Add m-esr52 at 52.6.0

27 files changed, 3349 insertions, 0 deletions

diff --git a/python/pyasn1/pyasn1/__init__.py b/python/pyasn1/pyasn1/__init__.py
new file mode 100644
index 000000000..88aff79c8
--- /dev/null
+++ b/python/pyasn1/pyasn1/__init__.py
@@ -0,0 +1,8 @@
+import sys
+
+# http://www.python.org/dev/peps/pep-0396/
+__version__ = '0.1.7'
+
+if sys.version_info[:2] < (2, 4):
+  raise RuntimeError('PyASN1 requires Python 2.4 or later')
+
diff --git a/python/pyasn1/pyasn1/codec/__init__.py b/python/pyasn1/pyasn1/codec/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/codec/ber/__init__.py b/python/pyasn1/pyasn1/codec/ber/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/ber/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/codec/ber/decoder.py b/python/pyasn1/pyasn1/codec/ber/decoder.py
new file mode 100644
index 000000000..be0cf4907
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/ber/decoder.py
@@ -0,0 +1,808 @@
+# BER decoder
+from pyasn1.type import tag, base, univ, char, useful, tagmap
+from pyasn1.codec.ber import eoo
+from pyasn1.compat.octets import oct2int, octs2ints, isOctetsType
+from pyasn1 import debug, error
+
+class AbstractDecoder:
+    protoComponent = None
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        raise error.PyAsn1Error('Decoder not implemented for %s' % (tagSet,))
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        raise error.PyAsn1Error('Indefinite length mode decoder not implemented for %s' % (tagSet,))
+
+class AbstractSimpleDecoder(AbstractDecoder):
+    tagFormats = (tag.tagFormatSimple,)
+    def _createComponent(self, asn1Spec, tagSet, value=None):
+        if tagSet[0][1] not in self.tagFormats:
+            raise error.PyAsn1Error('Invalid tag format %r for %r' % (tagSet[0], self.protoComponent,))
+        if asn1Spec is None:
+            return self.protoComponent.clone(value, tagSet)
+        elif value is None:
+            return asn1Spec
+        else:
+            return asn1Spec.clone(value)
+        
+class AbstractConstructedDecoder(AbstractDecoder):
+    tagFormats = (tag.tagFormatConstructed,)
+    def _createComponent(self, asn1Spec, tagSet, value=None):
+        if tagSet[0][1] not in self.tagFormats:
+            raise error.PyAsn1Error('Invalid tag format %r for %r' % (tagSet[0], self.protoComponent,))
+        if asn1Spec is None:
+            return self.protoComponent.clone(tagSet)
+        else:
+            return asn1Spec.clone()
+                                
+class EndOfOctetsDecoder(AbstractSimpleDecoder):
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        return eoo.endOfOctets, substrate[length:]
+
+class ExplicitTagDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.Any('')
+    tagFormats = (tag.tagFormatConstructed,)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        if substrateFun:
+            return substrateFun(
+                       self._createComponent(asn1Spec, tagSet, ''),
+                       substrate, length
+                   )
+        head, tail = substrate[:length], substrate[length:]
+        value, _ = decodeFun(head, asn1Spec, tagSet, length)
+        return value, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        if substrateFun:
+            return substrateFun(
+                       self._createComponent(asn1Spec, tagSet, ''),
+                       substrate, length
+                   )
+        value, substrate = decodeFun(substrate, asn1Spec, tagSet, length)
+        terminator, substrate = decodeFun(substrate)
+        if eoo.endOfOctets.isSameTypeWith(terminator) and \
+                terminator == eoo.endOfOctets:
+            return value, substrate
+        else:
+            raise error.PyAsn1Error('Missing end-of-octets terminator')
+
+explicitTagDecoder = ExplicitTagDecoder()
+
+class IntegerDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.Integer(0)
+    precomputedValues = {
+        '\x00':  0,
+        '\x01':  1,
+        '\x02':  2,
+        '\x03':  3,
+        '\x04':  4,
+        '\x05':  5,
+        '\x06':  6,
+        '\x07':  7,
+        '\x08':  8,
+        '\x09':  9,
+        '\xff': -1,
+        '\xfe': -2,
+        '\xfd': -3,
+        '\xfc': -4,
+        '\xfb': -5
+        }
+    
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet, length,
+                     state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if not head:
+            return self._createComponent(asn1Spec, tagSet, 0), tail
+        if head in self.precomputedValues:
+            value = self.precomputedValues[head]
+        else:
+            firstOctet = oct2int(head[0])
+            if firstOctet & 0x80:
+                value = -1
+            else:
+                value = 0
+            for octet in head:
+                value = value << 8 | oct2int(octet)
+        return self._createComponent(asn1Spec, tagSet, value), tail
+
+class BooleanDecoder(IntegerDecoder):
+    protoComponent = univ.Boolean(0)
+    def _createComponent(self, asn1Spec, tagSet, value=None):
+        return IntegerDecoder._createComponent(self, asn1Spec, tagSet, value and 1 or 0)
+
+class BitStringDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.BitString(())
+    tagFormats = (tag.tagFormatSimple, tag.tagFormatConstructed)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet, length,
+                     state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if tagSet[0][1] == tag.tagFormatSimple:    # XXX what tag to check?
+            if not head:
+                raise error.PyAsn1Error('Empty substrate')
+            trailingBits = oct2int(head[0])
+            if trailingBits > 7:
+                raise error.PyAsn1Error(
+                    'Trailing bits overflow %s' % trailingBits
+                    )
+            head = head[1:]
+            lsb = p = 0; l = len(head)-1; b = ()
+            while p <= l:
+                if p == l:
+                    lsb = trailingBits
+                j = 7                    
+                o = oct2int(head[p])
+                while j >= lsb:
+                    b = b + ((o>>j)&0x01,)
+                    j = j - 1
+                p = p + 1
+            return self._createComponent(asn1Spec, tagSet, b), tail
+        r = self._createComponent(asn1Spec, tagSet, ())
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while head:
+            component, head = decodeFun(head)
+            r = r + component
+        return r, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        r = self._createComponent(asn1Spec, tagSet, '')
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while substrate:
+            component, substrate = decodeFun(substrate)
+            if eoo.endOfOctets.isSameTypeWith(component) and \
+                    component == eoo.endOfOctets:
+                break
+            r = r + component
+        else:
+            raise error.SubstrateUnderrunError(
+                'No EOO seen before substrate ends'
+                )
+        return r, substrate
+
+class OctetStringDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.OctetString('')
+    tagFormats = (tag.tagFormatSimple, tag.tagFormatConstructed)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet, length,
+                     state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if tagSet[0][1] == tag.tagFormatSimple:    # XXX what tag to check?
