cti-python-stix2/stix2/markings/granular_markings.py

311 lines
11 KiB
Python

"""Functions for working with STIX2 granular markings."""
from stix2 import exceptions
from stix2.markings import utils
from stix2.utils import is_marking
from stix2.versioning import new_version
def get_markings(obj, selectors, inherited=False, descendants=False, marking_ref=True, lang=True):
"""
Get all granular markings associated to with the properties.
Args:
obj: An SDO or SRO object.
selectors: string or list of selector strings relative to the SDO or
SRO in which the properties appear.
inherited (bool): If True, include markings inherited relative to the
properties.
descendants (bool): If True, include granular markings applied to any
children relative to the properties.
marking_ref (bool): If False, excludes markings that use
``marking_ref`` property.
lang (bool): If False, excludes markings that use ``lang`` property.
Raises:
InvalidSelectorError: If `selectors` fail validation.
Returns:
list: Marking identifiers that matched the selectors expression.
"""
selectors = utils.convert_to_list(selectors)
utils.validate(obj, selectors)
granular_markings = obj.get('granular_markings', [])
if not granular_markings:
return []
results = set()
for marking in granular_markings:
for user_selector in selectors:
for marking_selector in marking.get('selectors', []):
if any([
(user_selector == marking_selector), # Catch explicit selectors.
(user_selector.startswith(marking_selector) and inherited), # Catch inherited selectors.
(marking_selector.startswith(user_selector) and descendants),
]): # Catch descendants selectors
ref = marking.get('marking_ref')
lng = marking.get('lang')
if ref and marking_ref:
results.add(ref)
if lng and lang:
results.add(lng)
return list(results)
def set_markings(obj, marking, selectors, marking_ref=True, lang=True):
"""
Remove all granular markings associated with selectors and append a new
granular marking. Refer to `clear_markings` and `add_markings` for details.
Args:
obj: An SDO or SRO object.
selectors: string or list of selector strings relative to the SDO or
SRO in which the properties appear.
marking: identifier or list of marking identifiers that apply to the
properties selected by `selectors`.
marking_ref (bool): If False, markings that use the ``marking_ref``
property will not be removed.
lang (bool): If False, markings that use the ``lang`` property
will not be removed.
Returns:
A new version of the given SDO or SRO with specified markings removed
and new ones added.
"""
obj = clear_markings(obj, selectors, marking_ref, lang)
return add_markings(obj, marking, selectors)
def remove_markings(obj, marking, selectors):
"""
Remove a granular marking from the granular_markings collection. The method
makes a best-effort attempt to distinguish between a marking-definition
or language granular marking.
Args:
obj: An SDO or SRO object.
marking: identifier or list of marking identifiers that apply to the
properties selected by `selectors`.
selectors: string or list of selectors strings relative to the SDO or
SRO in which the properties appear.
Raises:
InvalidSelectorError: If `selectors` fail validation.
MarkingNotFoundError: If markings to remove are not found on
the provided SDO or SRO.
Returns:
A new version of the given SDO or SRO with specified markings removed.
"""
selectors = utils.convert_to_list(selectors)
marking = utils.convert_to_marking_list(marking)
utils.validate(obj, selectors)
granular_markings = obj.get('granular_markings')
if not granular_markings:
return obj
granular_markings = utils.expand_markings(granular_markings)
to_remove = []
for m in marking:
if is_marking(m):
to_remove.append({'marking_ref': m, 'selectors': selectors})
else:
to_remove.append({'lang': m, 'selectors': selectors})
remove = utils.build_granular_marking(to_remove).get('granular_markings')
if not any(marking in granular_markings for marking in remove):
raise exceptions.MarkingNotFoundError(obj, remove)
granular_markings = [
m for m in granular_markings if m not in remove
]
granular_markings = utils.compress_markings(granular_markings)
if granular_markings:
return new_version(obj, granular_markings=granular_markings, allow_custom=True)
else:
return new_version(obj, granular_markings=None, allow_custom=True)
def add_markings(obj, marking, selectors):
"""
Append a granular marking to the granular_markings collection. The method
makes a best-effort attempt to distinguish between a marking-definition
or language granular marking.
Args:
obj: An SDO or SRO object.
marking: identifier or list of marking identifiers that apply to the
properties selected by `selectors`.
selectors: list of type string, selectors must be relative to the TLO
in which the properties appear.
