Fix bug when adding custom obj to FileSystemSink

... if the object type hasn't been registered.

Related: #439.

stix2/base.py

@@ -30,7 +30,7 @@ except ImportError:
     from collections import Mapping
 
 
-__all__ = ['STIXJSONEncoder', '_STIXBase']
+__all__ = ['STIXJSONEncoder', '_STIXBase', 'serialize']
 
 DEFAULT_ERROR = "{type} must have {property}='{expected}'."
 SCO_DET_ID_NAMESPACE = uuid.UUID("00abedb4-aa42-466c-9c01-fed23315a9b7")
@@ -74,6 +74,43 @@ class STIXJSONIncludeOptionalDefaultsEncoder(json.JSONEncoder):
             return super(STIXJSONIncludeOptionalDefaultsEncoder, self).default(obj)
 
 
+def serialize(obj, pretty=False, include_optional_defaults=False, **kwargs):
+    """
+    Serialize a STIX object.
+
+    Args:
+        obj: The STIX object to be serialized.
+        pretty (bool): If True, output properties following the STIX specs
+            formatting. This includes indentation. Refer to notes for more
+            details. (Default: ``False``)
+        include_optional_defaults (bool): Determines whether to include
+            optional properties set to the default value defined in the spec.
+        **kwargs: The arguments for a json.dumps() call.
+
+    Returns:
+        str: The serialized JSON object.
+
+    Note:
+        The argument ``pretty=True`` will output the STIX object following
+        spec order. Using this argument greatly impacts object serialization
+        performance. If your use case is centered across machine-to-machine
+        operation it is recommended to set ``pretty=False``.
+
+        When ``pretty=True`` the following key-value pairs will be added or
+        overridden: indent=4, separators=(",", ": "), item_sort_key=sort_by.
+    """
+    if pretty:
+        def sort_by(element):
+            return find_property_index(obj, *element)
+
+        kwargs.update({'indent': 4, 'separators': (',', ': '), 'item_sort_key': sort_by})
+
+    if include_optional_defaults:
+        return json.dumps(obj, cls=STIXJSONIncludeOptionalDefaultsEncoder, **kwargs)
+    else:
+        return json.dumps(obj, cls=STIXJSONEncoder, **kwargs)
+
+
 def get_required_properties(properties):
     return (k for k, v in properties.items() if v.required)
 
@@ -270,7 +307,7 @@ class _STIXBase(Mapping):
     def revoke(self):
         return _revoke(self)
 
-    def serialize(self, pretty=False, include_optional_defaults=False, **kwargs):
+    def serialize(self, *args, **kwargs):
         """
         Serialize a STIX object.
 
@@ -309,16 +346,7 @@ class _STIXBase(Mapping):
             When ``pretty=True`` the following key-value pairs will be added or
             overridden: indent=4, separators=(",", ": "), item_sort_key=sort_by.
         """
-        if pretty:
-            def sort_by(element):
-                return find_property_index(self, *element)
-
-            kwargs.update({'indent': 4, 'separators': (',', ': '), 'item_sort_key': sort_by})
-
-        if include_optional_defaults:
-            return json.dumps(self, cls=STIXJSONIncludeOptionalDefaultsEncoder, **kwargs)
-        else:
-            return json.dumps(self, cls=STIXJSONEncoder, **kwargs)
+        return serialize(self, *args, **kwargs)
 
 
 class _DomainObject(_STIXBase, _MarkingsMixin):

stix2/datastore/filesystem.py

@@ -9,13 +9,13 @@ import stat
 import six
 
 from stix2 import v20, v21
-from stix2.base import _STIXBase
+from stix2.base import _STIXBase, serialize
 from stix2.datastore import (
     DataSink, DataSource, DataSourceError, DataStoreMixin,
 )
 from stix2.datastore.filters import Filter, FilterSet, apply_common_filters
 from stix2.parsing import parse
-from stix2.utils import format_datetime, get_type_from_id
+from stix2.utils import format_datetime, get_type_from_id, parse_into_datetime
 
 
 def _timestamp2filename(timestamp):
@@ -24,10 +24,12 @@ def _timestamp2filename(timestamp):
     "modified" property value.  This should not include an extension.
 