+            return self._createComponent(asn1Spec, tagSet, head), tail
+        r = self._createComponent(asn1Spec, tagSet, '')
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while head:
+            component, head = decodeFun(head)
+            r = r + component
+        return r, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        r = self._createComponent(asn1Spec, tagSet, '')
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while substrate:
+            component, substrate = decodeFun(substrate)
+            if eoo.endOfOctets.isSameTypeWith(component) and \
+                    component == eoo.endOfOctets:
+                break
+            r = r + component
+        else:
+            raise error.SubstrateUnderrunError(
+                'No EOO seen before substrate ends'
+                )
+        return r, substrate
+
+class NullDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.Null('')
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        r = self._createComponent(asn1Spec, tagSet)
+        if head:
+            raise error.PyAsn1Error('Unexpected %d-octet substrate for Null' % length)
+        return r, tail
+
+class ObjectIdentifierDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.ObjectIdentifier(())
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet, length,
+                     state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if not head:
+            raise error.PyAsn1Error('Empty substrate')
+
+        # Get the first subid
+        subId = oct2int(head[0])
+        oid = divmod(subId, 40)
+
+        index = 1
+        substrateLen = len(head)
+        while index < substrateLen:
+            subId = oct2int(head[index])
+            index = index + 1
+            if subId == 128:
+                # ASN.1 spec forbids leading zeros (0x80) in sub-ID OID
+                # encoding, tolerating it opens a vulnerability.
+                # See http://www.cosic.esat.kuleuven.be/publications/article-1432.pdf page 7
+                raise error.PyAsn1Error('Invalid leading 0x80 in sub-OID')
+            elif subId > 128:
+                # Construct subid from a number of octets
+                nextSubId = subId
+                subId = 0
+                while nextSubId >= 128:
+                    subId = (subId << 7) + (nextSubId & 0x7F)
+                    if index >= substrateLen:
+                        raise error.SubstrateUnderrunError(
+                            'Short substrate for sub-OID past %s' % (oid,)
+                            )
+                    nextSubId = oct2int(head[index])
+                    index = index + 1
+                subId = (subId << 7) + nextSubId
+            oid = oid + (subId,)
+        return self._createComponent(asn1Spec, tagSet, oid), tail
+
+class RealDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.Real()
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if not head:
+            return self._createComponent(asn1Spec, tagSet, 0.0), tail
+        fo = oct2int(head[0]); head = head[1:]
+        if fo & 0x80:  # binary enoding
+            n = (fo & 0x03) + 1
+            if n == 4:
+                n = oct2int(head[0])
+            eo, head = head[:n], head[n:]
+            if not eo or not head:
+                raise error.PyAsn1Error('Real exponent screwed')
+            e = oct2int(eo[0]) & 0x80 and -1 or 0
+            while eo:         # exponent
+                e <<= 8
+                e |= oct2int(eo[0])
+                eo = eo[1:]
+            p = 0
+            while head:  # value
+                p <<= 8
+                p |= oct2int(head[0])
+                head = head[1:]
+            if fo & 0x40:    # sign bit
+                p = -p
+            value = (p, 2, e)
+        elif fo & 0x40:  # infinite value
+            value = fo & 0x01 and '-inf' or 'inf'
+        elif fo & 0xc0 == 0:  # character encoding
+            try:
+                if fo & 0x3 == 0x1:  # NR1
+                    value = (int(head), 10, 0)
+                elif fo & 0x3 == 0x2:  # NR2
+                    value = float(head)
+                elif fo & 0x3 == 0x3:  # NR3
+                    value = float(head)
+                else:
+                    raise error.SubstrateUnderrunError(
+                        'Unknown NR (tag %s)' % fo
+                        )
+            except ValueError:
+                raise error.SubstrateUnderrunError(
+                    'Bad character Real syntax'
+                    )
+        else:
+            raise error.SubstrateUnderrunError(
+                'Unknown encoding (tag %s)' % fo
+                )
+        return self._createComponent(asn1Spec, tagSet, value), tail
+        
+class SequenceDecoder(AbstractConstructedDecoder):
+    protoComponent = univ.Sequence()
+    def _getComponentTagMap(self, r, idx):
+        try:
+            return r.getComponentTagMapNearPosition(idx)
+        except error.PyAsn1Error:
+            return
+
+    def _getComponentPositionByType(self, r, t, idx):
+        return r.getComponentPositionNearType(t, idx)
+    
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        r = self._createComponent(asn1Spec, tagSet)
+        idx = 0
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while head:
+            asn1Spec = self._getComponentTagMap(r, idx)
+            component, head = decodeFun(head, asn1Spec)
+            idx = self._getComponentPositionByType(
+                r, component.getEffectiveTagSet(), idx
+                )
+            r.setComponentByPosition(idx, component, asn1Spec is None)
+            idx = idx + 1
+        r.setDefaultComponents()
+        r.verifySizeSpec()
+        return r, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        r = self._createComponent(asn1Spec, tagSet)
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        idx = 0
+        while substrate:
+            asn1Spec = self._getComponentTagMap(r, idx)
+            component, substrate = decodeFun(substrate, asn1Spec)
+            if eoo.endOfOctets.isSameTypeWith(component) and \
+                    component == eoo.endOfOctets:
+                break
+            idx = self._getComponentPositionByType(
+                r, component.getEffectiveTagSet(), idx
+                )            
+            r.setComponentByPosition(idx, component, asn1Spec is None)
+            idx = idx + 1                
+        else:
+            raise error.SubstrateUnderrunError(
+                'No EOO seen before substrate ends'
+                )
+        r.setDefaultComponents()
+        r.verifySizeSpec()
+        return r, substrate
+
+class SequenceOfDecoder(AbstractConstructedDecoder):
+    protoComponent = univ.SequenceOf()    
