388 lines
12 KiB
Python
388 lines
12 KiB
Python
import base64
|
|
import binascii
|
|
import collections
|
|
import inspect
|
|
import re
|
|
import uuid
|
|
|
|
from six import string_types, text_type
|
|
from stix2patterns.validator import run_validator
|
|
|
|
from .base import _STIXBase
|
|
from .exceptions import DictionaryKeyError
|
|
from .utils import get_dict, parse_into_datetime
|
|
|
|
|
|
class Property(object):
|
|
"""Represent a property of STIX data type.
|
|
|
|
Subclasses can define the following attributes as keyword arguments to
|
|
__init__():
|
|
|
|
- `required` - If `True`, the property must be provided when creating an
|
|
object with that property. No default value exists for these properties.
|
|
(Default: `False`)
|
|
- `fixed` - This provides a constant default value. Users are free to
|
|
provide this value explicity when constructing an object (which allows
|
|
you to copy *all* values from an existing object to a new object), but
|
|
if the user provides a value other than the `fixed` value, it will raise
|
|
an error. This is semantically equivalent to defining both:
|
|
- a `clean()` function that checks if the value matches the fixed
|
|
value, and
|
|
- a `default()` function that returns the fixed value.
|
|
(Default: `None`)
|
|
|
|
Subclasses can also define the following functions.
|
|
|
|
- `def clean(self, value) -> any:`
|
|
- Return a value that is valid for this property. If `value` is not
|
|
valid for this property, this will attempt to transform it first. If
|
|
`value` is not valid and no such transformation is possible, it should
|
|
raise a ValueError.
|
|
- `def default(self):`
|
|
- provide a default value for this property.
|
|
- `default()` can return the special value `NOW` to use the current
|
|
time. This is useful when several timestamps in the same object need
|
|
to use the same default value, so calling now() for each property--
|
|
likely several microseconds apart-- does not work.
|
|
|
|
Subclasses can instead provide a lambda function for `default` as a keyword
|
|
argument. `clean` should not be provided as a lambda since lambdas cannot
|
|
raise their own exceptions.
|
|
|
|
When instantiating Properties, `required` and `default` should not be used
|
|
together. `default` implies that the property is required in the specification
|
|
so this function will be used to supply a value if none is provided.
|
|
`required` means that the user must provide this; it is required in the
|
|
specification and we can't or don't want to create a default value.
|
|
"""
|
|
|
|
def _default_clean(self, value):
|
|
if value != self._fixed_value:
|
|
raise ValueError("must equal '{0}'.".format(self._fixed_value))
|
|
return value
|
|
|
|
def __init__(self, required=False, fixed=None, default=None, type=None):
|
|
self.required = required
|
|
self.type = type
|
|
if fixed:
|
|
self._fixed_value = fixed
|
|
self.clean = self._default_clean
|
|
self.default = lambda: fixed
|
|
if default:
|
|
self.default = default
|
|
|
|
def clean(self, value):
|
|
return value
|
|
|
|
def __call__(self, value=None):
|
|
"""Used by ListProperty to handle lists that have been defined with
|
|
either a class or an instance.
|
|
"""
|
|
return value
|
|
|
|
|
|
class ListProperty(Property):
|
|
|
|
def __init__(self, contained, **kwargs):
|
|
"""
|
|
Contained should be a function which returns an object from the value.
|
|
"""
|
|
if inspect.isclass(contained) and issubclass(contained, Property):
|
|
# If it's a class and not an instance, instantiate it so that
|
|
# clean() can be called on it, and ListProperty.clean() will
|
|
# use __call__ when it appends the item.
|
|
self.contained = contained()
|
|
else:
|
|
self.contained = contained
|
|
super(ListProperty, self).__init__(**kwargs)
|
|
|
|
def clean(self, value):
|
|
try:
|
|
iter(value)
|
|
except TypeError:
|
|
raise ValueError("must be an iterable.")
|
|
|
|
if isinstance(value, (_STIXBase, string_types)):
|
|
value = [value]
|
|
|
|
result = []
|
|
for item in value:
|
|
try:
|
|
valid = self.contained.clean(item)
|
|
except ValueError:
|
|
raise
|
|
except AttributeError:
|
|
# type of list has no clean() function (eg. built in Python types)
|
|
# TODO Should we raise an error here?
|
|
valid = item
|
|
|
|
if type(self.contained) is EmbeddedObjectProperty:
|
|
obj_type = self.contained.type
|
|
elif type(self.contained).__name__ is 'STIXObjectProperty':
|
|
# ^ this way of checking doesn't require a circular import
|
|
obj_type = type(valid)
|
|
else:
|
|
obj_type = self.contained
|
|
|
|
if isinstance(valid, collections.Mapping):
|
|
result.append(obj_type(**valid))
|
|
else:
|
|
result.append(obj_type(valid))
|
|
|
|
# STIX spec forbids empty lists
|
|
if len(result) < 1:
|
|
raise ValueError("must not be empty.")
