def from_bytes(octets, signed=False): if not octets: return 0 value = long(b2a_hex(ensureString(octets)), 16) if signed and oct2int(octets[0]) & 0x80: return value - (1 << len(octets) * 8) return value
def test_ensureString(self): assert 'abc'.encode() == octets.ensureString('abc'.encode()) assert bytes([1, 2, 3]) == octets.ensureString([1, 2, 3])
def test_ensureString(self): assert 'abc' == octets.ensureString('abc') assert '123' == octets.ensureString(123)
def __call__(self, substrate, asn1Spec=None, tagSet=None, length=None, state=stDecodeTag, recursiveFlag=True, substrateFun=None, allowEoo=False): if debug.logger and debug.logger & debug.flagDecoder: debug.logger('decoder called at scope %s with state %d, working with up to %d octets of substrate: %s' % (debug.scope, state, len(substrate), debug.hexdump(substrate))) substrate = ensureString(substrate) # Look for end-of-octets sentinel if allowEoo and self.supportIndefLength: if substrate.startswith(self.__eooSentinel): debug.logger and debug.logger & debug.flagDecoder and debug.logger('end-of-octets sentinel found') return eoo.endOfOctets, substrate[2:] value = base.noValue fullSubstrate = substrate while state != stStop: if state == stDecodeTag: if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on tag decoding' ) # Decode tag isShortTag = True firstOctet = substrate[0] substrate = substrate[1:] try: lastTag = self.__tagCache[firstOctet] except KeyError: integerTag = oct2int(firstOctet) tagClass = integerTag & 0xC0 tagFormat = integerTag & 0x20 tagId = integerTag & 0x1F if tagId == 0x1F: isShortTag = False lengthOctetIdx = 0 tagId = 0 try: while True: integerTag = oct2int(substrate[lengthOctetIdx]) lengthOctetIdx += 1 tagId <<= 7 tagId |= (integerTag & 0x7F) if not integerTag & 0x80: break substrate = substrate[lengthOctetIdx:] except IndexError: raise error.SubstrateUnderrunError( 'Short octet stream on long tag decoding' ) lastTag = tag.Tag( tagClass=tagClass, tagFormat=tagFormat, tagId=tagId ) if isShortTag: # cache short tags self.__tagCache[firstOctet] = lastTag if tagSet is None: if isShortTag: try: tagSet = self.__tagSetCache[firstOctet] except KeyError: # base tag not recovered tagSet = tag.TagSet((), lastTag) self.__tagSetCache[firstOctet] = tagSet else: tagSet = tag.TagSet((), lastTag) else: tagSet = lastTag + tagSet state = stDecodeLength debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'tag decoded into %s, decoding length' % tagSet) if state == stDecodeLength: # Decode length if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on length decoding' ) firstOctet = oct2int(substrate[0]) if firstOctet < 128: size = 1 length = firstOctet elif firstOctet == 128: size = 1 length = -1 else: size = firstOctet & 0x7F # encoded in size bytes encodedLength = octs2ints(substrate[1:size + 1]) # missing check on maximum size, which shouldn't be a # problem, we can handle more than is possible if len(encodedLength) != size: raise error.SubstrateUnderrunError( '%s<%s at %s' % (size, len(encodedLength), tagSet) ) length = 0 for lengthOctet in encodedLength: length <<= 8 length |= lengthOctet size += 1 substrate = substrate[size:] if length == -1: if not self.supportIndefLength: raise error.PyAsn1Error('Indefinite length encoding not supported by this codec') else: if len(substrate) < length: raise error.SubstrateUnderrunError('%d-octet short' % (length - len(substrate))) state = stGetValueDecoder debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value length decoded into %d, payload substrate is: %s' % (length, debug.hexdump(length == -1 and substrate or substrate[:length])) ) if state == stGetValueDecoder: if asn1Spec is None: state = stGetValueDecoderByTag else: state = stGetValueDecoderByAsn1Spec # # There're two ways of creating subtypes in ASN.1 what influences # decoder operation. These methods are: # 1) Either base types used in or no IMPLICIT tagging has been # applied on subtyping. # 2) Subtype syntax drops base type information (by means of # IMPLICIT tagging. # The first case allows for complete tag recovery from substrate # while the second one requires original ASN.1 type spec for # decoding. # # In either case a set of tags (tagSet) is coming from substrate # in an incremental, tag-by-tag fashion (this is the case of # EXPLICIT tag which is most basic). Outermost tag comes first # from the wire. # if state == stGetValueDecoderByTag: try: concreteDecoder = self.