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        r = self._createComponent(asn1Spec, tagSet)
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        asn1Spec = r.getComponentType()
+        idx = 0
+        while head:
+            component, head = decodeFun(head, asn1Spec)
+            r.setComponentByPosition(idx, component, asn1Spec is None)
+            idx = idx + 1
+        r.verifySizeSpec()
+        return r, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        r = self._createComponent(asn1Spec, tagSet)
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        asn1Spec = r.getComponentType()
+        idx = 0
+        while substrate:
+            component, substrate = decodeFun(substrate, asn1Spec)
+            if eoo.endOfOctets.isSameTypeWith(component) and \
+                    component == eoo.endOfOctets:
+                break
+            r.setComponentByPosition(idx, component, asn1Spec is None)
+            idx = idx + 1                
+        else:
+            raise error.SubstrateUnderrunError(
+                'No EOO seen before substrate ends'
+                )
+        r.verifySizeSpec()
+        return r, substrate
+
+class SetDecoder(SequenceDecoder):
+    protoComponent = univ.Set()
+    def _getComponentTagMap(self, r, idx):
+        return r.getComponentTagMap()
+
+    def _getComponentPositionByType(self, r, t, idx):
+        nextIdx = r.getComponentPositionByType(t)
+        if nextIdx is None:
+            return idx
+        else:
+            return nextIdx
+    
+class SetOfDecoder(SequenceOfDecoder):
+    protoComponent = univ.SetOf()
+    
+class ChoiceDecoder(AbstractConstructedDecoder):
+    protoComponent = univ.Choice()
+    tagFormats = (tag.tagFormatSimple, tag.tagFormatConstructed)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        r = self._createComponent(asn1Spec, tagSet)
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        if r.getTagSet() == tagSet: # explicitly tagged Choice
+            component, head = decodeFun(
+                head, r.getComponentTagMap()
+                )
+        else:
+            component, head = decodeFun(
+                head, r.getComponentTagMap(), tagSet, length, state
+                )
+        if isinstance(component, univ.Choice):
+            effectiveTagSet = component.getEffectiveTagSet()
+        else:
+            effectiveTagSet = component.getTagSet()
+        r.setComponentByType(effectiveTagSet, component, 0, asn1Spec is None)
+        return r, tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        r = self._createComponent(asn1Spec, tagSet)
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        if r.getTagSet() == tagSet: # explicitly tagged Choice
+            component, substrate = decodeFun(substrate, r.getComponentTagMap())
+            eooMarker, substrate = decodeFun(substrate)  # eat up EOO marker
+            if not eoo.endOfOctets.isSameTypeWith(eooMarker) or \
+                    eooMarker != eoo.endOfOctets:
+                raise error.PyAsn1Error('No EOO seen before substrate ends')
+        else:
+            component, substrate= decodeFun(
+                substrate, r.getComponentTagMap(), tagSet, length, state
+            )
+        if isinstance(component, univ.Choice):
+            effectiveTagSet = component.getEffectiveTagSet()
+        else:
+            effectiveTagSet = component.getTagSet()
+        r.setComponentByType(effectiveTagSet, component, 0, asn1Spec is None)
+        return r, substrate
+
+class AnyDecoder(AbstractSimpleDecoder):
+    protoComponent = univ.Any()
+    tagFormats = (tag.tagFormatSimple, tag.tagFormatConstructed)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                     length, state, decodeFun, substrateFun):
+        if asn1Spec is None or \
+               asn1Spec is not None and tagSet != asn1Spec.getTagSet():
+            # untagged Any container, recover inner header substrate
+            length = length + len(fullSubstrate) - len(substrate)
+            substrate = fullSubstrate
+        if substrateFun:
+            return substrateFun(self._createComponent(asn1Spec, tagSet),
+                                substrate, length)
+        head, tail = substrate[:length], substrate[length:]
+        return self._createComponent(asn1Spec, tagSet, value=head), tail
+
+    def indefLenValueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet,
+                             length, state, decodeFun, substrateFun):
+        if asn1Spec is not None and tagSet == asn1Spec.getTagSet():
+            # tagged Any type -- consume header substrate
+            header = ''
+        else:
+            # untagged Any, recover header substrate
+            header = fullSubstrate[:-len(substrate)]
+
+        r = self._createComponent(asn1Spec, tagSet, header)
+
+        # Any components do not inherit initial tag
+        asn1Spec = self.protoComponent
+        
+        if substrateFun:
+            return substrateFun(r, substrate, length)
+        while substrate:
+            component, substrate = decodeFun(substrate, asn1Spec)
+            if eoo.endOfOctets.isSameTypeWith(component) and \
+                    component == eoo.endOfOctets:
+                break
+            r = r + component
+        else:
+            raise error.SubstrateUnderrunError(
+                'No EOO seen before substrate ends'
+                )
+        return r, substrate
+
+# character string types
+class UTF8StringDecoder(OctetStringDecoder):
+    protoComponent = char.UTF8String()
+class NumericStringDecoder(OctetStringDecoder):
+    protoComponent = char.NumericString()
+class PrintableStringDecoder(OctetStringDecoder):
+    protoComponent = char.PrintableString()
+class TeletexStringDecoder(OctetStringDecoder):
+    protoComponent = char.TeletexString()
+class VideotexStringDecoder(OctetStringDecoder):
+    protoComponent = char.VideotexString()
+class IA5StringDecoder(OctetStringDecoder):
+    protoComponent = char.IA5String()
+class GraphicStringDecoder(OctetStringDecoder):
+    protoComponent = char.GraphicString()
+class VisibleStringDecoder(OctetStringDecoder):
+    protoComponent = char.VisibleString()
+class GeneralStringDecoder(OctetStringDecoder):
+    protoComponent = char.GeneralString()
+class UniversalStringDecoder(OctetStringDecoder):
+    protoComponent = char.UniversalString()
+class BMPStringDecoder(OctetStringDecoder):
+    protoComponent = char.BMPString()
+
+# "useful" types
+class GeneralizedTimeDecoder(OctetStringDecoder):
+    protoComponent = useful.GeneralizedTime()
+class UTCTimeDecoder(OctetStringDecoder):
+    protoComponent = useful.UTCTime()
+
+tagMap = {
+    eoo.endOfOctets.tagSet: EndOfOctetsDecoder(),
+    univ.Integer.tagSet: IntegerDecoder(),
