cti-python-stix2/stix2/__init__.py

258 lines
7.7 KiB
Python

import collections
from datetime import datetime
import json
import uuid
import pytz
def format_datetime(dt):
# TODO: how to handle naive datetime
# 1. Convert to UTC
# 2. Format in isoformat
# 3. Strip off "+00:00"
# 4. Add "Z"
# TODO: how to handle timestamps with subsecond 0's
return dt.astimezone(pytz.utc).isoformat()[:-6] + "Z"
class _STIXBase(collections.Mapping):
"""Base class for STIX object types"""
def __getitem__(self, key):
return self._inner[key]
def __iter__(self):
return iter(self._inner)
def __len__(self):
return len(self._inner)
# Handle attribute access just like key access
def __getattr__(self, name):
return self.get(name)
def __setattr__(self, name, value):
if name != '_inner':
raise ValueError("Cannot modify properties after creation.")
super(_STIXBase, self).__setattr__(name, value)
def __str__(self):
# TODO: put keys in specific order. Probably need custom JSON encoder.
return json.dumps(self._dict(), indent=4, sort_keys=True,
separators=(",", ": ")) # Don't include spaces after commas.
class Indicator(_STIXBase):
_properties = [
'type',
'id',
'created',
'modified',
'labels',
'pattern',
'valid_from',
]
def __init__(self, **kwargs):
# TODO:
# - created_by_ref
# - revoked
# - external_references
# - object_marking_refs
# - granular_markings
# - name
# - description
# - valid_until
# - kill_chain_phases
# TODO: do we care about the performance penalty of creating this
# if we won't need it?
now = datetime.now(tz=pytz.UTC)
if not kwargs.get('type'):
kwargs['type'] = 'indicator'
if kwargs['type'] != 'indicator':
raise ValueError("Indicator must have type='indicator'.")
if not kwargs.get('id'):
kwargs['id'] = 'indicator--' + str(uuid.uuid4())
if not kwargs['id'].startswith('indicator--'):
raise ValueError("Indicator id values must begin with 'indicator--'.")
if not kwargs.get('labels'):
raise ValueError("Missing required field for Indicator: 'labels'.")
if not kwargs.get('pattern'):
raise ValueError("Missing required field for Indicator: 'pattern'.")
extra_kwargs = list(set(kwargs.keys()) - set(self._properties))
if extra_kwargs:
raise TypeError("unexpected keyword arguments: " + str(extra_kwargs))
self._inner = {
'type': kwargs['type'],
'id': kwargs['id'],
'created': kwargs.get('created', now),
'modified': kwargs.get('modified', now),
'labels': kwargs['labels'],
'pattern': kwargs['pattern'],
'valid_from': kwargs.get('valid_from', now),
}
def _dict(self):
return {
'type': self['type'],
'id': self['id'],
'created': format_datetime(self['created']),
'modified': format_datetime(self['modified']),
'labels': self['labels'],
'pattern': self['pattern'],
'valid_from': format_datetime(self['valid_from']),
}
class Malware(_STIXBase):
_properties = [
'type',
'id',
'created',
'modified',
'labels',
'name',
]
def __init__(self, **kwargs):
# TODO:
# - created_by_ref
# - revoked
# - external_references
# - object_marking_refs
# - granular_markings
# - description
# - kill_chain_phases
# TODO: do we care about the performance penalty of creating this
# if we won't need it?
now = datetime.now(tz=pytz.UTC)
if not kwargs.get('type'):
kwargs['type'] = 'malware'
if kwargs['type'] != 'malware':
raise ValueError("Malware must have type='malware'.")
if not kwargs.get('id'):
kwargs['id'] = 'malware--' + str(uuid.uuid4())
if not kwargs['id'].startswith('malware--'):
raise ValueError("Malware id values must begin with 'malware--'.")
if not kwargs.get('labels'):
raise ValueError("Missing required field for Malware: 'labels'.")
if not kwargs.get('name'):
raise ValueError("Missing required field for Malware: 'name'.")
extra_kwargs = list(set(kwargs.keys()) - set(self._properties))
if extra_kwargs:
raise TypeError("unexpected keyword arguments: " + str(extra_kwargs))
self._inner = {
'type': kwargs['type'],
'id': kwargs['id'],
'created': kwargs.get('created', now),
'modified': kwargs.get('modified', now),
'labels': kwargs['labels'],
'name': kwargs['name'],
}
def _dict(self):
return {
'type': self['type'],
'id': self['id'],
'created': format_datetime(self['created']),
'modified': format_datetime(self['modified']),
'labels': self['labels'],
'name': self['name'],
}
class Relationship(_STIXBase):
_properties = [
'type',
'id',
'created',
'modified',
'relationship_type',
'source_ref',
'target_ref',
]
def __init__(self, **kwargs):
# TODO:
# - created_by_ref
# - revoked
# - external_references
# - object_marking_refs
# - granular_markings
# - description
# TODO: do we care about the performance penalty of creating this
# if we won't need it?
now = datetime.now(tz=pytz.UTC)
if not kwargs.get('type'):
kwargs['type'] = 'relationship'
if kwargs['type'] != 'relationship':
raise ValueError("Relationship must have type='relationship'.")
if not kwargs.get('id'):
kwargs['id'] = 'relationship--' + str(uuid.uuid4())
if not kwargs['id'].startswith('relationship--'):
raise ValueError("Relationship id values must begin with 'relationship--'.")
if not kwargs.get('relationship_type'):
raise ValueError("Missing required field for Relationship: 'relationship_type'.")
if not kwargs.get('source_ref'):
raise ValueError("Missing required field for Relationship: 'source_ref'.")
elif isinstance(kwargs['source_ref'], _STIXBase):
kwargs['source_ref'] = kwargs['source_ref'].id
if not kwargs.get('target_ref'):
raise ValueError("Missing required field for Relationship: 'target_ref'.")
elif isinstance(kwargs['target_ref'], _STIXBase):
kwargs['target_ref'] = kwargs['target_ref'].id
extra_kwargs = list(set(kwargs.keys()) - set(self._properties))
if extra_kwargs:
raise TypeError("unexpected keyword arguments: " + str(extra_kwargs))
self._inner = {
'type': kwargs['type'],
'id': kwargs['id'],
'created': kwargs.get('created', now),
'modified': kwargs.get('modified', now),
'relationship_type': kwargs['relationship_type'],
'source_ref': kwargs['source_ref'],
'target_ref': kwargs['target_ref'],
}
def _dict(self):
return {
'type': self['type'],
'id': self['id'],
'created': format_datetime(self['created']),
'modified': format_datetime(self['modified']),
'relationship_type': self['relationship_type'],
'source_ref': self['source_ref'],
'target_ref': self['target_ref'],
}