Small rewrite

CMakeLists.txt

@@ -1,15 +1,8 @@
 
-cmake_minimum_required(VERSION 2.6)
-project(nekohack)
+cmake_minimum_required(VERSION 3.14)
+project(crackem)
 
-set(CMAKE_CXX_STANDARD 17)
-file(GLOB_RECURSE NEKOHACK_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/src/*.cpp")
-add_library(nekohack STATIC ${NEKOHACK_SOURCES})
-target_include_directories(nekohack PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/include/hack")
-target_include_directories(nekohack PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include/")
-target_link_libraries(nekohack PUBLIC dl)
+set(CRACKEM_BUILD_SHARED OFF CACHE BOOL "Build the shared library")
+set(CRACKEM_BUILD_STATIC ON CACHE BOOL "Build the static library")
 
-add_library(nekohack-dummy SHARED "${CMAKE_CURRENT_SOURCE_DIR}/example/dummy.cpp")
-add_executable(nekohack-example "${CMAKE_CURRENT_SOURCE_DIR}/example/main.cpp")
-target_include_directories(nekohack-example PRIVATE nekohack)
-target_link_libraries(nekohack-example PRIVATE nekohack nekohack-dummy)
+add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/src/")

compile_commands.json

@@ -0,0 +1,27 @@
+[
+{
+  "directory": "/home/julianacat/github/crackem/build/src",
+  "command": "/usr/bin/clang++  -I/home/julianacat/github/crackem/src -I/home/julianacat/github/crackem/src/.. -std=gnu++17 -o CMakeFiles/crackem_static.dir/encrypt.cpp.o -c /home/julianacat/github/crackem/src/encrypt.cpp",
+  "file": "/home/julianacat/github/crackem/src/encrypt.cpp"
+},
+{
+  "directory": "/home/julianacat/github/crackem/build/src",
+  "command": "/usr/bin/clang++  -I/home/julianacat/github/crackem/src -I/home/julianacat/github/crackem/src/.. -std=gnu++17 -o CMakeFiles/crackem_static.dir/memory.cpp.o -c /home/julianacat/github/crackem/src/memory.cpp",
+  "file": "/home/julianacat/github/crackem/src/memory.cpp"
+},
+{
+  "directory": "/home/julianacat/github/crackem/build/src",
+  "command": "/usr/bin/clang++  -I/home/julianacat/github/crackem/src -I/home/julianacat/github/crackem/src/.. -std=gnu++17 -o CMakeFiles/crackem_static.dir/sharedlibrary.cpp.o -c /home/julianacat/github/crackem/src/sharedlibrary.cpp",
+  "file": "/home/julianacat/github/crackem/src/sharedlibrary.cpp"
+},
+{
+  "directory": "/home/julianacat/github/crackem/build/src",
+  "command": "/usr/bin/clang++  -I/home/julianacat/github/crackem/src -I/home/julianacat/github/crackem/src/.. -std=gnu++17 -o CMakeFiles/crackem_static.dir/signature.cpp.o -c /home/julianacat/github/crackem/src/signature.cpp",
+  "file": "/home/julianacat/github/crackem/src/signature.cpp"
+},
+{
+  "directory": "/home/julianacat/github/crackem/build/src",
+  "command": "/usr/bin/clang++  -I/home/julianacat/github/crackem/src -I/home/julianacat/github/crackem/src/.. -std=gnu++17 -o CMakeFiles/crackem_static.dir/vfthook.cpp.o -c /home/julianacat/github/crackem/src/vfthook.cpp",
+  "file": "/home/julianacat/github/crackem/src/vfthook.cpp"
+}
+]

