ADVobfuscator demonstates how to use C++11/14 language to generate, at compile time, obfuscated code without using any external tool and without modifying the compiler. The technics presented rely only on C++11/14, as standardized by ISO. It shows also how to introduce some form of randomness to generate polymorphic code and it gives some concrete examples like the encryption of strings literals and the obfuscation of calls using finite state machines.
ADVobfuscator is delivered as a set of source file (source code library). You have to include them into your project and call the appropriate functions or macro. This is not a magic black box, some kind of proprocessor or anything like that.
If you are looking for a more transparent obfuscator, look at Obfuscator-LLVM or strong.codes (commercial version of Obfuscator-LLVM). Note: I have no affiliation with Obfuscator-LLVM and strong.codes. I just know some of these swiss folks.
Several enhancement (suppress warnings, fix some errors, enhance portability). In more details:
- Increase the warning level for Visual Studio and GCC
- Remove several (all) compilation warnings
- Replace
intbysize_twhen it is appropriate (sizeof,position) - Remove unused parameters
- Keys are now of type
char(were of typeint, it was wrong) - Replace the non-portable
##__VA_ARGS__by the portable__VA_ARGS__. As a consequence, new macros (ending with0) are defined when there are no parameters - Remove some (stupid) syntax errors (
;at the end of some functions). C/C++ is odd: you have to put a;when you define astruct, but none when you define a function - A integral type is computed at compile time to store pointers to functions
ADVobfuscator code has been updated for Visual Studio 2015. ADVobfuscator is now compatible with the RTM release of Visual Studio 2015 (previous versions or CTP releases are not). The whitepaper is not yet updated. The code has also been modified in order to avoid problems with O3 optimization and GCC. GCC with O3 defeats obfuscation (because it optimizes too much) and sometimes generates wrong code (not clear yet if it is a bug in GCC or in ADVobfuscator).
These are ideas for the next few months:
- Switch to C++14. It will simplify some parts of the code and C++ is now well supported by compilers such as GCC and CLANG
- Try to better support Visual Studio 2015, but only if it does not implies a restructuring of the code
- Introduce White Box Cryptography (AES in particular). This is my current reseach project
- Clearly separate code from my talks (like
MetaFibonacci.h,MetaString1.h, ...) from the actual code of the library. It will be easier to integrate the library into projects - Is my code compatible with ASLR? In fact, I don't konw and I have to solve this (I need it for another project)
- Apply the techniques used in
MetaString4.hintoObfuscatedCall.h - )ntroduce Unit Testing
You have to install the Boost library in order to use ADVdetector (it is used by FSM). Alternatively, you can comment out lines related to ObfuscatCall* (includes and code) in main.cpp.
- Debian / Ubuntu:
sudo apt-get install libboost-all-dev - Mac OS X:
brew install boost - Windows: Download Boost and install it. Then you have to change the Visual Studio 2015 project to point to Boost
Debug builds are very special: Compiler do not have (and do not most of the time) respect statement such as inline or constexpr. All optimizations are also, by default, disabled. Compilers are doing this for a good reason: let you debug, single step, etc.
As a consequence, ADVobfuscator is not compatible with Debug builds. It works only for Release builds.
ADVobfuscator has been tested with:
- Xcode (LLVM) 7.3.0 under Mac OS X 10.11
- GCC 6.1.1 under Debian 9 (stretch/testing)
- Visual Studio 2015 (Update 3) under Windows 10
Other compilers are probably compatible if they are C++11/14 compliant.
| File | Description |
|---|---|
DetectDebugger.cpp |
Debugger detection, implemented for Mac OS X and iOS. It is used by ObfuscatedCallWithPredicate (FSM) |
DetectDebugger.h |
Debugger detection, declaration |
Indexes.h |
Generate list of indexes at compile time (0, 1, 2, ... N) |
Log.h |
Helper to log messages |
MetaFactorial.h |
Compute factorial at compile time |
MetaFibonacci.h |
Compute fibonacci sequence at compile time |
MetaFSM.h |
Template to generate Finite State Machines at compile time |
MetaRandom.h |
Generate a pseudo-random number at compile time |
MetaString1.h |
Obfuscated string - version 1 |
MetaString2.h |
Obfuscated string - version 2 - Remove truncation |
MetaString3.h |
Obfuscated string - version 3 - Random key |
MetaString4.h |
Obfuscated string - version 4 - Random encryption algorithm |
ObfuscatedCall.h |
Obfuscate function call |
ObfuscatedCallWithPredicate.h |
Obfuscate function call, execute a FSM based on a predicate (such as DetectDebugger) |
main.cpp |
Samples |
ADVobfuscator.xcodeproj |
Project for Apple Xcode |
ADVobfuscator.sln |
Visual Studio 2015 Solution |
Makefile |
Simple makefile for GCC |
Written by Sebastien Andrivet
Copyright © 2010-2016 - Sebastien Andrivet All rights reserved.
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