def __call__(self, asn1Value):
if not isinstance(asn1Value, base.Asn1Item):
raise error.PyAsn1Error('value is not valid (should be an instance of an ASN.1 Item)')
if debug.logger & debug.flagEncoder:
debug.scope.push(type(asn1Value).__name__)
debug.logger('encoder called for type %s <%s>' % (type(asn1Value).__name__, asn1Value.prettyPrint()))
tagSet = asn1Value.getTagSet()
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if asn1Value.typeId is not None and asn1Value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[asn1Value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = asn1Value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise error.PyAsn1Error('No encoder for %s' % (asn1Value,))
debug.logger & debug.flagEncoder and debug.logger('using value codec %s chosen by %s' % (type(concreteEncoder).__name__, tagSet))
pyObject = concreteEncoder.encode(self, asn1Value)
if debug.logger & debug.flagEncoder:
debug.logger('encoder %s produced: %s' % (type(concreteEncoder).__name__, repr(pyObject)))
debug.scope.pop()
return pyObject
def __call__(self, value, defMode=True, maxChunkSize=0):
if not defMode and not self.supportIndefLength:
raise error.PyAsn1Error('Indefinite length encoding not supported by this codec')
debug.logger & debug.flagEncoder and debug.logger(
'encoder called in %sdef mode, chunk size %s for type %s, value:\n%s' % (
not defMode and 'in' or '', maxChunkSize, value.prettyPrintType(), value.prettyPrint()))
tagSet = value.tagSet
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
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,))
debug.logger & debug.flagEncoder and debug.logger(
'using value codec %s chosen by %s' % (concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(
self, value, defMode, maxChunkSize
)
debug.logger & debug.flagEncoder and debug.logger(
'built %s octets of substrate: %s\nencoder completed' % (len(substrate), debug.hexdump(substrate)))
return substrate
def __call__(self, value, defMode=1, maxChunkSize=0):
debug.logger & debug.flagEncoder and debug.logger(
'encoder called for type %s, value:\n%s' %
(value.__class__.__name__, value.prettyPrint()))
tagSet = value.getTagSet()
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if value.typeId is not None and value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise Error('No encoder for %s' % (value, ))
debug.logger & debug.flagEncoder and debug.logger(
'using value codec %s chosen by %r' %
(concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(self, value, defMode, maxChunkSize)
debug.logger & debug.flagEncoder and debug.logger(
'built %s octets of substrate: %s\nencoder completed' %
(len(substrate), debug.hexdump(substrate)))
return substrate
def __call__(self, value, defMode=True, maxChunkSize=0):
if not isinstance(value, base.Asn1Item):
raise error.PyAsn1Error('value is not valid (should be an instance of an ASN.1 Item)')
if not defMode and not self.supportIndefLength:
raise error.PyAsn1Error('Indefinite length encoding not supported by this codec')
debug.logger & debug.flagEncoder and debug.logger(
'encoder called in %sdef mode, chunk size %s for type %s, value:\n%s' % (
not defMode and 'in' or '', maxChunkSize, value.prettyPrintType(), value.prettyPrint()))
tagSet = value.getTagSet()
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if value.typeId is not None and value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise Error('No encoder for %s' % (value,))
debug.logger & debug.flagEncoder and debug.logger(
'using value codec %s chosen by %s' % (concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(
self, value, defMode, maxChunkSize
)
debug.logger & debug.flagEncoder and debug.logger(
'built %s octets of substrate: %s\nencoder completed' % (len(substrate), debug.hexdump(substrate)))
return substrate
def __call__(self, asn1Value):
if not isinstance(asn1Value, base.Asn1Item):
raise error.PyAsn1Error('value is not valid (should be an instance of an ASN.1 Item)')
