
# <cstdlib> into every TU so `free`/`malloc` are always declared.
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -include cstdlib")

include(FetchContent)

# Disable unnecessary LIEF options (set before LIEF is configured).
set(LIEF_DOC OFF CACHE BOOL "" FORCE)
set(LIEF_C_API OFF CACHE BOOL "" FORCE)
set(LIEF_PYTHON_API OFF CACHE BOOL "" FORCE)
set(LIEF_ENABLE_JSON OFF CACHE BOOL "" FORCE)
set(LIEF_EXAMPLES OFF CACHE BOOL "" FORCE)
set(LIEF_TESTS OFF CACHE BOOL "" FORCE)
set(LIEF_INSTALL OFF CACHE BOOL "" FORCE)
set(LIEF_LOGGING OFF CACHE BOOL "" FORCE)
set(LIEF_LOGGING_DEBUG OFF CACHE BOOL "" FORCE)

if(MSVC)
set(LIEF_USE_CRT_RELEASE "MT" CACHE STRING "LIEF CRT option")
endif()

add_subdirectory(vendor/lief)
FetchContent_Declare(
LIEF
GIT_REPOSITORY https://github.com/lief-project/LIEF.git
GIT_TAG 0.17.6
GIT_SHALLOW TRUE
)
FetchContent_MakeAvailable(LIEF)

add_executable(postject src/postject.cpp)
set_target_properties(postject PROPERTIES LINK_FLAGS "-sSINGLE_FILE -sMODULARIZE=1 -sALLOW_MEMORY_GROWTH -sINITIAL_MEMORY=268435456 -sMAXIMUM_MEMORY=4294967296 --bind")
Expand Down
165 changes: 76 additions & 89 deletions src/postject.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@
#include <codecvt>
#include <locale>
#include <memory>
#include <string>
#include <vector>

#include <emscripten/bind.h>
Expand All @@ -22,6 +23,14 @@ std::vector<uint8_t> vec_from_val(const emscripten::val& value) {
return emscripten::convertJSArrayToNumberVector<uint8_t>(value);
}

static emscripten::val to_uint8array(const std::vector<uint8_t>& output) {
emscripten::val view{
emscripten::typed_memory_view(output.size(), output.data())};
auto output_data = emscripten::val::global("Uint8Array").new_(output.size());
output_data.call<void>("set", view);
return output_data;
}

ExecutableFormat get_executable_format(const emscripten::val& executable) {
std::vector<uint8_t> buffer = vec_from_val(executable);

Expand Down Expand Up @@ -51,10 +60,11 @@ emscripten::val inject_into_elf(const emscripten::val& executable,
return object;
}

// LIEF can return a length longer than it actually is, so use compare here.
LIEF::ELF::Note* existing_note = nullptr;

for (LIEF::ELF::Note& note : binary->notes()) {
if (note.name() == note_name) {
if (note.name().compare(0, note_name.size(), note_name) == 0) {
existing_note = &note;
}
}
Expand All @@ -68,21 +78,31 @@ emscripten::val inject_into_elf(const emscripten::val& executable,
}
}

LIEF::ELF::Note note;
note.name(note_name);
note.description(vec_from_val(data));
binary->add(note);
constexpr uint32_t kNoteType = 0;
std::unique_ptr<LIEF::ELF::Note> note = LIEF::ELF::Note::create(
note_name, kNoteType, vec_from_val(data), note_name);

// Construct a new Uint8Array in JS
std::vector<uint8_t> output = binary->raw();
emscripten::val view{
emscripten::typed_memory_view(output.size(), output.data())};
auto output_data = emscripten::val::global("Uint8Array").new_(output.size());
output_data.call<void>("set", view);
if (!note) {
object.set("result", emscripten::val(InjectResult::kError));
return object;
}

object.set("data", output_data);
object.set("result", emscripten::val(InjectResult::kSuccess));
binary->add(*note);

LIEF::ELF::Builder::config_t cfg;
cfg.notes = true;
cfg.dynamic_section = true;
LIEF::ELF::Builder builder(*binary, cfg);
builder.build();

const std::vector<uint8_t>& output = builder.get_build();
if (output.empty()) {
object.set("result", emscripten::val(InjectResult::kError));
return object;
}

object.set("data", to_uint8array(output));
object.set("result", emscripten::val(InjectResult::kSuccess));
return object;
}

Expand All @@ -102,33 +122,34 @@ emscripten::val inject_into_macho(const emscripten::val& executable,
return object;
}

std::vector<uint8_t> payload = vec_from_val(data);

// Inject into all Mach-O binaries if there's more than one in a fat binary
for (LIEF::MachO::Binary& binary : *fat_binary) {
LIEF::MachO::Section* existing_section =
binary.get_section(segment_name, section_name);

if (existing_section) {
if (!overwrite) {
object.set("result", emscripten::val(InjectResult::kAlreadyExists));
return object;
}

binary.remove_section(segment_name, section_name, true);
}

LIEF::MachO::SegmentCommand* segment = binary.get_segment(segment_name);
LIEF::MachO::Section section(section_name, vec_from_val(data));

if (!segment) {
// Create the segment and mark it read-only
LIEF::MachO::SegmentCommand new_segment(segment_name);
new_segment.max_protection(
static_cast<uint32_t>(LIEF::MachO::VM_PROTECTIONS::VM_PROT_READ));
new_segment.init_protection(
static_cast<uint32_t>(LIEF::MachO::VM_PROTECTIONS::VM_PROT_READ));
new_segment.max_protection(static_cast<uint32_t>(
LIEF::MachO::SegmentCommand::VM_PROTECTIONS::READ));
new_segment.init_protection(static_cast<uint32_t>(
LIEF::MachO::SegmentCommand::VM_PROTECTIONS::READ));
LIEF::MachO::Section section(section_name, payload);
new_segment.add_section(section);
binary.add(new_segment);
} else {
LIEF::MachO::Section* existing_section =
segment->get_section(section_name);
if (existing_section) {
if (!overwrite) {
object.set("result", emscripten::val(InjectResult::kAlreadyExists));
return object;
}
binary.remove_section(segment_name, section_name, true);
segment = binary.get_segment(segment_name);
}
LIEF::MachO::Section section(section_name, payload);
binary.add_section(*segment, section);
}

