mirror of
https://github.com/volatilityfoundation/volatility3.git
synced 2026-08-25 07:32:23 +02:00
199 lines
8.3 KiB
Python
199 lines
8.3 KiB
Python
if __name__ == "__main__":
|
|
import os
|
|
import sys
|
|
|
|
sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..', '..')))
|
|
|
|
import struct
|
|
|
|
from volatility.framework import interfaces, layers, validity
|
|
from volatility.framework.configuration import requirements
|
|
|
|
PAGE_SIZE = 0x1000
|
|
|
|
|
|
class DtbTest(validity.ValidityRoutines):
|
|
super_bit = 2
|
|
|
|
def __init__(self, layer_type = None, ptr_struct = None, ptr_reference = None, mask = None):
|
|
self.layer_type = self._check_class(layer_type, interfaces.layers.TranslationLayerInterface)
|
|
self.ptr_struct = self._check_type(ptr_struct, str)
|
|
self.ptr_size = struct.calcsize(ptr_struct)
|
|
self.ptr_reference = self._check_type(ptr_reference, int)
|
|
self.mask = self._check_type(mask, int)
|
|
|
|
def unpack(self, value):
|
|
return struct.unpack("<" + self.ptr_struct, value)[0]
|
|
|
|
def __call__(self, data, data_offset, page_offset):
|
|
value = data[page_offset + (self.ptr_reference * self.ptr_size):page_offset + (
|
|
(self.ptr_reference + 1) * self.ptr_size)]
|
|
ptr = self.unpack(value)
|
|
# The value *must* be present (bit 0) since it's a mapped page
|
|
# It's almost always writable (bit 1)
|
|
# It's occasionally Super, but not reliably so, haven't checked when/why not
|
|
# The top 3-bits are usually ignore (which in practice means 0
|
|
# Need to find out why the middle 3-bits are usually 6 (0110)
|
|
if ptr != 0 and (ptr & self.mask == data_offset + page_offset) & (ptr & 0xFF1 == 0x61):
|
|
dtb = (ptr & self.mask)
|
|
return self.second_pass(dtb, data, data_offset)
|
|
|
|
def second_pass(self, dtb, data, data_offset):
|
|
page = data[dtb - data_offset:dtb - data_offset + PAGE_SIZE]
|
|
usr_count, sup_count = 0, 0
|
|
for i in range(0, PAGE_SIZE, self.ptr_size):
|
|
val = self.unpack(page[i:i + self.ptr_size])
|
|
if val & 0x1:
|
|
sup_count += 0 if (val & 0x4) else 1
|
|
usr_count += 1 if (val & 0x4) else 0
|
|
# print(hex(dtb), usr_count, sup_count, usr_count + sup_count)
|
|
# We sometimes find bogus DTBs at 0x16000 with a very low sup_count and 0 usr_count
|
|
# I have a winxpsp2-x64 image with identical usr/sup counts at 0x16000 and 0x24c00 as well as the actual 0x3c3000
|
|
if usr_count or sup_count > 5:
|
|
return dtb
|
|
|
|
|
|
class DtbTest32bit(DtbTest):
|
|
def __init__(self):
|
|
super().__init__(layer_type = layers.intel.Intel,
|
|
ptr_struct = "I",
|
|
ptr_reference = 0x300,
|
|
mask = 0xFFFFF000)
|
|
|
|
|
|
class DtbTest64bit(DtbTest):
|
|
def __init__(self):
|
|
super().__init__(layer_type = layers.intel.Intel32e,
|
|
ptr_struct = "Q",
|
|
ptr_reference = 0x1ED,
|
|
mask = 0x3FFFFFFFFFF000)
|
|
|
|
|
|
class DtbTestPae(DtbTest):
|
|
def __init__(self):
|
|
super().__init__(layer_type = layers.intel.IntelPAE,
|
|
ptr_struct = "Q",
|
|
ptr_reference = 0x3,
|
|
mask = 0x3FFFFFFFFFF000)
|
|
|
|
def second_pass(self, dtb, data, data_offset):
|
|
dtb -= 0x4000
|
|
# If we're not in something that the overlap would pick up
|
|
if dtb - data_offset >= 0:
|
|
pointers = data[dtb - data_offset + (3 * self.ptr_size): dtb - data_offset + (4 * self.ptr_size)]
|
|
val = self.unpack(pointers)
|
|
if (val & self.mask == dtb + 0x4000) and (val & 0xFFF == 0x001):
|
|
return dtb
|
|
|
|
|
|
class DtbSelfReferential(DtbTest):
|
|
def __init__(self, layer_type, ptr_struct, ptr_reference, mask):
|
|
super().__init__(layer_type = layer_type,
|
|
ptr_struct = ptr_struct,
|
|
ptr_reference = ptr_reference,
|
|
mask = mask)
|
|
|
|
def __call__(self, data, data_offset, page_offset):
|
|
page = data[page_offset:page_offset + PAGE_SIZE]