+    univ.Boolean.tagSet: BooleanDecoder(),
+    univ.BitString.tagSet: BitStringDecoder(),
+    univ.OctetString.tagSet: OctetStringDecoder(),
+    univ.Null.tagSet: NullDecoder(),
+    univ.ObjectIdentifier.tagSet: ObjectIdentifierDecoder(),
+    univ.Enumerated.tagSet: IntegerDecoder(),
+    univ.Real.tagSet: RealDecoder(),
+    univ.Sequence.tagSet: SequenceDecoder(),  # conflicts with SequenceOf
+    univ.Set.tagSet: SetDecoder(),            # conflicts with SetOf
+    univ.Choice.tagSet: ChoiceDecoder(),      # conflicts with Any
+    # character string types
+    char.UTF8String.tagSet: UTF8StringDecoder(),
+    char.NumericString.tagSet: NumericStringDecoder(),
+    char.PrintableString.tagSet: PrintableStringDecoder(),
+    char.TeletexString.tagSet: TeletexStringDecoder(),
+    char.VideotexString.tagSet: VideotexStringDecoder(),
+    char.IA5String.tagSet: IA5StringDecoder(),
+    char.GraphicString.tagSet: GraphicStringDecoder(),
+    char.VisibleString.tagSet: VisibleStringDecoder(),
+    char.GeneralString.tagSet: GeneralStringDecoder(),
+    char.UniversalString.tagSet: UniversalStringDecoder(),
+    char.BMPString.tagSet: BMPStringDecoder(),
+    # useful types
+    useful.GeneralizedTime.tagSet: GeneralizedTimeDecoder(),
+    useful.UTCTime.tagSet: UTCTimeDecoder()
+    }
+
+# Type-to-codec map for ambiguous ASN.1 types
+typeMap = {
+    univ.Set.typeId: SetDecoder(),
+    univ.SetOf.typeId: SetOfDecoder(),
+    univ.Sequence.typeId: SequenceDecoder(),
+    univ.SequenceOf.typeId: SequenceOfDecoder(),
+    univ.Choice.typeId: ChoiceDecoder(),
+    univ.Any.typeId: AnyDecoder()
+    }
+
+( stDecodeTag, stDecodeLength, stGetValueDecoder, stGetValueDecoderByAsn1Spec,
+  stGetValueDecoderByTag, stTryAsExplicitTag, stDecodeValue,
+  stDumpRawValue, stErrorCondition, stStop ) = [x for x in range(10)]
+
+class Decoder:
+    defaultErrorState = stErrorCondition
+#    defaultErrorState = stDumpRawValue
+    defaultRawDecoder = AnyDecoder()
+    def __init__(self, tagMap, typeMap={}):
+        self.__tagMap = tagMap
+        self.__typeMap = typeMap
+        self.__endOfOctetsTagSet = eoo.endOfOctets.getTagSet()
+        # Tag & TagSet objects caches
+        self.__tagCache = {}
+        self.__tagSetCache = {}
+        
+    def __call__(self, substrate, asn1Spec=None, tagSet=None,
+                 length=None, state=stDecodeTag, recursiveFlag=1,
+                 substrateFun=None):
+        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)))
+        fullSubstrate = substrate
+        while state != stStop:
+            if state == stDecodeTag:
+                # Decode tag
+                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')
+                
+                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(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('  %r -> %s' % (t, v.__class__.__name__))
+                        if asn1Spec.getNegMap():
+                            debug.logger('but neither of: ')
+                            for i in asn1Spec.getNegMap().items():
+                                debug.logger('  %r -> %s' % (t, v.__class__.__name__))
+                        debug.logger('new candidate ASN.1 spec is %s, chosen by %r' % (__chosenSpec is None and '<none>' or __chosenSpec.__class__.__name__, 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 %r' % (baseTagSet,))
+                    else:
+                        concreteDecoder = None
+                    if concreteDecoder:
+                        asn1Spec = __chosenSpec
+                        state = stDecodeValue
+                    else:
+                        state = stTryAsExplicitTag
+                elif tagSet == self.__endOfOctetsTagSet:
+                    concreteDecoder = self.__tagMap[tagSet]
+                    state = stDecodeValue
+                    debug.logger and debug.logger & debug.flagDecoder and debug.logger('end-of-octets found')
+                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(
+                    '%r not in asn1Spec: %r' % (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
+            
+decode = Decoder(tagMap, typeMap)
+
+# XXX
+# non-recursive decoding; return position rather than substrate
diff --git a/python/pyasn1/pyasn1/codec/ber/encoder.py b/python/pyasn1/pyasn1/codec/ber/encoder.py
new file mode 100644
index 000000000..173949d0b
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/ber/encoder.py
@@ -0,0 +1,353 @@
+# BER encoder
+from pyasn1.type import base, tag, univ, char, useful
+from pyasn1.codec.ber import eoo
+from pyasn1.compat.octets import int2oct, oct2int, ints2octs, null, str2octs
+from pyasn1 import debug, error
+
+class Error(Exception): pass
+
+class AbstractItemEncoder:
+    supportIndefLenMode = 1
+    def encodeTag(self, t, isConstructed):
+        tagClass, tagFormat, tagId = t.asTuple()  # this is a hotspot
+        v = tagClass | tagFormat
+        if isConstructed:
+            v = v|tag.tagFormatConstructed
+        if tagId < 31:
+            return int2oct(v|tagId)
+        else:
+            s = int2oct(tagId&0x7f)
+            tagId = tagId >> 7
+            while tagId:
+                s = int2oct(0x80|(tagId&0x7f)) + s
+                tagId = tagId >> 7
+            return int2oct(v|0x1F) + s
+
+    def encodeLength(self, length, defMode):
+        if not defMode and self.supportIndefLenMode:
+            return int2oct(0x80)
+        if length < 0x80:
+            return int2oct(length)
+        else:
+            substrate = null
+            while length:
+                substrate = int2oct(length&0xff) + substrate
+                length = length >> 8
+            substrateLen = len(substrate)
+            if substrateLen > 126:
+                raise Error('Length octets overflow (%d)' % substrateLen)
+            return int2oct(0x80 | substrateLen) + substrate
+
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        raise Error('Not implemented')
+
+    def _encodeEndOfOctets(self, encodeFun, defMode):
+        if defMode or not self.supportIndefLenMode:
+            return null
+        else:
+            return encodeFun(eoo.endOfOctets, defMode)
+        
+    def encode(self, encodeFun, value, defMode, maxChunkSize):
+        substrate, isConstructed = self.encodeValue(
+            encodeFun, value, defMode, maxChunkSize
+            )
+        tagSet = value.getTagSet()
+        if tagSet:
+            if not isConstructed:  # primitive form implies definite mode
+                defMode = 1
+            return self.encodeTag(
+                tagSet[-1], isConstructed
+                ) + self.encodeLength(
+                len(substrate), defMode
+                ) + substrate + self._encodeEndOfOctets(encodeFun, defMode)