example/dummy.cpp

@@ -1,8 +0,0 @@
-
-extern "C" {
-
-int GetInt() {
-    return 5;
-}
-
-}

example/main.cpp

@@ -1,15 +0,0 @@
-
-#include <iostream>
-#include <hack/sharedlibrary.hpp>
-using namespace neko;
-
-int main() {
-    hack::SharedLibrary dummysl("libnekohack-dummy");
-    std::cout << "Lmap: " << dummysl.GetLMap() << std::endl;
-
-    using GetInt_f = int (*)();
-    GetInt_f GetInt = dummysl.GetSym<GetInt_f>("GetInt");
-    std::cout << "GetInt Location: " << std::hex << GetInt << std::endl;
-    std::cout << "GetInt: " << GetInt() << std::endl;
-
-}

include/hack/asmhook.hpp

@@ -1,44 +0,0 @@
-
-/*
- * Nekohack: Break things in cool ways!
- * Copyright (C) 2018 Rebekah Rowe
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-namespace neko::hack {
-
-// Overwrites calls in a function to the destination
-/*class Overwrite {
-public:
-    Overwrite(){}
-    Overwrite(void* func, std::size_t length, void* dest) {
-        this->Hook(func, length, dest);
-    }
-    Hook(void* func, std::size_t length, void* dest) {
-
-    }
-private:
-    void* overwritten = nullptr;
-};
-
-class ASMHook {
-public:
-    Hook();
-    ~Hook();
-    enum Type {kOverwrite
-    AddJump
-};*/
-
-}

include/hack/vfthook.hpp

@@ -1,59 +0,0 @@
-
-/*
- * Nekohack: Break things in cool ways!
- * Copyright (C) 2018 Rebekah Rowe
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-#include <cstdint>
-#include <memory>
-
-namespace neko::hack {
-
-// Virtual function table
-using VF = void*;
-using VFT = VF[];
-
-// Virtual Function Table Hook
-class VFTHook {
-public:
-    VFTHook();
-    ~VFTHook();
-    template<class TPtr>
-    void Init(TPtr instance) {
-        this->IntInit(reinterpret_cast<void*>(instance));
-    }
-    template<class TPtr>
-    void Hook(TPtr func, std::size_t idx) {
-        this->IntHook(reinterpret_cast<VF>(func), idx);
-    }
-    void Finish();
-    void Undo();
-    template <class T = void*>
-    inline T GetOriginal(std::size_t idx) const {
-        return reinterpret_cast<T>(this->original_data[idx]);
-    }
-    bool IsHooked();
-    std::size_t GetSize(){ return this->size; }
-private:
-    void IntInit(void* instance);
-    void IntHook(VF func_ptr, std::size_t);
-    void*** vtable = nullptr;
-    void** original_data = nullptr;
-    std::unique_ptr<void*[]> replacement;
-    std::size_t size;
-};
-
-}

src/CMakeLists.txt

@@ -0,0 +1,32 @@
+
+file(GLOB_RECURSE sources "${CMAKE_CURRENT_SOURCE_DIR}/*.cpp")
+file(GLOB_RECURSE headers "${CMAKE_CURRENT_SOURCE_DIR}/*.hpp")
+
+add_custom_target(crackem)
+
+macro(ApplyCommon in_target)
+    add_dependencies(crackem ${in_target})
+    set_property(TARGET ${in_target} PROPERTY OUTPUT_NAME crackem)
+    set_property(TARGET ${in_target} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+    set_property(TARGET ${in_target} PROPERTY CXX_STANDARD 17)
+
+    target_include_directories(${in_target} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/")
+    target_include_directories(${in_target} PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/../")
+    if (UNIX AND NOT APPLE)
+        target_link_libraries(${in_target} PUBLIC rt pthread)
+    endif ()
+
+    install(TARGETS ${in_target} DESTINATION lib)
+endmacro()
+
+if(CRACKEM_BUILD_SHARED)
+    add_library(crackem_shared SHARED ${sources})
+    ApplyCommon(crackem_shared)
+endif(CRACKEM_BUILD_SHARED)
+if(CRACKEM_BUILD_STATIC)
+    add_library(crackem_static STATIC ${sources})
+    ApplyCommon(crackem_static)
+endif(CRACKEM_BUILD_STATIC)
+
+
+install(FILES ${headers} DESTINATION include/crackem)

src/asmhook.hpp

@@ -1,6 +1,6 @@
 
 /*
- * Nekohack: Break things in cool ways!
+ * Crackem: Break things in cool ways!
  * Copyright (C) 2018 Rebekah Rowe
  *
  * This program is free software: you can redistribute it and/or modify
@@ -17,10 +17,30 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#include <r_asm.h>
+#pragma once 
 
