def __call__(self, pyObject, asn1Spec, **options):
if LOG:
debug.scope.push(type(pyObject).__name__)
LOG('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 LOG:
LOG('calling decoder %s on Python type %s <%s>' % (type(valueDecoder).__name__, type(pyObject).__name__, repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self, **options)
if LOG:
LOG('decoder %s produced ASN.1 type %s <%s>' % (type(valueDecoder).__name__, type(value).__name__, repr(value)))
debug.scope.pop()
return value
def encodeValue(self, value, asn1Spec, encodeFun, **options):
# Encoding constraints:
# - minutes are mandatory, seconds are optional
# - sub-seconds must NOT be zero
# - no hanging fraction dot
# - time in UTC (Z)
# - only dot is allowed for fractions
if asn1Spec is not None:
value = asn1Spec.clone(value)
octets = value.asOctets()
if not self.minLength < len(octets) < self.maxLength:
raise error.PyAsn1Error('Length constraint violated: %r' % value)
if self.pluschar in octets or self.minuschar in octets:
raise error.PyAsn1Error('Must be UTC time: %r' % octets)
if octets[-1] != self.zchar:
raise error.PyAsn1Error('Missing "Z" time zone specifier: %r' %
octets)
if self.commachar in octets:
raise error.PyAsn1Error('Comma in fractions disallowed: %r' %
value)
options.update(maxChunkSize=1000)
return encoder.OctetStringEncoder.encodeValue(self, value, asn1Spec,
encodeFun, **options)
def __call__(self, value, **options):
if not isinstance(value, base.Asn1Item):
raise error.PyAsn1Error('value is not valid (should be an instance of an ASN.1 Item)')
if LOG:
debug.scope.push(type(value).__name__)
LOG('encoder called for type %s <%s>' % (type(value).__name__, value.prettyPrint()))
tagSet = value.tagSet
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,))
if LOG:
LOG('using value codec %s chosen by %s' % (concreteEncoder.__class__.__name__, tagSet))
pyObject = concreteEncoder.encode(value, self, **options)
if LOG:
LOG('encoder %s produced: %s' % (type(concreteEncoder).__name__, repr(pyObject)))
debug.scope.pop()
return pyObject
def __call__(self, value, asn1Spec=None, **options):
try:
if asn1Spec is None:
typeId = value.typeId
else:
typeId = asn1Spec.typeId
except AttributeError:
raise error.PyAsn1Error('Value %r is not ASN.1 type instance '
'and "asn1Spec" not given' % (value, ))
if LOG:
LOG('encoder called in %sdef mode, chunk size %s for '
'type %s, value:\n%s' %
(not options.get('defMode', True) and 'in' or '',
options.get('maxChunkSize',
0), asn1Spec is None and value.prettyPrintType()
or asn1Spec.prettyPrintType(), value))
if self.fixedDefLengthMode is not None:
options.update(defMode=self.fixedDefLengthMode)
if self.fixedChunkSize is not None:
options.update(maxChunkSize=self.fixedChunkSize)
try:
concreteEncoder = self.__typeMap[typeId]
if LOG:
LOG('using value codec %s chosen by type ID %s' %
(concreteEncoder.__class__.__name__, typeId))
except KeyError:
if asn1Spec is None:
tagSet = value.tagSet
else:
tagSet = asn1Spec.tagSet
# use base type for codec lookup to recover untagged types
baseTagSet = tag.TagSet(tagSet.baseTag, tagSet.baseTag)
try:
concreteEncoder = self.__tagMap[baseTagSet]
except KeyError:
raise error.PyAsn1Error('No encoder for %r (%s)' %
(value, tagSet))
if LOG:
LOG('using value codec %s chosen by tagSet %s' %
(concreteEncoder.__class__.__name__, tagSet))
substrate = concreteEncoder.encode(value, asn1Spec, self, **options)
if LOG:
LOG('codec %s built %s octets of substrate: %s\nencoder completed'
% (concreteEncoder, len(substrate), debug.hexdump(substrate)))
return substrate
