Reverse engineering



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Reverse engineering

Postby michel123 » Sat Nov 12, 2011 2:17 am

Hello,

Do you know if there are tools to facilitate the reverse engineering of an assembly program?

And without tools, it is the safest way to achieve this?

Thank you.
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Re: Reverse engineering

 

Re: Reverse engineering

Postby NicC » Sat Nov 12, 2011 2:20 am

I was told that there was a guy who wrote a program that would reverse engineer a load module int various source code formats (PL/1 cobol etc). I believe he is in jail now. Totally irrelevant to your question unless yuou are trying to reverse engineer a proprietary load module!
The problem I have is that people can explain things quickly but I can only comprehend slowly.
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Nic
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Re: Reverse engineering

Postby Akatsukami » Sat Nov 12, 2011 3:03 am

I believe there are a variety of tools for converting load modules into source code of various sorts (search on "decompiler" or "disassembler"). The problem is that the load module does not preserve any name information, so you end up with pretty incomprehensible code, on the order of "MOVE $000TX4 TO $000FN7".

Decompilation is a gray area. Reverse engineering proprietary tools is generally forbidden under copyright law in both the U.S. and Europe, although of course it's always possible to cite a contradictory opinion. OTOH, there are commercial decompilers for re-creating source lost through disasters or to time.
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Re: Reverse engineering

Postby dick scherrer » Sat Nov 12, 2011 12:18 pm

Hello,

And without tools, it is the safest way to achieve this?
Assuming the code was written "on-site" find the original specifications and recode.

If the original specs are not to be found, Observe the actions of the code (depending on the functionality/comnplexity of the module, this may take considerable time) and write new specifications. Then re-code.

If you have hundreds or thousands of missing source modules investing in a "tool" might be worth it. For one or 2, just re-implement.

If you re-code, there is probably no need to re-write in assembler. . . Unless you happen to have considerable assembler expertise available.
Hope this helps,
d.sch.
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Re: Reverse engineering

Postby michel123 » Sat Nov 12, 2011 1:35 pm

Hello,

Yes, in fact it is moving from assembler to cobol. For now I do not know the level of complexity of applications.
Whether to invest in a tool, what would it be?
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Re: Reverse engineering

Postby enrico-sorichetti » Sat Nov 12, 2011 2:04 pm

check the PROGRAM UNDERSTANDING TOOL from the IBM ASSEMBLER TOOLKIT
cheers
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Re: Reverse engineering

Postby michel123 » Sat Nov 12, 2011 2:34 pm

I looked on the IBM site. This is very interesting. But what does it cost?
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Re: Reverse engineering

Postby dick scherrer » Sun Nov 13, 2011 10:16 am

Hello,

Ask IBM for prices. . .
Hope this helps,
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Re: Reverse engineering

Postby michel123 » Wed Nov 16, 2011 3:24 pm

Hello,


And thank you for your answers.


Michel.
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