Files
addon/lib/pyasn1/codec/native/encoder.py
2025-01-16 00:40:16 +01:00

270 lines
8.2 KiB
Python
Executable File

#
# This file is part of pyasn1 software.
#
# Copyright (c) 2005-2020, Ilya Etingof <etingof@gmail.com>
# License: http://snmplabs.com/pyasn1/license.html
#
from collections import OrderedDict
from pyasn1 import debug
from pyasn1 import error
from pyasn1.type import base
from pyasn1.type import char
from pyasn1.type import tag
from pyasn1.type import univ
from pyasn1.type import useful
__all__ = ['encode']
LOG = debug.registerLoggee(__name__, flags=debug.DEBUG_ENCODER)
class AbstractItemEncoder(object):
def encode(self, value, encodeFun, **options):
raise error.PyAsn1Error('Not implemented')
class BooleanEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return bool(value)
class IntegerEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return int(value)
class BitStringEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return str(value)
class OctetStringEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return value.asOctets()
class TextStringEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return str(value)
class NullEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return None
class ObjectIdentifierEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return str(value)
class RealEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return float(value)
class SetEncoder(AbstractItemEncoder):
protoDict = dict
def encode(self, value, encodeFun, **options):
inconsistency = value.isInconsistent
if inconsistency:
raise inconsistency
namedTypes = value.componentType
substrate = self.protoDict()
for idx, (key, subValue) in enumerate(value.items()):
if namedTypes and namedTypes[idx].isOptional and not value[idx].isValue:
continue
substrate[key] = encodeFun(subValue, **options)
return substrate
class SequenceEncoder(SetEncoder):
protoDict = OrderedDict
class SequenceOfEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
inconsistency = value.isInconsistent
if inconsistency:
raise inconsistency
return [encodeFun(x, **options) for x in value]
class ChoiceEncoder(SequenceEncoder):
pass
class AnyEncoder(AbstractItemEncoder):
def encode(self, value, encodeFun, **options):
return value.asOctets()
TAG_MAP = {
univ.Boolean.tagSet: BooleanEncoder(),
univ.Integer.tagSet: IntegerEncoder(),
univ.BitString.tagSet: BitStringEncoder(),
univ.OctetString.tagSet: OctetStringEncoder(),
univ.Null.tagSet: NullEncoder(),
univ.ObjectIdentifier.tagSet: ObjectIdentifierEncoder(),
univ.Enumerated.tagSet: IntegerEncoder(),
univ.Real.tagSet: RealEncoder(),
# Sequence & Set have same tags as SequenceOf & SetOf
univ.SequenceOf.tagSet: SequenceOfEncoder(),
univ.SetOf.tagSet: SequenceOfEncoder(),
univ.Choice.tagSet: ChoiceEncoder(),
# character string types
char.UTF8String.tagSet: TextStringEncoder(),
char.NumericString.tagSet: TextStringEncoder(),
char.PrintableString.tagSet: TextStringEncoder(),
char.TeletexString.tagSet: TextStringEncoder(),
char.VideotexString.tagSet: TextStringEncoder(),
char.IA5String.tagSet: TextStringEncoder(),
char.GraphicString.tagSet: TextStringEncoder(),
char.VisibleString.tagSet: TextStringEncoder(),
char.GeneralString.tagSet: TextStringEncoder(),
char.UniversalString.tagSet: TextStringEncoder(),
char.BMPString.tagSet: TextStringEncoder(),
# useful types
useful.ObjectDescriptor.tagSet: OctetStringEncoder(),
useful.GeneralizedTime.tagSet: OctetStringEncoder(),
useful.UTCTime.tagSet: OctetStringEncoder()
}
# Put in ambiguous & non-ambiguous types for faster codec lookup
TYPE_MAP = {
univ.Boolean.typeId: BooleanEncoder(),
univ.Integer.typeId: IntegerEncoder(),
