271 lines
11 KiB
Python
271 lines
11 KiB
Python
"""Python STIX2 Environment API."""
|
|
import copy
|
|
|
|
from .datastore import CompositeDataSource, DataStoreMixin
|
|
from .equivalence.graph import graphically_equivalent
|
|
from .equivalence.object import ( # noqa: F401
|
|
check_property_present, custom_pattern_based, exact_match,
|
|
list_reference_check, partial_external_reference_based, partial_list_based,
|
|
partial_location_distance, partial_string_based, partial_timestamp_based,
|
|
reference_check, semantically_equivalent,
|
|
)
|
|
from .parsing import parse as _parse
|
|
|
|
# TODO: Remove all unused imports that now belong to the equivalence module in the next major release.
|
|
# Kept for backwards compatibility.
|
|
|
|
|
|
class ObjectFactory(object):
|
|
"""Easily create STIX objects with default values for certain properties.
|
|
|
|
Args:
|
|
created_by_ref (optional): Default created_by_ref value to apply to all
|
|
objects created by this factory.
|
|
created (optional): Default created value to apply to all
|
|
objects created by this factory.
|
|
external_references (optional): Default `external_references` value to apply
|
|
to all objects created by this factory.
|
|
object_marking_refs (optional): Default `object_marking_refs` value to apply
|
|
to all objects created by this factory.
|
|
list_append (bool, optional): When a default is set for a list property like
|
|
`external_references` or `object_marking_refs` and a value for
|
|
that property is passed into `create()`, if this is set to True,
|
|
that value will be added to the list alongside the default. If
|
|
this is set to False, the passed in value will replace the
|
|
default. Defaults to True.
|
|
"""
|
|
|
|
def __init__(
|
|
self, created_by_ref=None, created=None,
|
|
external_references=None, object_marking_refs=None,
|
|
list_append=True,
|
|
):
|
|
|
|
self._defaults = {}
|
|
if created_by_ref:
|
|
self.set_default_creator(created_by_ref)
|
|
if created:
|
|
self.set_default_created(created)
|
|
if external_references:
|
|
self.set_default_external_refs(external_references)
|
|
if object_marking_refs:
|
|
self.set_default_object_marking_refs(object_marking_refs)
|
|
self._list_append = list_append
|
|
self._list_properties = ['external_references', 'object_marking_refs']
|
|
|
|
def set_default_creator(self, creator=None):
|
|
"""Set default value for the `created_by_ref` property.
|
|
|
|
"""
|
|
self._defaults['created_by_ref'] = creator
|
|
|
|
def set_default_created(self, created=None):
|
|
"""Set default value for the `created` property.
|
|
|
|
"""
|
|
self._defaults['created'] = created
|
|
# If the user provides a default "created" time, we also want to use
|
|
# that as the modified time.
|
|
self._defaults['modified'] = created
|
|
|
|
def set_default_external_refs(self, external_references=None):
|
|
"""Set default external references.
|
|
|
|
"""
|
|
self._defaults['external_references'] = external_references
|
|
|
|
def set_default_object_marking_refs(self, object_marking_refs=None):
|
|
"""Set default object markings.
|
|
|
|
"""
|
|
self._defaults['object_marking_refs'] = object_marking_refs
|
|
|
|
def create(self, cls, **kwargs):
|
|
"""Create a STIX object using object factory defaults.
|
|
|
|
Args:
|
|
cls: the python-stix2 class of the object to be created (eg. Indicator)
|
|
**kwargs: The property/value pairs of the STIX object to be created
|
|
"""
|
|
|
|
# Use self.defaults as the base, but update with any explicit args
|
|
# provided by the user.
|
|
properties = copy.deepcopy(self._defaults)
|
|
if kwargs:
|
|
if self._list_append:
|
|
# Append provided items to list properties instead of replacing them
|
|
for list_prop in set(self._list_properties).intersection(kwargs.keys(), properties.keys()):
|
|
kwarg_prop = kwargs.pop(list_prop)
|
|
if kwarg_prop is None:
|
|
del properties[list_prop]
|
|
continue
|
|
if not isinstance(properties[list_prop], list):
|
|
properties[list_prop] = [properties[list_prop]]
|
|
|
|
if isinstance(kwarg_prop, list):
|
|
properties[list_prop].extend(kwarg_prop)
|
|
else:
|
|
properties[list_prop].append(kwarg_prop)
|
|
|
|
properties.update(**kwargs)
|
|
|
|
return cls(**properties)
|
|
|
|
|
|
class Environment(DataStoreMixin):
|
|
"""Abstract away some of the nasty details of working with STIX content.
|
|
|
|
Args:
|
|
factory (ObjectFactory, optional): Factory for creating objects with common
|
|
defaults for certain properties.
|
|
store (DataStore, optional): Data store providing the source and sink for the
|
|
environment.
|
|
source (DataSource, optional): Source for retrieving STIX objects.
|
|
sink (DataSink, optional): Destination for saving STIX objects.
|
|
Invalid if `store` is also provided.
|
|
|
|
.. automethod:: get
|
|
.. automethod:: all_versions
|
|
.. automethod:: query
|
|
.. automethod:: creator_of
|
|
.. automethod:: relationships
|
|
.. automethod:: related_to
|
|
.. automethod:: add
|
|
|
|
"""
|
|
|
|
def __init__(self, factory=ObjectFactory(), store=None, source=None, sink=None):
|
|
self.factory = factory
|
|
self.source = CompositeDataSource()
|
|
if store:
|
|
self.source.add_data_source(store.source)
|
|
self.sink = store.sink
|
|
if source:
|
|
self.source.add_data_source(source)
|
|
if sink:
|
|
if store:
|
|
raise ValueError("Data store already provided! Environment may only have one data sink.")