-namespace neko::hack {
+namespace crackem {
 
-RAsmOp* asm = r_asm_op_new(void);
+// Overwrites calls in a function to the destination
+/*class Overwrite {
+public:
+    Overwrite(){}
+    Overwrite(void* func, std::size_t length, void* dest) {
+        this->Hook(func, length, dest);
+    }
+    Hook(void* func, std::size_t length, void* dest) {
+
+    }
+private:
+    void* overwritten = nullptr;
+};
+
+class ASMHook {
+public:
+    Hook();
+    ~Hook();
+    enum Type {kOverwrite
+    AddJump
+};*/
 
 }

src/memory.hpp

@@ -19,10 +19,10 @@
 
 #include <cstdint>
 
-namespace neko::hack::mem {
+namespace crackem::mem {
 
 template <typename Type, class Ptr>
-inline auto Offset(Ptr src, std::ptrdiff_t offset) {
+inline auto Offset(Ptr* src, std::ptrdiff_t offset) {
     return reinterpret_cast<Type*>(reinterpret_cast<uint64_t>(src) + offset);
 }
 

src/sharedlibrary.cpp

@@ -17,97 +17,110 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+#include <cassert>
 #include <cstring>
+#include <dlfcn.h>
 
 #include "memory.hpp"
 
 #include "sharedlibrary.hpp"
 
