Understanding EXE Internals

I was attempting to install an exe that requires a serial number before the install, which the vendor has not provided to us yet.

This got my wheels turning about whether there is an开发者_开发知识库y information that can be gained from viewing an exe using a hex editor/VI/etc?

Using VI to view an exe, I can see some sections of plain text, but it is difficult to determine what it refers to without any context around it.

Is it possible to determine any information by reading an exe?

Thanks

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A decent registration system will not embed the expected key into the EXE at all, but will rather require a code that has been signed by the vendor's private key.

If the system has been well-implemented (that's a big if), it is mathematically impossible to find a key using anything other than brute force.

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The only way to get some information out of the exe file is to disassemble it and try to understand the machine language the disassembler returns to you, it cannot salvage any of the original comments or variable names.

A poplar tool for that is IDA, there is an older free version available. It does make the task somewhat easier, but it does not free you from actually understanding what is actually happening in the code.

If it is just a simpler protection you will probably have to reverse engineer the checking code and try to derive a key from that.

But since it is probably a lot cheaper to just wait or buy a license then hiring an experienced programmer who would probably spent several days to get some result, I would recommend you to wait.

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Fravia left a legacy of reversing info (I didn't know he has passed on until looking him up again). According to that wiki page, the last known mirror of Fravia's reversing archive is here.

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What you need is actually called software cracking.