office.py

import os
import re
import shutil
import tempfile
import datetime
import zipfile
from typing import Dict, Set

from . import abstract, parser_factory

assert Set   # make pyflakes happy

class ArchiveBasedAbstractParser(abstract.AbstractParser):
    whitelist = set()  # type: Set[str]

    def _clean_zipinfo(self, zipinfo: zipfile.ZipInfo) -> zipfile.ZipInfo:
        zipinfo.compress_type = zipfile.ZIP_DEFLATED
        zipinfo.create_system = 3  # Linux
        zipinfo.comment = b''
        zipinfo.date_time = (1980, 1, 1, 0, 0, 0)
        return zipinfo

    def _get_zipinfo_meta(self, zipinfo: zipfile.ZipInfo) -> Dict[str, str]:
        metadata = {}
        if zipinfo.create_system == 3:
            #metadata['create_system'] = 'Linux'
            pass
        elif zipinfo.create_system == 2:
            metadata['create_system'] = 'Windows'
        else:
            metadata['create_system'] = 'Weird'

        if zipinfo.comment:
            metadata['comment'] = zipinfo.comment  # type: ignore

        if zipinfo.date_time != (1980, 1, 1, 0, 0, 0):
            metadata['date_time'] =str(datetime.datetime(*zipinfo.date_time))

        return metadata


    def _clean_internal_file(self, item: zipfile.ZipInfo, temp_folder: str,
                             zin: zipfile.ZipFile, zout: zipfile.ZipFile) -> bool:
        output = ''
        zin.extract(member=item, path=temp_folder)
        if item.filename not in self.whitelist:
            full_path = os.path.join(temp_folder, item.filename)
            tmp_parser, mtype = parser_factory.get_parser(full_path)  # type: ignore
            if not tmp_parser:
                print("%s's format (%s) isn't supported" % (item.filename, mtype))
                return False
            tmp_parser.remove_all()
            output = tmp_parser.output_filename
        else:
            output = os.path.join(temp_folder, item.filename)
        zinfo = zipfile.ZipInfo(item.filename)  # type: ignore
        clean_zinfo = self._clean_zipinfo(zinfo)
        with open(output, 'rb') as f:
            zout.writestr(clean_zinfo, f.read())
        return True


class MSOfficeParser(ArchiveBasedAbstractParser):
    mimetypes = {
        'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
        'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        'application/vnd.openxmlformats-officedocument.presentationml.presentation'
    }
    files_to_keep = {'_rels/.rels', 'word/_rels/document.xml.rels'}

    def get_meta(self):
        """
        Yes, I know that parsing xml with regexp ain't pretty,
        be my guest and fix it if you want.
        """
        metadata = {}
        zipin = zipfile.ZipFile(self.filename)
        for item in zipin.infolist():
            if item.filename.startswith('docProps/') and item.filename.endswith('.xml'):
                content = zipin.read(item).decode('utf-8')
                for (key, value) in re.findall(r"<(.+)>(.+)</\1>", content, re.I):
                    metadata[key] = value
                if not metadata:  # better safe than sorry
                    metadata[item] = 'harmful content'

            for key, value in self._get_zipinfo_meta(item).items():
                metadata[key] = value
        zipin.close()
        return metadata


    def remove_all(self):
        zin = zipfile.ZipFile(self.filename, 'r')
        zout = zipfile.ZipFile(self.output_filename, 'w')
        temp_folder = tempfile.mkdtemp()

        for item in zin.infolist():
            if item.filename[-1] == '/':
                continue  # `is_dir` is added in Python3.6
            elif item.filename.startswith('docProps/'):
                if not item.filename.endswith('.rels'):
                    continue  # don't keep metadata files
            if item.filename in self.files_to_keep:
                item = self._clean_zipinfo(item)
                zout.writestr(item, zin.read(item))
                continue

            if self._clean_internal_file(item, temp_folder, zin, zout) is False:
                zout.close()
                os.remove(self.output_filename)
                return False

        shutil.rmtree(temp_folder)
        zout.close()
        zin.close()
        return True



class LibreOfficeParser(ArchiveBasedAbstractParser):
    mimetypes = {
        'application/vnd.oasis.opendocument.text',
        'application/vnd.oasis.opendocument.spreadsheet',
        'application/vnd.oasis.opendocument.presentation',
        'application/vnd.oasis.opendocument.graphics',
        'application/vnd.oasis.opendocument.chart',
        'application/vnd.oasis.opendocument.formula',
        'application/vnd.oasis.opendocument.image',
    }
    whitelist = {'mimetype', 'manifest.rdf'}


    def get_meta(self):
        """
        Yes, I know that parsing xml with regexp ain't pretty,
        be my guest and fix it if you want.
        """
        metadata = {}
        zipin = zipfile.ZipFile(self.filename)
        for item in zipin.infolist():
            if item.filename == 'meta.xml':
                content = zipin.read(item).decode('utf-8')
                for (key, value) in re.findall(r"<((?:meta|dc|cp).+?)>(.+)</\1>", content, re.I):
                    metadata[key] = value
                if not metadata:  # better safe than sorry
                    metadata[item] = 'harmful content'
            for key, value in self._get_zipinfo_meta(item).items():
                metadata[key] = value
        zipin.close()
        return metadata

    def remove_all(self):
        zin = zipfile.ZipFile(self.filename, 'r')
        zout = zipfile.ZipFile(self.output_filename, 'w')
        temp_folder = tempfile.mkdtemp()

        for item in zin.infolist():
            if item.filename[-1] == '/':
                continue  # `is_dir` is added in Python3.6
            elif item.filename == 'meta.xml':
                continue  # don't keep metadata files

            if self._clean_internal_file(item, temp_folder, zin, zout) is False:
                os.remove(self.output_filename)
                return False

        shutil.rmtree(temp_folder)
        zout.close()
        zin.close()
        return True