WIP: changes to both similarity functions, expose settings

pull/1/head
Emmanuelle Vargas-Gonzalez 2021-02-26 19:19:33 -05:00
parent 173575205a
commit f9a52eeed3
3 changed files with 123 additions and 83 deletions

View File

@ -189,7 +189,8 @@ class Environment(DataStoreMixin):
return None
@staticmethod
def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
def object_similarity(obj1, obj2, prop_scores={}, ignore_spec_version=False,
versioning_checks=False, max_depth=1, **weight_dict):
"""This method returns a measure of how similar the two objects are.
Args:
@ -220,10 +221,12 @@ class Environment(DataStoreMixin):
see `the Committee Note <link here>`__.
"""
return object_similarity(obj1, obj2, prop_scores, **weight_dict)
return object_similarity(obj1, obj2, prop_scores, ignore_spec_version,
versioning_checks, max_depth, **weight_dict)
@staticmethod
def object_equivalence(obj1, obj2, prop_scores={}, threshold=70, **weight_dict):
def object_equivalence(obj1, obj2, prop_scores={}, threshold=70, ignore_spec_version=False,
versioning_checks=False, max_depth=1, **weight_dict):
"""This method returns a true/false value if two objects are semantically equivalent.
Internally, it calls the object_similarity function and compares it against the given
threshold value.
@ -263,7 +266,8 @@ class Environment(DataStoreMixin):
return object_equivalence(obj1, obj2, prop_scores, threshold, **weight_dict)
@staticmethod
def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
def graph_similarity(ds1, ds2, prop_scores={}, ignore_spec_version=False,
versioning_checks=False, max_depth=1, **weight_dict):
"""This method returns a similarity score for two given graphs.
Each DataStore can contain a connected or disconnected graph and the
final result is weighted over the amount of objects we managed to compare.
@ -298,10 +302,12 @@ class Environment(DataStoreMixin):
see `the Committee Note <link here>`__.
"""
return graph_similarity(ds1, ds2, prop_scores, **weight_dict)
return graph_similarity(ds1, ds2, prop_scores, ignore_spec_version,
versioning_checks, max_depth, **weight_dict)
@staticmethod
def graph_equivalence(ds1, ds2, prop_scores={}, threshold=70, **weight_dict):
def graph_equivalence(ds1, ds2, prop_scores={}, threshold=70, ignore_spec_version=False,
versioning_checks=False, max_depth=1, **weight_dict):
"""This method returns a true/false value if two graphs are semantically equivalent.
Internally, it calls the graph_similarity function and compares it against the given
threshold value.

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@ -53,7 +53,8 @@ def graph_equivalence(ds1, ds2, prop_scores={}, threshold=70, **weight_dict):
return False
def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
def graph_similarity(ds1, ds2, prop_scores={}, ignore_spec_version=False,
versioning_checks=False, max_depth=1, **weight_dict):
"""This method returns a similarity score for two given graphs.
Each DataStore can contain a connected or disconnected graph and the
final result is weighted over the amount of objects we managed to compare.
@ -65,6 +66,9 @@ def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
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.
ignore_spec_version: As
versioning_checks: As
max_depth: As
weight_dict: A dictionary that can be used to override settings
in the similarity process
@ -90,13 +94,21 @@ def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
"""
results = {}
similarity_score = 0
weights = GRAPH_WEIGHTS.copy()
weights = WEIGHTS.copy()
if weight_dict:
weights.update(weight_dict)
weights["_internal"] = {
"ignore_spec_version": ignore_spec_version,
"versioning_checks": versioning_checks,
"ds1": ds1,
"ds2": ds2,
"max_depth": max_depth,
}
if weights["_internal"]["max_depth"] <= 0:
raise ValueError("weight_dict['_internal']['max_depth'] must be greater than 0")
raise ValueError("'max_depth' must be greater than 0")
pairs = _object_pairs(
_bucket_per_type(ds1.query([])),
@ -104,16 +116,15 @@ def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
weights,
)
weights["_internal"]["ds1"] = ds1
weights["_internal"]["ds2"] = ds2
logger.debug("Starting graph similarity process between DataStores: '%s' and '%s'", ds1.id, ds2.id)
for object1, object2 in pairs:
iprop_score = {}
object1_id = object1["id"]
object2_id = object2["id"]
result = object_similarity(object1, object2, iprop_score, **weights)
result = object_similarity(object1, object2, iprop_score, ds1, ds2,
ignore_spec_version, versioning_checks,
max_depth, **weights)
if object1_id not in results:
results[object1_id] = {"lhs": object1_id, "rhs": object2_id, "prop_score": iprop_score, "value": result}
@ -141,40 +152,3 @@ def graph_similarity(ds1, ds2, prop_scores={}, **weight_dict):
similarity_score,
)
return similarity_score
# default weights used for the graph similarity process
GRAPH_WEIGHTS = WEIGHTS.copy()
GRAPH_WEIGHTS.update({
"grouping": {
"name": (20, partial_string_based),
"context": (20, partial_string_based),
"object_refs": (60, list_reference_check),
},
"relationship": {
"relationship_type": (20, exact_match),
"source_ref": (40, reference_check),
"target_ref": (40, reference_check),
},
"report": {
"name": (30, partial_string_based),
"published": (10, partial_timestamp_based),
"object_refs": (60, list_reference_check),
"tdelta": 1, # One day interval
},
"sighting": {
"first_seen": (5, partial_timestamp_based),
"last_seen": (5, partial_timestamp_based),
"sighting_of_ref": (40, reference_check),
"observed_data_refs": (20, list_reference_check),
"where_sighted_refs": (20, list_reference_check),
"summary": (10, exact_match),
},
"_internal": {
"ignore_spec_version": False,
"versioning_checks": False,
"ds1": None,
"ds2": None,
"max_depth": 1,
},
}) # :autodoc-skip:

