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