__tagMap[tagSet] except KeyError: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: try: concreteDecoder = self.__tagMap[tagSet[:1]] except KeyError: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: state = stTryAsExplicitTag if debug.logger and debug.logger & debug.flagDecoder: debug.logger('codec %s chosen by a built-in type, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push( concreteDecoder is None and '?' or concreteDecoder.protoComponent.__class__.__name__) if state == stGetValueDecoderByAsn1Spec: if asn1Spec.__class__ is dict or asn1Spec.__class__ is tagmap.TagMap: try: chosenSpec = asn1Spec[tagSet] except KeyError: chosenSpec = None if debug.logger and debug.logger & debug.flagDecoder: debug.logger('candidate ASN.1 spec is a map of:') for firstOctet, v in asn1Spec.presentTypes.items(): debug.logger(' %s -> %s' % (firstOctet, v.__class__.__name__)) if asn1Spec.skipTypes: debug.logger('but neither of: ') for firstOctet, v in asn1Spec.skipTypes.items(): debug.logger(' %s -> %s' % (firstOctet, v.__class__.__name__)) debug.logger('new candidate ASN.1 spec is %s, chosen by %s' % (chosenSpec is None and '<none>' or chosenSpec.prettyPrintType(), tagSet)) else: if tagSet == asn1Spec.tagSet or tagSet in asn1Spec.tagMap: chosenSpec = asn1Spec debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'candidate ASN.1 spec is %s' % asn1Spec.__class__.__name__) else: chosenSpec = None if chosenSpec is not None: try: # ambiguous type or just faster codec lookup concreteDecoder = self.__typeMap[chosenSpec.typeId] debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value decoder chosen for an ambiguous type by type ID %s' % (chosenSpec.typeId,)) except KeyError: # use base type for codec lookup to recover untagged types baseTagSet = tag.TagSet(chosenSpec.tagSet.baseTag, chosenSpec.tagSet.baseTag) try: # base type or tagged subtype concreteDecoder = self.__tagMap[baseTagSet] debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value decoder chosen by base %s' % (baseTagSet,)) except KeyError: concreteDecoder = None if concreteDecoder: asn1Spec = chosenSpec state = stDecodeValue else: state = stTryAsExplicitTag else: concreteDecoder = None state = stTryAsExplicitTag if debug.logger and debug.logger & debug.flagDecoder: debug.logger('codec %s chosen by ASN.1 spec, decoding %s' % (state == stDecodeValue and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push(chosenSpec is None and '?' or chosenSpec.__class__.__name__) if state == stTryAsExplicitTag: if tagSet and tagSet[0].tagFormat == tag.tagFormatConstructed and tagSet[0].tagClass != tag.tagClassUniversal: # Assume explicit tagging concreteDecoder = explicitTagDecoder state = stDecodeValue else: concreteDecoder = None state = self.defaultErrorState debug.logger and debug.logger & debug.flagDecoder and debug.logger('codec %s chosen, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as failure')) if state == stDumpRawValue: concreteDecoder = self.defaultRawDecoder debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'codec %s chosen, decoding value' % concreteDecoder.__class__.__name__) state = stDecodeValue if state == stDecodeValue: if not recursiveFlag and not substrateFun: # legacy def substrateFun(a, b, c): return a, b[:c] if length == -1: # indef length value, substrate = concreteDecoder.indefLenValueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun ) else: value, substrate = concreteDecoder.valueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun ) state = stStop debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'codec %s yields type %s, value:\n%s\n...remaining substrate is: %s' % (concreteDecoder.__class__.__name__, value.__class__.__name__, value.prettyPrint(), substrate and debug.hexdump(substrate) or '<none>')) if state == stErrorCondition: raise error.PyAsn1Error( '%s not in asn1Spec: %s' % (tagSet, asn1Spec) ) if debug.logger and debug.logger & debug.flagDecoder: debug.scope.pop() debug.logger('decoder left scope %s, call completed' % debug.scope) return value, substrate
