Python Hooking

Sometimes, you need to manipulate low-level functionality (C APIs, etc) from high-level languages (Python). Eg. Force the low-level side calls directly to your own Python override functions. This repo will help you do that.

It's python version of my Cpp Hooking👌

Available across all the platforms

✅ Windows

✅ Linux

✅ MacOS

✅ iOS

✅ Android

Installation

pip3 install git+https://github.com/vic4key/py-hooking.git

Documentation

See doc comments in the PyHooking.py file

Examples

Eg. To hook & unhook a function, you only need to write codes as the following

Example with mylib.print_message

import ctypes
from PyHooking import *

# define the hook function

mylib = load_external_shared_library(f"Examples/mylib_{arch}_{bits}")

@PyHooking.CPrototype(ctypes.CFUNCTYPE(None, ctypes.c_char_p))
def hk_print_message(message):
    message = f"Invoked `hk_print_message('{message.decode('utf-8')}')`"
    PyHooking().invoke(mylib.print_message, message.encode())

# perform hooking

PyHooking().hook(mylib.print_message, hk_print_message)

mylib.print_message(b"This is a string from Python code")
mylib.c_invoke_print_message()

# perform unhooking

PyHooking().unhook(mylib.print_message)

mylib.print_message(b"This is a string from Python code")
mylib.c_invoke_print_message()

# result

'''
Invoked `hk_print_message('This is a string from Python code')`
Invoked `hk_print_message('This is a string from C code')`
This is a string from Python code
This is a string from C code
'''

Example with user32.MessageBoxA

import ctypes
from PyHooking import *

# define the hook function

user32 = ctypes.CDLL(ctypes.util.find_library("user32"))

@PyHooking.CPrototype(ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_void_p, ctypes.c_char_p, ctypes.c_char_p, ctypes.c_ulong))
def hk_MessageBoxA(hWnd, lpText, lpCaption, uType):
    lpText = f"Invoked `hk_MessageBoxA({hWnd}, '{lpText.decode('utf-8')}', '{lpCaption.decode('utf-8')}', {uType})`"
    return PyHooking().invoke(user32.MessageBoxA, hWnd, lpText.encode(), lpCaption, uType)

# perform hooking

PyHooking().hook(user32.MessageBoxA, hk_MessageBoxA)

user32.MessageBoxA(0, b"text 1", b"", 0)

# perform unhooking

PyHooking().unhook(user32.MessageBoxA)

user32.MessageBoxA(0, b"text 2", b"", 0)

# result

'''
Invoked `hk_MessageBoxA(None, 'text 1', '', 0)`
<empty>
'''

Contact

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