     Args:
-        timestamp: A timestamp, as a datetime.datetime object.
+        timestamp: A timestamp, as a datetime.datetime object or string.
 
     """
     # The format_datetime will determine the correct level of precision.
+    if isinstance(timestamp, str):
+        timestamp = parse_into_datetime(timestamp)
     ts = format_datetime(timestamp)
     ts = re.sub(r"[-T:\.Z ]", "", ts)
     return ts
@@ -582,9 +584,9 @@ class FileSystemSink(DataSink):
 
         if os.path.isfile(file_path):
             raise DataSourceError("Attempted to overwrite file (!) at: {}".format(file_path))
-        else:
+
         with io.open(file_path, 'w', encoding=encoding) as f:
-                stix_obj = stix_obj.serialize(pretty=True, encoding=encoding, ensure_ascii=False)
+            stix_obj = serialize(stix_obj, pretty=True, encoding=encoding, ensure_ascii=False)
             f.write(stix_obj)
 
     def add(self, stix_data=None, version=None):
@@ -614,8 +616,12 @@ class FileSystemSink(DataSink):
             self._check_path_and_write(stix_data)
 
         elif isinstance(stix_data, (str, dict)):
-            stix_data = parse(stix_data, allow_custom=self.allow_custom, version=version)
-            self.add(stix_data, version=version)
+            parsed_data = parse(stix_data, allow_custom=self.allow_custom, version=version)
+            if isinstance(parsed_data, _STIXBase):
+                self.add(parsed_data, version=version)
+            else:
+                # custom unregistered object type
+                self._check_path_and_write(parsed_data)
 
         elif isinstance(stix_data, list):
             # recursively add individual STIX objects

stix2/test/v20/test_datastore_filesystem.py

@@ -633,6 +633,26 @@ def test_filesystem_object_with_custom_property_in_bundle(fs_store):
     assert camp_r.x_empire == camp.x_empire
 
 
+def test_filesystem_custom_object_dict(fs_store):
+    fs_store.sink.allow_custom = True
+    newobj = {
+        "type": "x-new-obj-2",
+        "id": "x-new-obj-2--d08dc866-6149-47db-aae6-7b58a827e7f0",
+        "created": "2020-07-20T03:45:02.879Z",
+        "modified": "2020-07-20T03:45:02.879Z",
+        "property1": "something",
+    }
+    fs_store.add(newobj)
+
+    newobj_r = fs_store.get(newobj["id"])
+    assert newobj_r["id"] == newobj["id"]
+    assert newobj_r["property1"] == 'something'
+
+    # remove dir
+    shutil.rmtree(os.path.join(FS_PATH, "x-new-obj-2"), True)
+    fs_store.sink.allow_custom = False
+
+
 def test_filesystem_custom_object(fs_store):
     @stix2.v20.CustomObject(
         'x-new-obj-2', [

stix2/test/v21/test_datastore_filesystem.py

@@ -654,6 +654,27 @@ def test_filesystem_object_with_custom_property_in_bundle(fs_store):
     assert camp_r.x_empire == camp.x_empire
 
 
+def test_filesystem_custom_object_dict(fs_store):
+    fs_store.sink.allow_custom = True
+    newobj = {
+        "type": "x-new-obj-2",
+        "id": "x-new-obj-2--d08dc866-6149-47db-aae6-7b58a827e7f0",
+        "spec_version": "2.1",
+        "created": "2020-07-20T03:45:02.879Z",
+        "modified": "2020-07-20T03:45:02.879Z",
+        "property1": "something",
+    }
+    fs_store.add(newobj)
+
+    newobj_r = fs_store.get(newobj["id"])
+    assert newobj_r["id"] == newobj["id"]
+    assert newobj_r["property1"] == 'something'
+
+    # remove dir
+    shutil.rmtree(os.path.join(FS_PATH, "x-new-obj-2"), True)
+    fs_store.sink.allow_custom = False
+
+
 def test_filesystem_custom_object(fs_store):
     @stix2.v21.CustomObject(
         'x-new-obj-2', [