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+#
+# This file is part of pyasn1 software.
+#
+# Copyright (c) 2005-2020, Ilya Etingof <etingof@gmail.com>
+# License: https://pyasn1.readthedocs.io/en/latest/license.html
+#
+import warnings
+
+from pyasn1 import error
+from pyasn1.codec.streaming import readFromStream
+from pyasn1.codec.ber import decoder
+from pyasn1.type import univ
+
+__all__ = ['decode', 'StreamingDecoder']
+
+SubstrateUnderrunError = error.SubstrateUnderrunError
+
+
+class BooleanPayloadDecoder(decoder.AbstractSimplePayloadDecoder):
+ protoComponent = univ.Boolean(0)
+
+ def valueDecoder(self, substrate, asn1Spec,
+ tagSet=None, length=None, state=None,
+ decodeFun=None, substrateFun=None,
+ **options):
+
+ if length != 1:
+ raise error.PyAsn1Error('Not single-octet Boolean payload')
+
+ for chunk in readFromStream(substrate, length, options):
+ if isinstance(chunk, SubstrateUnderrunError):
+ yield chunk
+
+ byte = chunk[0]
+
+ # CER/DER specifies encoding of TRUE as 0xFF and FALSE as 0x0, while
+ # BER allows any non-zero value as TRUE; cf. sections 8.2.2. and 11.1
+ # in https://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
+ if byte == 0xff:
+ value = 1
+
+ elif byte == 0x00:
+ value = 0
+
+ else:
+ raise error.PyAsn1Error('Unexpected Boolean payload: %s' % byte)
+
+ yield self._createComponent(asn1Spec, tagSet, value, **options)
+
+
+# TODO: prohibit non-canonical encoding
+BitStringPayloadDecoder = decoder.BitStringPayloadDecoder
+OctetStringPayloadDecoder = decoder.OctetStringPayloadDecoder
+RealPayloadDecoder = decoder.RealPayloadDecoder
+
+TAG_MAP = decoder.TAG_MAP.copy()
+TAG_MAP.update(
+ {univ.Boolean.tagSet: BooleanPayloadDecoder(),
+ univ.BitString.tagSet: BitStringPayloadDecoder(),
+ univ.OctetString.tagSet: OctetStringPayloadDecoder(),
+ univ.Real.tagSet: RealPayloadDecoder()}
+)
+
+TYPE_MAP = decoder.TYPE_MAP.copy()
+
+# Put in non-ambiguous types for faster codec lookup
+for typeDecoder in TAG_MAP.values():
+ if typeDecoder.protoComponent is not None:
+ typeId = typeDecoder.protoComponent.__class__.typeId
+ if typeId is not None and typeId not in TYPE_MAP:
+ TYPE_MAP[typeId] = typeDecoder
+
+
+class SingleItemDecoder(decoder.SingleItemDecoder):
+ __doc__ = decoder.SingleItemDecoder.__doc__
+
+ TAG_MAP = TAG_MAP
+ TYPE_MAP = TYPE_MAP
+
+
+class StreamingDecoder(decoder.StreamingDecoder):
+ __doc__ = decoder.StreamingDecoder.__doc__
+
+ SINGLE_ITEM_DECODER = SingleItemDecoder
+
+
+class Decoder(decoder.Decoder):
+ __doc__ = decoder.Decoder.__doc__
+
+ STREAMING_DECODER = StreamingDecoder
+
+
+#: Turns CER octet stream into an ASN.1 object.
+#:
+#: Takes CER octet-stream 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`
+#: CER octet-stream
+#:
+#: Keyword Args
+#: ------------
+#: 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 CER substrate (:py:class:`~pyasn1.type.base.PyAsn1Item` derivative)
+#: and the unprocessed trailing portion of the *substrate* (may be empty)
+#:
+#: Raises
+#: ------
+#: ~pyasn1.error.PyAsn1Error, ~pyasn1.error.SubstrateUnderrunError
+#: On decoding errors
+#:
+#: Examples
+#: --------
+#: Decode CER serialisation without ASN.1 schema
+#:
+#: .. code-block:: pycon
+#:
+#: >>> s, _ = decode(b'0\x80\x02\x01\x01\x02\x01\x02\x02\x01\x03\x00\x00')
+#: >>> str(s)
+#: SequenceOf:
+#: 1 2 3
+#:
+#: Decode CER serialisation with ASN.1 schema
+#:
+#: .. code-block:: pycon
+#:
+#: >>> seq = SequenceOf(componentType=Integer())
+#: >>> s, _ = decode(b'0\x80\x02\x01\x01\x02\x01\x02\x02\x01\x03\x00\x00', asn1Spec=seq)
+#: >>> str(s)
+#: SequenceOf:
+#: 1 2 3
+#:
+decode = Decoder()
+
+def __getattr__(attr: str):
+ if newAttr := {"tagMap": "TAG_MAP", "typeMap": "TYPE_MAP"}.get(attr):
+ warnings.warn(f"{attr} is deprecated. Please use {newAttr} instead.", DeprecationWarning)
+ return globals()[newAttr]
+ raise AttributeError(attr)