Raises:
InvalidSelectorError: If `selectors` fail validation.
Returns:
A new version of the given SDO or SRO with specified markings added.
"""
selectors = utils.convert_to_list(selectors)
marking = utils.convert_to_marking_list(marking)
utils.validate(obj, selectors)
granular_marking = []
for m in marking:
if is_marking(m):
granular_marking.append({'marking_ref': m, 'selectors': sorted(selectors)})
else:
granular_marking.append({'lang': m, 'selectors': sorted(selectors)})
if obj.get('granular_markings'):
granular_marking.extend(obj.get('granular_markings'))
granular_marking = utils.expand_markings(granular_marking)
granular_marking = utils.compress_markings(granular_marking)
return new_version(obj, granular_markings=granular_marking, allow_custom=True)
def clear_markings(obj, selectors, marking_ref=True, lang=True):
"""
Remove all granular markings associated with the selectors.
Args:
obj: An SDO or SRO object.
selectors: string or list of selectors strings relative to the SDO or
SRO in which the properties appear.
marking_ref (bool): If False, markings that use the ``marking_ref``
property will not be removed.
lang (bool): If False, markings that use the ``lang`` property
will not be removed.
Raises:
InvalidSelectorError: If `selectors` fail validation.
MarkingNotFoundError: If markings to remove are not found on
the provided SDO or SRO.
Returns:
A new version of the given SDO or SRO with specified markings cleared.
"""
selectors = utils.convert_to_list(selectors)
utils.validate(obj, selectors)
granular_markings = obj.get('granular_markings')
if not granular_markings:
return obj
granular_markings = utils.expand_markings(granular_markings)
granular_dict = utils.build_granular_marking([
{'selectors': selectors, 'marking_ref': 'N/A'},
{'selectors': selectors, 'lang': 'N/A'},
])
clear = granular_dict.get('granular_markings', [])
if not any(
clear_selector in sdo_selectors.get('selectors', [])
for sdo_selectors in granular_markings
for clear_marking in clear
for clear_selector in clear_marking.get('selectors', [])
):
raise exceptions.MarkingNotFoundError(obj, clear)
for granular_marking in granular_markings:
for s in selectors:
if s in granular_marking.get('selectors', []):
ref = granular_marking.get('marking_ref')
lng = granular_marking.get('lang')
if ref and marking_ref:
granular_marking['marking_ref'] = ''
if lng and lang:
granular_marking['lang'] = ''
granular_markings = utils.compress_markings(granular_markings)
if granular_markings:
return new_version(obj, granular_markings=granular_markings, allow_custom=True)
else:
return new_version(obj, granular_markings=None, allow_custom=True)
def is_marked(obj, marking=None, selectors=None, inherited=False, descendants=False):
"""
Check if field is marked by any marking or by specific marking(s).
Args:
obj: An SDO or SRO object.
marking: identifier or list of marking identifiers that apply to the
properties selected by `selectors`.
selectors (bool): string or list of selectors strings relative to the
SDO or SRO in which the properties appear.
inherited (bool): If True, return markings inherited from the given
selector.
descendants (bool): If True, return granular markings applied to any
children of the given selector.
Raises:
InvalidSelectorError: If `selectors` fail validation.
Returns:
bool: True if ``selectors`` is found on internal SDO or SRO collection.
False otherwise.
Note:
When a list of marking identifiers is provided, if ANY of the provided
marking identifiers match, True is returned.
"""
if selectors is None:
raise TypeError("Required argument 'selectors' must be provided")
selectors = utils.convert_to_list(selectors)
marking = utils.convert_to_marking_list(marking)
utils.validate(obj, selectors)
granular_markings = obj.get('granular_markings', [])
marked = False
markings = set()
for granular_marking in granular_markings:
for user_selector in selectors:
for marking_selector in granular_marking.get('selectors', []):
if any([
(user_selector == marking_selector), # Catch explicit selectors.
(user_selector.startswith(marking_selector) and inherited), # Catch inherited selectors.
(marking_selector.startswith(user_selector) and descendants),
]): # Catch descendants selectors
marking_ref = granular_marking.get('marking_ref', '')
lang = granular_marking.get('lang', '')
if marking and any(x == marking_ref for x in marking):
markings.update([marking_ref])
if marking and any(x == lang for x in marking):
markings.update([lang])
marked = True
if marking:
# All user-provided markings must be found.
return markings.issuperset(set(marking))
return marked