def encodeValue(self, value, asn1Spec, encodeFun, **options):
if asn1Spec is not None:
value = asn1Spec.clone(value)
oid = value.asTuple()
# Build the first pair
try:
first = oid[0]
second = oid[1]
except IndexError:
raise error.PyAsn1Error('Short OID %s' % (value, ))
if 0 <= second <= 39:
if first == 1:
oid = (second + 40, ) + oid[2:]
elif first == 0:
oid = (second, ) + oid[2:]
elif first == 2:
oid = (second + 80, ) + oid[2:]
else:
raise error.PyAsn1Error('Impossible first/second arcs at %s' %
(value, ))
elif first == 2:
oid = (second + 80, ) + oid[2:]
else:
raise error.PyAsn1Error('Impossible first/second arcs at %s' %
(value, ))
octets = ()
# Cycle through subIds
for subOid in oid:
if 0 <= subOid <= 127:
# Optimize for the common case
octets += (subOid, )
elif subOid > 127:
# Pack large Sub-Object IDs
res = (subOid & 0x7f, )
subOid >>= 7
while subOid:
res = (0x80 | (subOid & 0x7f), ) + res
subOid >>= 7
# Add packed Sub-Object ID to resulted Object ID
octets += res
else:
raise error.PyAsn1Error('Negative OID arc %s at %s' %
(subOid, value))
return octets, False, False
def _componentSortKey(componentAndType):
"""Sort SET components by tag
Sort depending on the actual Choice value (dynamic sort)
"""
component, asn1Spec = componentAndType
if asn1Spec is None:
compType = component
else:
compType = asn1Spec
if compType.typeId == univ.Choice.typeId and not compType.tagSet:
if asn1Spec is None:
return component.getComponent().tagSet
else:
# TODO: move out of sorting key function
names = [namedType.name for namedType in asn1Spec.componentType.namedTypes
if namedType.name in component]
if len(names) != 1:
raise error.PyAsn1Error(
'%s components for Choice at %r' % (len(names) and 'Multiple ' or 'None ', component))
# TODO: support nested CHOICE ordering
return asn1Spec[names[0]].tagSet
else:
return compType.tagSet
def getValues(self, *names):
try:
return [self.__names[name] for name in names]
except KeyError:
raise error.PyAsn1Error('Unknown bit identifier(s): %s' %
(set(names).difference(self.__names), ))
def getPositionNearType(self, tagSet, idx):
"""Return the closest field position where given ASN.1 type is allowed.
Some ASN.1 serialisation allow for skipping optional and defaulted fields.
Some constructed ASN.1 types allow reordering of the fields. When recovering
such objects it may be important to know at which field position, in field set,
given *tagSet* is allowed at or past *idx* position.
Parameters
----------
tagSet: :class:`~pyasn1.type.tag.TagSet`
ASN.1 type which field position to look up
idx: :py:class:`int`
Field position at or past which to perform ASN.1 type look up
Returns
-------
: :py:class:`int`
Field position in fields set
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If *tagSet* is not present or not unique within callee *NamedTypes*
or *idx* is out of fields range
"""
try:
return idx + self.__ambiguousTypes[idx].getPositionByType(tagSet)
except KeyError:
raise error.PyAsn1Error('Type position out of range')
def __bytes__(self):
try:
return self._value.encode(self.encoding)
except UnicodeEncodeError:
raise error.PyAsn1Error(
"Can't encode string '%s' with codec %s" %
(self._value, self.encoding))
def getTagMapNearPosition(self, idx):
"""Return ASN.1 types that are allowed at or past given field position.
Some ASN.1 serialisation allow for skipping optional and defaulted fields.
Some constructed ASN.1 types allow reordering of the fields. When recovering
such objects it may be important to know which types can possibly be
present at any given position in the field sets.