|
|
|
|
return result
|
|
|
|
|
|
class StringProperty(Property):
|
|
|
|
def __init__(self, **kwargs):
|
|
self.string_type = text_type
|
|
super(StringProperty, self).__init__(**kwargs)
|
|
|
|
def clean(self, value):
|
|
return self.string_type(value)
|
|
|
|
|
|
class TypeProperty(Property):
|
|
|
|
def __init__(self, type):
|
|
super(TypeProperty, self).__init__(fixed=type)
|
|
|
|
|
|
class IDProperty(Property):
|
|
|
|
def __init__(self, type):
|
|
self.required_prefix = type + "--"
|
|
super(IDProperty, self).__init__()
|
|
|
|
def clean(self, value):
|
|
if not value.startswith(self.required_prefix):
|
|
raise ValueError("must start with '{0}'.".format(self.required_prefix))
|
|
try:
|
|
uuid.UUID(value.split('--', 1)[1])
|
|
except Exception:
|
|
raise ValueError("must have a valid UUID after the prefix.")
|
|
return value
|
|
|
|
def default(self):
|
|
return self.required_prefix + str(uuid.uuid4())
|
|
|
|
|
|
class IntegerProperty(Property):
|
|
|
|
def clean(self, value):
|
|
try:
|
|
return int(value)
|
|
except Exception:
|
|
raise ValueError("must be an integer.")
|
|
|
|
|
|
class FloatProperty(Property):
|
|
def clean(self, value):
|
|
try:
|
|
return float(value)
|
|
except Exception:
|
|
raise ValueError("must be a float.")
|
|
|
|
|
|
class BooleanProperty(Property):
|
|
|
|
def clean(self, value):
|
|
if isinstance(value, bool):
|
|
return value
|
|
|
|
trues = ['true', 't']
|
|
falses = ['false', 'f']
|
|
try:
|
|
if value.lower() in trues:
|
|
return True
|
|
if value.lower() in falses:
|
|
return False
|
|
except AttributeError:
|
|
if value == 1:
|
|
return True
|
|
if value == 0:
|
|
return False
|
|
|
|
raise ValueError("must be a boolean value.")
|
|
|
|
|
|
class TimestampProperty(Property):
|
|
|
|
def __init__(self, precision=None, **kwargs):
|
|
self.precision = precision
|
|
super(TimestampProperty, self).__init__(**kwargs)
|
|
|
|
def clean(self, value):
|
|
return parse_into_datetime(value, self.precision)
|
|
|
|
|
|
class DictionaryProperty(Property):
|
|
|
|
def clean(self, value):
|
|
try:
|
|
dictified = get_dict(value)
|
|
except ValueError:
|
|
raise ValueError("The dictionary property must contain a dictionary")
|
|
if dictified == {}:
|
|
raise ValueError("The dictionary property must contain a non-empty dictionary")
|
|
|
|
for k in dictified.keys():
|
|
if len(k) < 3:
|
|
raise DictionaryKeyError(k, "shorter than 3 characters")
|
|
elif len(k) > 256:
|
|
raise DictionaryKeyError(k, "longer than 256 characters")
|
|
if not re.match('^[a-zA-Z0-9_-]+$', k):
|
|
raise DictionaryKeyError(k, "contains characters other than"
|
|
"lowercase a-z, uppercase A-Z, "
|
|
"numerals 0-9, hyphen (-), or "
|
|
"underscore (_)")
|
|
return dictified
|
|
|
|
|
|
HASHES_REGEX = {
|
|
"MD5": ("^[a-fA-F0-9]{32}$", "MD5"),
|
|
"MD6": ("^[a-fA-F0-9]{32}|[a-fA-F0-9]{40}|[a-fA-F0-9]{56}|[a-fA-F0-9]{64}|[a-fA-F0-9]{96}|[a-fA-F0-9]{128}$", "MD6"),
|
|
"RIPEMD160": ("^[a-fA-F0-9]{40}$", "RIPEMD-160"),
|
|
"SHA1": ("^[a-fA-F0-9]{40}$", "SHA-1"),
|
|
"SHA224": ("^[a-fA-F0-9]{56}$", "SHA-224"),
|
|
"SHA256": ("^[a-fA-F0-9]{64}$", "SHA-256"),
|
|
"SHA384": ("^[a-fA-F0-9]{96}$", "SHA-384"),
|
|
"SHA512": ("^[a-fA-F0-9]{128}$", "SHA-512"),
|
|
"SHA3224": ("^[a-fA-F0-9]{56}$", "SHA3-224"),
|
|
"SHA3256": ("^[a-fA-F0-9]{64}$", "SHA3-256"),
|
|
"SHA3384": ("^[a-fA-F0-9]{96}$", "SHA3-384"),
|
|
"SHA3512": ("^[a-fA-F0-9]{128}$", "SHA3-512"),
|
|
"SSDEEP": ("^[a-zA-Z0-9/+:.]{1,128}$", "ssdeep"),
|
|
"WHIRLPOOL": ("^[a-fA-F0-9]{128}$", "WHIRLPOOL"),
|
|
}
|
|
|
|
|
|
class HashesProperty(DictionaryProperty):