def __call__(self, substrate, asn1Spec=None, tagSet=None, length=None, state=stDecodeTag, recursiveFlag=1, substrateFun=None, allowEoo=False): if debug.logger & debug.flagDecoder: debug.logger( 'decoder called at scope %s with state %d, working with up to %d octets of substrate: %s' % (debug.scope, state, len(substrate), debug.hexdump(substrate))) substrate = ensureString(substrate) value = base.noValue fullSubstrate = substrate while state != stStop: if state == stDecodeTag: if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on tag decoding') # Decode tag firstOctet = substrate[0] substrate = substrate[1:] if firstOctet in self.__tagCache: lastTag = self.__tagCache[firstOctet] else: t = oct2int(firstOctet) # Look for end-of-octets sentinel if t == 0: if substrate and oct2int(substrate[0]) == 0: if allowEoo and self.supportIndefLength: debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'end-of-octets sentinel found') value, substrate = eoo.endOfOctets, substrate[ 1:] state = stStop continue else: raise error.PyAsn1Error( 'Unexpected end-of-contents sentinel') else: raise error.PyAsn1Error('Zero tag encountered') tagClass = t & 0xC0 tagFormat = t & 0x20 tagId = t & 0x1F short = True if tagId == 0x1F: short = False tagId = 0 while True: if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on long tag decoding') t = oct2int(substrate[0]) tagId = tagId << 7 | (t & 0x7F) substrate = substrate[1:] if not t & 0x80: break lastTag = tag.Tag(tagClass=tagClass, tagFormat=tagFormat, tagId=tagId) if short: # cache short tags self.__tagCache[firstOctet] = lastTag if tagSet is None: if firstOctet in self.__tagSetCache: tagSet = self.__tagSetCache[firstOctet] else: # base tag not recovered tagSet = tag.TagSet((), lastTag) if firstOctet in self.__tagCache: self.__tagSetCache[firstOctet] = tagSet else: tagSet = lastTag + tagSet state = stDecodeLength debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'tag decoded into %s, decoding length' % tagSet) if state == stDecodeLength: # Decode length if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on length decoding') firstOctet = oct2int(substrate[0]) if firstOctet == 128: size = 1 length = -1 elif firstOctet < 128: length, size = firstOctet, 1 else: size = firstOctet & 0x7F # encoded in size bytes length = 0 lengthString = substrate[1:size + 1] # missing check on maximum size, which shouldn't be a # problem, we can handle more than is possible if len(lengthString) != size: raise error.SubstrateUnderrunError( '%s<%s at %s' % (size, len(lengthString), tagSet)) for char in lengthString: length = (length << 8) | oct2int(char) size += 1 substrate = substrate[size:] if length != -1 and len(substrate) < length: raise error.SubstrateUnderrunError( '%d-octet short' % (length - len(substrate))) if length == -1 and not self.supportIndefLength: raise error.PyAsn1Error( 'Indefinite length encoding not supported by this codec' ) state = stGetValueDecoder debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value length decoded into %d, payload substrate is: %s' % (length, debug.hexdump(length == -1 and substrate or substrate[:length]))) if state == stGetValueDecoder: if asn1Spec is None: state = stGetValueDecoderByTag else: state = stGetValueDecoderByAsn1Spec # # There're two ways of creating subtypes in ASN.1 what influences # decoder operation. These methods are: # 1) Either base types used in or no IMPLICIT tagging has been # applied on subtyping. # 2) Subtype syntax drops base type information (by means of # IMPLICIT tagging. # The first case allows for complete tag recovery from substrate # while the second one requires original ASN.1 type spec for # decoding. # # In either case a set of tags (tagSet) is coming from substrate # in an incremental, tag-by-tag fashion (this is the case of # EXPLICIT tag which is most basic). Outermost tag comes first # from the wire. # if state == stGetValueDecoderByTag: if tagSet in self.