Parameters
----------
idx: :py:class:`int`
Field index
Returns
-------
: :class:`~pyasn1.type.tagmap.TagMap`
Map if ASN.1 types allowed at given field position
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If given position is out of fields range
"""
try:
return self.__ambiguousTypes[idx].tagMap
except KeyError:
raise error.PyAsn1Error('Type position out of range')
def __init__(self, tagClass, tagFormat, tagId):
if tagId < 0:
raise error.PyAsn1Error('Negative tag ID (%s) not allowed' % tagId)
self.__tagClass = tagClass
self.__tagFormat = tagFormat
self.__tagId = tagId
self.__tagClassId = tagClass, tagId
self.__hash = hash(self.__tagClassId)
def __str__(self):
try:
# `str` is Py2 text representation
return self._value.encode(self.encoding)
except UnicodeEncodeError:
raise error.PyAsn1Error(
"Can't encode string '%s' with codec %s" %
(self._value, self.encoding))
def __getitem__(self, tagSet):
try:
return self.__presentTypes[tagSet]
except KeyError:
if self.__defaultType is None:
raise KeyError()
elif tagSet in self.__skipTypes:
raise error.PyAsn1Error('Key in negative map')
else:
return self.__defaultType
def valueDecoder(self,
substrate,
asn1Spec,
tagSet=None,
length=None,
state=None,
decodeFun=None,
substrateFun=None,
**options):
head, tail = substrate[:length], substrate[length:]
if not head or length != 1:
raise error.PyAsn1Error('Not single-octet Boolean payload')
byte = oct2int(head[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)
return self._createComponent(asn1Spec, tagSet, value, **options), tail
def __init__(self, *args, **kwargs):
self.__names = {}
self.__numbers = {}
anonymousNames = []
for namedValue in args:
if isinstance(namedValue, (tuple, list)):
try:
name, number = namedValue
except ValueError:
raise error.PyAsn1Error(
'Not a proper attribute-value pair %r' %
(namedValue, ))
else:
anonymousNames.append(namedValue)
continue
if name in self.__names:
raise error.PyAsn1Error('Duplicate name %s' % (name, ))
if number in self.__numbers:
raise error.PyAsn1Error('Duplicate number %s=%s' %
(name, number))
self.__names[name] = number
self.__numbers[number] = name
for name, number in kwargs.items():
if name in self.__names:
raise error.PyAsn1Error('Duplicate name %s' % (name, ))
if number in self.__numbers:
raise error.PyAsn1Error('Duplicate number %s=%s' %
(name, number))
self.__names[name] = number
self.__numbers[number] = name
if anonymousNames:
number = self.__numbers and max(self.__numbers) + 1 or 0
for name in anonymousNames:
if name in self.__names:
raise error.PyAsn1Error('Duplicate name %s' % (name, ))
self.__names[name] = number
self.__numbers[number] = name
number += 1
def prettyIn(self, value):
try:
if isinstance(value, unicode):
return value
elif isinstance(value, str):
return value.decode(self.encoding)
elif isinstance(value, (tuple, list)):
return self.prettyIn(''.join([chr(x) for x in value]))
elif isinstance(value, univ.OctetString):
return value.asOctets().decode(self.encoding)
else:
return unicode(value)
except (UnicodeDecodeError, LookupError):
raise error.PyAsn1Error(
"Can't decode string '%s' with codec %s" %
(value, self.encoding))
def encodeLength(self, length, defMode):
if not defMode and self.supportIndefLenMode:
return (0x80, )
if length < 0x80:
return length,
else:
substrate = ()
while length:
substrate = (length & 0xff, ) + substrate
length >>= 8
substrateLen = len(substrate)
if substrateLen > 126:
raise error.PyAsn1Error('Length octets overflow (%d)' %
substrateLen)
return (0x80 | substrateLen, ) + substrate
def encodeValue(self, value, asn1Spec, encodeFun, **options):
if asn1Spec is None:
component = value.getComponent()
else:
names = [
namedType.name
for namedType in asn1Spec.componentType.namedTypes
if namedType.name in value
]
if len(names) != 1:
raise error.PyAsn1Error(
'%s components for Choice at %r' %
(len(names) and 'Multiple ' or 'None ', value))
name = names[0]
component = value[name]
asn1Spec = asn1Spec[name]
return encodeFun(component, asn1Spec, **options), True, True
def getPositionByName(self, name):
"""Return field position by filed name.
Parameters
----------
name: :py:class:`str`
Field name
Returns
-------
: :py:class:`int`
Field position in fields set
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If *name* is not present or not unique within callee *NamedTypes*
"""
try:
return self.__nameToPosMap[name]
except KeyError:
raise error.PyAsn1Error('Name %s not found' % (name, ))
def getNameByPosition(self, idx):
"""Return field name by its position in fields set.
