cti-python-stix2/stix2/sources/taxii.py

244 lines
8.8 KiB
Python

"""
Python STIX 2.x TaxiiCollectionStore
"""
from stix2.base import _STIXBase
from stix2.core import Bundle, parse
from stix2.sources import DataSink, DataSource, DataStore
from stix2.sources.filters import Filter, apply_common_filters
from stix2.utils import deduplicate
TAXII_FILTERS = ['added_after', 'id', 'type', 'version']
class TAXIICollectionStore(DataStore):
"""Provides an interface to a local/remote TAXII Collection
of STIX data. TAXIICollectionStore is a wrapper
around a paired TAXIICollectionSink and TAXIICollectionSource.
Args:
collection (taxii2.Collection): TAXII Collection instance
"""
def __init__(self, collection):
super(TAXIICollectionStore, self).__init__()
self.source = TAXIICollectionSource(collection)
self.sink = TAXIICollectionSink(collection)
class TAXIICollectionSink(DataSink):
"""Provides an interface for pushing STIX objects to a local/remote
TAXII Collection endpoint.
Args:
collection (taxii2.Collection): TAXII2 Collection instance
"""
def __init__(self, collection):
super(TAXIICollectionSink, self).__init__()
self.collection = collection
def add(self, stix_data, allow_custom=False):
"""Add/push STIX content to TAXII Collection endpoint
Args:
stix_data (STIX object OR dict OR str OR list): valid STIX 2.0 content
in a STIX object (or Bundle), STIX onject dict (or Bundle dict), or a STIX 2.0
json encoded string, or list of any of the following
allow_custom (bool): whether to allow custom objects/properties or
not. Default: False.
"""
if isinstance(stix_data, _STIXBase):
# adding python STIX object
bundle = dict(Bundle(stix_data, allow_custom=allow_custom))
elif isinstance(stix_data, dict):
# adding python dict (of either Bundle or STIX obj)
if stix_data["type"] == "bundle":
bundle = stix_data
else:
bundle = dict(Bundle(stix_data, allow_custom=allow_custom))
elif isinstance(stix_data, list):
# adding list of something - recurse on each
for obj in stix_data:
self.add(obj, allow_custom=allow_custom)
elif isinstance(stix_data, str):
# adding json encoded string of STIX content
stix_data = parse(stix_data, allow_custom=allow_custom)
if stix_data["type"] == "bundle":
bundle = dict(stix_data)
else:
bundle = dict(Bundle(stix_data, allow_custom=allow_custom))
else:
raise TypeError("stix_data must be as STIX object(or list of),json formatted STIX (or list of), or a json formatted STIX bundle")
self.collection.add_objects(bundle)
class TAXIICollectionSource(DataSource):
"""Provides an interface for searching/retrieving STIX objects
from a local/remote TAXII Collection endpoint.
Args:
collection (taxii2.Collection): TAXII Collection instance
"""
def __init__(self, collection):
super(TAXIICollectionSource, self).__init__()
self.collection = collection
def get(self, stix_id, _composite_filters=None, allow_custom=False):
"""Retrieve STIX object from local/remote STIX Collection
endpoint.
Args:
stix_id (str): The STIX ID of the STIX object to be retrieved.
composite_filters (set): set of filters passed from the parent
CompositeDataSource, not user supplied
allow_custom (bool): whether to retrieve custom objects/properties
or not. Default: False.
Returns:
(STIX object): STIX object that has the supplied STIX ID.
The STIX object is received from TAXII has dict, parsed into
a python STIX object and then returned
"""
# combine all query filters
query = set()
if self.filters:
query.update(self.filters)
if _composite_filters:
query.update(_composite_filters)
# dont extract TAXII filters from query (to send to TAXII endpoint)
# as directly retrieveing a STIX object by ID
stix_objs = self.collection.get_object(stix_id)["objects"]
stix_obj = list(apply_common_filters(stix_objs, query))
if len(stix_obj):
stix_obj = parse(stix_obj[0], allow_custom=allow_custom)
if stix_obj.id != stix_id:
# check - was added to handle erroneous TAXII servers
stix_obj = None
else:
stix_obj = None
return stix_obj
def all_versions(self, stix_id, _composite_filters=None, allow_custom=False):
"""Retrieve STIX object from local/remote TAXII Collection
endpoint, all versions of it
Args:
stix_id (str): The STIX ID of the STIX objects to be retrieved.
composite_filters (set): set of filters passed from the parent
CompositeDataSource, not user supplied
allow_custom (bool): whether to retrieve custom objects/properties
or not. Default: False.
Returns:
(see query() as all_versions() is just a wrapper)
"""
# make query in TAXII query format since 'id' is TAXII field
query = [
Filter("match[id]", "=", stix_id),
Filter("match[version]", "=", "all")
]
all_data = self.query(query=query, _composite_filters=_composite_filters, allow_custom=allow_custom)
# parse STIX objects from TAXII returned json
all_data = [parse(stix_obj) for stix_obj in all_data]
# check - was added to handle erroneous TAXII servers
all_data_clean = [stix_obj for stix_obj in all_data if stix_obj.id == stix_id]
return all_data_clean
def query(self, query=None, _composite_filters=None, allow_custom=False):
"""Search and retreive STIX objects based on the complete query
A "complete query" includes the filters from the query, the filters
attached to MemorySource, and any filters passed from a
CompositeDataSource (i.e. _composite_filters)
Args:
query (list): list of filters to search on
composite_filters (set): set of filters passed from the
CompositeDataSource, not user supplied
allow_custom (bool): whether to retrieve custom objects/properties
or not. Default: False.
Returns:
(list): list of STIX objects that matches the supplied
query. The STIX objects are received from TAXII as dicts,
parsed into python STIX objects and then returned.
"""
if query is None:
query = set()
else:
if not isinstance(query, list):
# make sure dont make set from a Filter object,
# need to make a set from a list of Filter objects (even if just one Filter)
query = [query]
query = set(query)
# combine all query filters
if self.filters:
query.update(self.filters)
if _composite_filters:
query.update(_composite_filters)
# separate taxii query terms (can be done remotely)
taxii_filters = self._parse_taxii_filters(query)
# query TAXII collection
all_data = self.collection.get_objects(filters=taxii_filters, allow_custom=allow_custom)["objects"]
# deduplicate data (before filtering as reduces wasted filtering)
all_data = deduplicate(all_data)
# apply local (CompositeDataSource, TAXIICollectionSource and query filters)
all_data = list(apply_common_filters(all_data, query))
# parse python STIX objects from the STIX object dicts
stix_objs = [parse(stix_obj_dict, allow_custom=allow_custom) for stix_obj_dict in all_data]
return stix_objs
def _parse_taxii_filters(self, query):
"""Parse out TAXII filters that the TAXII server can filter on.
Note:
For instance - "?match[type]=indicator,sighting" should be in a
query dict as follows:
Filter("type", "=", "indicator,sighting")
Args:
query (list): list of filters to extract which ones are TAXII
specific.
Returns:
params (dict): dict of the TAXII filters but in format required
for 'requests.get()'.
"""
params = {}
for filter_ in query:
if filter_.field in TAXII_FILTERS:
if filter_.field == "added_after":
params[filter_.field] = filter_.value
else:
taxii_field = "match[%s]" % filter_.field
params[taxii_field] = filter_.value
return params