cti-python-stix2/stix2/environment.py

173 lines
6.7 KiB
Python

import copy
from .core import parse as _parse
from .sources import CompositeDataSource, DataStore
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._defaults['created_by_ref'] = created_by_ref
if created:
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
if external_references:
self._defaults['external_references'] = external_references
if object_marking_refs:
self._defaults['object_marking_refs'] = object_marking_refs
self._list_append = list_append
self._list_properties = ['external_references', '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(object):
"""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.
"""
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 get(self, *args, **kwargs):
try:
return self.source.get(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data source to query')
get.__doc__ = DataStore.get.__doc__
def all_versions(self, *args, **kwargs):
"""Retrieve all versions of a single STIX object by ID.
"""
try:
return self.source.all_versions(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data source to query')
all_versions.__doc__ = DataStore.all_versions.__doc__
def query(self, *args, **kwargs):
"""Retrieve STIX objects matching a set of filters.
"""
try:
return self.source.query(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data source to query')
query.__doc__ = DataStore.query.__doc__
def add_filters(self, *args, **kwargs):
try:
return self.source.filters.update(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data source')
def add_filter(self, *args, **kwargs):
try:
return self.source.filters.add(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data source')
def add(self, *args, **kwargs):
try:
return self.sink.add(*args, **kwargs)
except AttributeError:
raise AttributeError('Environment has no data sink to put objects in')
add.__doc__ = DataStore.add.__doc__
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:
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