Parameters
----------
idx: :py:class:`idx`
Field index
Returns
-------
: :py:class:`str`
Field name
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If given field name is not present in callee *NamedTypes*
"""
try:
return self.__namedTypes[idx].name
except IndexError:
raise error.PyAsn1Error('Type position out of range')
def getPositionByType(self, tagSet):
"""Return field position by its ASN.1 type.
Parameters
----------
tagSet: :class:`~pysnmp.type.tag.TagSet`
ASN.1 tag set distinguishing one ASN.1 type from others.
Returns
-------
: :py:class:`int`
ASN.1 type position in fields set
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If *tagSet* is not present or ASN.1 types are not unique within callee *NamedTypes*
"""
try:
return self.__tagToPosMap[tagSet]
except KeyError:
raise error.PyAsn1Error('Type %s not found' % (tagSet, ))
def getTypeByPosition(self, idx):
"""Return ASN.1 type object by its position in fields set.
Parameters
----------
idx: :py:class:`int`
Field index
Returns
-------
:
ASN.1 type
Raises
------
: :class:`~pyasn1.error.PyAsn1Error`
If given position is out of fields range
"""
try:
return self.__namedTypes[idx].asn1Object
except IndexError:
raise error.PyAsn1Error('Type position out of range')
def tagExplicitly(self, superTag):
"""Return explicitly tagged *TagSet*
Create a new *TagSet* representing callee *TagSet* explicitly tagged
with passed tag(s). With explicit tagging mode, new tags are appended
to existing tag(s).
Parameters
----------
superTag: :class:`~pyasn1.type.tag.Tag`
*Tag* object to tag this *TagSet*
Returns
-------
: :class:`~pyasn1.type.tag.TagSet`
New *TagSet* object
"""
if superTag.tagClass == tagClassUniversal:
raise error.PyAsn1Error("Can't tag with UNIVERSAL class tag")
if superTag.tagFormat != tagFormatConstructed:
superTag = Tag(superTag.tagClass, tagFormatConstructed,
superTag.tagId)
return self + superTag
def __getattr__(self, attr):
if attr in self.skipMethods:
raise AttributeError('Attribute %s not present' % attr)
raise error.PyAsn1Error(
'Attempted "%s" operation on ASN.1 schema object' % attr)
def encode(self, value, encodeFun, **options):
raise error.PyAsn1Error('Not implemented')
def __setattr__(self, name, value):
if name[0] != '_' and name in self._readOnly:
raise error.PyAsn1Error('read-only instance attribute "%s"' % name)
self.__dict__[name] = value
def encodeValue(self, value, asn1Spec, encodeFun, **options):
substrate = null
comps = []
compsMap = {}
if asn1Spec is None:
# instance of ASN.1 schema
value.verifySizeSpec()
namedTypes = value.componentType
for idx, component in enumerate(value.values()):
if namedTypes:
namedType = namedTypes[idx]
if namedType.isOptional and not component.isValue:
continue
if namedType.isDefaulted and component == namedType.asn1Object:
continue
compsMap[id(component)] = namedType
else:
compsMap[id(component)] = None
comps.append((component, asn1Spec))
else:
# bare Python value + ASN.1 schema
for idx, namedType in enumerate(asn1Spec.componentType.namedTypes):
try:
component = value[namedType.name]
except KeyError:
raise error.PyAsn1Error(
'Component name "%s" not found in %r' %
(namedType.name, value))
if namedType.isOptional and namedType.name not in value:
continue
if namedType.isDefaulted and component == namedType.asn1Object:
continue
compsMap[id(component)] = namedType
comps.append((component, asn1Spec[idx]))
for comp, compType in sorted(comps, key=self._componentSortKey):
namedType = compsMap[id(comp)]
if namedType:
options.update(ifNotEmpty=namedType.isOptional)
chunk = encodeFun(comp, compType, **options)
# wrap open type blob if needed
if namedType and namedType.openType:
wrapType = namedType.asn1Object
if wrapType.tagSet and not wrapType.isSameTypeWith(comp):
chunk = encodeFun(chunk, wrapType, **options)
substrate += chunk
return substrate, True, True
def getComponentByPosition(self, idx):
raise error.PyAsn1Error('Method not implemented')
def setComponentByPosition(self, idx, value, verifyConstraints=True):
raise error.PyAsn1Error('Method not implemented')
def __getitem__(self, item):
raise error.PyAsn1Error(self.__errorMsg)
