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Sep 07

A Reverse Engineering Tool for Static Analysis Which Performs Equational Reasoning on X86 Assembly Code

Master thesis by Marien Bourguignon

Abstract

Kevin Coogan and Saumya Debray, two researchers focused on digital reverse engi-
neering, identified an issue within that field, and exposed it in a paper titled Equational
Reasoning on x86 Assembly Code[1]. They stated that, while there is a great amount of
tools able to perform reverse engineering analysis on high-level source code, there is a
lack of such tool able to used on assembly code. The aim of this thesis is to show how the
tool proposed in the aforementioned paper, which performs equational reasoning on x86
traces with the intend of improving their readability, could be extended to also perform
static analysis. In this context, two additional issues have to be solved: Modelising the
non-linear control flow, and deciding whether or not specific pointers are aliased. The
former is solved using the static single assignment form, the later is handled thanks to
a pointer analysis.
When performing manually what the static analysis tool would do, one can notice
how the readability of its output has decreased compared to the one working on traces.
This is due to the fact that the φ-functions introduced by the static single assignment
form does not clearly show which control structure has led to its existence, but also
because of the undecidability of the pointer analysis problem, which implies that the
used algorithm will only be able to provide approximative results.

The project was supervised by Nikita Veshchikov.

The director of the project is Olivier Markowitch.