PyMISP/pymisp/tools/machoobject.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from ..exceptions import InvalidMISPObject
from .abstractgenerator import AbstractMISPObjectGenerator
from io import BytesIO
from hashlib import md5, sha1, sha256, sha512
import logging
from typing import Optional, Union
from pathlib import Path
from . import FileObject

import lief  # type: ignore

try:
    import pydeep  # type: ignore
    HAS_PYDEEP = True
except ImportError:
    HAS_PYDEEP = False

logger = logging.getLogger('pymisp')


def make_macho_objects(lief_parsed: lief.Binary, misp_file: FileObject, standalone: bool=True, default_attributes_parameters: dict={}):
    macho_object = MachOObject(parsed=lief_parsed, standalone=standalone, default_attributes_parameters=default_attributes_parameters)
    misp_file.add_reference(macho_object.uuid, 'includes', 'MachO indicators')
    macho_sections = []
    for s in macho_object.sections:
        macho_sections.append(s)
    return misp_file, macho_object, macho_sections


class MachOObject(AbstractMISPObjectGenerator):

    def __init__(self, parsed: Optional[lief.MachO.Binary]=None, filepath: Optional[Union[Path, str]]=None, pseudofile: Optional[BytesIO]=None, standalone: bool=True, **kwargs):
        # Python3 way
        # super().__init__('elf')
        super(MachOObject, self).__init__('macho', standalone=standalone, **kwargs)
        if not HAS_PYDEEP:
            logger.warning("Please install pydeep: pip install git+https://github.com/kbandla/pydeep.git")
        if pseudofile:
            if isinstance(pseudofile, BytesIO):
                self.__macho = lief.MachO.parse(raw=pseudofile.getvalue())
            elif isinstance(pseudofile, bytes):
                self.__macho = lief.MachO.parse(raw=pseudofile)
            else:
                raise InvalidMISPObject('Pseudo file can be BytesIO or bytes got {}'.format(type(pseudofile)))
        elif filepath:
            self.__macho = lief.MachO.parse(filepath)
        elif parsed:
            # Got an already parsed blob
            if isinstance(parsed, lief.MachO.Binary):
                self.__macho = parsed
            else:
                raise InvalidMISPObject('Not a lief.MachO.Binary: {}'.format(type(parsed)))
        self.generate_attributes()

    def generate_attributes(self):
        self.add_attribute('type', value=str(self.__macho.header.file_type).split('.')[1])
        self.add_attribute('name', value=self.__macho.name)
        # General information
        if self.__macho.has_entrypoint:
            self.add_attribute('entrypoint-address', value=self.__macho.entrypoint)
        # Sections
        self.sections = []
        if self.__macho.sections:
            pos = 0
            for section in self.__macho.sections:
                s = MachOSectionObject(section, self._standalone, default_attributes_parameters=self._default_attributes_parameters)
                self.add_reference(s.uuid, 'includes', 'Section {} of MachO'.format(pos))
                pos += 1
                self.sections.append(s)
        self.add_attribute('number-sections', value=len(self.sections))


class MachOSectionObject(AbstractMISPObjectGenerator):

    def __init__(self, section: lief.MachO.Section, standalone: bool=True, **kwargs):
        # Python3 way
        # super().__init__('pe-section')
        super(MachOSectionObject, self).__init__('macho-section', standalone=standalone, **kwargs)
        self.__section = section
        self.__data = bytes(self.__section.content)
        self.generate_attributes()

    def generate_attributes(self):
        self.add_attribute('name', value=self.__section.name)
        size = self.add_attribute('size-in-bytes', value=self.__section.size)
        if int(size.value) > 0:
            self.add_attribute('entropy', value=self.__section.entropy)
            self.add_attribute('md5', value=md5(self.__data).hexdigest())
            self.add_attribute('sha1', value=sha1(self.__data).hexdigest())
            self.add_attribute('sha256', value=sha256(self.__data).hexdigest())
            self.add_attribute('sha512', value=sha512(self.__data).hexdigest())
            if HAS_PYDEEP:
                self.add_attribute('ssdeep', value=pydeep.hash_buf(self.__data).decode())