repair dex by fart

fart_repair.py

import base64
import os
import re
import sys

def parse_ins_bin(ins_path):
    with open(ins_path, 'r') as f:
        content = f.read()
    ins_array=re.findall(r"{name:(.*?),method_idx:(.*?),offset:(.*?),code_item_len:(.*?),ins:(.*?)}", content) #(.*?)最短匹配
    code_items = []
    for ins in ins_array:
        offset=(int)(ins[2])
        code_item = base64.b64decode(ins[4])
        code_items.append((offset, code_item))
    return code_items

def parse_all_ins_bin(ins_dir, keyword):
    ins_bins = os.listdir(ins_dir)
    ins_bins = [i for i in ins_bins if '.bin' in i and keyword in i]
    code_items = []
    for ins_bin in ins_bins:
        code_items += parse_ins_bin('{}/{}'.format(ins_dir, ins_bin))
    return code_items

if __name__ == "__main__":
    dex_path = sys.argv[1]
    ins_dir = sys.argv[2]

    keyword = dex_path.split('/')[-1].split('_')[0]

    with open(dex_path, 'rb') as f:
        dex = bytearray(f.read())

    code_items = parse_all_ins_bin(ins_dir, keyword)
    for offset, code_item in code_items:
        size = len(code_item)
        dex[offset:offset+size] = code_item

    output_path = dex_path.replace('.dex', '_repair.dex')
    with open(output_path, 'wb') as f:
        f.write(dex)