__tagMap: concreteDecoder = self.__tagMap[tagSet] else: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: _k = tagSet[:1] if _k in self.__tagMap: concreteDecoder = self.__tagMap[_k] else: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: state = stTryAsExplicitTag if debug.logger and debug.logger & debug.flagDecoder: debug.logger( 'codec %s chosen by a built-in type, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push( concreteDecoder is None and '?' or concreteDecoder.protoComponent.__class__.__name__) if state == stGetValueDecoderByAsn1Spec: if asn1Spec.__class__ is dict or asn1Spec.__class__ is tagmap.TagMap: if tagSet in asn1Spec: __chosenSpec = asn1Spec[tagSet] else: __chosenSpec = None if debug.logger and debug.logger & debug.flagDecoder: debug.logger('candidate ASN.1 spec is a map of:') for t, v in asn1Spec.getPosMap().items(): debug.logger(' %s -> %s' % (t, v.__class__.__name__)) if asn1Spec.getNegMap(): debug.logger('but neither of: ') for t, v in asn1Spec.getNegMap().items(): debug.logger(' %s -> %s' % (t, v.__class__.__name__)) debug.logger( 'new candidate ASN.1 spec is %s, chosen by %s' % (__chosenSpec is None and '<none>' or __chosenSpec.prettyPrintType(), tagSet)) else: __chosenSpec = asn1Spec debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'candidate ASN.1 spec is %s' % asn1Spec.__class__.__name__) if __chosenSpec is not None and ( tagSet == __chosenSpec.getTagSet() or tagSet in __chosenSpec.getTagMap()): # use base type for codec lookup to recover untagged types baseTagSet = __chosenSpec.baseTagSet if __chosenSpec.typeId is not None and \ __chosenSpec.typeId in self.__typeMap: # ambiguous type concreteDecoder = self.__typeMap[__chosenSpec.typeId] debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value decoder chosen for an ambiguous type by type ID %s' % (__chosenSpec.typeId, )) elif baseTagSet in self.__tagMap: # base type or tagged subtype concreteDecoder = self.__tagMap[baseTagSet] debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'value decoder chosen by base %s' % (baseTagSet, )) else: concreteDecoder = None if concreteDecoder: asn1Spec = __chosenSpec state = stDecodeValue else: state = stTryAsExplicitTag else: concreteDecoder = None state = stTryAsExplicitTag if debug.logger and debug.logger & debug.flagDecoder: debug.logger( 'codec %s chosen by ASN.1 spec, decoding %s' % (state == stDecodeValue and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push(__chosenSpec is None and '?' or __chosenSpec.__class__.__name__) if state == stTryAsExplicitTag: if tagSet and tagSet[0][1] == tag.tagFormatConstructed and \ tagSet[0][0] != tag.tagClassUniversal: # Assume explicit tagging concreteDecoder = explicitTagDecoder state = stDecodeValue else: concreteDecoder = None state = self.defaultErrorState debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'codec %s chosen, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'as failure')) if state == stDumpRawValue: concreteDecoder = self.defaultRawDecoder debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'codec %s chosen, decoding value' % concreteDecoder.__class__.__name__) state = stDecodeValue if state == stDecodeValue: if recursiveFlag == 0 and not substrateFun: # legacy def substrateFun(a, b, c): return a, b[:c] if length == -1: # indef length value, substrate = concreteDecoder.indefLenValueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun) else: value, substrate = concreteDecoder.valueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun) state = stStop debug.logger and debug.logger & debug.flagDecoder and debug.logger( 'codec %s yields type %s, value:\n%s\n...remaining substrate is: %s' % (concreteDecoder.__class__.__name__, value.__class__.__name__, value.prettyPrint(), substrate and debug.hexdump(substrate) or '<none>')) if state == stErrorCondition: raise error.PyAsn1Error('%s not in asn1Spec: %s' % (tagSet, asn1Spec)) if debug.logger and debug.logger & debug.flagDecoder: debug.scope.pop() debug.logger('decoder left scope %s, call completed' % debug.scope) return value, substrate
