prepare-frida-gadget.py

# Automatically download the iOS gadget file for the currently used Frida version.
# The gadget .xz file is downloaded to the same directory where frida expects the 
# gadget dylib. After download the file is decompresed and written to gadget-ios.dylib

import os
import shutil
import sys
from pathlib import Path
import logging

import requests
import frida
import lzma

logging.basicConfig(stream=sys.stderr, level=logging.INFO, format='[%(levelname)5s] %(message)s', datefmt='%H:%M:%S')

frida_ver = frida.__version__

gadget_filename = f'frida-gadget-{frida_ver}-ios-universal.dylib.xz'

cache_dir = os.environ.get('XDG_CACHE_HOME')
if cache_dir is None:
    cache_dir = os.path.join(Path.home(), '.cache')

frida_dir = os.path.join(cache_dir, 'frida')
os.makedirs(frida_dir, exist_ok=True)

frida_gadget_file = os.path.join(frida_dir, 'gadget-ios.dylib') # file that Frida expects
downloaded_gadget_file = os.path.join(frida_dir, gadget_filename)

if os.path.exists(downloaded_gadget_file):
    logging.info('Download gadget already exists: %s', downloaded_gadget_file)
else:    
    logging.info('Download frida-gadget-%s-ios-universal.dylib.xz to %s', frida_ver, downloaded_gadget_file)
    download_url = f'https://github.com/frida/frida/releases/download/{frida_ver}/{gadget_filename}'
    tmp_file = downloaded_gadget_file + '.tmp'
    with requests.get(download_url, stream=True) as response:
        response.raise_for_status()
        with open(tmp_file, 'wb') as out_file:
            shutil.copyfileobj(response.raw, out_file)
    os.replace(tmp_file, downloaded_gadget_file)


logging.info("Decompressing %s to %s", downloaded_gadget_file, frida_gadget_file)
with open(frida_gadget_file, 'wb') as out_file:
    with lzma.LZMAFile(downloaded_gadget_file, mode='rb') as uncompressed:
        shutil.copyfileobj(uncompressed, out_file)