if debug.logger & debug.flagEncoder:
debug.scope.push(type(asn1Value).__name__)
debug.logger('encoder called for type %s <%s>' % (type(asn1Value).__name__, asn1Value.prettyPrint()))
tagSet = asn1Value.tagSet
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if asn1Value.typeId is not None and asn1Value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[asn1Value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = asn1Value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise error.PyAsn1Error('No encoder for %s' % (asn1Value,))
debug.logger & debug.flagEncoder and debug.logger('using value codec %s chosen by %s' % (type(concreteEncoder).__name__, tagSet))
pyObject = concreteEncoder.encode(self, asn1Value)
if debug.logger & debug.flagEncoder:
debug.logger('encoder %s produced: %s' % (type(concreteEncoder).__name__, repr(pyObject)))
debug.scope.pop()
return pyObject
def __call__(self, value, defMode=True, maxChunkSize=0):
if not defMode and not self.supportIndefLength:
raise error.PyAsn1Error(
'Indefinite length encoding not supported by this codec')
debug.logger & debug.flagEncoder and debug.logger(
'encoder called in %sdef mode, chunk size %s for type %s, value:\n%s'
% (not defMode and 'in' or '', maxChunkSize,
value.prettyPrintType(), value.prettyPrint()))
tagSet = value.getTagSet()
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if value.typeId is not None and value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise Error('No encoder for %s' % (value, ))
debug.logger & debug.flagEncoder and debug.logger(
'using value codec %s chosen by %s' %
(concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(self, value, defMode, maxChunkSize)
debug.logger & debug.flagEncoder and debug.logger(
'built %s octets of substrate: %s\nencoder completed' %
(len(substrate), debug.hexdump(substrate)))
return substrate
def __call__(self, pyObject, asn1Spec):
if debug.logger & debug.flagDecoder:
debug.scope.push(type(pyObject).__name__)
debug.logger('decoder called at scope %s, working with type %s' % (debug.scope, type(pyObject).__name__))
if asn1Spec is None or not isinstance(asn1Spec, base.Asn1Item):
raise error.PyAsn1Error('asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)' % asn1Spec.__class__.__name__)
if asn1Spec.typeId is not None and asn1Spec.typeId in self.__typeMap:
valueDecoder = self.__typeMap[asn1Spec.typeId]
elif asn1Spec.tagSet.getBaseTag() in self.__tagMap:
valueDecoder = self.__tagMap[asn1Spec.tagSet.getBaseTag()]
else:
raise error.PyAsn1Error('Unknown ASN.1 tag %s' % asn1Spec.tagSet)
if debug.logger & debug.flagDecoder:
debug.logger('calling decoder %s on Python type %s <%s>' % (type(valueDecoder).__name__, type(pyObject).__name__, repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self)
if debug.logger & debug.flagDecoder:
debug.logger('decoder %s produced ASN.1 type %s <%s>' % (type(valueDecoder).__name__, type(value).__name__, repr(value)))
debug.scope.pop()
return value
def __call__(self, pyObject, asn1Spec):
if debug.logger & debug.flagDecoder:
debug.scope.push(type(pyObject).__name__)
debug.logger('decoder called at scope %s, working with type %s' %
(debug.scope, type(pyObject).__name__))
if asn1Spec is None or not isinstance(asn1Spec, base.Asn1Item):
raise error.PyAsn1Error(
'asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)'
% asn1Spec.__class__.__name__)
if asn1Spec.typeId is not None and asn1Spec.typeId in self.__typeMap:
valueDecoder = self.__typeMap[asn1Spec.typeId]
elif asn1Spec.tagSet.getBaseTag() in self.__tagMap:
valueDecoder = self.__tagMap[asn1Spec.tagSet.getBaseTag()]
else:
raise error.PyAsn1Error('Unknown ASN.1 tag %s' % asn1Spec.tagSet)
if debug.logger & debug.flagDecoder:
debug.logger('calling decoder %s on Python type %s <%s>' %
(type(valueDecoder).__name__, type(pyObject).__name__,
repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self)
if debug.logger & debug.flagDecoder:
debug.logger('decoder %s produced ASN.1 type %s <%s>' %