def __call__(self, substrate, asn1Spec=None, tagSet=None, length=None, state=stDecodeTag, recursiveFlag=True, substrateFun=None, allowEoo=False): if debug.logger & debug.flagDecoder: logger = debug.logger else: logger = None if logger: logger( 'decoder called at scope %s with state %d, working with up to %d octets of substrate: %s' % (debug.scope, state, len(substrate), debug.hexdump(substrate))) substrate = ensureString(substrate) # Look for end-of-octets sentinel if allowEoo and self.supportIndefLength: if substrate.startswith(self.__eooSentinel): if logger: logger('end-of-octets sentinel found') return eoo.endOfOctets, substrate[2:] value = base.noValue fullSubstrate = substrate while not state is stStop: if state is stDecodeTag: if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on tag decoding') # Decode tag isShortTag = True firstOctet = substrate[0] substrate = substrate[1:] try: lastTag = self.__tagCache[firstOctet] except KeyError: integerTag = oct2int(firstOctet) tagClass = integerTag & 0xC0 tagFormat = integerTag & 0x20 tagId = integerTag & 0x1F if tagId == 0x1F: isShortTag = False lengthOctetIdx = 0 tagId = 0 try: while True: integerTag = oct2int(substrate[lengthOctetIdx]) lengthOctetIdx += 1 tagId <<= 7 tagId |= (integerTag & 0x7F) if not integerTag & 0x80: break substrate = substrate[lengthOctetIdx:] except IndexError: raise error.SubstrateUnderrunError( 'Short octet stream on long tag decoding') lastTag = tag.Tag(tagClass=tagClass, tagFormat=tagFormat, tagId=tagId) if isShortTag: # cache short tags self.__tagCache[firstOctet] = lastTag if tagSet is None: if isShortTag: try: tagSet = self.__tagSetCache[firstOctet] except KeyError: # base tag not recovered tagSet = tag.TagSet((), lastTag) self.__tagSetCache[firstOctet] = tagSet else: tagSet = tag.TagSet((), lastTag) else: tagSet = lastTag + tagSet state = stDecodeLength if logger: logger('tag decoded into %s, decoding length' % tagSet) if state is stDecodeLength: # Decode length if not substrate: raise error.SubstrateUnderrunError( 'Short octet stream on length decoding') firstOctet = oct2int(substrate[0]) if firstOctet < 128: size = 1 length = firstOctet elif firstOctet == 128: size = 1 length = -1 else: size = firstOctet & 0x7F # encoded in size bytes encodedLength = octs2ints(substrate[1:size + 1]) # missing check on maximum size, which shouldn't be a # problem, we can handle more than is possible if len(encodedLength) != size: raise error.SubstrateUnderrunError( '%s<%s at %s' % (size, len(encodedLength), tagSet)) length = 0 for lengthOctet in encodedLength: length <<= 8 length |= lengthOctet size += 1 substrate = substrate[size:] if length == -1: if not self.supportIndefLength: raise error.PyAsn1Error( 'Indefinite length encoding not supported by this codec' ) else: if len(substrate) < length: raise error.SubstrateUnderrunError( '%d-octet short' % (length - len(substrate))) state = stGetValueDecoder if logger: logger( 'value length decoded into %d, payload substrate is: %s' % (length, debug.hexdump(length == -1 and substrate or substrate[:length]))) if state is stGetValueDecoder: if asn1Spec is None: state = stGetValueDecoderByTag else: state = stGetValueDecoderByAsn1Spec # # There're two ways of creating subtypes in ASN.1 what influences # decoder operation. These methods are: # 1) Either base types used in or no IMPLICIT tagging has been # applied on subtyping. # 2) Subtype syntax drops base type information (by means of # IMPLICIT tagging. # The first case allows for complete tag recovery from substrate # while the second one requires original ASN.1 type spec for # decoding. # # In either case a set of tags (tagSet) is coming from substrate # in an incremental, tag-by-tag fashion (this is the case of # EXPLICIT tag which is most basic). Outermost tag comes first # from the wire. # if state is stGetValueDecoderByTag: try: concreteDecoder = self.