-namespace neko::hack {
+namespace crackem {
 
-struct Passthrough {
-    std::string name;
-    fs::path path;
-    void* begin;
-    std::size_t size;
-};
-
-SharedLibrary::SharedLibrary(){}
-SharedLibrary::SharedLibrary(std::string_view _name) : name(_name) {
-    try {
-        this->Init(_name);
-    } catch(...){}
-}
-
-void SharedLibrary::Init(std::string_view _name){
-    if (!init_flag) {
-        this->name = _name;
-        if (this->name.empty())
-            throw std::runtime_error("SharedLibrary: no name avaiable.");
-        Passthrough pass;
-        pass.name = '/' + std::string(_name) + '.';
-        if (!dl_iterate_phdr([](struct dl_phdr_info* info, size_t, void* _pass) {
-            auto* pass = reinterpret_cast<Passthrough*>(_pass);
-            if (!strstr(info->dlpi_name, pass->name.c_str()))
-                return 0;
-
-            pass->path = info->dlpi_name;
-            pass->begin = reinterpret_cast<void*>(info->dlpi_addr + info->dlpi_phdr[0].p_vaddr);
-            pass->size = info->dlpi_phdr[0].p_memsz;
-            return 1;
-        }, reinterpret_cast<void*>(&pass)))
-            throw std::runtime_error("SharedLibrary: Unable to find loaded library");
-
-        this->path = pass.path;
-        this->_begin = pass.begin;
-        this->_end = mem::Offset<void*>(pass.begin, pass.size);
-        this->_size = pass.size;
-
-        this->lmap = static_cast<LMap>(dlopen(this->path.c_str(), RTLD_NOLOAD));
-        if (const char* error = dlerror())
-            throw std::runtime_error("SharedLibrary recieved dlerror: " + std::string(error));
-
-        this->init_flag = true;
+SharedLibrary::SharedLibrary() : loaded(false) {}
+SharedLibrary::SharedLibrary(std::string_view _name) { this->Load(_name); }
+SharedLibrary::SharedLibrary(const SharedLibrary& v) { *this = v; }
+SharedLibrary::SharedLibrary(SharedLibrary&& v) { *this = v; }
+SharedLibrary& SharedLibrary::operator=(SharedLibrary&& v) {
+    this->loaded = false;
+    this->name = v.name;
+    if (v.loaded) {
+        v.loaded = false;    
+        this->path = std::move(v.path);
+        this->_begin = v._begin;
+        this->_end = v._end;
+        this->_size = v._size;
+        this->lmap = v.lmap;
+        this->loaded = true;
     }
+    return *this;
 }
-void SharedLibrary::ForceInit(std::string_view _name) {
-    while(!this->init_flag) {
-        try {
-            this->Init();
-        } catch(...) {}
+SharedLibrary& SharedLibrary::operator=(const SharedLibrary& v) {
+    this->loaded = false;
+    this->name = v.name;
+    if (v.loaded) {
+        this->path = v.path;
+        this->_begin = v._begin;
+        this->_end = v._end;
+        this->_size = v._size;
+        this->lmap = v.lmap;
+        this->loaded = true;
     }
+    return *this;
 }
-std::string_view SharedLibrary::GetName() {
-    return name;
+void SharedLibrary::Load(std::string_view _name) {
+    this->name = _name;
+    this->Load();
 }
-void* SharedLibrary::begin() {
-    this->Init();
+void SharedLibrary::Load() { 
+    assert(!this->loaded && !this->name.empty());
+    this->loaded = false;
+    
+    if (!dl_iterate_phdr([](struct dl_phdr_info* info, size_t, void* _pass) {
+        auto* _this = reinterpret_cast<SharedLibrary*>(_pass);
+        _this->path = info->dlpi_name;
+        if (_this->path.stem() != _this->name/* || _this->path.extention() ==*/)
+            return 0;
+
+        _this->_begin = reinterpret_cast<void*>(info->dlpi_addr + info->dlpi_phdr[0].p_vaddr);
+        _this->_size = info->dlpi_phdr[0].p_memsz;
+        return 1;
+    }, reinterpret_cast<void*>(this)))
+        return;
+    
+    this->loaded = true;
+    this->_end = mem::Offset<void*>(this->_begin, this->_size);
+    this->lmap = static_cast<Handle>(dlopen(this->path.c_str(), RTLD_NOLOAD));
+    if (const char* error = dlerror())
+        throw std::runtime_error("SharedLibrary recieved dlerror(dlopen): " + std::string(error));
+}
+bool SharedLibrary::IsLoaded() const {
+    return this->loaded;
+}
+std::string_view SharedLibrary::GetName() const {
+    assert(this->loaded);
+    return this->name;
+}
+const fs::path& SharedLibrary::GetPath() const {
+    assert(this->loaded);
+    return this->path;
+}
+void* SharedLibrary::begin() const {
+    assert(this->loaded);
     return this->_begin;
 }
-void* SharedLibrary::end() {
-    this->Init();
+void* SharedLibrary::end() const {
+    assert(this->loaded);
     return this->_end;
 }
-std::size_t SharedLibrary::size() {
-    this->Init();
+std::size_t SharedLibrary::size() const {
+    assert(this->loaded);
     return this->_size;
 }
-LMap SharedLibrary::GetLMap() {
-    this->Init();
+Handle SharedLibrary::GetHandle() const {
+    assert(this->loaded);
     return this->lmap;
 }
-void SharedLibrary::Clear(){
-    this->init_flag = false;
-    this->name = std::string_view();
-}
-void* SharedLibrary::GetSymInternal(SymStr name) {
+void* SharedLibrary::GetSymInternal(SymStr name) const {
     #if defined(__linux__)
-        void* symbol = dlsym(this->GetLMap(), name);
+        void* symbol = dlsym(this->GetHandle(), name);
         if (const char* error = dlerror())
-            throw std::runtime_error("SharedLibrary recieved dlerror: " + std::string(error));
+            throw std::runtime_error("SharedLibrary recieved dlerror(dlsym): " + std::string(error));
         return symbol;
     #elif defined(_WIN32)
         return GetProcAddress(this->GetLMap(), name);
+    #else
+        assert(false);
     #endif
 }
 

