codekingpro/portable-devtools

1#2# This file is part of pyasn1 software.3#4# Copyright (c) 2005-2020, Ilya Etingof <etingof@gmail.com>5# License: https://pyasn1.readthedocs.io/en/latest/license.html6#7import warnings8 9from pyasn1 import error10from pyasn1.codec.streaming import readFromStream11from pyasn1.codec.ber import decoder12from pyasn1.type import univ13 14__all__ = ['decode', 'StreamingDecoder']15 16SubstrateUnderrunError = error.SubstrateUnderrunError17 18 19class BooleanPayloadDecoder(decoder.AbstractSimplePayloadDecoder):20    protoComponent = univ.Boolean(0)21 22    def valueDecoder(self, substrate, asn1Spec,23                     tagSet=None, length=None, state=None,24                     decodeFun=None, substrateFun=None,25                     **options):26 27        if length != 1:28            raise error.PyAsn1Error('Not single-octet Boolean payload')29 30        for chunk in readFromStream(substrate, length, options):31            if isinstance(chunk, SubstrateUnderrunError):32                yield chunk33 34        byte = chunk[0]35 36        # CER/DER specifies encoding of TRUE as 0xFF and FALSE as 0x0, while37        # BER allows any non-zero value as TRUE; cf. sections 8.2.2. and 11.1 38        # in https://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf39        if byte == 0xff:40            value = 141 42        elif byte == 0x00:43            value = 044 45        else:46            raise error.PyAsn1Error('Unexpected Boolean payload: %s' % byte)47 48        yield self._createComponent(asn1Spec, tagSet, value, **options)49 50 51# TODO: prohibit non-canonical encoding52BitStringPayloadDecoder = decoder.BitStringPayloadDecoder53OctetStringPayloadDecoder = decoder.OctetStringPayloadDecoder54RealPayloadDecoder = decoder.RealPayloadDecoder55 56TAG_MAP = decoder.TAG_MAP.copy()57TAG_MAP.update(58    {univ.Boolean.tagSet: BooleanPayloadDecoder(),59     univ.BitString.tagSet: BitStringPayloadDecoder(),60     univ.OctetString.tagSet: OctetStringPayloadDecoder(),61     univ.Real.tagSet: RealPayloadDecoder()}62)63 64TYPE_MAP = decoder.TYPE_MAP.copy()65 66# Put in non-ambiguous types for faster codec lookup67for typeDecoder in TAG_MAP.values():68    if typeDecoder.protoComponent is not None:69        typeId = typeDecoder.protoComponent.__class__.typeId70        if typeId is not None and typeId not in TYPE_MAP:71            TYPE_MAP[typeId] = typeDecoder72 73 74class SingleItemDecoder(decoder.SingleItemDecoder):75    __doc__ = decoder.SingleItemDecoder.__doc__76 77    TAG_MAP = TAG_MAP78    TYPE_MAP = TYPE_MAP79 80 81class StreamingDecoder(decoder.StreamingDecoder):82    __doc__ = decoder.StreamingDecoder.__doc__83 84    SINGLE_ITEM_DECODER = SingleItemDecoder85 86 87class Decoder(decoder.Decoder):88    __doc__ = decoder.Decoder.__doc__89 90    STREAMING_DECODER = StreamingDecoder91 92 93#: Turns CER octet stream into an ASN.1 object.94#:95#: Takes CER octet-stream and decode it into an ASN.1 object96#: (e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative) which97#: may be a scalar or an arbitrary nested structure.98#:99#: Parameters100#: ----------101#: substrate: :py:class:`bytes`102#:     CER octet-stream103#:104#: Keyword Args105#: ------------106#: asn1Spec: any pyasn1 type object e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative107#:     A pyasn1 type object to act as a template guiding the decoder. Depending on the ASN.1 structure108#:     being decoded, *asn1Spec* may or may not be required. Most common reason for109#:     it to require is that ASN.1 structure is encoded in *IMPLICIT* tagging mode.110#:111#: Returns112#: -------113#: : :py:class:`tuple`114#:     A tuple of pyasn1 object recovered from CER substrate (:py:class:`~pyasn1.type.base.PyAsn1Item` derivative)115#:     and the unprocessed trailing portion of the *substrate* (may be empty)116#:117#: Raises118#: ------119#: ~pyasn1.error.PyAsn1Error, ~pyasn1.error.SubstrateUnderrunError120#:     On decoding errors121#:122#: Examples123#: --------124#: Decode CER serialisation without ASN.1 schema125#:126#: .. code-block:: pycon127#:128#:    >>> s, _ = decode(b'0\x80\x02\x01\x01\x02\x01\x02\x02\x01\x03\x00\x00')129#:    >>> str(s)130#:    SequenceOf:131#:     1 2 3132#:133#: Decode CER serialisation with ASN.1 schema134#:135#: .. code-block:: pycon136#:137#:    >>> seq = SequenceOf(componentType=Integer())138#:    >>> s, _ = decode(b'0\x80\x02\x01\x01\x02\x01\x02\x02\x01\x03\x00\x00', asn1Spec=seq)139#:    >>> str(s)140#:    SequenceOf:141#:     1 2 3142#:143decode = Decoder()144 145def __getattr__(attr: str):146    if newAttr := {"tagMap": "TAG_MAP", "typeMap": "TYPE_MAP"}.get(attr):147        warnings.warn(f"{attr} is deprecated. Please use {newAttr} instead.", DeprecationWarning, stacklevel=2)148        return globals()[newAttr]149    raise AttributeError(attr)150