Re: reverse engineer c or java

[Liviu.Daia () IMAR RO (Liviu Daia)]

On 21 May 2000, Warner Losh <imp () VILLAGE ORG> wrote:
> In message
> <Pine.LNX.4.10.10005210045330.21360-100000 () battlemech talocan dhs org>
> phazer writes:
> : It will decompile java .class files into java source code.. I don't
> : know if there are similar programs for C, but i believe it's a lot
> : harder to decompile than java.
>
> Much harder. java -> jvm is basically 1-1 so reversing it is easy.
> I said basically because there are exceptions.  Also, the distance
> between java and jvm is relatively small. intel assember code doesn't
> map backwards to C easily and the distance it much larger.  The larger
> the distance between source and object, the harder it is to convert
> backwards.  Also, C doesn't have the nice 1-1 mapping to object code
> java does.  Especially for heavily optimized functions.

    To paraphrase Rain Forest Puppy:

(1) For white hats: this topic is raised every once in a while on
    news:comp.compilers.  The standard answer has been for a long time
    to look at Christina Cifuentes' page

        http://www.csee.uq.edu.au/csm/decompilation/

(2) For black hats: forget about decompilation, use IDA instead.

    Regards,

    Liviu Daia

--
Dr. Liviu Daia               e-mail:   Liviu.Daia () imar ro
Institute of Mathematics     web page: http://www.imar.ro/~daia
of the Romanian Academy      PGP key:  http://www.imar.ro/~daia/daia.asc