src/sharedlibrary.hpp

@@ -21,45 +21,53 @@
 
 #if defined(__linux__)
 #include <link.h>  // link maps
-using LMap = link_map*;
+using Handle = link_map*;
 using SymStr = const char*;
 #elif defined(_WIN32)
 #include <windows.h>  // loadlibrary
-using LMap = HMODULE;
+using Handle = HMODULE;
 using SymStr = LPCSTR;
 #endif
 
 #include <string_view>
 #include <filesystem>
-namespace fs = std::filesystem;
 
-namespace neko::hack {
+namespace crackem {
+namespace fs = std::filesystem;
 
 class SharedLibrary {
 public:
     SharedLibrary();
     SharedLibrary(std::string_view _name);
-    void Init() { this->Init(this->name); }
-    void ForceInit() { this->ForceInit(this->name); }
-    void Init(std::string_view _name);
-    void ForceInit(std::string_view _name);
-    std::string_view GetName();
-    void* begin();
-    void* end();
-    std::size_t size();
-    void Clear();
-    LMap GetLMap();
+    SharedLibrary(const SharedLibrary&);
+    SharedLibrary(SharedLibrary&&);
+    void Load();
+    void Load(std::string_view _name);
+    
+    SharedLibrary& operator=(SharedLibrary&& v);
+    SharedLibrary& operator=(const SharedLibrary& v);
+
+    bool IsLoaded() const;
+    std::string_view GetName() const;
+    const fs::path& GetPath() const;
+    void* begin() const;
+    void* end() const;
+    std::size_t size() const;
+    Handle GetHandle() const;
+
+    void Clear() const;
     template<typename T>
     T GetSym(SymStr s) { return reinterpret_cast<T>(this->GetSymInternal(s)); }
 private:
-    void* GetSymInternal(SymStr);
-    bool init_flag = false;
+    void* GetSymInternal(SymStr) const;
+
+    bool loaded;
     std::string_view name;
     fs::path path;
     void* _begin;
     void* _end;
     std::size_t _size;
-    LMap lmap;
+    Handle lmap;
 };
 
 }

src/signature.cpp

@@ -24,58 +24,41 @@
 
 #include "signature.hpp"
 
-class Pattern {
-public:
-    Pattern(std::string_view input) {
-        while (!input.empty()) {
-            // Discard whitespace
-            std::size_t non_white_start = input.find_first_not_of(' ');
-            if (non_white_start == std::string_view::npos) break;
-            input.remove_prefix(non_white_start);
+namespace crackem::sig {
 
-            // act on delim
-            // Wildcard
-            if (input.front() == '?') {
-                this->wilds.push_back(true);
-                std::size_t next = input.find_first_not_of('?');
-                if (next == std::string_view::npos)
-                    break;
-                input.remove_prefix(next);
-            } else {
-                this->wilds.push_back(false);
-                if (input.size() < 2)
-                    break;
+// Original function by learn_more -- https://github.com/learn-more/findpattern-bench
+static bool InRange(uint8_t x, uint8_t a, uint8_t b) { return x >= a && x <= b; }
+static uint8_t GetBits(uint8_t x) { return InRange((x & (~0x20)), 'A', 'F') ? ((x & (~0x20)) - 'A' + 0xA): (InRange(x, '0', '9') ? x - '0': 0); }
+static uint8_t GetByte(const char* x) { return GetBits(x[0]) << 4 | GetBits(x[1]); }
 
