Re: Changing Python Opcodes
Sreejith K wrote: I know this is not the best way to do it. But I have to do it at least to make it *hard* to decompile the python bytecode. So I compiled Python from source changing some opcode values It probably wouldn't be all that hard for someone to figure this out. A possible avenue of attack would be to use your python to compile a known piece of code that exercises all the opcodes, and compare the result with that from a standard python. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing Python Opcodes
Diez B. Roggisch wrote: Sreejith K wrote: So I compiled Python from source changing some opcode values Nobody can be helping you there, because it's *your* code, not Python anymore. And giving others access to it defies somewhat the purpose of the whole exercise ...and everyone with the expertise to decompile your application and do something useful with the result will also be able to find this thread. Basically you're trying the security through obscurity stunt without the obscurity... Peter -- http://mail.python.org/mailman/listinfo/python-list
Changing Python Opcodes
Hi, I know this is not the best way to do it. But I have to do it at least to make it *hard* to decompile the python bytecode. I want to distribute a software written in Python without the source. So I compiled Python from source changing some opcode values (Taking care of HAVE_ARGUMENT value) and distributed with the .pyc files. It did compile but when I'm installing additional python modules using easy_install, the import fails with a segmentation fault. It worked in a 32 bit Centos 5.2 but not on 64bit Centos 5.2. I am using python 2.5.4 source. I changed only the Include/opcode.py source with my jumbled opcode values. Was I correct here ? I would like to know what all changes to be made as to successfully compile a custom python with different opcode values ? -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing Python Opcodes
Sreejith K schrieb: Hi, I know this is not the best way to do it. But I have to do it at least to make it *hard* to decompile the python bytecode. I want to distribute a software written in Python without the source. So I compiled Python from source changing some opcode values (Taking care of HAVE_ARGUMENT value) and distributed with the .pyc files. It did compile but when I'm installing additional python modules using easy_install, the import fails with a segmentation fault. It worked in a 32 bit Centos 5.2 but not on 64bit Centos 5.2. I am using python 2.5.4 source. I changed only the Include/opcode.py source with my jumbled opcode values. Was I correct here ? I would like to know what all changes to be made as to successfully compile a custom python with different opcode values ? As you are the one who modified your Python, you are the one responsible for debugging that - noone else can. Did you try installing the egg *without* pyc-files in there? Because naturally those shouldn't work. They shouldn't crash the interpreter either, but then again - you *did* modify it. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing Python Opcodes
On Aug 18, 12:19 pm, Diez B. Roggisch de...@nospam.web.de wrote: Did you try installing the egg *without* pyc-files in there? Because naturally those shouldn't work. They shouldn't crash the interpreter either, but then again - you *did* modify it. Hi Diez, thanks for the immediate reply :) I installed the setuptools using ez_setup.py script. Then I used the easy_install to install additional modules. When importing the installed modules segfault occurs. The module I installed was TurboGears. Then I thought that it happened maybe because the easy_install script is downloading eggs for original python (I'm not sure if it is what easy_install is doing). So I also tried to install the module by downloading all the dependencies (tar.gz files) and building it. Even then segfault occured. Is there any problem in changing only the opcodes.py file ? I did something horribly wrong here. Hope someone will help... -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing Python Opcodes
Sreejith K wrote: On Aug 18, 12:19 pm, Diez B. Roggisch de...@nospam.web.de wrote: Did you try installing the egg *without* pyc-files in there? Because naturally those shouldn't work. They shouldn't crash the interpreter either, but then again - you *did* modify it. Hi Diez, thanks for the immediate reply :) I installed the setuptools using ez_setup.py script. Then I used the easy_install to install additional modules. When importing the installed modules segfault occurs. The module I installed was TurboGears. Then I thought that it happened maybe because the easy_install script is downloading eggs for original python (I'm not sure if it is what easy_install is doing). Yep, that's actually it's main purpose. So I also tried to install the module by downloading all the dependencies (tar.gz files) and building it. Even then segfault occured. Is there any problem in changing only the opcodes.py file ? I did something horribly wrong here. Hope someone will help... I don't know. You modified this yourself. If I were in your situation, what I would have done is to - modify the version-information stored in my PYC-files so that I'm sure I don't accidentally load any normal PYC-files. Python does check that through some magic number, make sure you use your own. - fire up the debugger and see where the segfault actually happens. Nobody can be helping you there, because it's *your* code, not Python anymore. And giving others access to it defies somewhat the purpose of the whole exercise Diez -- http://mail.python.org/mailman/listinfo/python-list
