Ok, I'll give you a result, meanwhile fixing some imprecisions.
The "class" is CogVmSimulator but it's use is very far from my knowlegde,
I recalled having seen a picture of Pharo-in-Pharo (or Squeak-in-Squeak)
running under this simulator.
It lives near the Cog side (or the OpenVM side) of Squeak/Pharo
(If I'm not wrong Squeak ran into an emulator, before walking on his
legs-his VM).
There are many of these simulator, for other Smalltalk :
- Hobbes and others for Xerox (thanks to files of Mario Molczko and/or
Bitsavers
- Dan Ingalls Apda Smalltalk + old Smalltalk -72 /-76
and maybe others I don't yet know about
The reason is quite simple : the object memory is written to disk
and the spec of executing Smalltalk are known either from the books
or by the source.
The root is Xerox's SystemTracer, a class that wrote a running image
to disk, optionally changing object format (see the Green Book).
So :
- if you can read the image
- you can run into a simulator
- or decode it without to much effort (5 emulators for Xerox V2 image,
so far).
(try to open an image with a text editor : intriguing !)
I don't know how Cincom or Instantiations protect the released st code,
but for Pharo and Squeak this is not a point : they are all open.
So, as if you wanna "protect" names and methods of a running image ...
... you have to (IMHO) :
- encrypt executable and image (and modify the VM)
- or obfuscate your classes and methods renaming it to
C1, C2, ..., m1:p1:p2: and so on (keeping a map for debugging)
Sorry to be imprecise about names and locations
apart from suggest to see 4 emulators 4 running in a squeak image
running ... in javascript in your browser (so total is 5) at :
https://smalltalkzoo.thechm.org/HOPL-Squeak.html?earlyst80
(thanks to Vanessa Freudemberg & Dan Ingalls).
Sorry again & best regards,
Davide Grandi
On 06/09/2020 23:51, Esteban Maringolo wrote:
If somebody gets to open the image and loads it with an Smalltalk
Emulator to execute it I'll ask him/her to start working together, and
even teach me how to do it.
I don't want to shield the image from being accessed, just want to
make it harder than simply removing the '--headless' parameter to the
VM executable.
Of course removing sources is a plus (I do for a VW deployed image),
but even for this particular piece of software that I'm asking for, I
don't need it.
If I wanted to make the source public, I'll publish it in
Github/Gitlab, otherwise I'd rather keep the code private.
Regards,
Esteban A. Maringolo
On Sun, Sep 6, 2020 at 6:29 PM Davide Grandi <davide.gra...@email.it> wrote:
I mean that with SmalltalkEmulator, the Smalltalk interpreter
written in Smalltalk, one can execute an image looking at
classes, methods and maybe executing code at will.
And the only practical form of protection I see in Squeak/Pharo
is to obfuscate code.
Maybe I'm wrong.
Davide Grandi
On 06/09/2020 22:27, Esteban Maringolo wrote:
On Sun, Sep 6, 2020 at 12:52 PM Davide Grandi <davide.gra...@email.it> wrote:
Does "competition" has SmalltalkEmulator ?
A Smalltalk-written VM will defeat any simple obfuscation scheme.
Sorry, but I don't understand what you mean.
Best regards,
--
Ing. Davide Grandi
email : davide.gra...@email.it
mobile : +39 339 7468 778
linkedin : http://linkedin.com/in/davidegrandi
--
Ing. Davide Grandi
email : davide.gra...@email.it
mobile : +39 339 7468 778
linkedin : http://linkedin.com/in/davidegrandi