-                std::string hex = {input[0], input[1]};
-                uint8_t nibble = std::stoul(hex, nullptr, 16);
-                this->pat.push_back(*reinterpret_cast<std::byte*>(nibble));
-                input.remove_prefix(2);
-            }
-        }
-    }
-    inline std::byte Get(std::size_t i) {
-        assert(!this->IsWild(i));
-        return pat[i];
-    }
-    inline bool IsWild(std::size_t i) {
-        auto find = std::find(wilds.begin(), wilds.end(), i);
-        return find != wilds.end();
-    }
-    inline std::size_t size(){
-        return this->pat.size();
-    }
-private:
-std::vector<std::byte> pat;
-std::vector<bool> wilds;
-};
+uintptr_t FindPattern(uintptr_t start_address, uintptr_t end_address, const char* target_pattern) {
+	const char* pattern = target_pattern;
+
+	uintptr_t first_match = 0;
+
+	for (uintptr_t position = start_address; position < end_address; position++) {
+		if (!*pattern)
+			return first_match;
+
+		const uint8_t pattern_current = *reinterpret_cast<const uint8_t*>(pattern);
+		const uint8_t memory_current = *reinterpret_cast<const uint8_t*>(position);
+
+		if (pattern_current == '\?' || memory_current == GetByte(pattern)) {
+			if (!first_match)
+				first_match = position;
+
+			if (!pattern[2])
+				return first_match;
+
+			pattern += pattern_current != '\?' ? 3 : 2;
+		}
+		else {
+			pattern = target_pattern;
+			first_match = 0;
+		}
+	}
+
+	return NULL;
+}
 
-void* SearchN(void* _begin, void* _end, std::string_view _pat){
-    return nullptr;
-    /*Pattern pat(_pat);
-    std::byte* begin = reinterpret_cast<std::byte*>(_begin);
-    std::byte* end = reinterpret_cast<std::byte*>(_end);
-    auto find = std::find_if(begin, end, [&](std::byte* s) {
-        // Pattern equality
-        for (int )
-    });*/
 }

src/signature.hpp

@@ -21,8 +21,8 @@
 
 #include <string_view>
 
-namespace neko::hack::sig {
+namespace crackem::sig {
 
-void* SearchN(void* where, std::size_t len, std::string_view pat);
+uintptr_t FindPattern(uintptr_t start_address, uintptr_t end_address, const char* target_pattern);
 
 }

src/vfthook.cpp

@@ -1,50 +1,74 @@
 
 #include <cstring>
 
+#include "memory.hpp"
 #include "vfthook.hpp"
 
-namespace neko::hack {
+namespace crackem::vft::hook {
 
-VFTHook::VFTHook(){}
-VFTHook::~VFTHook() {
-    try {
-        this->Undo();
-    }catch(...){}
-}
-
-void VFTHook::IntInit(void* instance) {
-    try {
-        this->Undo();
-    }catch(...){}
-
-    this->vtable = reinterpret_cast<void***>(instance);
-    this->original_data = *this->vtable;
-
-    this->size = 0;
-    while (this->original_data[this->size]) this->size++;
-
-    this->replacement = std::make_unique<VFT>(this->size);
-    memcpy(this->replacement.get(), this->original_data, sizeof(VF) * this->size);
+struct Ref::HookData {
+    bool Verify() {
+        return this->magic = kMagic;
+    }
+    static HookData* Get(VInst* v) {
+        return mem::Offset<HookData>(*v, -int(sizeof(HookData)));
+    }
+    VInst* instance;
+    VFT* original;
+    std::size_t size;
+    constexpr static uint32_t kMagic = 0xCAFEBEEF;
+    uint32_t magic;
+    VF* replacement[];
 };
-void VFTHook::Finish() {
-    if (this->IsHooked())
-        throw std::logic_error("VTFHook: Cant finish, hook in place");
-    *this->vtable = this->replacement.get();
-}
-void VFTHook::Undo() {
-    if (!this->IsHooked())
-        throw std::logic_error("VTFHook: Cant undo a hook that isnt there");
-}
-bool VFTHook::IsHooked() {
-    if (!this->vtable || !this->replacement)
-        return false;
-    return *this->vtable == this->replacement.get();
-}
 
