# This file is Copyright 2019 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#
from typing import Optional, Union
from volatility3.framework import interfaces, objects, constants
[docs]def rol(value: int, count: int, max_bits: int = 64) -> int:
"""A rotate-left instruction in Python"""
max_bits_mask = (1 << max_bits) - 1
return (value << count % max_bits) & max_bits_mask | (
(value & max_bits_mask) >> (max_bits - (count % max_bits))
)
[docs]def bswap_32(value: int) -> int:
value = ((value << 8) & 0xFF00FF00) | ((value >> 8) & 0x00FF00FF)
return ((value << 16) | (value >> 16)) & 0xFFFFFFFF
[docs]def bswap_64(value: int) -> int:
low = bswap_32((value >> 32))
high = bswap_32((value & 0xFFFFFFFF))
return ((high << 32) | low) & 0xFFFFFFFFFFFFFFFF
[docs]def array_to_string(
array: "objects.Array", count: Optional[int] = None, errors: str = "replace"
) -> interfaces.objects.ObjectInterface:
"""Takes a volatility Array of characters and returns a string."""
# TODO: Consider checking the Array's target is a native char
if count is None:
count = array.vol.count
if not isinstance(array, objects.Array):
raise TypeError("Array_to_string takes an Array of char")
return array.cast("string", max_length=count, errors=errors)
[docs]def pointer_to_string(pointer: "objects.Pointer", count: int, errors: str = "replace"):
"""Takes a volatility Pointer to characters and returns a string."""
if not isinstance(pointer, objects.Pointer):
raise TypeError("pointer_to_string takes a Pointer")
if count < 1:
raise ValueError("pointer_to_string requires a positive count")
char = pointer.dereference()
return char.cast("string", max_length=count, errors=errors)
[docs]def array_of_pointers(
array: interfaces.objects.ObjectInterface,
count: int,
subtype: Union[str, interfaces.objects.Template],
context: interfaces.context.ContextInterface,
) -> interfaces.objects.ObjectInterface:
"""Takes an object, and recasts it as an array of pointers to subtype."""
symbol_table = array.vol.type_name.split(constants.BANG)[0]
if isinstance(subtype, str) and context is not None:
subtype = context.symbol_space.get_type(subtype)
if not isinstance(subtype, interfaces.objects.Template) or subtype is None:
raise TypeError(
"Subtype must be a valid template (or string name of an object template)"
)
# We have to clone the pointer class, or we'll be defining the pointer subtype for all future pointers
subtype_pointer = context.symbol_space.get_type(
symbol_table + constants.BANG + "pointer"
).clone()
subtype_pointer.update_vol(subtype=subtype)
return array.cast("array", count=count, subtype=subtype_pointer)