+        else:
+            return substrate  # untagged value
+
+class EndOfOctetsEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        return null, 0
+
+class ExplicitlyTaggedItemEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        if isinstance(value, base.AbstractConstructedAsn1Item):
+            value = value.clone(tagSet=value.getTagSet()[:-1],
+                                cloneValueFlag=1)
+        else:
+            value = value.clone(tagSet=value.getTagSet()[:-1])
+        return encodeFun(value, defMode, maxChunkSize), 1
+
+explicitlyTaggedItemEncoder = ExplicitlyTaggedItemEncoder()
+
+class BooleanEncoder(AbstractItemEncoder):
+    supportIndefLenMode = 0
+    _true = ints2octs((1,))
+    _false = ints2octs((0,))
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        return value and self._true or self._false, 0
+
+class IntegerEncoder(AbstractItemEncoder):
+    supportIndefLenMode = 0
+    supportCompactZero = False
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        if value == 0:  # shortcut for zero value
+            if self.supportCompactZero:
+                # this seems to be a correct way for encoding zeros
+                return null, 0
+            else:
+                # this seems to be a widespread way for encoding zeros
+                return ints2octs((0,)), 0
+        octets = []
+        value = int(value) # to save on ops on asn1 type
+        while 1:
+            octets.insert(0, value & 0xff)
+            if value == 0 or value == -1:
+                break
+            value = value >> 8
+        if value == 0 and octets[0] & 0x80:
+            octets.insert(0, 0)
+        while len(octets) > 1 and \
+                  (octets[0] == 0 and octets[1] & 0x80 == 0 or \
+                   octets[0] == 0xff and octets[1] & 0x80 != 0):
+            del octets[0]
+        return ints2octs(octets), 0
+
+class BitStringEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        if not maxChunkSize or len(value) <= maxChunkSize*8:
+            r = {}; l = len(value); p = 0; j = 7
+            while p < l:
+                i, j = divmod(p, 8)
+                r[i] = r.get(i,0) | value[p]<<(7-j)
+                p = p + 1
+            keys = list(r); keys.sort()
+            return int2oct(7-j) + ints2octs([r[k] for k in keys]), 0
+        else:
+            pos = 0; substrate = null
+            while 1:
+                # count in octets
+                v = value.clone(value[pos*8:pos*8+maxChunkSize*8])
+                if not v:
+                    break
+                substrate = substrate + encodeFun(v, defMode, maxChunkSize)
+                pos = pos + maxChunkSize
+            return substrate, 1
+
+class OctetStringEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        if not maxChunkSize or len(value) <= maxChunkSize:
+            return value.asOctets(), 0
+        else:
+            pos = 0; substrate = null
+            while 1:
+                v = value.clone(value[pos:pos+maxChunkSize])
+                if not v:
+                    break
+                substrate = substrate + encodeFun(v, defMode, maxChunkSize)
+                pos = pos + maxChunkSize
+            return substrate, 1
+
+class NullEncoder(AbstractItemEncoder):
+    supportIndefLenMode = 0
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        return null, 0
+
+class ObjectIdentifierEncoder(AbstractItemEncoder):
+    supportIndefLenMode = 0
+    precomputedValues = {
+        (1, 3, 6, 1, 2): (43, 6, 1, 2),        
+        (1, 3, 6, 1, 4): (43, 6, 1, 4)
+        }
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):    
+        oid = value.asTuple()
+        if oid[:5] in self.precomputedValues:
+            octets = self.precomputedValues[oid[:5]]
+            index = 5
+        else:
+            if len(oid) < 2:
+                raise error.PyAsn1Error('Short OID %s' % (value,))
+
+            # Build the first twos
+            if oid[0] > 6 or oid[1] > 39 or oid[0] == 6 and oid[1] > 15:
+                raise error.PyAsn1Error(
+                    'Initial sub-ID overflow %s in OID %s' % (oid[:2], value)
+                    )
+            octets = (oid[0] * 40 + oid[1],)
+            index = 2
+
+        # Cycle through subids
+        for subid in oid[index:]:
+            if subid > -1 and subid < 128:
+                # Optimize for the common case
+                octets = octets + (subid & 0x7f,)
+            elif subid < 0 or subid > 0xFFFFFFFF:
+                raise error.PyAsn1Error(
+                    'SubId overflow %s in %s' % (subid, value)
+                    )
+            else:
+                # Pack large Sub-Object IDs
+                res = (subid & 0x7f,)
+                subid = subid >> 7
+                while subid > 0:
+                    res = (0x80 | (subid & 0x7f),) + res
+                    subid = subid >> 7 
+                # Add packed Sub-Object ID to resulted Object ID
+                octets += res
+                
+        return ints2octs(octets), 0
+
+class RealEncoder(AbstractItemEncoder):
+    supportIndefLenMode = 0
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        if value.isPlusInfinity():
+            return int2oct(0x40), 0
+        if value.isMinusInfinity():
+            return int2oct(0x41), 0
+        m, b, e = value
+        if not m:
+            return null, 0
+        if b == 10:
+            return str2octs('\x03%dE%s%d' % (m, e == 0 and '+' or '', e)), 0
+        elif b == 2:
+            fo = 0x80                 # binary enoding
+            if m < 0:
+                fo = fo | 0x40  # sign bit
+                m = -m
+            while int(m) != m: # drop floating point
+                m *= 2
+                e -= 1
+            while m & 0x1 == 0: # mantissa normalization
+                m >>= 1
+                e += 1
+            eo = null
+            while e not in (0, -1):
+                eo = int2oct(e&0xff) + eo
+                e >>= 8
+            if e == 0 and eo and oct2int(eo[0]) & 0x80:
+                eo = int2oct(0) + eo
+            n = len(eo)
+            if n > 0xff:
+                raise error.PyAsn1Error('Real exponent overflow')
+            if n == 1:
+                pass
+            elif n == 2:
+                fo |= 1
+            elif n == 3:
+                fo |= 2
+            else:
+                fo |= 3
+                eo = int2oct(n//0xff+1) + eo
+            po = null
+            while m:
+                po = int2oct(m&0xff) + po
+                m >>= 8
+            substrate = int2oct(fo) + eo + po
+            return substrate, 0
+        else:
+            raise error.PyAsn1Error('Prohibited Real base %s' % b)
+
