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Current Path : /proc/thread-self/root/lib/python3.6/site-packages/pyasn1/codec/der/ |
Current File : //proc/thread-self/root/lib/python3.6/site-packages/pyasn1/codec/der/decoder.py |
# # This file is part of pyasn1 software. # # Copyright (c) 2005-2017, Ilya Etingof <etingof@gmail.com> # License: http://pyasn1.sf.net/license.html # from pyasn1.type import univ from pyasn1.codec.cer import decoder __all__ = ['decode'] class BitStringDecoder(decoder.BitStringDecoder): supportConstructedForm = False class OctetStringDecoder(decoder.OctetStringDecoder): supportConstructedForm = False # TODO: prohibit non-canonical encoding RealDecoder = decoder.RealDecoder tagMap = decoder.tagMap.copy() tagMap.update( {univ.BitString.tagSet: BitStringDecoder(), univ.OctetString.tagSet: OctetStringDecoder(), univ.Real.tagSet: RealDecoder()} ) typeMap = decoder.typeMap.copy() # Put in non-ambiguous types for faster codec lookup for typeDecoder in tagMap.values(): if typeDecoder.protoComponent is not None: typeId = typeDecoder.protoComponent.__class__.typeId if typeId is not None and typeId not in typeMap: typeMap[typeId] = typeDecoder class Decoder(decoder.Decoder): supportIndefLength = False #: Turns DER octet stream into an ASN.1 object. #: #: Takes DER octetstream and decode it into an ASN.1 object #: (e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative) which #: may be a scalar or an arbitrary nested structure. #: #: Parameters #: ---------- #: substrate: :py:class:`bytes` (Python 3) or :py:class:`str` (Python 2) #: DER octetstream #: #: asn1Spec: any pyasn1 type object e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative #: A pyasn1 type object to act as a template guiding the decoder. Depending on the ASN.1 structure #: being decoded, *asn1Spec* may or may not be required. Most common reason for #: it to require is that ASN.1 structure is encoded in *IMPLICIT* tagging mode. #: #: Returns #: ------- #: : :py:class:`tuple` #: A tuple of pyasn1 object recovered from DER substrate (:py:class:`~pyasn1.type.base.PyAsn1Item` derivative) #: and the unprocessed trailing portion of the *substrate* (may be empty) #: #: Raises #: ------ #: : :py:class:`pyasn1.error.PyAsn1Error` #: On decoding errors decode = Decoder(tagMap, typeMap)