volatility3.framework.automagic.stacker module

This module attempts to automatically stack layers.

This automagic module fulfills TranslationLayerRequirement that are not already fulfilled, by attempting to stack as many layers on top of each other as possible. The base/lowest layer is derived from the “automagic.general.single_location” configuration path. Layers are then attempting in likely height order, and once a layer successfully stacks on top of the existing layers, it is removed from the possible choices list (so no layer type can exist twice in the layer stack).

class LayerStacker(*args, **kwargs)

Bases: volatility3.framework.interfaces.automagic.AutomagicInterface

Builds up layers in a single stack.

This class mimics the volatility 2 style of stacking address spaces. It builds up various layers based on separate StackerLayerInterface classes. These classes are built up based on a stack_order class variable each has.

This has a high priority to provide other automagic modules as complete a context/configuration tree as possible. Upon completion it will re-call the ConstructionMagic, so that any stacked layers are actually constructed and added to the context.

Basic initializer that allows configurables to access their own config settings.

build_configuration()

Constructs a HierarchicalDictionary of all the options required to build this component in the current context.

Ensures that if the class has been created, it can be recreated using the configuration built Inheriting classes must override this to ensure any dependent classes update their configurations too

Return type

HierarchicalDict

property config

The Hierarchical configuration Dictionary for this Configurable object.

Return type

HierarchicalDict

property config_path

The configuration path on which this configurable lives.

Return type

str

property context

The context object that this configurable belongs to/configuration is stored in.

Return type

ContextInterface

create_stackers_list()

Creates the list of stackers to use based on the config option

Return type

List[Type[StackerLayerInterface]]

find_requirements(context, config_path, requirement_root, requirement_type, shortcut=True)

Determines if there is actually an unfulfilled Requirement waiting.

This ensures we do not carry out an expensive search when there is no need for a particular Requirement

Parameters

• context (ContextInterface) – Context on which to operate

• config_path (str) – Configuration path of the top-level requirement

• requirement_root (RequirementInterface) – Top-level requirement whose subrequirements will all be searched

• requirement_type (Union[Tuple[Type[RequirementInterface], …], Type[RequirementInterface]]) – Type of requirement to find

• shortcut (bool) – Only returns requirements that live under unsatisfied requirements

Return type

List[Tuple[str, RequirementInterface]]

Returns

A list of tuples containing the config_path, sub_config_path and requirement identifying the unsatisfied Requirements

classmethod find_suitable_requirements(context, config_path, requirement, stacked_layers)

Looks for translation layer requirements and attempts to apply the stacked layers to it. If it succeeds it returns the configuration path and layer name where the stacked nodes were spliced into the tree.

Return type

Optional[Tuple[str, str]]

Returns

A tuple of a configuration path and layer name for the top of the stacked layers

or None if suitable requirements are not found

classmethod get_requirements()

Returns a list of RequirementInterface objects required by this object.

Return type

List[RequirementInterface]

classmethod make_subconfig(context, base_config_path, **kwargs)

Convenience function to allow constructing a new randomly generated sub-configuration path, containing each element from kwargs.

Parameters

• context (ContextInterface) – The context in which to store the new configuration

• base_config_path (str) – The base configuration path on which to build the new configuration

• kwargs – Keyword arguments that are used to populate the new configuration path

Returns

The newly generated full configuration path

Return type

str

priority = 10

stack(context, config_path, requirement, progress_callback)

Stacks the various layers and attaches these to a specific requirement.

Parameters

• context (ContextInterface) – Context on which to operate

• config_path (str) – Configuration path under which to store stacking data

• requirement (RequirementInterface) – Requirement that should have layers stacked on it

• progress_callback (Optional[Callable[[float, str], None]]) – Function to provide callback progress

Return type

None

classmethod stack_layer(context, initial_layer, stack_set=None, progress_callback=None)

Stacks as many possible layers on top of the initial layer as can be done.

WARNING: This modifies the context provided and may pollute it with unnecessary layers Recommended use is to: 1. Pass in context.clone() instead of context 2. When provided the layer list, choose the desired layer 3. Build the configuration using layer.build_configuration() 4. Merge the configuration into the original context with context.config.merge() 5. Call Construction magic to reconstruct the layers from just the configuration

Parameters

• context (ContextInterface) – The context on which to operate

• initial_layer (str) – The name of the initial layer within the context

• stack_set (Optional[List[Type[StackerLayerInterface]]]) – A list of StackerLayerInterface objects in the order they should be stacked

• progress_callback (Optional[Callable[[float, str], None]]) – A function to report progress during the process

Returns

A list of layer names that exist in the provided context, stacked in order (highest to lowest)

classmethod unsatisfied(context, config_path)

Returns a list of the names of all unsatisfied requirements.

Since a satisfied set of requirements will return [], it can be used in tests as follows:

unmet = configurable.unsatisfied(context, config_path)
if unmet:
    raise RuntimeError("Unsatisfied requirements: {}".format(unmet)

Return type

Dict[str, RequirementInterface]

choose_os_stackers(plugin)

Identifies the stackers that should be run, based on the plugin (and thus os) provided

Return type

List[str]