Files
volatility3/volatility/framework/automagic/linux_symbol_cache.py
T

98 lines
4.3 KiB
Python

import logging
import os
import pickle
import typing
import urllib
import urllib.parse
import urllib.request
from volatility.framework import constants, exceptions, interfaces
from volatility.framework.symbols import intermed
vollog = logging.getLogger(__name__)
LinuxBanners = typing.Dict[bytes, typing.List[str]]
class LinuxSymbolCache(interfaces.automagic.AutomagicInterface):
"""Runs through all Linux symbols tables and caches their banners"""
# Since this is necessary for ConstructionMagic, we set a lower priority
# The user would run it eventually either way, but running it first means it can be used that run
priority = 0
@classmethod
def load_linux_banners(cls) -> LinuxBanners:
linux_banners = {} # type: LinuxBanners
if os.path.exists(constants.LINUX_BANNERS_PATH):
with open(constants.LINUX_BANNERS_PATH, "rb") as f:
# We use pickle over JSON because we're dealing with bytes objects
linux_banners.update(pickle.load(f))
# Remove possibilities that can't exist locally.
remove_banners = []
for banner in linux_banners:
for path in linux_banners[banner]:
url = urllib.parse.urlparse(path)
if url.scheme == 'file' and not os.path.exists(urllib.request.url2pathname(url.path)):
vollog.log(constants.LOGLEVEL_V,
"Removing cached path {} for banner {}: file does not exist".format(path, banner))
linux_banners[banner].remove(path)
# This is probably excessive, but it's here if we need it
# if url.scheme == 'jar':
# zip_file, zip_path = url.path.split("!")
# zip_file = urllib.parse.urlparse(zip_file).path
# if ((not os.path.exists(zip_file)) or (zip_path not in zipfile.ZipFile(zip_file).namelist())):
# vollog.log(constants.LOGLEVEL_V,
# "Removing cached path {} for banner {}: file does not exist".format(path, banner))
# linux_banners[banner].remove(path)
if not linux_banners[banner]:
remove_banners.append(banner)
for remove_banner in remove_banners:
del linux_banners[remove_banner]
return linux_banners
@classmethod
def save_linux_banners(cls, linux_banners):
with open(constants.LINUX_BANNERS_PATH, "wb") as f:
pickle.dump(linux_banners, f)
def __call__(self, context, config_path, configurable, progress_callback = None):
"""Runs the automagic over the configurable"""
# We only need to be called once, so no recursion necessary
linuxbanners = self.load_linux_banners()
cacheables = list(intermed.IntermediateSymbolTable.file_symbol_url("linux"))
for banner in linuxbanners:
for json_file in linuxbanners[banner]:
if json_file in cacheables:
cacheables.remove(json_file)
total = len(cacheables)
if total > 0:
vollog.info("Building linux caches...")
for current in range(total):
progress_callback(current * 100 / total, "Building linux caches")
isf_url = cacheables[current]
try:
# Loading the symbol table will be very slow until it's been validated
isf = intermed.IntermediateSymbolTable(context, config_path, "temp", isf_url, validate = False)
# We should store the banner against the filename
# We don't bother with the hash (it'll likely take too long to validate)
# but we should check at least that the banner matches on load.
banner = isf.get_symbol("linux_banner").constant_data
vollog.log(constants.LOGLEVEL_V, "Caching banner {} for file {}".format(banner, isf_url))
bannerlist = linuxbanners.get(banner, [])
bannerlist.append(isf_url)
linuxbanners[banner] = bannerlist
except exceptions.SymbolError:
pass
# Rewrite the cached linuxbanners each run, since writing is faster than the cache validation portion
self.save_linux_banners(linuxbanners)