View File

@ -4,7 +4,7 @@ import itertools
import logging
import time
from ...datastore import Filter
from ...datastore import Filter, DataStoreMixin, DataSink, DataSource
from ...utils import STIXdatetime, parse_into_datetime
from ..pattern import equivalent_patterns
@ -54,7 +54,9 @@ def object_equivalence(obj1, obj2, prop_scores={}, threshold=70, **weight_dict):
return False
def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
def object_similarity(obj1, obj2, prop_scores={}, ds1=None, ds2=None,
ignore_spec_version=False, versioning_checks=False,
max_depth=1, **weight_dict):
"""This method returns a measure of similarity depending on how
similar the two objects are.
@ -63,6 +65,11 @@ def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
obj2: A stix2 object instance
prop_scores: A dictionary that can hold individual property scores,
weights, contributing score, matching score and sum of weights.
ds1: As
ds2: As
ignore_spec_version: As
versioning_checks: As
max_depth: As
weight_dict: A dictionary that can be used to override settings
in the similarity process
@ -91,6 +98,14 @@ def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
if weight_dict:
weights.update(weight_dict)
weights["_internal"] = {
"ignore_spec_version": ignore_spec_version,
"versioning_checks": versioning_checks,
"ds1": ds1,
"ds2": ds2,
"max_depth": max_depth,
}
type1, type2 = obj1["type"], obj2["type"]
ignore_spec_version = weights["_internal"]["ignore_spec_version"]
@ -117,6 +132,7 @@ def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
if check_property_present(prop, obj1, obj2):
w = weights[type1][prop][0]
comp_funct = weights[type1][prop][1]
prop_scores[prop] = {}
if comp_funct == partial_timestamp_based:
contributing_score = w * comp_funct(obj1[prop], obj2[prop], weights[type1]["tdelta"])
@ -124,24 +140,30 @@ def object_similarity(obj1, obj2, prop_scores={}, **weight_dict):
threshold = weights[type1]["threshold"]
contributing_score = w * comp_funct(obj1["latitude"], obj1["longitude"], obj2["latitude"], obj2["longitude"], threshold)
elif comp_funct == reference_check or comp_funct == list_reference_check:
max_depth = weights["_internal"]["max_depth"]
if max_depth > 0:
weights["_internal"]["max_depth"] = max_depth - 1
max_depth_i = weights["_internal"]["max_depth"]
if max_depth_i > 0:
weights["_internal"]["max_depth"] = max_depth_i - 1
ds1, ds2 = weights["_internal"]["ds1"], weights["_internal"]["ds2"]
contributing_score = w * comp_funct(obj1[prop], obj2[prop], ds1, ds2, **weights)
if _datastore_check(ds1, ds2):
contributing_score = w * comp_funct(obj1[prop], obj2[prop], ds1, ds2, **weights)
elif comp_funct == reference_check:
comp_funct = exact_match
contributing_score = w * comp_funct(obj1[prop], obj2[prop])
elif comp_funct == list_reference_check:
comp_funct = partial_list_based
contributing_score = w * comp_funct(obj1[prop], obj2[prop])
prop_scores[prop]["method"] = comp_funct.__name__
else:
continue # prevent excessive recursion
weights["_internal"]["max_depth"] = max_depth
weights["_internal"]["max_depth"] = max_depth_i
else:
contributing_score = w * comp_funct(obj1[prop], obj2[prop])
sum_weights += w
matching_score += contributing_score
prop_scores[prop] = {
"weight": w,
"contributing_score": contributing_score,
}
prop_scores[prop]["weight"] = w
prop_scores[prop]["contributing_score"] = contributing_score
logger.debug("'%s' check -- weight: %s, contributing score: %s", prop, w, contributing_score)
prop_scores["matching_score"] = matching_score
@ -196,7 +218,9 @@ def partial_timestamp_based(t1, t2, tdelta):
def partial_list_based(l1, l2):
"""Performs a partial list matching via finding the intersection between common values.
"""Performs a partial list matching via finding the intersection between
common values. Repeated values are counted only once. This method can be
used for *_refs equality checks when de-reference is not possible.
Args:
l1: A list of values.
@ -213,7 +237,8 @@ def partial_list_based(l1, l2):
def exact_match(val1, val2):
"""Performs an exact value match based on two values
"""Performs an exact value match based on two values. This method can be
used for *_ref equality check when de-reference is not possible.
Args:
val1: A value suitable for an equality test.
