Cycling 74 » Topic: Reverse engineering a Max collective, is it possible?

Reverse engineering a Max collective, is it possible?

chaostheory — Fri, 22 Feb 2008 11:13:01 +0000

Soon I will be performing a piece of my own that will be manipulated live using a MaxMSP patch. Because I don’t want to reload the patch between the rehearsal and the performance (i.e. keep it running on the computer) I thought of creating an application so my work is ‘protected’.

I will be using a public computer and I don’t mind if people take the application, but I am very hesitant to show the coding behind it so very early on after its completion. Therefore, if I create a collective application I would just like to know if it possible to reverse engineer the .mxo collective (contained package contents) such that someone could view and edit the source code?

Also, I am using the MacOS version of MaxMSP.

Re: Reverse engineering a Max collective, is it possible?

thezer0ist@gmail.com — Fri, 22 Feb 2008 16:38:00 +0000

short answer: no.
long answer: if you’re nuts enough to attempt it, you’d have to reverse engineer the mxo file format. this would likely involve a LOT of testing. you’d write a simple patch, compile it to an mxo, and examine the result. then you’d modify the patch slightly and do the same thing. then you compare the two for differences. then you try varying other parameters.
so… unless you’re very very very obsessive and good at this sort of thing (as in you have experience working with the underlying stucture of various file formats), the answer is no.

Re: Reverse engineering a Max collective, is it possible?

nick rothwell / cassiel — Fri, 22 Feb 2008 17:01:45 +0000

> long answer: if you’re nuts enough to attempt it, you’d have to
> reverse engineer the mxo file format.

A .mxo file is an external binary. I assume you mean .mxf.

Actually, I doubt that the .mxf format is that complex: it’s designed
for convenience, not for security. I’ve never looked at it, but
wouldn’t be surprised to find it no more complicated than TAR or ZIP.

– N.

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Re: Reverse engineering a Max collective, is it possible?

jasch — Fri, 22 Feb 2008 17:27:15 +0000

years ago, there was an explanation on how to achieve this by mr.
ziccharelli himself. it’s probably still in the mc gill max-list
archives somewhere. that being said, the best way to make sure that
even a reverse engineered mxf-collective doesn’t work is to add some
custom c-code to the soup.

/*j

Re: Reverse engineering a Max collective, is it possible?

thezer0ist@gmail.com — Fri, 22 Feb 2008 17:38:39 +0000

Quote: jasch wrote on Fri, 22 February 2008 12:27
—————————————————-
> years ago, there was an explanation on how to achieve this by mr.
> ziccharelli himself. it’s probably still in the mc gill max-list
> archives somewhere. that being said, the best way to make sure that
> even a reverse engineered mxf-collective doesn’t work is to add some
> custom c-code to the soup.
>
> /*j
>
>
>
—————————————————-

even then, if you were particularly crazy, you could write a program that exports functions with the same signatures as any detected max runtime calls, and then relink the binary external and have the program output the results of all calls to max functions, by which you could figure out pretty much everything that goes on in the setup function…

Re: Reverse engineering a Max collective, is it possible?

Olivier Pasquet — Fri, 22 Feb 2008 17:59:45 +0000

> by which you could figure out pretty much everything that goes on
in the setup function…
< And why not some mlp for guessing the output without thinking about
the external function ? :)

Re: Reverse engineering a Max collective, is it possible?

Trond Lossius — Fri, 22 Feb 2008 19:32:03 +0000

As far as I remember from earlier threads the format of collectives and
stand-alones is now encrypted.

Best,
Trond

Nick Rothwell wrote:
>> long answer: if you’re nuts enough to attempt it, you’d have to
>> reverse engineer the mxo file format.
>
> A .mxo file is an external binary. I assume you mean .mxf.
>
> Actually, I doubt that the .mxf format is that complex: it’s designed
> for convenience, not for security. I’ve never looked at it, but wouldn’t
> be surprised to find it no more complicated than TAR or ZIP.

Re: Reverse engineering a Max collective, is it possible?

chaostheory — Fri, 22 Feb 2008 19:46:48 +0000

Thanks all. Just a bit of peace of mind really!

Re: Reverse engineering a Max collective, is it possible?

nick rothwell / cassiel — Fri, 22 Feb 2008 20:42:27 +0000

On 22 Feb 2008, at 19:32, Trond Lossius wrote:

> As far as I remember from earlier threads the format of collectives
> and stand-alones is now encrypted.

Ooh, I don’t think so.

I just compared Emacs dumps of a patcher in binary with a collective
built from it. Apart from some predictable topping and tailing, they
look pretty much identical.

– N.

Re: Reverse engineering a Max collective, is it possible?

Stefan Tiedje — Tue, 26 Feb 2008 09:51:28 +0000

Chris Robson schrieb:
> I will be using a public computer and I don’t mind if people take the
> application, but I am very hesitant to show the coding behind it so
> very early on after its completion.

I wouldn’t worry at all about that, usually the amount of work necessary
to only understand how you patched it, even with sources, is more work
than repatching the same thing…

Just look at the time you needed to create it, the amount of knowledge
you have about your own piece. Imagine someone who would want to steal
it… I can’t imagine that… He would have to put more work into it
than you did…

I made my Ondes Memorielles for example just for myself. Even if I would
publish the sources, nobody would be able to play them the way I do, I
doubt anybody would use them as they are. To make something publicly
usefull requires not only some, but a lot of extra work, usually more
than was necessary to make it into a personal instrument…

Stefan

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