ExtensionCrawler/ExtensionCrawler/js_decomposer.py

503 lines
19 KiB
Python

#!/usr/bin/env python3.7
#
# Copyright (C) 2016,2017 The University of Sheffield, UK
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Python analys providing a decomposition analysis of JavaScript code in
general and Chrome extensions in particular."""
import os
from io import StringIO
import re
import json
import zlib
from enum import Enum
from ExtensionCrawler.js_mincer import mince_js
from ExtensionCrawler.file_identifiers import get_file_identifiers, is_binary_resource
from ExtensionCrawler.dbbackend.mysql_backend import MysqlBackend
from ExtensionCrawler.util import log_info
import ExtensionCrawler.config as config
class DetectionType(Enum):
"""Enumeration for detection types."""
# EMPTY_FILE
FILE_SIZE = "file size"
DEC_FILE_SIZE = "file size (after decompression)"
STRIPPED_FILE_SIZE = "file size (after stripping)"
DEC_STRIPPED_FILE_SIZE = "file size (after decompression and stripping)"
# LIBRARY
SHA1 = "sha1"
MD5 = "md5"
SHA1_DECOMPRESSED = "sha1 (after decompression)"
MD5_DECOMPRESSED = "md5 (after decompression)"
# VERY_LIKELY_LIBRARY
SHA1_NORMALIZED = "sha1 (after normalization)"
MD5_NORMALIZED = "md5 (after normalization)"
SHA1_DECOMPRESSED_NORMALIZED = "sha1 (after decompression and normalization)"
MD5_DECOMPRESSED_NORMALIZED = "md5 (after decompression and normalization)"
FILENAME_COMMENTBLOCK = "filename and witness in comment block"
FILENAME_CODEBLOCK = "filename and witness in code block"
# LIKELY_LIBRARY
COMMENTBLOCK = "witness in comment block"
CODEBLOCK = "witness in code block"
FILENAME = "known file name"
URL = "known URL"
# LIKELY_APPLICATION
DEFAULT = "default"
class FileClassification(Enum):
""" Enumeration for file classification"""
EMPTY_FILE = "other (empty file)"
METADATA = "metadata"
LIBRARY = "known library"
LIBRARY_RSC = "known library ressource"
VERY_LIKELY_LIBRARY = "very likely known library"
VERY_LIKELY_LIBRARY_RSC = "very likely known library"
LIKELY_LIBRARY = "likely known library"
LIKELY_LIBRARY_RSC = "likely known library ressource"
LIKELY_APPLICATION = "likely application"
LIKELY_APPLICATION_RSC = "likely application ressource"
ERROR = "error"
def load_lib_identifiers():
"""Initialize identifiers for known libraries from JSON file."""
regex_file = os.path.join(
os.path.dirname(os.path.realpath(__file__)), '../resources/',
'js_identifier.json')
with open(regex_file, 'r') as json_file:
json_content = json_file.read()
return json.loads(json_content)
def is_ressource(file_info):
"""Chedk if file info indicates that it represents a ressource type."""
if file_info['mimetype_magic'] is not None and is_binary_resource(file_info['mimetype_magic']):
return True
if file_info['dec_mimetype_magic'] is not None and is_binary_resource(file_info['dec_mimetype_magic']):
return True
return False
def unknown_filename_identifier():
"""Identifier for extracting version information from unknown/generic file names."""
return re.compile(
r'(.+)[\-\_]([0-9]{1,2}[\.|\-|\_][0-9a-z]{1,2}[\.|\-|\_][0-9a-z\-\_]*)',
re.IGNORECASE)
def unknown_lib_identifiers():
"""List of identifiers for generic library version headers."""
return ([
re.compile(
r'[\/|\/\/|\s]\*?\s?([a-zA-Z0-9\.]+)\sv?([0-9][\.|\-|\_][0-9.a-z_\\\\-]+)',
re.IGNORECASE
), # MatchType: name version, e.g. mylib v1.2.9b or mylib.anything 1.2.8
re.compile(
r'[\/|\/\/|\s]\*?\s?([a-zA-Z0-9\.]+)\s(?: version)\:?\s?v?([0-9][0-9.a-z_\\\\-]+)',
re.IGNORECASE
), # MatchType: name version: ver, e.g. mylib version: v1.2.9, or mylib.js version 1.2.8
re.compile(
r'\@*(version)\s?[\:|-]?\s?v?([0-9][\.|\-|\_][0-9.a-z_\\\\-]+)',
re.IGNORECASE
), # MatchType: version x.x.x, e.g. @version: 1.2.5 or version - 1.2.5 etc.
