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PyCIRCLean/bin/filecheck.py

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os
import mimetypes
import shlex
import subprocess
import zipfile
import argparse
import shutil
import oletools.oleid
import olefile
import officedissector
import warnings
import exifread
from PIL import Image
from pdfid import PDFiD, cPDFiD
from kittengroomer import FileBase, KittenGroomerBase, Logging
SEVENZ_PATH = '/usr/bin/7z'
class Config:
"""Configuration information for Filecheck."""
# Application subtypes (mimetype: 'application/<subtype>')
mimes_ooxml = ['vnd.openxmlformats-officedocument.']
mimes_office = ['msword', 'vnd.ms-']
mimes_libreoffice = ['vnd.oasis.opendocument']
mimes_rtf = ['rtf', 'richtext']
mimes_pdf = ['pdf', 'postscript']
mimes_xml = ['xml']
mimes_ms = ['dosexec']
mimes_compressed = ['zip', 'rar', 'bzip2', 'lzip', 'lzma', 'lzop',
'xz', 'compress', 'gzip', 'tar']
mimes_data = ['octet-stream']
# Image subtypes
mimes_exif = ['image/jpeg', 'image/tiff']
mimes_png = ['image/png']
# Mimetypes with metadata
mimes_metadata = ['image/jpeg', 'image/tiff', 'image/png']
# Commonly used malicious extensions
# Sources: http://www.howtogeek.com/137270/50-file-extensions-that-are-potentially-dangerous-on-windows/
# https://github.com/wiregit/wirecode/blob/master/components/core-settings/src/main/java/org/limewire/core/settings/FilterSettings.java
malicious_exts = (
# Applications
".exe", ".pif", ".application", ".gadget", ".msi", ".msp", ".com", ".scr",
".hta", ".cpl", ".msc", ".jar",
# Scripts
".bat", ".cmd", ".vb", ".vbs", ".vbe", ".js", ".jse", ".ws", ".wsf",
".wsc", ".wsh", ".ps1", ".ps1xml", ".ps2", ".ps2xml", ".psc1", ".psc2",
".msh", ".msh1", ".msh2", ".mshxml", ".msh1xml", ".msh2xml",
# Shortcuts
".scf", ".lnk", ".inf",
# Other
".reg", ".dll",
# Office macro (OOXML with macro enabled)
".docm", ".dotm", ".xlsm", ".xltm", ".xlam", ".pptm", ".potm", ".ppam",
".ppsm", ".sldm",
# banned from wirecode
".asf", ".asx", ".au", ".htm", ".html", ".mht", ".vbs",
".wax", ".wm", ".wma", ".wmd", ".wmv", ".wmx", ".wmz", ".wvx",
# Google chrome malicious extensions
".ad", ".ade", ".adp", ".ah", ".apk", ".app", ".application", ".asp",
".asx", ".bas", ".bash", ".bat", ".cfg", ".chi", ".chm", ".class",
".cmd", ".com", ".command", ".crt", ".crx", ".csh", ".deb", ".dex",
".dll", ".drv", ".exe", ".fxp", ".grp", ".hlp", ".hta", ".htm", ".html",
".htt", ".inf", ".ini", ".ins", ".isp", ".jar", ".jnlp", ".user.js",
".js", ".jse", ".ksh", ".lnk", ".local", ".mad", ".maf", ".mag", ".mam",
".manifest", ".maq", ".mar", ".mas", ".mat", ".mau", ".mav", ".maw",
".mda", ".mdb", ".mde", ".mdt", ".mdw", ".mdz", ".mht", ".mhtml", ".mmc",
".mof", ".msc", ".msh", ".mshxml", ".msi", ".msp", ".mst", ".ocx", ".ops",
".pcd", ".pif", ".pkg", ".pl", ".plg", ".prf", ".prg", ".pst", ".py",
".pyc", ".pyw", ".rb", ".reg", ".rpm", ".scf", ".scr", ".sct", ".sh",
".shar", ".shb", ".shs", ".shtm", ".shtml", ".spl", ".svg", ".swf", ".sys",
".tcsh", ".url", ".vb", ".vbe", ".vbs", ".vsd", ".vsmacros", ".vss",
".vst", ".vsw", ".ws", ".wsc", ".wsf", ".wsh", ".xbap", ".xht", ".xhtm",
".xhtml", ".xml", ".xsl", ".xslt", ".website", ".msh1", ".msh2", ".msh1xml",
".msh2xml", ".ps1", ".ps1xml", ".ps2", ".ps2xml", ".psc1", ".psc2", ".xnk",
".appref-ms", ".gadget", ".efi", ".fon", ".partial", ".svg", ".xml",
".xrm_ms", ".xsl", ".action", ".bin", ".inx", ".ipa", ".isu", ".job",
".out", ".pad", ".paf", ".rgs", ".u3p", ".vbscript", ".workflow", ".001",
".ace", ".arc", ".arj", ".b64", ".balz", ".bhx", ".cab", ".cpio", ".fat",
".hfs", ".hqx", ".iso", ".lha", ".lpaq1", ".lpaq5", ".lpaq8", ".lzh",
".mim", ".ntfs", ".paq8f", ".paq8jd", ".paq8l", ".paq8o", ".pea", ".quad",
".r00", ".r01", ".r02", ".r03", ".r04", ".r05", ".r06", ".r07", ".r08",
".r09", ".r10", ".r11", ".r12", ".r13", ".r14", ".r15", ".r16", ".r17",
".r18", ".r19", ".r20", ".r21", ".r22", ".r23", ".r24", ".r25", ".r26",
".r27", ".r28", ".r29", ".squashfs", ".swm", ".tpz", ".txz", ".tz", ".udf",
".uu", ".uue", ".vhd", ".vmdk", ".wim", ".wrc", ".xar", ".xxe", ".z",
".zipx", ".zpaq", ".cdr", ".dart", ".dc42", ".diskcopy42", ".dmg",
".dmgpart", ".dvdr", ".img", ".imgpart", ".ndif", ".smi", ".sparsebundle",
".sparseimage", ".toast", ".udif",
)
# Aliases
aliases = {
# Win executables
'application/x-msdos-program': 'application/x-dosexec',
'application/x-dosexec': 'application/x-msdos-program',
# Other apps with confusing mimetypes
'application/rtf': 'text/rtf',
}
# Sometimes, mimetypes.guess_type gives unexpected results, such as for .tar.gz files:
# In [12]: mimetypes.guess_type('toot.tar.gz', strict=False)
# Out[12]: ('application/x-tar', 'gzip')
# It works as expected if you do mimetypes.guess_type('application/gzip', strict=False)
override_ext = {'.gz': 'application/gzip'}
ignored_mimes = ['inode', 'model', 'multipart', 'example']
class File(FileBase):
"""
Main file object
Created for each file that is processed by KittenGroomer. Contains all
filetype-specific processing methods.
"""
def __init__(self, src_path, dst_path, logger):
super(File, self).__init__(src_path, dst_path)
self.is_archive = False
self.logger = logger
self.tempdir_path = self.dst_path + '_temp'
subtypes_apps = (
(Config.mimes_office, self._winoffice),
(Config.mimes_ooxml, self._ooxml),
(Config.mimes_rtf, self.text),
(Config.mimes_libreoffice, self._libreoffice),
(Config.mimes_pdf, self._pdf),
(Config.mimes_xml, self.text),
(Config.mimes_ms, self._executables),
(Config.mimes_compressed, self._archive),
(Config.mimes_data, self._binary_app),
)
self.app_subtype_methods = self._make_method_dict(subtypes_apps)
types_metadata = (
(Config.mimes_exif, self._metadata_exif),
(Config.mimes_png, self._metadata_png),
)
self.metadata_mimetype_methods = self._make_method_dict(types_metadata)
self.mime_processing_options = {
'text': self.text,
'audio': self.audio,
'image': self.image,
'video': self.video,
'application': self.application,
'example': self.example,
'message': self.message,
'model': self.model,
'multipart': self.multipart,
'inode': self.inode,
}
def _check_dangerous(self):
if not self.has_mimetype:
self.make_dangerous('File has no mimetype')
if not self.has_extension:
self.make_dangerous('File has no extension')
if self.extension in Config.malicious_exts:
self.make_dangerous('Extension identifies file as potentially dangerous')
def _check_extension(self):
"""
Guess the file's mimetype based on its extension.
If the file's mimetype (as determined by libmagic) is contained in
the `mimetype` module's list of valid mimetypes and the expected
mimetype based on its extension differs from the mimetype determined
by libmagic, then mark the file as dangerous.
"""
if self.extension in Config.override_ext:
expected_mimetype = Config.override_ext[self.extension]
else:
expected_mimetype, encoding = mimetypes.guess_type(self.src_path,
strict=False)
if expected_mimetype in Config.aliases:
expected_mimetype = Config.aliases[expected_mimetype]
is_known_extension = self.extension in mimetypes.types_map.keys()
if is_known_extension and expected_mimetype != self.mimetype:
self.make_dangerous('Mimetype does not match expected mimetype for this extension')
def _check_mimetype(self):
"""
Compare mimetype (as determined by libmagic) to extension.
Determine whether the extension that are normally associated with
the mimetype include the file's actual extension.
"""
if self.mimetype in Config.aliases:
mimetype = Config.aliases[self.mimetype]
else:
mimetype = self.mimetype
expected_extensions = mimetypes.guess_all_extensions(mimetype,
strict=False)
if expected_extensions:
if self.has_extension and self.extension not in expected_extensions:
self.make_dangerous('Extension does not match expected extensions for this mimetype')
def _check_filename(self):
"""
Verify the filename
If the filename contains any dangerous or specific characters, handle
them appropriately.
"""
if self.filename[0] is '.':
# TODO: handle dotfiles here
pass
right_to_left_override = u"\u202E"
if right_to_left_override in self.filename:
self.make_dangerous('Filename contains dangerous character')
self.filename = self.filename.replace(right_to_left_override, '')
self.set_property('filename', self.filename)
def check(self):
"""
Main file processing method
Delegates to various helper methods including filetype-specific checks.
"""
if self.maintype in Config.ignored_mimes:
self.should_copy = False
self.mime_processing_options.get(self.maintype, self.unknown)()
else:
self._check_dangerous()
self._check_filename()
if self.has_extension:
self._check_extension()
if self.has_mimetype:
self._check_mimetype()
if not self.is_dangerous:
self.mime_processing_options.get(self.maintype, self.unknown)()
def write_log(self):
"""Pass information about the file to self.logger"""
props = self.get_all_props()
if not self.is_archive:
if os.path.exists(self.tempdir_path):
# FIXME: Hack to make images appear at the correct tree depth in log
self.logger.add_file(self.src_path, props, in_tempdir=True)
return
self.logger.add_file(self.src_path, props)
# ##### Helper functions #####
def _make_method_dict(self, list_of_tuples):
"""Returns a dictionary with mimetype: method pairs."""
dict_to_return = {}
for list_of_subtypes, method in list_of_tuples:
for subtype in list_of_subtypes:
dict_to_return[subtype] = method
return dict_to_return
@property
def has_metadata(self):
"""True if filetype typically contains metadata, else False."""
if self.mimetype in Config.mimes_metadata:
return True
return False
def make_tempdir(self):
"""Make a temporary directory at self.tempdir_path."""
if not os.path.exists(self.tempdir_path):
os.makedirs(self.tempdir_path)
return self.tempdir_path
#######################
# ##### Discarded mimetypes, reason in the docstring ######
def inode(self):
"""Empty file or symlink."""
if self.is_symlink:
symlink_path = self.get_property('symlink')
self.add_description('File is a symlink to {}'.format(symlink_path))
else:
self.add_description('File is an inode (empty file)')
def unknown(self):
"""Main type should never be unknown."""
self.add_description('Unknown mimetype')
def example(self):
"""Used in examples, should never be returned by libmagic."""
self.add_description('Example file')
def multipart(self):
"""Used in web apps, should never be returned by libmagic"""
self.add_description('Multipart file - usually found in web apps')
# ##### Treated as malicious, no reason to have it on a USB key ######
def message(self):
"""Process a message file."""
self.make_dangerous('Message file - should not be found on USB key')
def model(self):
"""Process a model file."""
self.make_dangerous('Model file - should not be found on USB key')
# ##### Files that will be converted ######
def text(self):
"""Process an rtf, ooxml, or plaintext file."""
for mt in Config.mimes_rtf:
if mt in self.subtype:
self.add_description('Rich Text (rtf) file')
# TODO: need a way to convert it to plain text
self.force_ext('.txt')
return
for mt in Config.mimes_ooxml:
if mt in self.subtype:
self.add_description('OOXML (openoffice) file')
self._ooxml()
return
self.add_description('Plain text file')
self.force_ext('.txt')
def application(self):
"""Process an application specific file according to its subtype."""
if self.subtype in self.app_subtype_methods:
method = self.app_subtype_methods[self.subtype]
method()
# TODO: should these application methods return a value?
else:
self._unknown_app()
def _executables(self):
"""Process an executable file."""
# LOG: change the processing_type property to some other name or include in file_string
self.make_dangerous('Executable file')
def _winoffice(self):
"""Process a winoffice file using olefile/oletools."""
oid = oletools.oleid.OleID(self.src_path) # First assume a valid file
if not olefile.isOleFile(self.src_path):
# Manual processing, may already count as suspicious
try:
ole = olefile.OleFileIO(self.src_path, raise_defects=olefile.DEFECT_INCORRECT)
except:
self.make_dangerous('Unparsable WinOffice file')
if ole.parsing_issues:
self.make_dangerous('Parsing issues with WinOffice file')
else:
if ole.exists('macros/vba') or ole.exists('Macros') \
or ole.exists('_VBA_PROJECT_CUR') or ole.exists('VBA'):
self.make_dangerous('WinOffice file containing a macro')
else:
indicators = oid.check()
# Encrypted can be set by multiple checks on the script
if oid.encrypted.value:
self.make_dangerous('Encrypted WinOffice file')
if oid.macros.value or oid.ole.exists('macros/vba') or oid.ole.exists('Macros') \
or oid.ole.exists('_VBA_PROJECT_CUR') or oid.ole.exists('VBA'):
self.make_dangerous('WinOffice file containing a macro')
for i in indicators:
if i.id == 'ObjectPool' and i.value:
# TODO: is having an ObjectPool suspicious?
self.add_description('WinOffice file containing an object pool')
elif i.id == 'flash' and i.value:
self.make_dangerous('WinOffice file with embedded flash')
self.add_description('WinOffice file')
def _ooxml(self):
"""Process an ooxml file."""
try:
doc = officedissector.doc.Document(self.src_path)
except Exception:
self.make_dangerous('Invalid ooxml file')
return
# There are probably other potentially malicious features:
# fonts, custom props, custom XML
if doc.is_macro_enabled or len(doc.features.macros) > 0:
self.make_dangerous('Ooxml file containing macro')
if len(doc.features.embedded_controls) > 0:
self.make_dangerous('Ooxml file with activex')
if len(doc.features.embedded_objects) > 0:
# Exploited by CVE-2014-4114 (OLE)
self.make_dangerous('Ooxml file with embedded objects')
if len(doc.features.embedded_packages) > 0:
self.make_dangerous('Ooxml file with embedded packages')
if not self.is_dangerous:
self.add_description('Ooxml file')
def _libreoffice(self):
"""Process a libreoffice file."""
# As long as there is no way to do a sanity check on the files => dangerous
try:
lodoc = zipfile.ZipFile(self.src_path, 'r')
except:
# TODO: are there specific exceptions we should catch here? Or should it be everything
self.make_dangerous('Invalid libreoffice file')
for f in lodoc.infolist():
fname = f.filename.lower()
if fname.startswith('script') or fname.startswith('basic') or \
fname.startswith('object') or fname.endswith('.bin'):
self.make_dangerous('Libreoffice file containing executable code')
if not self.is_dangerous:
self.add_description('Libreoffice file')
def _pdf(self):
"""Process a PDF file."""