Expand All @@ -140,12 +161,7 @@ emscripten::val inject_into_macho(const emscripten::val& executable,

// Construct a new Uint8Array in JS
std::vector<uint8_t> output = fat_binary->raw();
emscripten::val view{
emscripten::typed_memory_view(output.size(), output.data())};
auto output_data = emscripten::val::global("Uint8Array").new_(output.size());
output_data.call<void>("set", view);

object.set("data", output_data);
object.set("data", to_uint8array(output));
object.set("result", emscripten::val(InjectResult::kSuccess));

return object;
Expand Down Expand Up @@ -181,29 +197,28 @@ emscripten::val inject_into_pe(const emscripten::val& executable,
LIEF::PE::ResourceNode* id_node = nullptr;

// First level => Type (ResourceDirectory node)
auto rcdata_node_iter = std::find_if(
std::begin(resources->childs()), std::end(resources->childs()),
[](const LIEF::PE::ResourceNode& node) {
return node.id() ==
static_cast<uint32_t>(LIEF::PE::RESOURCE_TYPES::RCDATA);
});
constexpr uint32_t kRcdataId =
static_cast<uint32_t>(LIEF::PE::ResourcesManager::TYPE::RCDATA);
auto rcdata_node_iter = std::find_if(std::begin(resources->childs()),
std::end(resources->childs()),
[](const LIEF::PE::ResourceNode& node) {
return node.id() == kRcdataId;
});

if (rcdata_node_iter != std::end(resources->childs())) {
rcdata_node = &*rcdata_node_iter;
} else {
LIEF::PE::ResourceDirectory new_rcdata_node;
new_rcdata_node.id(static_cast<uint32_t>(LIEF::PE::RESOURCE_TYPES::RCDATA));
new_rcdata_node.id(kRcdataId);
rcdata_node = &resources->add_child(new_rcdata_node);
}

// Second level => ID (ResourceDirectory node)
// Second level => ID (ResourceDirectory node).
std::u16string resource_name_u16(resource_name.begin(), resource_name.end());
auto id_node_iter = std::find_if(
std::begin(rcdata_node->childs()), std::end(rcdata_node->childs()),
[resource_name](const LIEF::PE::ResourceNode& node) {
return node.name() ==
std::wstring_convert<std::codecvt_utf8_utf16<char16_t>,
char16_t>{}
.from_bytes(resource_name);
[&resource_name_u16](const LIEF::PE::ResourceNode& node) {
return node.name() == resource_name_u16;
});

if (id_node_iter != std::end(rcdata_node->childs())) {
Expand All @@ -228,49 +243,21 @@ emscripten::val inject_into_pe(const emscripten::val& executable,
id_node->delete_child(*id_node->childs());
}

LIEF::PE::ResourceData lang_node;
lang_node.content(vec_from_val(data));
LIEF::PE::ResourceData lang_node(vec_from_val(data));
id_node->add_child(lang_node);

binary->remove_section(".rsrc", true);

// Write out the binary, only modifying the resources
LIEF::PE::Builder builder(*binary);
builder.build_dos_stub(true);
builder.build_imports(false);
builder.build_overlay(false);
builder.build_relocations(false);
builder.build_resources(true);
builder.build_tls(false);
builder.build();

// TODO - Why doesn't LIEF just replace the .rsrc section?
// Can we at least change build_resources to take a section name?

// Re-parse the output so the .l2 section is available
binary = LIEF::PE::Parser::parse(builder.get_build());

// Rename the rebuilt resource section
LIEF::PE::Section* section = binary->get_section(".l2");
section->name(".rsrc");

LIEF::PE::Builder builder2(*binary);
builder2.build_dos_stub(true);
builder2.build_imports(false);
builder2.build_overlay(false);
builder2.build_relocations(false);
builder2.build_resources(false);
builder2.build_tls(false);
builder2.build();

// Construct a new Uint8Array in JS
const std::vector<uint8_t>& output = builder2.get_build();
emscripten::val view{
emscripten::typed_memory_view(output.size(), output.data())};
auto output_data = emscripten::val::global("Uint8Array").new_(output.size());
output_data.call<void>("set", view);
// Rebuild only the resources, keeping the section named .rsrc.
LIEF::PE::Builder::config_t cfg;
cfg.resources = true;
cfg.rsrc_section = ".rsrc";
LIEF::PE::Builder builder(*binary, cfg);
if (!builder.build()) {
object.set("result", emscripten::val(InjectResult::kError));
return object;
}

object.set("data", output_data);
const std::vector<uint8_t>& output = builder.get_build();
object.set("data", to_uint8array(output));
object.set("result", emscripten::val(InjectResult::kSuccess));

return object;
Expand Down
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