re.compile(
r'(version)[\:|\=]\s?.?([0-9]{1,2}[\.|\-|\_][0-9.a-z_\\\\-]+).?',
re.IGNORECASE),
re.compile(r'(.+) v([0-9]{1,2}[\.|\-|\_][0-9]{1,2}[0-9.a-z_\\\\-]*)',
re.IGNORECASE)
])
def init_file_info(path, data):
"""Initialize jsinfo record."""
file_info = get_file_identifiers(path, data)
file_info['lib'] = None
file_info['version'] = None
file_info['detectionMethod'] = None
file_info['detectionMethodDetails'] = None
file_info['type'] = None
file_info['evidenceStartPos'] = None
file_info['evidenceEndPos'] = None
file_info['evidenceText'] = None
file_info['lib_filename'] = None
return file_info
def check_empty_file(file_info):
"""Check if file is empty."""
if file_info['size'] == 0:
file_info['detectionMethod'] = DetectionType.FILE_SIZE
file_info['type'] = FileClassification.EMPTY_FILE
elif file_info['dec_size'] == 0:
file_info['detectionMethod'] = DetectionType.DEC_FILE_SIZE
file_info['type'] = FileClassification.EMPTY_FILE
elif file_info['size_stripped'] == 0:
file_info['detectionMethod'] = DetectionType.STRIPPED_FILE_SIZE
file_info['type'] = FileClassification.EMPTY_FILE
elif file_info['dec_size_stripped'] == 0:
file_info['detectionMethod'] = DetectionType.DEC_STRIPPED_FILE_SIZE
file_info['type'] = FileClassification.EMPTY_FILE
return file_info
def check_metadata(file_info):
"""Check for metadata (based on filename/path)."""
if file_info['path'] == "manifest.json" or file_info['path'] == "_metadata/verified_contents.json":
file_info['detectionMethod'] = DetectionType.FILENAME
file_info['type'] = FileClassification.METADATA
return file_info
def check_md5(con, file_info):
"""Check for known md5 hash (file content)."""
if con is None:
return file_info
libver = con.get_cdnjs_info(file_info['md5'])
if libver is None:
return file_info
else:
file_info['lib'] = libver[0]
file_info['version'] = libver[1]
file_info['lib_filename'] = libver[2]
if is_ressource(file_info):
file_info['type'] = FileClassification.LIBRARY_RSC
else:
file_info['type'] = FileClassification.LIBRARY
file_info['detectionMethod'] = DetectionType.MD5
return file_info
def check_md5_decompressed(con, file_info):
"""Check for known md5 hash (decompressed file content)."""
if con is None:
return file_info
if file_info['dec_md5'] is not None:
libver = con.get_cdnjs_info(file_info['dec_md5'])
if libver is not None:
file_info['lib'] = libver[0]
file_info['version'] = libver[1]
file_info['lib_filename'] = libver[2]
if is_ressource(file_info):
file_info['type'] = FileClassification.LIBRARY_RSC
else:
file_info['type'] = FileClassification.LIBRARY
file_info['detectionMethod'] = DetectionType.MD5_DECOMPRESSED
return file_info
def check_md5_normalized(con, file_info):
"""Check for known md5 hash (normalized file content)."""
if con is None:
return file_info
if file_info['normalized_md5'] is None:
return file_info
elif file_info['normalized_size'] == 0:
return file_info
else:
libver = con.get_cdnjs_info(file_info['normalized_md5'])
if libver is None:
return file_info
else:
file_info['lib'] = libver[0]
file_info['version'] = libver[1]
file_info['lib_filename'] = libver[2]
if is_ressource(file_info):
file_info['type'] = FileClassification.VERY_LIKELY_LIBRARY_RSC
else:
file_info['type'] = FileClassification.VERY_LIKELY_LIBRARY
file_info['detectionMethod'] = DetectionType.MD5_NORMALIZED
return file_info
def check_md5_decompressed_normalized(con, file_info):
"""Check for known md5 hash (decompressed normalized file content)."""