__tagMap[tagSet] except KeyError: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: try: concreteDecoder = self.__tagMap[tagSet[:1]] except KeyError: concreteDecoder = None if concreteDecoder: state = stDecodeValue else: state = stTryAsExplicitTag if logger: logger( 'codec %s chosen by a built-in type, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state is stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push( concreteDecoder is None and '?' or concreteDecoder.protoComponent.__class__.__name__) if state is stGetValueDecoderByAsn1Spec: if asn1Spec.__class__ is dict or asn1Spec.__class__ is tagmap.TagMap: try: chosenSpec = asn1Spec[tagSet] except KeyError: chosenSpec = None if logger: logger('candidate ASN.1 spec is a map of:') for firstOctet, v in asn1Spec.presentTypes.items(): logger(' %s -> %s' % (firstOctet, v.__class__.__name__)) if asn1Spec.skipTypes: logger('but neither of: ') for firstOctet, v in asn1Spec.skipTypes.items(): logger(' %s -> %s' % (firstOctet, v.__class__.__name__)) logger('new candidate ASN.1 spec is %s, chosen by %s' % (chosenSpec is None and '<none>' or chosenSpec.prettyPrintType(), tagSet)) else: if tagSet == asn1Spec.tagSet or tagSet in asn1Spec.tagMap: chosenSpec = asn1Spec if logger: logger('candidate ASN.1 spec is %s' % asn1Spec.__class__.__name__) else: chosenSpec = None if chosenSpec is not None: try: # ambiguous type or just faster codec lookup concreteDecoder = self.__typeMap[chosenSpec.typeId] if logger: logger( 'value decoder chosen for an ambiguous type by type ID %s' % (chosenSpec.typeId, )) except KeyError: # use base type for codec lookup to recover untagged types baseTagSet = tag.TagSet(chosenSpec.tagSet.baseTag, chosenSpec.tagSet.baseTag) try: # base type or tagged subtype concreteDecoder = self.__tagMap[baseTagSet] if logger: logger('value decoder chosen by base %s' % (baseTagSet, )) except KeyError: concreteDecoder = None if concreteDecoder: asn1Spec = chosenSpec state = stDecodeValue else: state = stTryAsExplicitTag else: concreteDecoder = None state = stTryAsExplicitTag if logger: logger('codec %s chosen by ASN.1 spec, decoding %s' % (state is stDecodeValue and concreteDecoder.__class__.__name__ or "<none>", state is stDecodeValue and 'value' or 'as explicit tag')) debug.scope.push(chosenSpec is None and '?' or chosenSpec.__class__.__name__) if state is stTryAsExplicitTag: if tagSet and tagSet[ 0].tagFormat == tag.tagFormatConstructed and tagSet[ 0].tagClass != tag.tagClassUniversal: # Assume explicit tagging concreteDecoder = explicitTagDecoder state = stDecodeValue else: concreteDecoder = None state = self.defaultErrorState if logger: logger( 'codec %s chosen, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state is stDecodeValue and 'value' or 'as failure')) if state is stDumpRawValue: concreteDecoder = self.defaultRawDecoder if logger: logger('codec %s chosen, decoding value' % concreteDecoder.__class__.__name__) state = stDecodeValue if state is stDecodeValue: if not recursiveFlag and not substrateFun: # legacy def substrateFun(a, b, c): return a, b[:c] if length == -1: # indef length value, substrate = concreteDecoder.indefLenValueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun) else: value, substrate = concreteDecoder.valueDecoder( fullSubstrate, substrate, asn1Spec, tagSet, length, stGetValueDecoder, self, substrateFun) state = stStop if logger: logger( 'codec %s yields type %s, value:\n%s\n...remaining substrate is: %s' % (concreteDecoder.__class__.__name__, value.__class__.__name__, value.prettyPrint(), substrate and debug.hexdump(substrate) or '<none>')) if state is stErrorCondition: raise error.PyAsn1Error('%s not in asn1Spec: %r' % (tagSet, asn1Spec)) if logger: debug.scope.pop() logger('decoder left scope %s, call completed' % debug.scope) return value, substrate