+class SequenceEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        value.setDefaultComponents()
+        value.verifySizeSpec()
+        substrate = null; idx = len(value)
+        while idx > 0:
+            idx = idx - 1
+            if value[idx] is None:  # Optional component
+                continue
+            component = value.getDefaultComponentByPosition(idx)
+            if component is not None and component == value[idx]:
+                continue
+            substrate = encodeFun(
+                value[idx], defMode, maxChunkSize
+                ) + substrate
+        return substrate, 1
+
+class SequenceOfEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        value.verifySizeSpec()
+        substrate = null; idx = len(value)
+        while idx > 0:
+            idx = idx - 1
+            substrate = encodeFun(
+                value[idx], defMode, maxChunkSize
+                ) + substrate
+        return substrate, 1
+
+class ChoiceEncoder(AbstractItemEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        return encodeFun(value.getComponent(), defMode, maxChunkSize), 1
+
+class AnyEncoder(OctetStringEncoder):
+    def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
+        return value.asOctets(), defMode == 0
+
+tagMap = {
+    eoo.endOfOctets.tagSet: EndOfOctetsEncoder(),
+    univ.Boolean.tagSet: BooleanEncoder(),
+    univ.Integer.tagSet: IntegerEncoder(),
+    univ.BitString.tagSet: BitStringEncoder(),
+    univ.OctetString.tagSet: OctetStringEncoder(),
+    univ.Null.tagSet: NullEncoder(),
+    univ.ObjectIdentifier.tagSet: ObjectIdentifierEncoder(),
+    univ.Enumerated.tagSet: IntegerEncoder(),
+    univ.Real.tagSet: RealEncoder(),
+    # Sequence & Set have same tags as SequenceOf & SetOf
+    univ.SequenceOf.tagSet: SequenceOfEncoder(),
+    univ.SetOf.tagSet: SequenceOfEncoder(),
+    univ.Choice.tagSet: ChoiceEncoder(),
+    # character string types
+    char.UTF8String.tagSet: OctetStringEncoder(),
+    char.NumericString.tagSet: OctetStringEncoder(),
+    char.PrintableString.tagSet: OctetStringEncoder(),
+    char.TeletexString.tagSet: OctetStringEncoder(),
+    char.VideotexString.tagSet: OctetStringEncoder(),
+    char.IA5String.tagSet: OctetStringEncoder(),
+    char.GraphicString.tagSet: OctetStringEncoder(),
+    char.VisibleString.tagSet: OctetStringEncoder(),
+    char.GeneralString.tagSet: OctetStringEncoder(),
+    char.UniversalString.tagSet: OctetStringEncoder(),
+    char.BMPString.tagSet: OctetStringEncoder(),
+    # useful types
+    useful.GeneralizedTime.tagSet: OctetStringEncoder(),
+    useful.UTCTime.tagSet: OctetStringEncoder()        
+    }
+
+# Type-to-codec map for ambiguous ASN.1 types
+typeMap = {
+    univ.Set.typeId: SequenceEncoder(),
+    univ.SetOf.typeId: SequenceOfEncoder(),
+    univ.Sequence.typeId: SequenceEncoder(),
+    univ.SequenceOf.typeId: SequenceOfEncoder(),
+    univ.Choice.typeId: ChoiceEncoder(),
+    univ.Any.typeId: AnyEncoder()
+    }
+
+class Encoder:
+    def __init__(self, tagMap, typeMap={}):
+        self.__tagMap = tagMap
+        self.__typeMap = typeMap
+
+    def __call__(self, value, defMode=1, maxChunkSize=0):
+        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.__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
+
+encode = Encoder(tagMap, typeMap)
diff --git a/python/pyasn1/pyasn1/codec/ber/eoo.py b/python/pyasn1/pyasn1/codec/ber/eoo.py
new file mode 100644
index 000000000..379be1996
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/ber/eoo.py
@@ -0,0 +1,8 @@
+from pyasn1.type import base, tag
+
+class EndOfOctets(base.AbstractSimpleAsn1Item):
+    defaultValue = 0
+    tagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x00)
+        )
+endOfOctets = EndOfOctets()
diff --git a/python/pyasn1/pyasn1/codec/cer/__init__.py b/python/pyasn1/pyasn1/codec/cer/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/cer/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/codec/cer/decoder.py b/python/pyasn1/pyasn1/codec/cer/decoder.py
new file mode 100644
index 000000000..9fd37c134
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/cer/decoder.py
@@ -0,0 +1,35 @@
+# CER decoder
+from pyasn1.type import univ
+from pyasn1.codec.ber import decoder
+from pyasn1.compat.octets import oct2int
+from pyasn1 import error
+
+class BooleanDecoder(decoder.AbstractSimpleDecoder):
+    protoComponent = univ.Boolean(0)
+    def valueDecoder(self, fullSubstrate, substrate, asn1Spec, tagSet, length,
+                     state, decodeFun, substrateFun):
+        head, tail = substrate[:length], substrate[length:]
+        if not head:
+            raise error.PyAsn1Error('Empty substrate')
+        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 http://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('Boolean CER violation: %s' % byte)
+        return self._createComponent(asn1Spec, tagSet, value), tail
+
+tagMap = decoder.tagMap.copy()
+tagMap.update({
+    univ.Boolean.tagSet: BooleanDecoder()
+    })
+
+typeMap = decoder.typeMap
+
+class Decoder(decoder.Decoder): pass
+
+decode = Decoder(tagMap, decoder.typeMap)
diff --git a/python/pyasn1/pyasn1/codec/cer/encoder.py b/python/pyasn1/pyasn1/codec/cer/encoder.py
new file mode 100644
index 000000000..4c05130af
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/cer/encoder.py
@@ -0,0 +1,87 @@
+# CER encoder
+from pyasn1.type import univ
+from pyasn1.codec.ber import encoder
+from pyasn1.compat.octets import int2oct, null
+
+class BooleanEncoder(encoder.IntegerEncoder):
+    def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
+        if client == 0:
+            substrate = int2oct(0)
+        else:
+            substrate = int2oct(255)
+        return substrate, 0
+
+class BitStringEncoder(encoder.BitStringEncoder):
+    def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
+        return encoder.BitStringEncoder.encodeValue(
+            self, encodeFun, client, defMode, 1000
+            )
+
+class OctetStringEncoder(encoder.OctetStringEncoder):
+    def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
+        return encoder.OctetStringEncoder.encodeValue(
+            self, encodeFun, client, defMode, 1000
+            )
+
+# specialized RealEncoder here
+# specialized GeneralStringEncoder here
+# specialized GeneralizedTimeEncoder here
+# specialized UTCTimeEncoder here
+
+class SetOfEncoder(encoder.SequenceOfEncoder):
+    def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
+        if isinstance(client, univ.SequenceAndSetBase):
+            client.setDefaultComponents()
+        client.verifySizeSpec()
+        substrate = null; idx = len(client)
+        # This is certainly a hack but how else do I distinguish SetOf
+        # from Set if they have the same tags&constraints?