if con is None:
return file_info
if file_info['dec_normalized_md5'] is None:
return file_info
elif file_info['dec_normalized_size'] == 0:
return file_info
else:
libver = con.get_cdnjs_info(file_info['dec_normalized_md5'])
if libver is None:
return file_info
else:
file_info['lib'] = libver[0]
file_info['version'] = libver[1]
file_info['lib_filename'] = libver[2]
if is_ressource(file_info):
file_info['type'] = FileClassification.VERY_LIKELY_LIBRARY_RSC
else:
file_info['type'] = FileClassification.VERY_LIKELY_LIBRARY
file_info[
'detectionMethod'] = DetectionType.MD5_DECOMPRESSED_NORMALIZED
return file_info
def check_filename(file_info):
"""Check for known filename and typical library filename patterns."""
# TODO
return file_info
def check_data_blocks(file_info, str_data):
"""Check for known pattern in data (comment or code) blocks."""
# TODO
with StringIO(str_data) as str_obj:
for block in mince_js(str_obj, single_line_comments_block=True):
if block.is_comment():
pass # TODO
else:
pass # TODO
return []
def analyse_checksum(zipfile, js_file, js_info):
"""Check for known md5 hashes (file content)."""
json_data = load_lib_identifiers()
for lib in json_data:
for info in json_data[lib]:
if info == 'sha1':
for lib_file in json_data[lib]['sha1']:
if lib_file['sha1'].lower() == js_info['sha1'].hex():
js_info['lib'] = lib
js_info['version'] = lib_file['version']
js_info['type'] = FileClassification.LIBRARY
js_info['detectionMethod'] = DetectionType.SHA1,
if 'comment' in lib_file:
js_info['detectionMethodDetails'] = lib_file[
'comment']
return [js_info]
if info == 'md5':
for lib_file in json_data[lib]['md5']:
if lib_file['md5'].lower() == js_info['md5'].hex():
js_info['lib'] = lib
js_info['version'] = lib_file['version']
js_info['type'] = FileClassification.LIBRARY
js_info['detectionMethod'] = DetectionType.MD5
if 'comment' in lib_file:
js_info['detectionMethodDetails'] = lib_file[
'comment']
return [js_info]
return None
def analyse_known_filename(zipfile, js_file, js_info):
"""Check for known file name patterns."""
libs = list()
for lib, regex in load_lib_identifiers().items():
if 'filename' in regex:
if zipfile is not None:
filename = js_file.filename
else:
filename = js_file
filename_matched = re.search(regex['filename'], filename,
re.IGNORECASE)
if filename_matched:
js_info['lib'] = lib
js_info['version'] = filename_matched.group(2)
js_info['type'] = FileClassification.LIBRARY
js_info['detectionMethod'] = DetectionType.FILENAME
js_info['detectionMethodDetails'] = regex['filename']
libs.append(js_info)
return libs
def analyse_generic_filename(zipfile, js_file, js_info):
"""Check for generic file name patterns."""
libs = list()
if zipfile is not None:
filename = js_file.filename
else:
filename = js_file
unknown_filename_match = unknown_filename_identifier().search(filename)
if unknown_filename_match:
js_info['lib'] = os.path.basename(
unknown_filename_match.group(1)).replace('.js', '').replace(
'.min', '')
js_info['version'] = unknown_filename_match.group(2)
js_info['type'] = FileClassification.LIKELY_LIBRARY
js_info['detectionMethod'] = DetectionType.FILENAME
libs.append(js_info)
return libs
def analyse_filename(zipfile, js_file, js_info):
"""Check for file name patterns of libraries (known and generic as fall back)`"""
res = analyse_known_filename(zipfile, js_file, js_info)
if not res:
res = analyse_generic_filename(zipfile, js_file, js_info)
return res
def analyse_comment_known_libs(zipfile, js_file, js_info, comment):
"""Search for library specific identifiers in comment block."""
