add checks to initialize References() when missing, prevent empty TTPs tags. closes #366

Author: emmanvg

stix/common/information_source.py

@@ -22,7 +22,7 @@ class InformationSource(stix.Entity):
     _binding_class = stix_common_binding.InformationSourceType
     _namespace = 'http://stix.mitre.org/common-1'
 
-    identity = fields.TypedField("Identity", type_=Identity, factory=IdentityFactory)
+    identity = fields.TypedField("Identity", Identity, factory=IdentityFactory)
     descriptions = fields.TypedField("Description", StructuredTextList)
     contributing_sources = fields.TypedField("Contributing_Sources", type_="stix.common.information_source.ContributingSources")
     time = fields.TypedField("Time", cybox.common.Time)
@@ -39,15 +39,15 @@ def __init__(self, description=None, identity=None, time=None, tools=None, contr
         self.time = time
         self.tools = tools
         self.references = references
-        #self.roles = None
 
     def add_contributing_source(self, value):
         self.contributing_sources.append(value)
 
-
     def add_reference(self, value):
         if not value:
             return
+        if self.references is None:
+            self.references = References()
         # TODO: Check if it's a valid URI?
         self.references.append(value)
 
@@ -80,7 +80,6 @@ def add_description(self, description):
         """
         self.descriptions.add(description)
 
-
     def add_role(self, value):
         self.roles.append(value)
 
@@ -95,4 +94,3 @@ class ContributingSources(stix.EntityList):
     @classmethod
     def _dict_as_list(cls):
         return False
-    

stix/core/stix_package.py

@@ -104,7 +104,7 @@ def __init__(self, id_=None, idref=None, timestamp=None, stix_header=None,
         self.indicators = indicators or Indicators()
         self.incidents = incidents or Incidents()
         self.threat_actors = threat_actors or ThreatActors()
-        self.ttps = ttps or TTPs()
+        self.ttps = ttps
         self.related_packages = related_packages
         self.reports = reports or Reports()
         self.timestamp = timestamp

stix/core/ttps.py

@@ -32,3 +32,8 @@ def __init__(self, ttps=None):
 
     def add_ttp(self, ttp):
         self.ttp.append(ttp)
+
+    def add_kill_chain(self, kc):
+        if self.kill_chains is None:
+            self.kill_chains = KillChains()
+        self.kill_chains.kill_chain.append(kc)

stix/exploit_target/vulnerability.py

@@ -4,13 +4,10 @@
 from mixbox import fields
 
 import stix
-import stix.utils as utils
 import stix.bindings.exploit_target as exploit_target_binding
-import stix.bindings.stix_common as stix_common_binding
-from stix.common import DateTimeWithPrecision, StructuredTextList
+from stix.common import DateTimeWithPrecision, References, StructuredTextList
 from stix.common.related import GenericRelationshipList, RelatedObservable
-from mixbox import entities, fields
-from stix.common import References
+
 
 class Vulnerability(stix.Entity):
     """Implementation of STIX ``Vulnerability``.
@@ -44,7 +41,6 @@ def __init__(self, title=None, description=None, short_description=None):
         self.title = title
         self.descriptions = StructuredTextList(description)
         self.short_descriptions = StructuredTextList(short_description)
-        self.references = []
 
     @property
     def description(self):
@@ -102,9 +98,11 @@ def add_short_description(self, description):
     def add_reference(self, reference):
         if not reference:
             return
-
+        if self.references is None:
+            self.references = References()
         self.references.append(reference)
 
+
 class CVSSVector(stix.Entity):
     """
     Common Vulnerabilit Scoring System object, representing its component measures