(type(valueDecoder).__name__, type(value).__name__,
repr(value)))
debug.scope.pop()
return value
def __call__(self, pyObject, asn1Spec):
if debug.logger & debug.flagDecoder:
debug.scope.push(type(pyObject).__name__)
debug.logger('decoder called at scope %s, working with type %s' % (debug.scope, type(pyObject).__name__))
if asn1Spec is None or not isinstance(asn1Spec, base.Asn1Item):
raise error.PyAsn1Error('asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)' % asn1Spec.__class__.__name__)
try:
valueDecoder = self.__typeMap[asn1Spec.typeId]
except KeyError:
# use base type for codec lookup to recover untagged types
baseTagSet = tag.TagSet(asn1Spec.tagSet.baseTag, asn1Spec.tagSet.baseTag)
try:
valueDecoder = self.__tagMap[baseTagSet]
except KeyError:
raise error.PyAsn1Error('Unknown ASN.1 tag %s' % asn1Spec.tagSet)
if debug.logger & debug.flagDecoder:
debug.logger('calling decoder %s on Python type %s <%s>' % (type(valueDecoder).__name__, type(pyObject).__name__, repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self)
if debug.logger & debug.flagDecoder:
debug.logger('decoder %s produced ASN.1 type %s <%s>' % (type(valueDecoder).__name__, type(value).__name__, repr(value)))
debug.scope.pop()
return value
def __call__(self, value, defMode=1, maxChunkSize=0):
debug.logger & debug.flagEncoder and debug.logger('encoder called for type %s, value:\n%s' % (value.__class__.__name__, value.prettyPrint()))
tagSet = value.getTagSet()
if len(tagSet) > 1:
concreteEncoder = explicitlyTaggedItemEncoder
else:
if value.typeId is not None and value.typeId in self.__typeMap:
concreteEncoder = self.__typeMap[value.typeId]
elif tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
tagSet = value.baseTagSet
if tagSet in self.__tagMap:
concreteEncoder = self.__tagMap[tagSet]
else:
raise Error('No encoder for %s' % (value,))
debug.logger & debug.flagEncoder and debug.logger('using value codec %s chosen by %r' % (concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(
self, value, defMode, maxChunkSize
)
debug.logger & debug.flagEncoder and debug.logger('built %s octets of substrate: %s\nencoder completed' % (len(substrate), debug.hexdump(substrate)))
return substrate
def __call__(self, pyObject, asn1Spec):
if debug.logger & debug.flagDecoder:
debug.scope.push(type(pyObject).__name__)
debug.logger('decoder called at scope %s, working with type %s' %
(debug.scope, type(pyObject).__name__))
if asn1Spec is None or not isinstance(asn1Spec, base.Asn1Item):
raise error.PyAsn1Error(
'asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)'
% asn1Spec.__class__.__name__)
try:
valueDecoder = self.__typeMap[asn1Spec.typeId]
except KeyError:
# use base type for codec lookup to recover untagged types
baseTagSet = tag.TagSet(asn1Spec.tagSet.baseTag,
asn1Spec.tagSet.baseTag)
try:
valueDecoder = self.__tagMap[baseTagSet]
except KeyError:
raise error.PyAsn1Error('Unknown ASN.1 tag %s' %
asn1Spec.tagSet)
if debug.logger & debug.flagDecoder:
debug.logger('calling decoder %s on Python type %s <%s>' %
(type(valueDecoder).__name__, type(pyObject).__name__,
repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self)
if debug.logger & debug.flagDecoder:
debug.logger('decoder %s produced ASN.1 type %s <%s>' %
(type(valueDecoder).__name__, type(value).__name__,
repr(value)))
debug.scope.pop()
return value
def __call__(self, substrate, asn1Spec=None, tagSet=None,
length=None, state=stDecodeTag, recursiveFlag=1):
debug.logger & debug.flagDecoder and debug.logger('decoder called with state %d, working with up to %d octets of substrate: %s' % (state, len(substrate), debug.hexdump(substrate)))
fullSubstrate = substrate
while state != stStop:
if state == stDecodeTag:
# Decode tag
if not substrate:
raise error.SubstrateUnderrunError(
'Short octet stream on tag decoding'
)
firstOctet = substrate[0]
substrate = substrate[1:]
if firstOctet in self.__tagCache:
lastTag = self.__tagCache[firstOctet]
else:
t = oct2int(firstOctet)
tagClass = t&0xC0
tagFormat = t&0x20
tagId = t&0x1F
if tagId == 0x1F:
tagId = 0
while 1:
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 tagId < 31:
# 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 %r, 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 = size + 1
substrate = substrate[size:]
if length != -1 and 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(substrate)))
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
debug.logger and debug.logger & debug.flagDecoder and debug.logger('codec %s chosen by a built-in type, decoding %s' % (concreteDecoder and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'explicit tag'))
if state == stGetValueDecoderByAsn1Spec:
if isinstance(asn1Spec, (dict, tagmap.TagMap)):
if tagSet in asn1Spec:
__chosenSpec = asn1Spec[tagSet]
else:
__chosenSpec = None
else:
__chosenSpec = asn1Spec
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]
elif baseTagSet in self.__tagMap:
# base type or tagged subtype
concreteDecoder = self.__tagMap[baseTagSet]
else:
concreteDecoder = None
if concreteDecoder:
asn1Spec = __chosenSpec
state = stDecodeValue
else:
state = stTryAsExplicitTag
elif tagSet == self.__endOfOctetsTagSet:
concreteDecoder = self.__tagMap[tagSet]
state = stDecodeValue
else:
state = stTryAsExplicitTag
if debug.logger and debug.logger & debug.flagDecoder:
if isinstance(asn1Spec, base.Asn1Item):
debug.logger('choosing value codec by ASN.1 spec:\n %r -> %r' % (asn1Spec.getTagSet(), asn1Spec.__class__.__name__))
else:
debug.logger('choosing value codec by ASN.1 spec that offers either of the following: ')
for t, v in asn1Spec.getPosMap().items():
debug.logger(' %r -> %s' % (t, v.__class__.__name__))
debug.logger('but neither of: ')
for i in asn1Spec.getNegMap().items():
debug.logger(' %r -> %s' % (t, v.__class__.__name__))
debug.logger('codec %s chosen by ASN.1 spec, decoding %s' % (state == stDecodeValue and concreteDecoder.__class__.__name__ or "<none>", state == stDecodeValue and 'value' or 'explicit tag'))
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:
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:
decodeFun = self
else:
decodeFun = None
if length == -1: # indef length
value, substrate = concreteDecoder.indefLenValueDecoder(
fullSubstrate, substrate, asn1Spec, tagSet, length,
stGetValueDecoder, decodeFun
)
else:
value, _substrate = concreteDecoder.valueDecoder(
fullSubstrate, substrate, asn1Spec, tagSet, length,
stGetValueDecoder, decodeFun
)
if recursiveFlag:
substrate = substrate[length:]
else:
substrate = _substrate
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(
'%r not in asn1Spec: %r' % (tagSet, asn1Spec)
)
debug.logger and debug.logger & debug.flagDecoder and debug.logger('decoder call completed')
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)))
if asn1Spec is not None and not isinstance(asn1Spec, (base.Asn1Item, tagmap.TagMap)):
raise error.PyAsn1Error('asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)' % asn1Spec.__class__.__name__)
fullSubstrate = substrate
while state != stStop:
if state == stDecodeTag:
if not substrate:
raise error.SubstrateUnderrunError(
'Short octet stream on tag decoding'
)
if not isOctetsType(substrate) and \
not isinstance(substrate, univ.OctetString):
raise error.PyAsn1Error('Bad octet stream type')
# 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
if tagId == 0x1F:
tagId = 0
while 1:
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 tagId < 31:
# 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:
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 isinstance(asn1Spec, (dict, 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
substrateFun = lambda a,b,c: (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)))
if asn1Spec is not None and not isinstance(
asn1Spec, (base.Asn1Item, tagmap.TagMap)):
raise error.PyAsn1Error(
'asn1Spec is not valid (should be an instance of an ASN.1 Item, not %s)'
% asn1Spec.__class__.__name__)