xmlDoc = PDFiD(self.src_path)
oPDFiD = cPDFiD(xmlDoc, True)
# TODO: are there other pdf characteristics which should be dangerous?
if oPDFiD.encrypt.count > 0:
self.make_dangerous('Encrypted pdf')
if oPDFiD.js.count > 0 or oPDFiD.javascript.count > 0:
self.make_dangerous('Pdf with embedded javascript')
if oPDFiD.aa.count > 0 or oPDFiD.openaction.count > 0:
self.make_dangerous('Pdf with openaction(s)')
if oPDFiD.richmedia.count > 0:
self.make_dangerous('Pdf containing flash')
if oPDFiD.launch.count > 0:
self.make_dangerous('Pdf with launch action(s)')
if oPDFiD.xfa.count > 0:
self.make_dangerous('Pdf with XFA structures')
if oPDFiD.objstm.count > 0:
self.make_dangerous('Pdf with ObjectStream structures')
if not self.is_dangerous:
self.add_description('Pdf file')
def _archive(self):
"""
Process an archive using 7zip.
The archive is extracted to a temporary directory and self.process_dir
is called on that directory. The recursive archive depth is increased
to protect against archive bombs.
"""
# TODO: change this to something archive type specific instead of generic 'Archive'
self.add_description('Archive')
self.should_copy = False
self.is_archive = True
def _unknown_app(self):
"""Process an unknown file."""
self.add_description('Unknown application file')
self.make_unknown()
def _binary_app(self):
"""Process an unknown binary file."""
self.add_description('Unknown binary file')
self.make_binary()
#######################
# Metadata extractors
def _metadata_exif(self, metadata_file_path):
"""Read exif metadata from a jpg or tiff file using exifread."""
# TODO: can we shorten this method somehow?
img = open(self.src_path, 'rb')
tags = None
try:
tags = exifread.process_file(img, debug=True)
except Exception as e:
self.add_error(e, "Error while trying to grab full metadata for file {}; retrying for partial data.".format(self.src_path))
if tags is None:
try:
tags = exifread.process_file(img, debug=True)
except Exception as e:
self.add_error(e, "Failed to get any metadata for file {}.".format(self.src_path))
img.close()
return False
for tag in sorted(tags.keys()):
# These tags are long and obnoxious/binary so we don't add them
if tag not in ('JPEGThumbnail', 'TIFFThumbnail'):
tag_string = str(tags[tag])
# Exifreader truncates data.
if len(tag_string) > 25 and tag_string.endswith(", ... ]"):
tag_value = tags[tag].values
tag_string = str(tag_value)
with open(metadata_file_path, 'w+') as metadata_file:
metadata_file.write("Key: {}\tValue: {}\n".format(tag, tag_string))
# TODO: how do we want to log metadata?
self.set_property('metadata', 'exif')
img.close()
return True
def _metadata_png(self, metadata_file_path):
"""Extract metadata from a png file using PIL/Pillow."""
warnings.simplefilter('error', Image.DecompressionBombWarning)
try:
img = Image.open(self.src_path)
for tag in sorted(img.info.keys()):
# These are long and obnoxious/binary
if tag not in ('icc_profile'):
with open(metadata_file_path, 'w+') as metadata_file:
metadata_file.write("Key: {}\tValue: {}\n".format(tag, img.info[tag]))
# LOG: handle metadata
self.set_property('metadata', 'png')
img.close()
except Exception as e: # Catch decompression bombs
# TODO: only catch DecompressionBombWarnings here?
self.add_error(e, "Caught exception processing metadata for {}".format(self.src_path))
self.make_dangerous('exception processing metadata')
return False
def extract_metadata(self):
"""Create metadata file and call correct metadata extraction method."""
metadata_file_path = self.create_metadata_file(".metadata.txt")
mt = self.mimetype
metadata_processing_method = self.metadata_mimetype_methods.get(mt)
if metadata_processing_method:
# TODO: should we return metadata and write it here instead of in processing method?
metadata_processing_method(metadata_file_path)
#######################
# ##### Media - audio and video aren't converted ######
def audio(self):
"""Process an audio file."""
self.add_description('Audio file')
self._media_processing()
def video(self):
"""Process a video."""
self.add_description('Video file')
self._media_processing()
def _media_processing(self):
"""Generic way to process all media files."""
self.add_description('Media file')
def image(self):
"""
Process an image.
