How .net obfuscators work

Are there any articles on this I know about ildasm, and I'm interested in how the standard PE files are built, where the certain information is stored (meta-deta, IL, etc), how an application starts up for the first time (prior and after being jitted and stored in the gac). etc, etc.

Basically, everything about how .net works :)

Can I read up about this anywhere, or do I have to create my own sample .net executables, and guess/reverse engineer the contents

My long term aim is to eventually create a freeware obfuscator. I'm not really interested in disassembling existing net assemblies, but I'm guessing the software will have to do a certain amount of that in order to know what it's working with or what it can and can't change.

Apologies if this is posted in the wrong sub-forum - there doesn't seem to be a correct one from the forum list descriptions for this kind of question.

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How .net obfuscators work

Ron Gliane
I think one of the best source of informatuion to do what you want is to read all about the CLS specification in http://msdn.microsoft.com/netframework/programming/clr/

If you really want to do what you said, I think you will find very interenting and usefull this files ammong the others there:

CLI Partition I - Concepts and Architecture
CLI Partition II - Metadata Definition and Semantics
CLI Partition III - Common Intermediate Language (CIL) Instruction Set
CLI Partition IV - Profiles and Libraries
CLI Partition V - Annexes

This site have what you need in order to do all about reverse engineering.
Ryan Po
Thanks for the suggestion! It seems from the TOC that the book you mention will be an invaluable resource. I doubt my local bookshop would have such a title, so I've just ordered it from Amazon :)
jkreps
My favorite book on MSIL, maybe you will find it useful: Inside Microsoft .NET IL Assembler by Serge Lidin.
How .net obfuscators work

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