value = base.noValue
fullSubstrate = substrate
while state != stStop:
if state == stDecodeTag:
if not substrate:
raise error.SubstrateUnderrunError(
'Short octet stream on tag decoding')
if not isOctetsType(substrate) and \
not isinstance(substrate, univ.OctetString):
raise error.PyAsn1Error('Bad octet stream type')
# 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:
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 isinstance(asn1Spec, (dict, 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 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):
debug.logger & debug.flagDecoder and debug.logger(
'decoder called with state %d, working with up to %d octets of substrate: %s'
% (state, len(substrate), debug.hexdump(substrate)))
fullSubstrate = substrate
while state != stStop:
if state == stDecodeTag:
# Decode tag
if not substrate:
raise error.SubstrateUnderrunError(
'Short octet stream on tag decoding')
firstOctet = substrate[0]
substrate = substrate[1:]
if firstOctet in self.__tagCache:
lastTag = self.__tagCache[firstOctet]
else:
t = oct2int(firstOctet)
tagClass = t & 0xC0
tagFormat = t & 0x20
tagId = t & 0x1F
if tagId == 0x1F:
tagId = 0
while 1:
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 tagId < 31:
# 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 %r, 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 = size + 1
substrate = substrate[size:]
if length != -1 and 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(substrate)))
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
debug.logger and debug.logger & debug.flagDecoder and debug.logger(
'codec %s chosen by a built-in type, decoding %s' %
(concreteDecoder and concreteDecoder.__class__.__name__
or "<none>", state == stDecodeValue and 'value'
or 'explicit tag'))
if state == stGetValueDecoderByAsn1Spec:
if isinstance(asn1Spec, (dict, tagmap.TagMap)):
if tagSet in asn1Spec:
__chosenSpec = asn1Spec[tagSet]
else:
__chosenSpec = None
else:
__chosenSpec = asn1Spec
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]
elif baseTagSet in self.__tagMap:
# base type or tagged subtype
concreteDecoder = self.__tagMap[baseTagSet]
else:
concreteDecoder = None
if concreteDecoder:
asn1Spec = __chosenSpec
state = stDecodeValue
else:
state = stTryAsExplicitTag
elif tagSet == self.__endOfOctetsTagSet:
concreteDecoder = self.__tagMap[tagSet]
state = stDecodeValue
else:
state = stTryAsExplicitTag
if debug.logger and debug.logger & debug.flagDecoder:
if isinstance(asn1Spec, base.Asn1Item):
debug.logger(
'choosing value codec by ASN.1 spec:\n %r -> %r' %
(asn1Spec.getTagSet(),
asn1Spec.__class__.__name__))
else:
debug.logger(
'choosing value codec by ASN.1 spec that offers either of the following: '
)
for t, v in list(asn1Spec.getPosMap().items()):
debug.logger(' %r -> %s' %
(t, v.__class__.__name__))
debug.logger('but neither of: ')
for i in list(asn1Spec.getNegMap().items()):
debug.logger(' %r -> %s' %
(t, v.__class__.__name__))
debug.logger(
'codec %s chosen by ASN.1 spec, decoding %s' %
(state == stDecodeValue
and concreteDecoder.__class__.__name__ or "<none>",
state == stDecodeValue and 'value' or 'explicit tag'))
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:
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:
decodeFun = self
else:
decodeFun = None
if length == -1: # indef length
value, substrate = concreteDecoder.indefLenValueDecoder(
fullSubstrate, substrate, asn1Spec, tagSet, length,
stGetValueDecoder, decodeFun)
else:
value, _substrate = concreteDecoder.valueDecoder(
fullSubstrate, substrate, asn1Spec, tagSet, length,
stGetValueDecoder, decodeFun)
if recursiveFlag:
substrate = substrate[length:]
else:
substrate = _substrate
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('%r not in asn1Spec: %r' %
(tagSet, asn1Spec))
debug.logger and debug.logger & debug.flagDecoder and debug.logger(
'decoder call completed')
return value, substrate
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
