Obfuscating Java bytecode with LLVM and Epona

In this article I describe my two-months summer internship project at Quarkslab: obfuscating Java bytecode using the [Epona] Code Obfuscator. This article explains our approach, its advantages and limitations.

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Global Dead Code Elimination for LLVM, revisited

While building an LLVM-based obfuscator, we explore some unexpected code areas. For instance, what happens when you try to optimize a single function that holds millions of instructions? Some LLVM passes start to suffer, including an unexpected one: Global Dead Code Elimination. Let's investigate!

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Back from CppCon 2016

Quarkslab was present at CppCon 2016, presenting general thoughts on the C++ optimization process and how much the so-called zero-cost abstraction relied on the compiler implementation, and not on the standard. Now comes a humble report from this great event!

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Implementing a Custom Directive Handler in Clang

HOW-TO: Implementing a custom directive processor in clang to drive the compilation process of our LLVM-base code obfuscator, while maintaining backward-compatibility if another compiler is used. What a good opportunity for a journey in the first compiler stages!

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Clang Hardening Cheat Sheet

While improving the documentation (d'oh!) of our home grew obfuscator based on LLVM, we wrote a cheat sheet on clang's hardening features, and some of ld ones. It turns out existing hardening guides generally focus on GCC, while Clang also has an interesting set of hardening features. So let's share it in this blog post!

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llvm_dev_meeting:

LLVM developer Meeting report

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goto llvm_dev_meeting;

Quarkslab's compiler crew is going to LLVM developer Meeting in CA!

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Turning Regular Code Into Atrocities With LLVM: The Return

Where a simple xor gets transformed beyond what it ever thought

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Turning Regular Code Into Atrocities With LLVM

A "hands-on" introduction to LLVM passes through obfuscation.

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A glance at compiler internals: Keep my memset

Why does some memset calls get optimized away by the compiler? Let's investigate!

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