univ.BitString.typeId: BitStringEncoder(),
univ.OctetString.typeId: OctetStringEncoder(),
univ.Null.typeId: NullEncoder(),
univ.ObjectIdentifier.typeId: ObjectIdentifierEncoder(),
univ.Enumerated.typeId: IntegerEncoder(),
univ.Real.typeId: RealEncoder(),
# Sequence & Set have same tags as SequenceOf & SetOf
univ.Set.typeId: SetEncoder(),
univ.SetOf.typeId: SequenceOfEncoder(),
univ.Sequence.typeId: SequenceEncoder(),
univ.SequenceOf.typeId: SequenceOfEncoder(),
univ.Choice.typeId: ChoiceEncoder(),
univ.Any.typeId: AnyEncoder(),
# character string types
char.UTF8String.typeId: OctetStringEncoder(),
char.NumericString.typeId: OctetStringEncoder(),
char.PrintableString.typeId: OctetStringEncoder(),
char.TeletexString.typeId: OctetStringEncoder(),
char.VideotexString.typeId: OctetStringEncoder(),
char.IA5String.typeId: OctetStringEncoder(),
char.GraphicString.typeId: OctetStringEncoder(),
char.VisibleString.typeId: OctetStringEncoder(),
char.GeneralString.typeId: OctetStringEncoder(),
char.UniversalString.typeId: OctetStringEncoder(),
char.BMPString.typeId: OctetStringEncoder(),
# useful types
useful.ObjectDescriptor.typeId: OctetStringEncoder(),
useful.GeneralizedTime.typeId: OctetStringEncoder(),
useful.UTCTime.typeId: OctetStringEncoder()
}
class SingleItemEncoder(object):
TAG_MAP = TAG_MAP
TYPE_MAP = TYPE_MAP
def __init__(self, **options):
self._tagMap = options.get('tagMap', self.TAG_MAP)
self._typeMap = options.get('typeMap', self.TYPE_MAP)
def __call__(self, value, **options):
if not isinstance(value, base.Asn1Item):
raise error.PyAsn1Error(
'value is not valid (should be an instance of an ASN.1 Item)')
if LOG:
debug.scope.push(type(value).__name__)
LOG('encoder called for type %s '
'<%s>' % (type(value).__name__, value.prettyPrint()))
tagSet = value.tagSet
try:
concreteEncoder = self._typeMap[value.typeId]
except KeyError:
# use base type for codec lookup to recover untagged types
baseTagSet = tag.TagSet(
value.tagSet.baseTag, value.tagSet.baseTag)
try:
concreteEncoder = self._tagMap[baseTagSet]
except KeyError:
raise error.PyAsn1Error('No encoder for %s' % (value,))
if LOG:
LOG('using value codec %s chosen by '
'%s' % (concreteEncoder.__class__.__name__, tagSet))
pyObject = concreteEncoder.encode(value, self, **options)
if LOG:
LOG('encoder %s produced: '
'%s' % (type(concreteEncoder).__name__, repr(pyObject)))
debug.scope.pop()
return pyObject
class Encoder(object):
SINGLE_ITEM_ENCODER = SingleItemEncoder
def __init__(self, **options):
self._singleItemEncoder = self.SINGLE_ITEM_ENCODER(**options)
def __call__(self, pyObject, asn1Spec=None, **options):
return self._singleItemEncoder(
pyObject, asn1Spec=asn1Spec, **options)
#: Turns ASN.1 object into a Python built-in type object(s).
#:
#: Takes any ASN.1 object (e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative)
#: walks all its components recursively and produces a Python built-in type or a tree
#: of those.
#:
#: One exception is that instead of :py:class:`dict`, the :py:class:`OrderedDict`
#: is used to preserve ordering of the components in ASN.1 SEQUENCE.
#:
#: Parameters
#: ----------
# asn1Value: any pyasn1 object (e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative)
#: pyasn1 object to encode (or a tree of them)
#:
#: Returns
#: -------
#: : :py:class:`object`
#: Python built-in type instance (or a tree of them)
#:
#: Raises
#: ------
#: ~pyasn1.error.PyAsn1Error
#: On encoding errors
#:
#: Examples
#: --------
#: Encode ASN.1 value object into native Python types
#:
#: .. code-block:: pycon
#:
#: >>> seq = SequenceOf(componentType=Integer())
#: >>> seq.extend([1, 2, 3])
#: >>> encode(seq)
#: [1, 2, 3]
#:
encode = SingleItemEncoder()