|
|
if not page:
|
|
return
|
|
ref_pages = set()
|
|
for ref in range(0, PAGE_SIZE, self.ptr_size):
|
|
ptr_data = page[ref:ref + self.ptr_size]
|
|
if len(ptr_data) == self.ptr_size:
|
|
ptr, = struct.unpack(self.ptr_struct, ptr_data)
|
|
if ((ptr & self.mask) == (data_offset + page_offset)) and (data_offset + page_offset > 0):
|
|
ref_pages.add(ref)
|
|
# The DTB is extremely unlikely to refer back to itself. so the number of reference should always be exactly 1
|
|
if len(ref_pages) == 1:
|
|
return (data_offset + page_offset), ref_pages
|
|
|
|
|
|
class DtbSelfRef32bit(DtbSelfReferential):
|
|
def __init__(self):
|
|
super().__init__(layer_type = layers.intel.Intel, ptr_struct = "I", ptr_reference = 0x300,
|
|
mask = 0xFFFFF000)
|
|
|
|
|
|
class DtbSelfRef64bit(DtbSelfReferential):
|
|
def __init__(self):
|
|
super().__init__(layer_type = layers.intel.Intel32e, ptr_struct = "Q", ptr_reference = 0x1ED,
|
|
mask = 0x3FFFFFFFFFF000)
|
|
|
|
|
|
class PageMapScanner(interfaces.layers.ScannerInterface):
|
|
overlap = 0x4000
|
|
tests = [DtbTest32bit, DtbTest64bit, DtbTestPae]
|
|
|
|
def __init__(self, tests):
|
|
super().__init__()
|
|
for value in tests:
|
|
self._check_type(value, DtbTest)
|
|
self.tests = tests
|
|
|
|
def __call__(self, data, data_offset):
|
|
results = {}
|
|
for test in self.tests:
|
|
results[test] = set()
|
|
|
|
for test in self.tests:
|
|
for page_offset in range(0, len(data), PAGE_SIZE):
|
|
result = test(data, data_offset, page_offset)
|
|
if result is not None:
|
|
yield (test, result)
|
|
|
|
|
|
class WintelHelper(interfaces.automagic.AutomagicInterface, interfaces.automagic.StackerLayerInterface):
|
|
priority = 20
|
|
stack_order = 90
|
|
tests = [DtbTest32bit(), DtbTest64bit(), DtbTestPae()]
|
|
|
|
def branch_leave(self, node, config_path):
|
|
"""Ensure we're called on internal nodes as well as external"""
|
|
self(node, config_path)
|
|
return True
|
|
|
|
def __call__(self, context, config_path, requirement):
|
|
useful = []
|
|
sub_config_path = interfaces.configuration.path_join(config_path, requirement.name)
|
|
if (isinstance(requirement, requirements.TranslationLayerRequirement) and
|
|
requirement.requirements.get("class", None)):
|
|
class_req = requirement.requirements["class"]
|
|
|
|
for test in self.tests:
|
|
if (test.layer_type.__module__ + "." + test.layer_type.__name__ ==
|
|
class_req.config_value(context, sub_config_path)):
|
|
useful.append(test)
|
|
|
|
# Determine if a class has been chosen
|
|
# Once an appropriate class has been chosen, attempt to determine the page_map_offset value
|
|
if ("memory_layer" in requirement.requirements and
|
|
requirement.requirements["memory_layer"].validate(context, sub_config_path)):
|
|
physical_layer = requirement.requirements["memory_layer"].config_value(context, sub_config_path)
|
|
hits = context.memory[physical_layer].scan(context, PageMapScanner(useful))
|
|
for test, dtb in hits:
|
|
context.config[interfaces.configuration.path_join(sub_config_path, "page_map_offset")] = dtb
|
|
requirement.construct(context, config_path)
|
|
break
|
|
else:
|
|
for subreq in requirement.requirements.values():
|
|
self(context, sub_config_path, subreq)
|
|
|
|
@classmethod
|
|
def stack(cls, context, layer_name):
|
|
"""Attempts to determine and stack an intel layer on a physical layer where possible"""
|
|
hits = context.memory[layer_name].scan(context, PageMapScanner(cls.tests))
|
|
layer = None
|
|
for test, dtb in hits:
|
|
new_layer_name = context.memory.free_layer_name("IntelLayer")
|
|
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")] = dtb
|
|
layer = test.layer_type(context,
|
|
config_path = config_path,
|
|
name = new_layer_name)
|
|
break
|
|
return layer
|
|
|
|
|