# -*- coding: utf-8 -*-
"""JSON attribute container serializer."""
import binascii
import codecs
import collections
import json
from acstore.containers import interface as containers_interface
from acstore.helpers import json_serializer
from acstore.helpers import schema as schema_helper
from dfdatetime import interface as dfdatetime_interface
from dfdatetime import serializer as dfdatetime_serializer
from dfvfs.lib import definitions as dfvfs_definitions
from dfvfs.path import path_spec as dfvfs_path_spec
from dfvfs.path import factory as dfvfs_path_spec_factory
# The following import is needed to make sure TSKTime is registered with
# the dfDateTime factory.
from dfvfs.vfs import tsk_file_entry # pylint: disable=unused-import
from plaso.storage import serializers
schema_helper.SchemaHelper.RegisterDataTypes({
'dfdatetime.DateTimeValues': {
'json': serializers.JSONDateTimeAttributeSerializer()},
'dfvfs.PathSpec': {
'json': serializers.JSONPathSpecAttributeSerializer()},
'List[int]': {
'json': serializers.JSONValueListAttributeSerializer()},
'List[str]': {
'json': serializers.JSONValueListAttributeSerializer()}})
[docs]
class JSONAttributeContainerSerializer(
json_serializer.AttributeContainerJSONSerializer):
"""JSON attribute container serializer."""
_convert_json_to_value = {}
@classmethod
def _ConvertAttributeContainerToJSON(cls, attribute_container):
"""Converts an attribute container object into a JSON dictionary.
The resulting dictionary of the JSON serialized objects consists of:
{
'__type__': 'AttributeContainer'
'__container_type__': ...
...
}
Here '__type__' indicates the object base type. In this case
'AttributeContainer'.
'__container_type__' indicates the container type and rest of the elements
of the dictionary that make up the attributes of the container.
Args:
attribute_container (AttributeContainer): attribute container.
Returns:
dict[str, object]: JSON serialized objects.
"""
if attribute_container.CONTAINER_TYPE not in (
'event_data', 'system_configuration'):
return cls.ConvertAttributeContainerToJSON(attribute_container)
json_dict = {
'__type__': 'AttributeContainer',
'__container_type__': attribute_container.CONTAINER_TYPE}
for attribute_name, attribute_value in attribute_container.GetAttributes():
json_dict[attribute_name] = cls._ConvertValueToJSON(attribute_value)
return json_dict
@classmethod
def _ConvertBytesToJSON(cls, bytes_value):
"""Converts a bytes value into a JSON dictionary.
Args:
bytes_value (bytes): a bytes value.
Returns:
dict: JSON serialized object of a bytes value.
"""
encoded_value = binascii.b2a_qp(bytes_value)
encoded_value = codecs.decode(encoded_value, 'ascii')
return {
'__encoding__': 'base16',
'__type__': 'bytes',
'stream': encoded_value}
@classmethod
def _ConvertCollectionsCounterToJSON(cls, counter_value):
"""Converts a collections.Counter object into a JSON dictionary.
The resulting dictionary of the JSON serialized objects consists of:
{
'__type__': 'collections.Counter'
...
}
Here '__type__' indicates the object base type. In this case
'collections.Counter'. The rest of the elements of the dictionary make up
the collections.Counter object attributes.
Args:
counter_value (collections.Counter): a collections.Counter value.
Returns:
dict[str, object]: JSON serialized objects.
"""
json_dict = {'__type__': 'collections.Counter'}
for attribute_name, attribute_value in counter_value.items():
if attribute_value:
if isinstance(attribute_value, bytes):
attribute_value = cls._ConvertBytesToJSON(attribute_value)
json_dict[attribute_name] = attribute_value
return json_dict
@classmethod
def _ConvertJSONToAttributeContainer(cls, json_dict):
"""Converts a JSON dictionary into an attribute container.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'AttributeContainer'
'__container_type__': ...
...
}
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
AttributeContainer: an attribute container.
Raises:
ValueError: if the container type or attribute type of an event data
attribute container is not supported.
"""
# Use __container_type__ to indicate the attribute container type.
container_type = json_dict.get('__container_type__', None)
if container_type not in ('event_data', 'system_configuration'):
return cls.ConvertJSONToAttributeContainer(json_dict)
attribute_container = cls._CONTAINERS_MANAGER.CreateAttributeContainer(
container_type)
for attribute_name, attribute_value in json_dict.items():
if isinstance(attribute_value, dict):
attribute_value = cls._ConvertJSONToValue(attribute_value)
elif isinstance(attribute_value, list):
attribute_value = cls._ConvertListToValue(attribute_value)
if isinstance(attribute_value, bytes):
raise ValueError((
f'Event data attribute value: {attribute_name:s} of type bytes '
f'is not supported.'))
if isinstance(attribute_value, dict):
raise ValueError((
f'Event data attribute value: {attribute_name:s} of type dict '
f'is not supported.'))
setattr(attribute_container, attribute_name, attribute_value)
return attribute_container
@classmethod
def _ConvertJSONToBytes(cls, json_dict):
"""Converts a JSON dictionary into a bytes value.
