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

208 lines
9.1 KiB
Python

import logging
import struct
import typing
from volatility.framework import interfaces, constants, validity, layers
from volatility.framework import symbols
from volatility.framework.automagic import symbol_cache, symbol_finder
from volatility.framework.layers import intel, scanners
from volatility.framework.symbols import mac
vollog = logging.getLogger(__name__)
class MacBannerCache(symbol_cache.SymbolBannerCache):
"""Caches the banners found in the Mac symbol files"""
os = "mac"
symbol_name = "version"
banner_path = constants.MAC_BANNERS_PATH
class MacSymbolFinder(symbol_finder.SymbolFinder):
"""Mac symbol loader based on uname signature strings"""
banner_config_key = 'mac_banner'
banner_cache = MacBannerCache
symbol_class = "volatility.framework.symbols.mac.MacKernelIntermedSymbols"
class MacintelStacker(interfaces.automagic.StackerLayerInterface):
stack_order = 12
@classmethod
def stack(cls,
context: interfaces.context.ContextInterface,
layer_name: str,
progress_callback: validity.ProgressCallback = None) \
-> typing.Optional[interfaces.layers.DataLayerInterface]:
"""Attempts to identify mac within this layer"""
# Bail out by default unless we can stack properly
layer = context.memory[layer_name]
new_layer = None
join = interfaces.configuration.path_join
# Never stack on top of an intel layer
# FIXME: Find a way to improve this check
if isinstance(layer, intel.Intel):
return None
mac_banners = MacBannerCache.load_banners()
for banner_offset, banner in layer.scan(context = context,
scanner = scanners.MultiStringScanner([x for x in mac_banners if x]),
progress_callback = progress_callback):
dtb = None
vollog.debug("Identified banner: {}".format(repr(banner)))
symbol_files = mac_banners.get(banner, None)
if symbol_files:
isf_path = symbol_files[0]
table_name = context.symbol_space.free_table_name('MacintelStacker')
table = mac.MacKernelIntermedSymbols(context = context,
config_path = join('temporary', table_name),
name = table_name,
isf_url = isf_path)
context.symbol_space.append(table)
kaslr_shift = MacUtilities.find_aslr(context = context,
symbol_table = table_name,
layer_name = layer_name,
compare_banner = banner,
compare_banner_offset = banner_offset,
progress_callback = progress_callback)
######################
# ikelos: The following is what I tried to get the dtb, but couldn't figure out how to do
# as you will see after the commented block of code is just a hardcoding of the DTB to my test sample's value
#######################
'''
bootpml4_addr = table.get_symbol("BootPML4").address + kaslr_shift
new_layer_name = context.memory.free_layer_name("MacDTBTempLayer")
config_path = interfaces.configuration.path_join("IntelHelper", new_layer_name)
context.config[interfaces.configuration.path_join(config_path, "memory_layer")] = layer_name
context.config[interfaces.configuration.path_join(config_path, "page_map_offset")] = bootpml4_addr
layer = layers.intel.Intel32e(context, config_path = config_path,
name = new_layer_name, metadata = {'os': 'Mac'})
print("KEYS: {}".format("\n".join([k for k in layer.context.memory.keys()])))
print("DIR: {}".format(dir(layer)))
idlepml4_ptr = table.get_symbol("IdlePML4").address + kaslr_shift
idlepml4_str = layer.read(idlepml4_ptr, 4)
idlepml4_addr = struct.unpack("<I", idlepml4_str)[0]
print("new dtb / idlepml4_addr = {:x".format(idlepml4_addr))
sys.exit(1)
'''
dtb = 0x1ef6e000
# Build the new layer
new_layer_name = context.memory.free_layer_name("IntelLayer")
config_path = join("IntelHelper", new_layer_name)
context.config[join(config_path, "memory_layer")] = layer_name
context.config[join(config_path, "page_map_offset")] = dtb
context.config[join(config_path, MacSymbolFinder.banner_config_key)] = str(banner, 'latin-1')
new_layer = intel.Intel32e(context, config_path = config_path, name = new_layer_name)
if new_layer and dtb:
vollog.debug("DTB was found at: 0x{:0x}".format(dtb))
return new_layer
return None
class MacUtilities(object):
"""Class with multiple useful mac functions"""
@classmethod
def aslr_mask_symbol_table(cls,
config,
context: interfaces.context.ContextInterface,
aslr_shift = 0):
if aslr_shift == 0:
aslr_layer = config['primary.memory_layer']
aslr_shift = MacUtilities.find_aslr(context, config["darwin"], aslr_layer)
sym_table_name = config["darwin"]
sym_layer_name = config["primary"]
symbols.utility.mask_symbol_table(context.symbol_space[sym_table_name],
context.memory[sym_layer_name].address_mask, aslr_shift)
@classmethod
def _scan_generator(cls, context, layer_name, progress_callback):
darwin_signature = b"Darwin Kernel Version \d{1,3}\.\d{1,3}\.\d{1,3}: [^\x00]+\x00"
for offset in context.memory[layer_name].scan(scanner = scanners.RegExScanner(darwin_signature),
context = context, progress_callback = progress_callback):
banner = context.memory[layer_name].read(offset, 128)
idx = banner.find(b"\x00")
if idx != -1:
banner = banner[:idx]
yield offset, banner
@classmethod
def find_aslr(cls,
context: interfaces.context.ContextInterface,
symbol_table: str,
layer_name: str,
compare_banner: str = "",
compare_banner_offset: int = 0,
progress_callback: validity.ProgressCallback = None) \
-> typing.Tuple[int, int]:
"""Determines the offset of the actual DTB in physical space and its symbol offset"""
version_symbol = symbol_table + constants.BANG + 'version'
version_json_address = context.symbol_space.get_symbol(version_symbol).address
version_major_symbol = symbol_table + constants.BANG + 'version_major'
version_major_json_address = context.symbol_space.get_symbol(version_major_symbol).address
version_major_phys_offset = MacUtilities.virtual_to_physical_address(version_major_json_address)
version_minor_symbol = symbol_table + constants.BANG + 'version_minor'
version_minor_json_address = context.symbol_space.get_symbol(version_minor_symbol).address
version_minor_phys_offset = MacUtilities.virtual_to_physical_address(version_minor_json_address)
if compare_banner_offset == 0 or compare_banner == "":
offset_generator = cls._scan_generator(context, layer_name, progress_callback)
else:
offset_generator = [(compare_banner_offset, compare_banner)]
aslr_shift = 0
for offset, banner in offset_generator:
banner_major, banner_minor = [int(x) for x in banner[22:].split(b".")[0:2]]
tmp_aslr_shift = offset - (version_json_address - 0xffffff8000000000)
major_string = context.memory[layer_name].read(version_major_phys_offset + tmp_aslr_shift, 4)
major = struct.unpack("<I", major_string)[0]
if major != banner_major:
continue
minor_string = context.memory[layer_name].read(version_minor_phys_offset + tmp_aslr_shift, 4)
minor = struct.unpack("<I", minor_string)[0]
if minor != banner_minor:
continue
if aslr_shift & 0xfff != 0:
continue
aslr_shift = tmp_aslr_shift & 0xffffffff
break
vollog.debug("Mac ASLR shift value determined: {:0x}".format(aslr_shift))
return aslr_shift
@classmethod
def virtual_to_physical_address(cls, addr: int) -> int:
"""Converts a virtual mac address to a physical one (does not account of ASLR)"""
return addr - 0xffffff8000000000