|
|
self.sink = sink
|
|
|
|
def create(self, *args, **kwargs):
|
|
return self.factory.create(*args, **kwargs)
|
|
create.__doc__ = ObjectFactory.create.__doc__
|
|
|
|
def set_default_creator(self, *args, **kwargs):
|
|
return self.factory.set_default_creator(*args, **kwargs)
|
|
set_default_creator.__doc__ = ObjectFactory.set_default_creator.__doc__
|
|
|
|
def set_default_created(self, *args, **kwargs):
|
|
return self.factory.set_default_created(*args, **kwargs)
|
|
set_default_created.__doc__ = ObjectFactory.set_default_created.__doc__
|
|
|
|
def set_default_external_refs(self, *args, **kwargs):
|
|
return self.factory.set_default_external_refs(*args, **kwargs)
|
|
set_default_external_refs.__doc__ = ObjectFactory.set_default_external_refs.__doc__
|
|
|
|
def set_default_object_marking_refs(self, *args, **kwargs):
|
|
return self.factory.set_default_object_marking_refs(*args, **kwargs)
|
|
set_default_object_marking_refs.__doc__ = ObjectFactory.set_default_object_marking_refs.__doc__
|
|
|
|
def add_filters(self, *args, **kwargs):
|
|
return self.source.filters.add(*args, **kwargs)
|
|
|
|
def add_filter(self, *args, **kwargs):
|
|
return self.source.filters.add(*args, **kwargs)
|
|
|
|
def parse(self, *args, **kwargs):
|
|
return _parse(*args, **kwargs)
|
|
parse.__doc__ = _parse.__doc__
|
|
|
|
def creator_of(self, obj):
|
|
"""Retrieve the Identity refered to by the object's `created_by_ref`.
|
|
|
|
Args:
|
|
obj: The STIX object whose `created_by_ref` property will be looked
|
|
up.
|
|
|
|
Returns:
|
|
str: The STIX object's creator, or None, if the object contains no
|
|
`created_by_ref` property or the object's creator cannot be
|
|
found.
|
|
|
|
"""
|
|
creator_id = obj.get('created_by_ref', '')
|
|
if creator_id:
|
|
return self.get(creator_id)
|
|
else:
|
|
return None
|
|
|
|
@staticmethod
|
|
def semantically_equivalent(obj1, obj2, prop_scores={}, **weight_dict):
|
|
"""This method verifies if two objects of the same type are
|
|
semantically equivalent.
|
|
|
|
Args:
|
|
obj1: A stix2 object instance
|
|
obj2: A stix2 object instance
|
|
prop_scores: A dictionary that can hold individual property scores,
|
|
weights, contributing score, matching score and sum of weights.
|
|
weight_dict: A dictionary that can be used to override settings
|
|
in the semantic equivalence process
|
|
|
|
Returns:
|
|
float: A number between 0.0 and 100.0 as a measurement of equivalence.
|
|
|
|
Warning:
|
|
Object types need to have property weights defined for the equivalence process.
|
|
Otherwise, those objects will not influence the final score. The WEIGHTS
|
|
dictionary under `stix2.equivalence.object` can give you an idea on how to add
|
|
new entries and pass them via the `weight_dict` argument. Similarly, the values
|
|
or methods can be fine tuned for a particular use case.
|
|
|
|
Note:
|
|
Default weights_dict:
|
|
|
|
.. include:: ../default_sem_eq_weights.rst
|
|
|
|
Note:
|
|
This implementation follows the Semantic Equivalence Committee Note.
|
|
see `the Committee Note <link here>`__.
|
|
|
|
"""
|
|
return semantically_equivalent(obj1, obj2, prop_scores, **weight_dict)
|
|
|
|
@staticmethod
|
|
def graphically_equivalent(ds1, ds2, prop_scores={}, **weight_dict):
|
|
"""This method verifies if two graphs are semantically equivalent.
|
|
Each DataStore can contain a connected or disconnected graph and the
|
|
final result is weighted over the amount of objects we managed to compare.
|
|
This approach builds on top of the object-based semantic equivalence process
|
|
and each comparison can return a value between 0 and 100.
|
|
|
|
Args:
|
|
ds1: A DataStore object instance representing your graph
|
|
ds2: A DataStore object instance representing your graph
|
|
prop_scores: A dictionary that can hold individual property scores,
|
|
weights, contributing score, matching score and sum of weights.
|
|
weight_dict: A dictionary that can be used to override settings
|
|
in the semantic equivalence process
|
|
|
|
Returns:
|
|
float: A number between 0.0 and 100.0 as a measurement of equivalence.
|
|
|
|
Warning:
|
|
Object types need to have property weights defined for the equivalence process.
|
|
Otherwise, those objects will not influence the final score. The WEIGHTS
|
|
dictionary under `stix2.equivalence.graph` can give you an idea on how to add
|
|
new entries and pass them via the `weight_dict` argument. Similarly, the values
|
|
or methods can be fine tuned for a particular use case.
|
|
|
|
Note:
|
|
Default weights_dict:
|
|
|
|
.. include:: ../default_sem_eq_weights.rst
|
|
|
|
Note:
|
|
This implementation follows the Semantic Equivalence Committee Note.
|
|
see `the Committee Note <link here>`__.
|
|
|
|
"""
|
|
return graphically_equivalent(ds1, ds2, prop_scores, **weight_dict)
|