|
|
|
|
def clean(self, value):
|
|
clean_dict = super(HashesProperty, self).clean(value)
|
|
for k, v in clean_dict.items():
|
|
key = k.upper().replace('-', '')
|
|
if key in HASHES_REGEX:
|
|
vocab_key = HASHES_REGEX[key][1]
|
|
if not re.match(HASHES_REGEX[key][0], v):
|
|
raise ValueError("'%s' is not a valid %s hash" % (v, vocab_key))
|
|
if k != vocab_key:
|
|
clean_dict[vocab_key] = clean_dict[k]
|
|
del clean_dict[k]
|
|
return clean_dict
|
|
|
|
|
|
class BinaryProperty(Property):
|
|
|
|
def clean(self, value):
|
|
try:
|
|
base64.b64decode(value)
|
|
except (binascii.Error, TypeError):
|
|
raise ValueError("must contain a base64 encoded string")
|
|
return value
|
|
|
|
|
|
class HexProperty(Property):
|
|
|
|
def clean(self, value):
|
|
if not re.match('^([a-fA-F0-9]{2})+$', value):
|
|
raise ValueError("must contain an even number of hexadecimal characters")
|
|
return value
|
|
|
|
|
|
REF_REGEX = re.compile("^[a-z][a-z-]+[a-z]--[0-9a-fA-F]{8}-[0-9a-fA-F]{4}"
|
|
"-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$")
|
|
|
|
|
|
class ReferenceProperty(Property):
|
|
|
|
def __init__(self, required=False, type=None):
|
|
"""
|
|
references sometimes must be to a specific object type
|
|
"""
|
|
self.type = type
|
|
super(ReferenceProperty, self).__init__(required, type=type)
|
|
|
|
def clean(self, value):
|
|
if isinstance(value, _STIXBase):
|
|
value = value.id
|
|
if self.type:
|
|
if not value.startswith(self.type):
|
|
raise ValueError("must start with '{0}'.".format(self.type))
|
|
if not REF_REGEX.match(value):
|
|
raise ValueError("must match <object-type>--<guid>.")
|
|
return value
|
|
|
|
|
|
SELECTOR_REGEX = re.compile("^[a-z0-9_-]{3,250}(\\.(\\[\\d+\\]|[a-z0-9_-]{1,250}))*$")
|
|
|
|
|
|
class SelectorProperty(Property):
|
|
|
|
def __init__(self, type=None):
|
|
# ignore type
|
|
super(SelectorProperty, self).__init__()
|
|
|
|
def clean(self, value):
|
|
if not SELECTOR_REGEX.match(value):
|
|
raise ValueError("must adhere to selector syntax.")
|
|
return value
|
|
|
|
|
|
class ObjectReferenceProperty(StringProperty):
|
|
|
|
def __init__(self, valid_types=None, **kwargs):
|
|
if valid_types and type(valid_types) is not list:
|
|
valid_types = [valid_types]
|
|
self.valid_types = valid_types
|
|
super(ObjectReferenceProperty, self).__init__(**kwargs)
|
|
|
|
|
|
class EmbeddedObjectProperty(Property):
|
|
|
|
def __init__(self, type, required=False):
|
|
self.type = type
|
|
super(EmbeddedObjectProperty, self).__init__(required, type=type)
|
|
|
|
def clean(self, value):
|
|
if type(value) is dict:
|
|
value = self.type(**value)
|
|
elif not isinstance(value, self.type):
|
|
raise ValueError("must be of type %s." % self.type.__name__)
|
|
return value
|
|
|
|
|
|
class EnumProperty(StringProperty):
|
|
|
|
def __init__(self, allowed, **kwargs):
|
|
if type(allowed) is not list:
|
|
allowed = list(allowed)
|
|
self.allowed = allowed
|
|
super(EnumProperty, self).__init__(**kwargs)
|
|
|
|
def clean(self, value):
|
|
value = super(EnumProperty, self).clean(value)
|
|
if value not in self.allowed:
|
|
raise ValueError("value '%s' is not valid for this enumeration." % value)
|
|
return self.string_type(value)
|
|
|
|
|
|
class PatternProperty(StringProperty):
|
|
|
|
def __init__(self, **kwargs):
|
|
super(PatternProperty, self).__init__(**kwargs)
|
|
|
|
def clean(self, value):
|
|
str_value = super(PatternProperty, self).clean(value)
|
|
errors = run_validator(str_value)
|
|
if errors:
|
|
raise ValueError(str(errors[0]))
|
|
|
|
return self.string_type(value)
|