86 lines
3.0 KiB
Python
86 lines
3.0 KiB
Python
"""STIX2 core serialization methods."""
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import copy
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import datetime as dt
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import simplejson as json
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import stix2.base
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from .utils import find_property_index, format_datetime
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class STIXJSONEncoder(json.JSONEncoder):
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"""Custom JSONEncoder subclass for serializing Python ``stix2`` objects.
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If an optional property with a default value specified in the STIX 2 spec
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is set to that default value, it will be left out of the serialized output.
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An example of this type of property include the ``revoked`` common property.
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"""
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def default(self, obj):
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if isinstance(obj, (dt.date, dt.datetime)):
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return format_datetime(obj)
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elif isinstance(obj, stix2.base._STIXBase):
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tmp_obj = dict(copy.deepcopy(obj))
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for prop_name in obj._defaulted_optional_properties:
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del tmp_obj[prop_name]
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return tmp_obj
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else:
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return super(STIXJSONEncoder, self).default(obj)
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class STIXJSONIncludeOptionalDefaultsEncoder(json.JSONEncoder):
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"""Custom JSONEncoder subclass for serializing Python ``stix2`` objects.
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Differs from ``STIXJSONEncoder`` in that if an optional property with a default
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value specified in the STIX 2 spec is set to that default value, it will be
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included in the serialized output.
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"""
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def default(self, obj):
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if isinstance(obj, (dt.date, dt.datetime)):
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return format_datetime(obj)
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elif isinstance(obj, stix2.base._STIXBase):
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return dict(obj)
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else:
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return super(STIXJSONIncludeOptionalDefaultsEncoder, self).default(obj)
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def serialize(obj, pretty=False, include_optional_defaults=False, **kwargs):
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"""
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Serialize a STIX object.
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Args:
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obj: The STIX object to be serialized.
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pretty (bool): If True, output properties following the STIX specs
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formatting. This includes indentation. Refer to notes for more
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details. (Default: ``False``)
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include_optional_defaults (bool): Determines whether to include
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optional properties set to the default value defined in the spec.
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**kwargs: The arguments for a json.dumps() call.
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Returns:
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str: The serialized JSON object.
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Note:
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The argument ``pretty=True`` will output the STIX object following
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spec order. Using this argument greatly impacts object serialization
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performance. If your use case is centered across machine-to-machine
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operation it is recommended to set ``pretty=False``.
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When ``pretty=True`` the following key-value pairs will be added or
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overridden: indent=4, separators=(",", ": "), item_sort_key=sort_by.
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"""
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if pretty:
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def sort_by(element):
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return find_property_index(obj, *element)
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kwargs.update({'indent': 4, 'separators': (',', ': '), 'item_sort_key': sort_by})
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if include_optional_defaults:
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return json.dumps(obj, cls=STIXJSONIncludeOptionalDefaultsEncoder, **kwargs)
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else:
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return json.dumps(obj, cls=STIXJSONEncoder, **kwargs)
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