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Reverse engineering

PostPosted: Sat Nov 12, 2011 2:17 am
by michel123
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.

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 2:20 am
by NicC
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!

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 3:03 am
by Akatsukami
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.

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 12:18 pm
by dick scherrer
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.

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 1:35 pm
by michel123
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?

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 2:04 pm
by enrico-sorichetti
check the PROGRAM UNDERSTANDING TOOL from the IBM ASSEMBLER TOOLKIT

Re: Reverse engineering

PostPosted: Sat Nov 12, 2011 2:34 pm
by michel123
I looked on the IBM site. This is very interesting. But what does it cost?

Re: Reverse engineering

PostPosted: Sun Nov 13, 2011 10:16 am
by dick scherrer
Hello,

Ask IBM for prices. . .

Re: Reverse engineering

PostPosted: Wed Nov 16, 2011 3:24 pm
by michel123
Hello,


And thank you for your answers.


Michel.