+        if isinstance(client, univ.SequenceAndSetBase):
+            # Set
+            comps = []
+            while idx > 0:
+                idx = idx - 1
+                if client[idx] is None:  # Optional component
+                    continue
+                if client.getDefaultComponentByPosition(idx) == client[idx]:
+                    continue
+                comps.append(client[idx])
+            comps.sort(key=lambda x: isinstance(x, univ.Choice) and \
+                                     x.getMinTagSet() or x.getTagSet())
+            for c in comps:
+                substrate += encodeFun(c, defMode, maxChunkSize)
+        else:
+            # SetOf
+            compSubs = []
+            while idx > 0:
+                idx = idx - 1
+                compSubs.append(
+                    encodeFun(client[idx], defMode, maxChunkSize)
+                    )
+            compSubs.sort()  # perhaps padding's not needed
+            substrate = null
+            for compSub in compSubs:
+                substrate += compSub
+        return substrate, 1
+
+tagMap = encoder.tagMap.copy()
+tagMap.update({
+    univ.Boolean.tagSet: BooleanEncoder(),
+    univ.BitString.tagSet: BitStringEncoder(),
+    univ.OctetString.tagSet: OctetStringEncoder(),
+    univ.SetOf().tagSet: SetOfEncoder()  # conflcts with Set
+    })
+
+typeMap = encoder.typeMap.copy()
+typeMap.update({
+    univ.Set.typeId: SetOfEncoder(),
+    univ.SetOf.typeId: SetOfEncoder()
+    })
+
+class Encoder(encoder.Encoder):
+    def __call__(self, client, defMode=0, maxChunkSize=0):
+        return encoder.Encoder.__call__(self, client, defMode, maxChunkSize)
+
+encode = Encoder(tagMap, typeMap)
+
+# EncoderFactory queries class instance and builds a map of tags -> encoders
diff --git a/python/pyasn1/pyasn1/codec/der/__init__.py b/python/pyasn1/pyasn1/codec/der/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/der/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/codec/der/decoder.py b/python/pyasn1/pyasn1/codec/der/decoder.py
new file mode 100644
index 000000000..604abec2b
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/der/decoder.py
@@ -0,0 +1,9 @@
+# DER decoder
+from pyasn1.type import univ
+from pyasn1.codec.cer import decoder
+
+tagMap = decoder.tagMap
+typeMap = decoder.typeMap
+Decoder = decoder.Decoder
+
+decode = Decoder(tagMap, typeMap)
diff --git a/python/pyasn1/pyasn1/codec/der/encoder.py b/python/pyasn1/pyasn1/codec/der/encoder.py
new file mode 100644
index 000000000..4e5faefad
--- /dev/null
+++ b/python/pyasn1/pyasn1/codec/der/encoder.py
@@ -0,0 +1,28 @@
+# DER encoder
+from pyasn1.type import univ
+from pyasn1.codec.cer import encoder
+
+class SetOfEncoder(encoder.SetOfEncoder):
+    def _cmpSetComponents(self, c1, c2):
+        tagSet1 = isinstance(c1, univ.Choice) and \
+                  c1.getEffectiveTagSet() or c1.getTagSet()
+        tagSet2 = isinstance(c2, univ.Choice) and \
+                  c2.getEffectiveTagSet() or c2.getTagSet()        
+        return cmp(tagSet1, tagSet2)
+
+tagMap = encoder.tagMap.copy()
+tagMap.update({
+    # Overload CER encodrs with BER ones (a bit hackerish XXX)
+    univ.BitString.tagSet: encoder.encoder.BitStringEncoder(),
+    univ.OctetString.tagSet: encoder.encoder.OctetStringEncoder(),
+    # Set & SetOf have same tags
+    univ.SetOf().tagSet: SetOfEncoder()
+    })
+
+typeMap = encoder.typeMap
+
+class Encoder(encoder.Encoder):
+    def __call__(self, client, defMode=1, maxChunkSize=0):
+        return encoder.Encoder.__call__(self, client, defMode, maxChunkSize)
+        
+encode = Encoder(tagMap, typeMap)
diff --git a/python/pyasn1/pyasn1/compat/__init__.py b/python/pyasn1/pyasn1/compat/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/compat/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/compat/octets.py b/python/pyasn1/pyasn1/compat/octets.py
new file mode 100644
index 000000000..f7f2a29bf
--- /dev/null
+++ b/python/pyasn1/pyasn1/compat/octets.py
@@ -0,0 +1,20 @@
+from sys import version_info
+
+if version_info[0] <= 2:
+    int2oct = chr
+    ints2octs = lambda s: ''.join([ int2oct(x) for x in s ])
+    null = ''
+    oct2int = ord
+    octs2ints = lambda s: [ oct2int(x) for x in s ]
+    str2octs = lambda x: x
+    octs2str = lambda x: x
+    isOctetsType = lambda s: isinstance(s, str)
+else:
+    ints2octs = bytes
+    int2oct = lambda x: ints2octs((x,))
+    null = ints2octs()
+    oct2int = lambda x: x
+    octs2ints = lambda s: [ x for x in s ]
+    str2octs = lambda x: x.encode()
+    octs2str = lambda x: x.decode()
+    isOctetsType = lambda s: isinstance(s, bytes)
diff --git a/python/pyasn1/pyasn1/debug.py b/python/pyasn1/pyasn1/debug.py
new file mode 100644
index 000000000..c27cb1d44
--- /dev/null
+++ b/python/pyasn1/pyasn1/debug.py
@@ -0,0 +1,65 @@
+import sys
+from pyasn1.compat.octets import octs2ints
+from pyasn1 import error
+from pyasn1 import __version__
+
+flagNone     = 0x0000
+flagEncoder  = 0x0001
+flagDecoder  = 0x0002
+flagAll      = 0xffff
+
+flagMap = {
+    'encoder': flagEncoder,
+    'decoder': flagDecoder,
+    'all': flagAll
+    }
+
+class Debug:
+    defaultPrinter = sys.stderr.write
+    def __init__(self, *flags):
+        self._flags = flagNone
+        self._printer = self.defaultPrinter
+        self('running pyasn1 version %s' % __version__)
+        for f in flags:
+            if f not in flagMap:
+                raise error.PyAsn1Error('bad debug flag %s' % (f,))
+            self._flags = self._flags | flagMap[f]
+            self('debug category \'%s\' enabled' % f)
+        
+    def __str__(self):
+        return 'logger %s, flags %x' % (self._printer, self._flags)
+    
+    def __call__(self, msg):
+        self._printer('DBG: %s\n' % msg)
+
+    def __and__(self, flag):
+        return self._flags & flag
+
+    def __rand__(self, flag):
+        return flag & self._flags
+
+logger = 0
+
+def setLogger(l):
+    global logger
+    logger = l
+
+def hexdump(octets):
+    return ' '.join(
+            [ '%s%.2X' % (n%16 == 0 and ('\n%.5d: ' % n) or '', x) 
+              for n,x in zip(range(len(octets)), octs2ints(octets)) ]
+        )
+
+class Scope:
+    def __init__(self):
+        self._list = []
+
+    def __str__(self): return '.'.join(self._list)
+
+    def push(self, token):
+        self._list.append(token)
+
+    def pop(self):
+        return self._list.pop()
+
+scope = Scope()
diff --git a/python/pyasn1/pyasn1/error.py b/python/pyasn1/pyasn1/error.py
new file mode 100644
index 000000000..716406ff6
--- /dev/null
+++ b/python/pyasn1/pyasn1/error.py
@@ -0,0 +1,3 @@
+class PyAsn1Error(Exception): pass
+class ValueConstraintError(PyAsn1Error): pass
+class SubstrateUnderrunError(PyAsn1Error): pass
diff --git a/python/pyasn1/pyasn1/type/__init__.py b/python/pyasn1/pyasn1/type/__init__.py
new file mode 100644
index 000000000..8c3066b2e
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/__init__.py
@@ -0,0 +1 @@
+# This file is necessary to make this directory a package.