The dictionary of the JSON serialized objects consists of:
{
'__encoding__': encoding of stream, typically base16.
'__type__': 'bytes'
'stream': encoded bytes value.
}
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
bytes: a bytes value.
Raises:
ValueError: if the encoding is not supported.
"""
encoding = json_dict.get('__encoding__', None) or 'base16'
if encoding != 'base16':
raise ValueError(f'Unsupported byte stream encoding: {encoding:s}')
return binascii.a2b_qp(json_dict['stream'])
@classmethod
def _ConvertJSONToCollectionsCounter(cls, json_dict):
"""Converts a JSON dictionary into a collections.Counter.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'collections.Counter'
...
}
Here '__type__' indicates the object base type. In this case
'collections.Counter'. The rest of the elements of the dictionary make up
the collections.Counter object attributes.
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
collections.Counter: a collections.Counter value.
"""
collections_counter = collections.Counter()
for key, value in json_dict.items():
if key != '__type__':
collections_counter[key] = value
return collections_counter
@classmethod
def _ConvertJSONToTuple(cls, json_dict):
"""Converts a JSON dictionary into a tuple value.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'tuple'
'values': elements of the tuple.
}
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
tuple: a tuple value.
"""
return tuple(cls._ConvertListToValue(json_dict['values']))
# Pylint is confused by the formatting of the return type.
# pylint: disable=missing-return-type-doc
@classmethod
def _ConvertJSONToValue(cls, json_dict):
"""Converts a JSON dictionary into a value.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'AttributeContainer'
'__container_type__': ...
...
}
Here '__type__' indicates the object base type. In this case
'AttributeContainer'.
'__container_type__' indicates the attribute container type.
The rest of the elements of the dictionary make up the attributes.
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
AttributeContainer|dict|list|tuple: deserialized object.
Raises:
ValueError: if the type of a JSON dictionary value is not supported.
"""
if not cls._convert_json_to_value:
cls._convert_json_to_value = {
'AttributeContainer': cls._ConvertJSONToAttributeContainer,
'bytes': cls._ConvertJSONToBytes,
'collections.Counter': cls._ConvertJSONToCollectionsCounter,
'DateTimeValues': (
dfdatetime_serializer.Serializer.ConvertDictToDateTimeValues),
'PathSpec': cls._ConvertJSONToPathSpec,
'tuple': cls._ConvertJSONToTuple}
json_dict_type = json_dict.get('__type__', None)
if not json_dict_type:
return json_dict
convert_function = cls._convert_json_to_value.get(json_dict_type, None)
if not convert_function:
raise ValueError(f'Unsupported JSON dictionary type: {json_dict_type:s}')
return convert_function(json_dict)
@classmethod
def _ConvertJSONToPathSpec(cls, json_dict):
"""Converts a JSON dictionary into a path specification object.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'PathSpec'
'type_indicator': 'OS'
'parent': { ... }
...
}
Here '__type__' indicates the object base type. In this case this should
be 'PathSpec'. The rest of the elements of the dictionary make up the
path specification object properties.
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
dfvfs.PathSpec: path specification.
"""
type_indicator = json_dict.get('type_indicator', None)
if type_indicator:
del json_dict['type_indicator']
if 'parent' in json_dict:
json_dict['parent'] = cls._ConvertJSONToPathSpec(json_dict['parent'])
# Remove the class type from the JSON dictionary since we cannot pass it.
del json_dict['__type__']
path_spec = dfvfs_path_spec_factory.Factory.NewPathSpec(
type_indicator, **json_dict)
if type_indicator == dfvfs_definitions.TYPE_INDICATOR_OS:
# dfvfs.OSPathSpec() will change the location to an absolute path
# here we want to preserve the original location.
path_spec.location = json_dict.get('location', None)
return path_spec
@classmethod
def _ConvertListToJSON(cls, value):
"""Converts a list value into a JSON dictionary.
Args:
value (list): a list value.
Returns:
list: JSON serialized object of a list value.
"""
return [cls._ConvertValueToJSON(element) for element in value]
@classmethod
def _ConvertListToValue(cls, json_list):
"""Converts a JSON list into an object.
Args:
json_list (list[object]): JSON serialized objects.
Returns:
list[object]: a deserialized list.
"""
list_value = []
for json_list_element in json_list:
if isinstance(json_list_element, dict):
list_value.append(cls._ConvertJSONToValue(json_list_element))
elif isinstance(json_list_element, list):
list_value.append(cls._ConvertListToValue(json_list_element))
else:
list_value.append(json_list_element)
return list_value
@classmethod
def _ConvertTupleToJSON(cls, value):
"""Converts a tuple value into a JSON dictionary.
The dictionary of the JSON serialized objects consists of:
{
'__type__': 'tuple'
'values': elements of the tuple.
}
Args:
value (tuple): a tuple value.
Returns:
dict: JSON serialized object of a tuple value.