libs = list()
if zipfile is not None:
filename = js_file.filename
else:
filename = js_file
for lib, regex in load_lib_identifiers().items():
if 'filecontent' in regex:
for unkregex in regex['filecontent']:
unkown_lib_matched = unkregex.finditer(comment.content)
for match in unkown_lib_matched:
js_info['lib'] = lib
js_info['version'] = match.group(2)
js_info['detectionMethod'] = DetectionType.COMMENTBLOCK
js_info['detectionMethodDetails'] = unkregex
js_info['type'] = FileClassification.LIBRARY
libs.append(js_info)
return libs
def analyse_comment_generic_libs(zipfile, js_file, js_info, comment):
"""Search for generic identifiers in comment block."""
libs = list()
if zipfile is not None:
filename = js_file.filename
else:
filename = js_file
for unkregex in unknown_lib_identifiers():
unkown_lib_matched = unkregex.finditer(comment.content)
for match in unkown_lib_matched:
js_info['lib'] = ((os.path.basename(filename)).replace(
'.js', '')).replace('.min', '')
js_info['version'] = match.group(2)
js_info['detectionMethod'] = DetectionType.COMMENTBLOCK
js_info['detectionMethodDetails'] = unkregex
js_info['type'] = FileClassification.LIKELY_LIBRARY
libs.append(js_info)
return libs
def decompose_js(path_or_zipfileobj, use_db=True):
if use_db:
with MysqlBackend(
None,
read_default_file=config.const_mysql_config_file(),
charset='utf8mb4',
compress=True) as con:
return decompose_js_with_connection(path_or_zipfileobj, con)
else:
return decompose_js_with_connection(path_or_zipfileobj, None)
def merge_filename_and_data_info(file_filename_info, info_data_blocks):
"""Merge file information based on filename heuristics and data block analysis."""
# TODO
return info_data_blocks
def decompose_js_with_connection(path_or_zipfileobj, con):
"""JavaScript decomposition analysis for extensions."""
zipfile = None
inventory = []
if isinstance(path_or_zipfileobj, str):
path_list = [path_or_zipfileobj]
else:
zipfile = path_or_zipfileobj
path_list = list(
filter(lambda x: os.path.basename(x.filename) != "",
zipfile.infolist()))
for path_or_zipentry in path_list:
if zipfile is not None:
with zipfile.open(path_or_zipentry) as js_file_obj:
data = js_file_obj.read()
path = path_or_zipentry.filename
else:
with open(path_or_zipentry, mode='rb') as js_file_obj:
data = js_file_obj.read()
path = path_or_zipentry
file_info = init_file_info(path, data)
file_info = check_empty_file(file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_info = check_metadata(file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_info = check_md5(con, file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_info = check_md5_decompressed(con, file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_info = check_md5_normalized(con, file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_info = check_md5_decompressed_normalized(con, file_info)
if not file_info['detectionMethod'] is None:
inventory.append(file_info)
continue
file_filename_info = check_filename(file_info)
if file_info['detectionMethod'] is None:
if not file_info['dec_encoding'] is None:
try:
with zlib.decompressobj(zlib.MAX_WBITS | 16) as dec:
dec_data = dec.decompress(data,
100 * file_info['size'])
str_data = dec_data.decode(file_info['dec_encoding'])
del dec_data
except Exception:
log_info("Exception during data decoding (decompressed) for entry " + file_info['filename'], 3)
str_data = ''
elif file_info["encoding"] is not None:
try:
str_data = data.decode(file_info['encoding'])
except Exception:
log_info("Exception during data decoding for entry " + file_info['filename'], 3)
str_data = ''
else:
str_data = ''
info_data_blocks = check_data_blocks(file_info, str_data)
else:
info_data_blocks = None
if info_data_blocks:
inventory = inventory + merge_filename_and_data_info(
file_filename_info, info_data_blocks)
continue
else:
file_info = file_filename_info
# if no library could be detected, we report the JavaScript file as 'application'.
if file_info['detectionMethod'] is None:
file_info['lib'] = None
file_info['version'] = None
file_info['detectionMethod'] = DetectionType.DEFAULT
if is_ressource(file_info):
file_info['type'] = FileClassification.LIKELY_APPLICATION_RSC
else:
file_info['type'] = FileClassification.LIKELY_APPLICATION
inventory.append(file_info)
return inventory