-void VFTHook::IntHook(VF func, std::size_t idx) {
-    //if (this->original[idx] != this->replacement[idx])
-        //throw std::logic_error("Already Hooked");
-    this->replacement[idx] = func;
+Ref::HookData* Ref::IntCreate(VInst* v) {
+    if (HookData::Get(v)->Verify())
+        throw std::runtime_error("Hook already exists!");
+    
+    std::size_t size = 0;
+    while ((*v)[size]) 
+        size++;
+    
+    HookData* hd = reinterpret_cast<HookData*>(malloc(sizeof(HookData) + (sizeof(VF*) * size)));
+    hd->instance = v;
+    hd->original = *v;
+    hd->size = size;
+    hd->magic = HookData::kMagic;
+    memcpy(hd->replacement, hd->original, sizeof(VF*) * size);
+
+    *hd->instance = hd->replacement;
+    return hd; 
+}
+Ref::HookData* Ref::IntGet(VInst* v) {
+    HookData* r = HookData::Get(v);
+    if (r->Verify())
+        return r;
+    else
+        throw std::runtime_error("Hook not found!");
+}
+bool Ref::IntContains(VInst* v) {
+    return HookData::Get(v)->Verify();
+}
+void Ref::IntReplace(int idx, VF* fn) const {
+    assert(this->data && !this->Exists(idx));
+    this->data->replacement[idx] = fn;
+}
+VF* Ref::IntGetOriginal(int idx) const {
+    assert(this->data);
+    return this->data->original[idx];
+}
+void Ref::Clear(int idx) const {
+    assert(this->data && this->Exists(idx));
+    this->data->replacement[idx] = this->data->original[idx];
+}
+bool Ref::Exists(int idx) const {
+    assert(this->data);
+    return this->data->original[idx] == this->data->replacement[idx];
+}
+void Ref::Destroy() {
+    assert(this->data);
+    
+    this->data = nullptr;
 }
 
 }

src/vfthook.hpp

@@ -0,0 +1,72 @@
+
+/*
+ * Nekohack: Break things in cool ways!
+ * Copyright (C) 2018 Rebekah Rowe
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <cassert>
+#include <cstdint>
+#include <memory>
+
+namespace crackem::vft::hook {
+
+using VF = void;
+using VFT = VF*;
+using VInst = VFT*;
+
+class Ref {
+    struct HookData;
+    static HookData* IntCreate(VInst*);
+    static HookData* IntGet(VInst*);
+    static bool IntContains(VInst*);
+
+    HookData* data = nullptr;
+    void IntReplace(int idx, VF*) const;
+    VF* IntGetOriginal(int idx) const;
+public:
+    Ref() {}
+    Ref(HookData* _data) : data(_data) { assert(this->data); }
+    void Clear(int idx) const;
+    bool Exists(int idx) const;
+    void Destroy();
+
+    template<class T> Ref(T* inst) : Ref(Ref::Get(inst)) {
+        static_assert(!std::is_same_v<T, HookData>);
+    }
+    template<class T> void Replace(int idx, T replace_func) const {
+        this->IntReplace(idx, reinterpret_cast<void*>(&replace_func));
+    }
+    template<typename T>
+    T GetOriginal(std::size_t idx) const {
+        return reinterpret_cast<T>(this->IntGetOriginal(idx));
+    }
+    template<typename Ret, typename... T>
+    Ret CallOriginal(std::size_t idx, T... args) const {
+        using Func_t = Ret (*)(T...);
+        return this->GetOriginal<Func_t>(idx)(args...);
+    }
+    template<class T> static Ref Create(T* instance) {
+        return IntCreate(reinterpret_cast<VInst*>(instance));
+    }
+    template<class T> static Ref Get(T* instance) {
+        return IntGet(reinterpret_cast<VInst*>(instance));
+    }
+    template<class T> static bool Contains(T* instance) {
+        return IntContains(reinterpret_cast<VInst*>(instance));
+    }
+};
+
+}