"""
return {
'__type__': 'tuple',
'values': cls._ConvertListToJSON(value)}
@classmethod
def _ConvertPathSpecToJSON(cls, path_spec_object):
"""Converts a path specification object into a JSON dictionary.
The resulting dictionary of the JSON serialized objects consists of:
{
'__type__': 'PathSpec'
'type_indicator': 'OS'
'parent': { ... }
...
}
Here '__type__' indicates the object base type. In this case 'PathSpec'.
The rest of the elements of the dictionary make up the path specification
object properties. The supported property names are defined in
path_spec_factory.Factory.PROPERTY_NAMES. Note that this method is called
recursively for every path specification object and creates a dict of
dicts in the process.
Args:
path_spec_object (dfvfs.PathSpec): path specification.
Returns:
dict[str, object]: JSON serialized objects.
Raises:
TypeError: if not an instance of dfvfs.PathSpec.
"""
if not isinstance(path_spec_object, dfvfs_path_spec.PathSpec):
raise TypeError
json_dict = {'__type__': 'PathSpec'}
for property_name in dfvfs_path_spec_factory.Factory.PROPERTY_NAMES:
property_value = getattr(path_spec_object, property_name, None)
if property_value is not None:
json_dict[property_name] = property_value
if path_spec_object.HasParent():
json_dict['parent'] = cls._ConvertPathSpecToJSON(path_spec_object.parent)
json_dict['type_indicator'] = path_spec_object.type_indicator
location = getattr(path_spec_object, 'location', None)
if location:
json_dict['location'] = location
return json_dict
# Pylint is confused by the formatting of the return type.
# pylint: disable=missing-return-type-doc
@classmethod
def _ConvertValueToJSON(cls, attribute_value):
"""Converts a value into a JSON dictionary.
Args:
attribute_value (object): an attribute value.
Returns:
dict|list: The JSON serialized object which can be a dictionary or a list.
"""
convert_function = None
if isinstance(attribute_value, bytes):
convert_function = cls._ConvertBytesToJSON
elif isinstance(attribute_value, list):
convert_function = cls._ConvertListToJSON
elif isinstance(attribute_value, tuple):
convert_function = cls._ConvertTupleToJSON
elif isinstance(attribute_value, collections.Counter):
convert_function = cls._ConvertCollectionsCounterToJSON
elif isinstance(attribute_value, dfdatetime_interface.DateTimeValues):
convert_function = (
dfdatetime_serializer.Serializer.ConvertDateTimeValuesToDict)
elif isinstance(attribute_value, dfvfs_path_spec.PathSpec):
convert_function = cls._ConvertPathSpecToJSON
elif isinstance(attribute_value, containers_interface.AttributeContainer):
convert_function = cls.ConvertAttributeContainerToJSON
if convert_function:
attribute_value = convert_function(attribute_value)
return attribute_value
[docs]
@classmethod
def ReadSerialized(cls, json_string): # pylint: disable=arguments-renamed
"""Reads an attribute container from serialized form.
Args:
json_string (str): JSON serialized attribute container.
Returns:
AttributeContainer: attribute container or None.
"""
if json_string:
json_dict = json.loads(json_string)
return cls.ReadSerializedDict(json_dict)
return None
[docs]
@classmethod
def ReadSerializedDict(cls, json_dict):
"""Reads an attribute container from serialized dictionary form.
Args:
json_dict (dict[str, object]): JSON serialized objects.
Returns:
AttributeContainer: attribute container or None.
Raises:
TypeError: if the serialized dictionary does not contain an
AttributeContainer.
"""
if not json_dict:
return None
if isinstance(json_dict, list):
return json_dict
json_object = cls._ConvertJSONToValue(json_dict)
if not isinstance(json_object, (
containers_interface.AttributeContainer,
dfdatetime_interface.DateTimeValues,
dfvfs_path_spec.PathSpec)):
json_object_type = type(json_object)
raise TypeError(f'{json_object_type!s} is not a supported type.')
return json_object
[docs]
@classmethod
def WriteSerialized(cls, attribute_container):
"""Writes an attribute container to serialized form.
Args:
attribute_container (AttributeContainer): attribute container.
Returns:
str: A JSON string containing the serialized form.
"""
json_dict = cls.WriteSerializedDict(attribute_container)
return json.dumps(json_dict)
[docs]
@classmethod
def WriteSerializedDict(cls, attribute_container):
"""Writes an attribute container to serialized form.
Args:
attribute_container (AttributeContainer): attribute container.
Returns:
dict[str, object]: JSON serialized objects.
"""
if isinstance(attribute_container, list):
return attribute_container
if isinstance(attribute_container, dfdatetime_interface.DateTimeValues):
return dfdatetime_serializer.Serializer.ConvertDateTimeValuesToDict(
attribute_container)
if isinstance(attribute_container, dfvfs_path_spec.PathSpec):
return cls._ConvertPathSpecToJSON(attribute_container)
return cls._ConvertAttributeContainerToJSON(attribute_container)