Extracts metadata to dest key using self.extract_metada() if metadata
is present. Creates a temporary directory on dest key, opens the image
using PIL.Image, saves it to the temporary directory, and copies it to
the destination.
"""
# TODO: make sure this method works for png, gif, tiff
if self.has_metadata:
self.extract_metadata()
tempdir_path = self.make_tempdir()
tempfile_path = os.path.join(tempdir_path, self.filename)
warnings.simplefilter('error', Image.DecompressionBombWarning)
try: # Do image conversions
img_in = Image.open(self.src_path)
img_out = Image.frombytes(img_in.mode, img_in.size, img_in.tobytes())
img_out.save(tempfile_path)
self.src_path = tempfile_path
except Exception as e: # Catch decompression bombs
# TODO: change this from all Exceptions to specific DecompressionBombWarning
self.add_error(e, "Caught exception (possible decompression bomb?) while translating file {}.".format(self.src_path))
self.make_dangerous('Image file containing decompression bomb')
if not self.is_dangerous:
self.add_description('Image file')
class GroomerLogger(object):
"""Groomer logging interface."""
def __init__(self, src_root_path, dst_root_path, debug=False):
self._src_root_path = src_root_path
self._dst_root_path = dst_root_path
self._log_dir_path = self._make_log_dir(dst_root_path)
self.log_path = os.path.join(self._log_dir_path, 'circlean_log.txt')
self._add_root_dir(src_root_path)
if debug:
self.log_debug_err = os.path.join(self._log_dir_path, 'debug_stderr.log')
self.log_debug_out = os.path.join(self._log_dir_path, 'debug_stdout.log')
else:
self.log_debug_err = os.devnull
self.log_debug_out = os.devnull
def _make_log_dir(self, root_dir_path):
"""Create the directory in the dest dir that will hold the logs"""
log_dir_path = os.path.join(root_dir_path, 'logs')
if os.path.exists(log_dir_path):
shutil.rmtree(log_dir_path)
os.makedirs(log_dir_path)
return log_dir_path
def _add_root_dir(self, root_path):
"""Add the root directory to the log"""
dirname = os.path.split(root_path)[1] + '/'
with open(self.log_path, mode='ab') as lf:
lf.write(bytes(dirname, 'utf-8'))
lf.write(b'\n')
def add_file(self, file_path, file_props, in_tempdir=False):
"""Add a file to the log. Takes a dict of file properties."""
depth = self._get_path_depth(file_path)
description_string = ', '.join(file_props['description_string'])
file_hash = Logging.computehash(file_path)[:6]
if file_props['is_dangerous']:
description_category = "Dangerous"
else:
description_category = "Normal"
size_string = self._format_file_size(file_props['file_size'])
file_template = "+- {name} ({sha_hash}): {size}, type: {mt}/{st}. {desc}: {desc_str}"
file_string = file_template.format(
name=file_props['filename'],
sha_hash=file_hash,
size=size_string,
mt=file_props['maintype'],
st=file_props['subtype'],
desc=description_category,
desc_str=description_string,
)
# TODO: finish adding Errors and check that they appear properly
# if file_props['errors']:
# error_string = ', '.join([str(key) for key in file_props['errors']])
# file_string.append(' Errors: ' + error_string)
if in_tempdir:
depth -= 1
self._write_line_to_log(file_string, depth)
def add_dir(self, dir_path):
"""Add a directory to the log"""
path_depth = self._get_path_depth(dir_path)
dirname = os.path.split(dir_path)[1] + '/'
log_line = '+- ' + dirname
self._write_line_to_log(log_line, path_depth)
def _format_file_size(self, size):
"""Returns a string with the file size and appropriate unit"""
file_size = size
for unit in ('B', 'KB', 'MB', 'GB'):
if file_size < 1024:
return str(int(file_size)) + unit
else:
file_size = file_size / 1024
return str(int(file_size)) + 'GB'
def _get_path_depth(self, path):
"""Returns the relative path depth compared to root directory"""
if self._dst_root_path in path:
base_path = self._dst_root_path
elif self._src_root_path in path:
base_path = self._src_root_path
relpath = os.path.relpath(path, base_path)
path_depth = relpath.count(os.path.sep)
return path_depth
def _write_line_to_log(self, line, indentation_depth):
"""
Write a line to the log
Pad the line according to the `indentation_depth`.