@ -275,15 +300,8 @@ def partial_external_reference_based(refs1, refs2):
allowed = {"veris", "cve", "capec", "mitre-attack"}
matches = 0
if len(refs1) >= len(refs2):
l1 = refs1
l2 = refs2
else:
l1 = refs2
l2 = refs1
for ext_ref1 in l1:
for ext_ref2 in l2:
for ext_ref1 in refs1:
for ext_ref2 in refs2:
sn_match = False
ei_match = False
url_match = False
@ -352,17 +370,21 @@ def _versioned_checks(ref1, ref2, ds1, ds2, **weights):
"""Checks multiple object versions if present in graph.
Maximizes for the similarity score of a particular version."""
results = {}
objects1 = ds1.query([Filter("id", "=", ref1)])
objects2 = ds2.query([Filter("id", "=", ref2)])
pairs = _object_pairs(
_bucket_per_type(objects1),
_bucket_per_type(objects2),
_bucket_per_type(ds1.query([Filter("id", "=", ref1)])),
_bucket_per_type(ds2.query([Filter("id", "=", ref2)])),
weights,
)
ignore_spec_version = weights["_internal"]["ignore_spec_version"]
versioning_checks = weights["_internal"]["versioning_checks"]
max_depth = weights["_internal"]["max_depth"]
for object1, object2 in pairs:
result = object_similarity(object1, object2, **weights)
result = object_similarity(object1, object2, ds1=ds1, ds2=ds2,
ignore_spec_version=ignore_spec_version,
versioning_checks=versioning_checks,
max_depth=max_depth, **weights)
if ref1 not in results:
results[ref1] = {"matched": ref2, "value": result}
elif result > results[ref1]["value"]:
@ -383,12 +405,18 @@ def reference_check(ref1, ref2, ds1, ds2, **weights):
result = 0.0
if type1 == type2 and type1 in weights:
if weights["_internal"]["versioning_checks"]:
ignore_spec_version = weights["_internal"]["ignore_spec_version"]
versioning_checks = weights["_internal"]["versioning_checks"]
max_depth = weights["_internal"]["max_depth"]
if versioning_checks:
result = _versioned_checks(ref1, ref2, ds1, ds2, **weights) / 100.0
else:
o1, o2 = ds1.get(ref1), ds2.get(ref2)
if o1 and o2:
result = object_similarity(o1, o2, **weights) / 100.0
result = object_similarity(o1, o2, ds1=ds1, ds2=ds2,
ignore_spec_version=ignore_spec_version,
versioning_checks=versioning_checks,
max_depth=max_depth, **weights) / 100.0
logger.debug(
"--\t\treference_check '%s' '%s'\tresult: '%s'",
@ -439,6 +467,13 @@ def list_reference_check(refs1, refs2, ds1, ds2, **weights):
return result
def _datastore_check(ds1, ds2):
if (issubclass(ds1.__class__, (DataStoreMixin, DataSink, DataSource)) or
issubclass(ds2.__class__, (DataStoreMixin, DataSink, DataSource))):
return True
return False
def _bucket_per_type(graph, mode="type"):
"""Given a list of objects or references, bucket them by type.
Depending on the list type: extract from 'type' property or using
@ -480,11 +515,20 @@ WEIGHTS = {
"name": (60, partial_string_based),
"external_references": (40, partial_external_reference_based),
},
"grouping": {
"name": (20, partial_string_based),
"context": (20, partial_string_based),
"object_refs": (60, list_reference_check),
},
"identity": {
"name": (60, partial_string_based),
"identity_class": (20, exact_match),
"sectors": (20, partial_list_based),
},
"incident": {
"name": (60, partial_string_based),
"external_references": (40, partial_external_reference_based),
},
"indicator": {
"indicator_types": (15, partial_list_based),
"pattern": (80, custom_pattern_based),
@ -511,6 +555,25 @@ WEIGHTS = {
"definition": (60, exact_match),
"definition_type": (20, exact_match),
},
"relationship": {
"relationship_type": (20, exact_match),
"source_ref": (40, reference_check),
"target_ref": (40, reference_check),
},
"report": {
"name": (30, partial_string_based),
"published": (10, partial_timestamp_based),
"object_refs": (60, list_reference_check),
"tdelta": 1, # One day interval
},
"sighting": {
"first_seen": (5, partial_timestamp_based),
"last_seen": (5, partial_timestamp_based),
"sighting_of_ref": (40, reference_check),
"observed_data_refs": (20, list_reference_check),
"where_sighted_refs": (20, list_reference_check),
"summary": (10, exact_match),
},
"threat-actor": {
"name": (60, partial_string_based),
"threat_actor_types": (20, partial_list_based),
@ -523,8 +586,5 @@ WEIGHTS = {
"vulnerability": {
"name": (30, partial_string_based),
"external_references": (70, partial_external_reference_based),
},
"_internal": {
"ignore_spec_version": False,
},
}
} # :autodoc-skip: