Leagsoft-decode.py

import os.path
from zipfile import ZipFile
from struct import unpack
from os import walk

CONSTANT_POOL_COUNT_INDEX = 8
CONSTANT_Utf8_info = 1
CONSTANT_Methodref_info = 0x0A
CONSTANT_ITEM_SIZE = 0x13
CONSTANT_ITEM_LENGTH = (0, 0, 0, 5, 5, 9, 9, 3, 3, 5, 5, 5, 5, 0, 0, 4, 3, 0, 5)


def bytes2int(data: bytes, start: int, size: int) -> int:
    if size == 2:
        return unpack('>H', data[start:start + 2])[0]
    elif size == 1:
        return data[start]


def decode(class_data: bytes) -> bytes:
    new_class_data = bytearray(class_data)
    constant_pool_size = bytes2int(class_data, CONSTANT_POOL_COUNT_INDEX, 2)
    cur = CONSTANT_POOL_COUNT_INDEX + 2
    for i in range(0, constant_pool_size):
        constant_type = bytes2int(class_data, cur, 1)
        cur += 1
        if constant_type == CONSTANT_Utf8_info:
            cur += bytes2int(class_data, cur, 2) + 2
        elif constant_type == CONSTANT_Methodref_info:
            for idx in range(cur, cur + 4):
                new_class_data[idx] = 0xff & (new_class_data[idx] + 1)
            cur += 4
        elif constant_type > CONSTANT_ITEM_SIZE:
            print('???? ERROR   ???')
            break
        else:
            cur += CONSTANT_ITEM_LENGTH[constant_type] - 1
    return bytes(new_class_data)


def decode_file(path: str):
    try:
        with open(path, 'rb+') as f:
            class_data = f.read()
            new_class_data = decode(class_data)
            f.seek(0)
            f.write(new_class_data)
            f.truncate()
    except Exception as e:
        print(f'{path}: {e}')


def need_decode(name: str) -> bool:
    if not name.endswith('.class'):
        return False
    if name.startswith(('com/leagsoft/emm/', 'com/leagsoft/sdp/')):
        if '$$FastClassBySpringCGLIB$$' not in name and '$$EnhancerBySpringCGLIB$$' not in name:
            return True
    elif name in ('org/springframework/core/type/classreading/SimpleMetadataReader',
                  'org/springframework/core/LocalVariableTableParameterNameDiscoverer'):
        return True
    return False


def decode_all_class(classes_path: str):
    for root, _, files in walk(classes_path):
        for fn in files:
            path = os.path.join(root, fn)
            name = path[len(classes_path) + 1:]
            name = name.replace('\\', '/')
            if not need_decode(name):
                continue
            decode_file(path)


def decode_jar(jar_path: str):
    jar = ZipFile(jar_path, 'a')
    for filename in jar.namelist():
        if not need_decode(filename):
            continue
        class_data = jar.read(filename)
        new_class_data = decode(class_data)
        jar.writestr(filename, new_class_data)


def decode_all_lib(lib_path: str):
    for root, _, files in walk(lib_path):
        for fn in files:
            path = os.path.join(root, fn)
            try:
                decode_jar(path)
            except Exception as err:
                print(err)


def main():
    webapp_path = r'D:\leagsoft\LeagView\tomcat-service\webapps\emm-api'
    classes_path = os.path.join(webapp_path, r'WEB-INF\lib')
    decode_all_lib(classes_path)
    lib_path = os.path.join(webapp_path, r'WEB-INF\classes')
    decode_all_class(lib_path)


if __name__ == '__main__':
    main()