"""
padding = b' '
padding += b'| ' * indentation_depth
line_bytes = os.fsencode(line)
with open(self.log_path, mode='ab') as lf:
lf.write(padding)
lf.write(line_bytes)
lf.write(b'\n')
class KittenGroomerFileCheck(KittenGroomerBase):
def __init__(self, root_src, root_dst, max_recursive_depth=2, debug=False):
super(KittenGroomerFileCheck, self).__init__(root_src, root_dst)
self.recursive_archive_depth = 0
self.max_recursive_depth = max_recursive_depth
self.cur_file = None
self.logger = GroomerLogger(root_src, root_dst, debug)
def process_dir(self, src_dir, dst_dir):
"""Process a directory on the source key."""
for srcpath in self.list_files_dirs(src_dir):
if os.path.isdir(srcpath):
self.logger.add_dir(srcpath)
else:
dstpath = os.path.join(dst_dir, os.path.basename(srcpath))
self.cur_file = File(srcpath, dstpath, self.logger)
self.process_file(self.cur_file)
def process_file(self, file):
"""
Process an individual file.
Check the file, handle archives using self.process_archive, copy
the file to the destionation key, and clean up temporary directory.
"""
file.check()
if file.should_copy:
file.safe_copy()
file.set_property('copied', True)
file.write_log()
if file.is_archive:
self.process_archive(file)
# TODO: Can probably handle cleaning up the tempdir better
if hasattr(file, 'tempdir_path'):
self.safe_rmtree(file.tempdir_path)
def process_archive(self, file):
"""
Unpack an archive using 7zip and process contents using process_dir.
Should be given a Kittengroomer file object whose src_path points
to an archive.
"""
self.recursive_archive_depth += 1
if self.recursive_archive_depth >= self.max_recursive_depth:
file.make_dangerous('Archive bomb')
else:
tempdir_path = file.make_tempdir()
# TODO: double check we are properly escaping file.src_path
# otherwise we are running unsanitized user input directly in the shell
command_str = '{} -p1 x "{}" -o"{}" -bd -aoa'
unpack_command = command_str.format(SEVENZ_PATH,
file.src_path, tempdir_path)
self._run_process(unpack_command)
file.write_log()
self.process_dir(tempdir_path, file.dst_path)
self.safe_rmtree(tempdir_path)
self.recursive_archive_depth -= 1
def _run_process(self, command_string, timeout=None):
"""Run command_string in a subprocess, wait until it finishes."""
args = shlex.split(command_string)
with open(self.logger.log_debug_err, 'ab') as stderr, open(self.logger.log_debug_out, 'ab') as stdout:
try:
subprocess.check_call(args, stdout=stdout, stderr=stderr, timeout=timeout)
except (subprocess.TimeoutExpired, subprocess.CalledProcessError):
return
return True
def list_files_dirs(self, root_dir_path):
"""
Returns a list of all files and directories
Performs a depth-first traversal of the file tree.
"""
queue = []
for path in sorted(os.listdir(root_dir_path), key=lambda x: str.lower(x)):
full_path = os.path.join(root_dir_path, path)
if os.path.isdir(full_path):
queue.append(full_path)
queue += self.list_files_dirs(full_path)
elif os.path.isfile(full_path):
queue.append(full_path)
return queue
def run(self):
self.process_dir(self.src_root_path, self.dst_root_path)
def main(kg_implementation, description):
parser = argparse.ArgumentParser(prog='KittenGroomer', description=description)
parser.add_argument('-s', '--source', type=str, help='Source directory')
parser.add_argument('-d', '--destination', type=str, help='Destination directory')
args = parser.parse_args()
kg = kg_implementation(args.source, args.destination)
kg.run()
if __name__ == '__main__':
main(KittenGroomerFileCheck, 'File sanitizer used in CIRCLean. Renames potentially dangerous files.')
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