[![Build Status](https://travis-ci.org/oasis-open/cti-python-stix2.svg?branch=master)](https://travis-ci.org/oasis-open/cti-python-stix2) [![codecov](https://codecov.io/gh/oasis-open/cti-python-stix2/branch/master/graph/badge.svg)](https://codecov.io/gh/oasis-open/cti-python-stix2) # cti-python-stix2 *This is an [OASIS Open Repository](https://www.oasis-open.org/resources/open-repositories/). See the [Governance](#governance) section for more information.* This repository provides Python APIs for serializing and de-serializing STIX 2 JSON content, along with higher-level APIs for common tasks, including data markings, versioning, and for resolving STIX IDs across multiple data sources. ## Installation Install with [`pip`](https://pip.pypa.io/en/stable/): ``` pip install stix2 ``` ## Usage ### Creating STIX Domain Objects To create a STIX object, provide keyword arguments to the type's constructor: ```python from stix2 import Indicator indicator = Indicator(name="File hash for malware variant", labels=['malicious-activity'], pattern='file:hashes.md5 = "d41d8cd98f00b204e9800998ecf8427e"') ``` Certain required attributes of all objects will be set automatically if not provided as keyword arguments: - If not provided, `type` will be set automatically to the correct type. You can also provide the type explicitly, but this is not necessary: ```python indicator = Indicator(type='indicator', ...) ``` Passing a value for `type` that does not match the class being constructed will cause an error: ```python >>> indicator = Indicator(type='xxx', ...) stix2.exceptions.InvalidValueError: Invalid value for Indicator 'type': must equal 'indicator'. ``` - If not provided, `id` will be generated randomly. If you provide an `id` argument, it must begin with the correct prefix: ```python >>> indicator = Indicator(id="campaign--63ce9068-b5ab-47fa-a2cf-a602ea01f21a") stix2.exceptions.InvalidValueError: Invalid value for Indicator 'id': must start with 'indicator--'. ``` - If not provided, `created` and `modified` will be set to the (same) current time. For indicators, `labels` and `pattern` are required and cannot be set automatically. Trying to create an indicator that is missing one of these properties will result in an error: ```python >>> indicator = Indicator() stix2.exceptions.MissingPropertiesError: No values for required properties for Indicator: (labels, pattern). ``` However, the required `valid_from` attribute on Indicators will be set to the current time if not provided as a keyword argument. Once created, the object acts like a frozen dictionary. Properties can be accessed using the standard Python dictionary syntax: ```python >>> indicator['name'] 'File hash for malware variant' ``` TBD: Should we allow property access using the standard Python attribute syntax? ```python >>> indicator.name 'File hash for malware variant' ``` Attempting to modify any attributes will raise an error: ```python >>> indicator['name'] = "This is a revised name" TypeError: 'Indicator' object does not support item assignment >>> indicator.name = "This is a revised name" stix2.exceptions.ImmutableError: Cannot modify properties after creation. ``` To update the properties of an object, see [Versioning](#versioning) below. Creating a Malware object follows the same pattern: ```python from stix2 import Malware malware = Malware(name="Poison Ivy", labels=['remote-access-trojan']) ``` As with indicators, the `type`, `id`, `created`, and `modified` properties will be set automatically if not provided. For Malware objects, the `labels` and `name` properties must be provided. ### Creating Relationships STIX 2 Relationships are separate objects, not properties of the object on either side of the relationship. They are constructed similarly to other STIX objects. The `type`, `id`, `created`, and `modified` properties are added automatically if not provided. Callers must provide the `relationship_type`, `source_ref`, and `target_ref` properties. ```python from stix2 import Relationship relationship = Relationship(relationship_type='indicates', source_ref=indicator.id, target_ref=malware.id) ``` The `source_ref` and `target_ref` properties can be either the ID's of other STIX objects, or the STIX objects themselves. For readability, Relationship objects can also be constructed with the `source_ref`, `relationship_type`, and `target_ref` as positional (non-keyword) arguments: ```python relationship = Relationship(indicator, 'indicates', malware) ``` ### Creating Bundles STIX Bundles can be created by passing objects as arguments to the Bundle constructor. All required properties (`type`, `id`, and `spec_version`) will be set automatically if not provided, or can be provided as keyword arguments: ```python from stix2 import bundle bundle = Bundle(indicator, malware, relationship) ``` ### Serializing STIX objects The string representation of all STIX classes is a valid STIX JSON object. ```python indicator = Indicator(...) print(str(indicator)) ``` ### Versioning TBD ## Governance This GitHub public repository ( **** ) was [proposed](https://lists.oasis-open.org/archives/cti/201702/msg00008.html) and [approved](https://www.oasis-open.org/committees/download.php/60009/) \[[bis](https://issues.oasis-open.org/browse/TCADMIN-2549)\] by the [OASIS Cyber Threat Intelligence (CTI) TC](https://www.oasis-open.org/committees/cti/) as an [OASIS Open Repository](https://www.oasis-open.org/resources/open-repositories/) to support development of open source resources related to Technical Committee work. While this Open Repository remains associated with the sponsor TC, its development priorities, leadership, intellectual property terms, participation rules, and other matters of governance are [separate and distinct](https://github.com/oasis-open/cti-python-stix2/blob/master/CONTRIBUTING.md#governance-distinct-from-oasis-tc-process) from the OASIS TC Process and related policies. All contributions made to this Open Repository are subject to open source license terms expressed in the [BSD-3-Clause License](https://www.oasis-open.org/sites/www.oasis-open.org/files/BSD-3-Clause.txt). That license was selected as the declared ["Applicable License"](https://www.oasis-open.org/resources/open-repositories/licenses) when the Open Repository was created. 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