[Tutorial] Using FASM to create python modules

Hello!
I've being playing with Python, and I have to say it's a wonderful language!
It really makes life easier.

Now, I'm here to show you how to use FASM to create new modules for using in Python. Razz

1) The first step is to create a DLL in FASM:

Code:

; TESTDLL.DLL

format PE GUI 4.0 DLL
entry DllEntryPoint

include 'win32a.inc'

section '.code' code readable executable

proc DllEntryPoint hinstDLL,fdwReason,lpvReserved
        mov     eax,TRUE
        ret
endp

; void showMessage(char * msg);

proc showMessage, msg
     invoke MessageBox,0,[msg],[msg],0
ret
endp

proc addnums, x : DWORD, y : DWORD
     mov eax, [x]
     add eax, [y]
     ret
endp

section '.idata' import data readable writeable

  library user,'USER32.DLL'

  import user,\
         MessageBox,'MessageBoxA'

section '.edata' export data readable

  export 'testDLL.DLL',\
         showMessage,'_showMessage',\
         addnums,'_addnums'

section '.reloc' fixups data discardable

As you can see, it's pretty easy to do. You can just modify the template that comes in \examples folder.

2) Now we can wrap the calling of that function in a nice python module (you can wrap as many functions as you need):
This is python code:

Code:

# fasmmodule.py
from ctypes import *

mydll = windll.LoadLibrary("testDLL.dll")

def showMessage(n):
    mydll._showMessage(n)

def addnums(x, y):
    return mydll._addnums(x, y)

3) Now you can use that function just like you do with any Python Module:

Code:

# test.py
from fasmmodule import *

showMessage("Hello world!")

print addnums(2,3)

There you go! Use the power of ASM in a easy and syntax-clear scripting language known as Python!
Just remember to put the DLL and the Module on your path or script directory!
You can even generate the EXE with py2exe to distribute your application.

Feel free to leave comments!
And I hope you like my simple tutorial.

EDIT: Added addnums function example. Should be enough if you want to do you complex calculus in FASM and use it your Python program. I'll add more data passing soon.

def bind(name): mydll = windll.LoadLibrary('testDLL.dll') if hasattr(mydll,name): func = getattr(mydll,name) return func else: raise AttributeError("Function '%s' does not exist in mydll!" % name)