Obfuscar: Why NCloak Does Not Work
This post talks about why NCloak does not work.
Mono.Cecil is an important library which enables very easy MSIL/CIL manipulation. Upon it several projects are built, both commercial and open source. In obfuscator land, Obfuscar is such a typical example, but it is obviously not the only one.
NCloak is another MIT licensed obfuscator based on Mono.Cecil and it introduces a few interesting features,
- Full obfuscation of all members (already in Obfuscar)
- String encryption (already in Obfuscar)
- Simplification and Optimization of code
- Anti-reflection and anti-ildasm methods
- Basic tamper proofing solution (resource based)
Is it possible to reuse some of the code in Obfuscar? I just finished a few experiments.
- Sadly its code simplification code cannot be used, as .NET CLR (at least 4.0) does not recognize the generated assembly.
- For the same reason, anti-reflection is also broken.
- Basic tamper proofing seems to be experimental, so I did not touch it.
- Anti-ildasm is almost useless.
Thus, the last useful bit is code optimization. As a result, a new option is now added, named OptimizeMethods.
There are other open source obfuscators, but their licenses are too restrictive, and I could not reuse their code at this moment.
© Lex Li. All rights reserved. The code included is licensed under CC BY 4.0 unless otherwise noted.
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