diff --git a/python/pyasn1/pyasn1/type/base.py b/python/pyasn1/pyasn1/type/base.py
new file mode 100644
index 000000000..40873719c
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/base.py
@@ -0,0 +1,249 @@
+# Base classes for ASN.1 types
+import sys
+from pyasn1.type import constraint, tagmap
+from pyasn1 import error
+
+class Asn1Item: pass
+
+class Asn1ItemBase(Asn1Item):
+    # Set of tags for this ASN.1 type
+    tagSet = ()
+    
+    # A list of constraint.Constraint instances for checking values
+    subtypeSpec = constraint.ConstraintsIntersection()
+
+    # Used for ambiguous ASN.1 types identification
+    typeId = None
+    
+    def __init__(self, tagSet=None, subtypeSpec=None):
+        if tagSet is None:
+            self._tagSet = self.tagSet
+        else:
+            self._tagSet = tagSet
+        if subtypeSpec is None:
+            self._subtypeSpec = self.subtypeSpec
+        else:
+            self._subtypeSpec = subtypeSpec
+
+    def _verifySubtypeSpec(self, value, idx=None):
+        try:
+            self._subtypeSpec(value, idx)
+        except error.PyAsn1Error:
+            c, i, t = sys.exc_info()
+            raise c('%s at %s' % (i, self.__class__.__name__))
+        
+    def getSubtypeSpec(self): return self._subtypeSpec
+    
+    def getTagSet(self): return self._tagSet
+    def getEffectiveTagSet(self): return self._tagSet  # used by untagged types
+    def getTagMap(self): return tagmap.TagMap({self._tagSet: self})
+    
+    def isSameTypeWith(self, other):
+        return self is other or \
+               self._tagSet == other.getTagSet() and \
+               self._subtypeSpec == other.getSubtypeSpec()
+    def isSuperTypeOf(self, other):
+        """Returns true if argument is a ASN1 subtype of ourselves"""
+        return self._tagSet.isSuperTagSetOf(other.getTagSet()) and \
+               self._subtypeSpec.isSuperTypeOf(other.getSubtypeSpec())
+
+class __NoValue:
+    def __getattr__(self, attr):
+        raise error.PyAsn1Error('No value for %s()' % attr)
+    def __getitem__(self, i):
+        raise error.PyAsn1Error('No value')
+    
+noValue = __NoValue()
+
+# Base class for "simple" ASN.1 objects. These are immutable.
+class AbstractSimpleAsn1Item(Asn1ItemBase):    
+    defaultValue = noValue
+    def __init__(self, value=None, tagSet=None, subtypeSpec=None):
+        Asn1ItemBase.__init__(self, tagSet, subtypeSpec)
+        if value is None or value is noValue:
+            value = self.defaultValue
+        if value is None or value is noValue:
+            self.__hashedValue = value = noValue
+        else:
+            value = self.prettyIn(value)
+            self._verifySubtypeSpec(value)
+            self.__hashedValue = hash(value)
+        self._value = value
+        self._len = None
+        
+    def __repr__(self):
+        if self._value is noValue:
+            return self.__class__.__name__ + '()'
+        else:
+            return self.__class__.__name__ + '(%s)' % (self.prettyOut(self._value),)
+    def __str__(self): return str(self._value)
+    def __eq__(self, other):
+        return self is other and True or self._value == other
+    def __ne__(self, other): return self._value != other
+    def __lt__(self, other): return self._value < other
+    def __le__(self, other): return self._value <= other
+    def __gt__(self, other): return self._value > other
+    def __ge__(self, other): return self._value >= other
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(self._value)
+    else:
+        def __bool__(self): return bool(self._value)
+    def __hash__(self): return self.__hashedValue
+
+    def clone(self, value=None, tagSet=None, subtypeSpec=None):
+        if value is None and tagSet is None and subtypeSpec is None:
+            return self
+        if value is None:
+            value = self._value
+        if tagSet is None:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        return self.__class__(value, tagSet, subtypeSpec)
+
+    def subtype(self, value=None, implicitTag=None, explicitTag=None,
+                subtypeSpec=None):
+        if value is None:
+            value = self._value
+        if implicitTag is not None:
+            tagSet = self._tagSet.tagImplicitly(implicitTag)
+        elif explicitTag is not None:
+            tagSet = self._tagSet.tagExplicitly(explicitTag)
+        else:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        else:
+            subtypeSpec = subtypeSpec + self._subtypeSpec
+        return self.__class__(value, tagSet, subtypeSpec)
+
+    def prettyIn(self, value): return value
+    def prettyOut(self, value): return str(value)
+
+    def prettyPrint(self, scope=0):
+        if self._value is noValue:
+            return '<no value>'
+        else:
+            return self.prettyOut(self._value)
+
+    # XXX Compatibility stub
+    def prettyPrinter(self, scope=0): return self.prettyPrint(scope)
+    
+#
+# Constructed types:
+# * There are five of them: Sequence, SequenceOf/SetOf, Set and Choice
+# * ASN1 types and values are represened by Python class instances
+# * Value initialization is made for defaulted components only
+# * Primary method of component addressing is by-position. Data model for base
+#   type is Python sequence. Additional type-specific addressing methods
+#   may be implemented for particular types.
+# * SequenceOf and SetOf types do not implement any additional methods
+# * Sequence, Set and Choice types also implement by-identifier addressing
+# * Sequence, Set and Choice types also implement by-asn1-type (tag) addressing
+# * Sequence and Set types may include optional and defaulted
+#   components
+# * Constructed types hold a reference to component types used for value
+#   verification and ordering.
+# * Component type is a scalar type for SequenceOf/SetOf types and a list
+#   of types for Sequence/Set/Choice.
+#
+
+class AbstractConstructedAsn1Item(Asn1ItemBase):
+    componentType = None
+    sizeSpec = constraint.ConstraintsIntersection()
+    def __init__(self, componentType=None, tagSet=None,
+                 subtypeSpec=None, sizeSpec=None):
+        Asn1ItemBase.__init__(self, tagSet, subtypeSpec)
+        if componentType is None:
+            self._componentType = self.componentType
+        else:
+            self._componentType = componentType
+        if sizeSpec is None:
+            self._sizeSpec = self.sizeSpec
+        else:
+            self._sizeSpec = sizeSpec
+        self._componentValues = []
+        self._componentValuesSet = 0
+
+    def __repr__(self):
+        r = self.__class__.__name__ + '()'
+        for idx in range(len(self._componentValues)):
+            if self._componentValues[idx] is None:
+                continue
+            r = r + '.setComponentByPosition(%s, %r)' % (
+                idx, self._componentValues[idx]
+                )
+        return r
+
+    def __eq__(self, other):
+        return self is other and True or self._componentValues == other
+    def __ne__(self, other): return self._componentValues != other
+    def __lt__(self, other): return self._componentValues < other
+    def __le__(self, other): return self._componentValues <= other
+    def __gt__(self, other): return self._componentValues > other
+    def __ge__(self, other): return self._componentValues >= other
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(self._componentValues)
+    else:
+        def __bool__(self): return bool(self._componentValues)
+
+    def getComponentTagMap(self):
+        raise error.PyAsn1Error('Method not implemented')
+
+    def _cloneComponentValues(self, myClone, cloneValueFlag): pass
+
+    def clone(self, tagSet=None, subtypeSpec=None, sizeSpec=None, 
+              cloneValueFlag=None):
+        if tagSet is None:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        if sizeSpec is None:
+            sizeSpec = self._sizeSpec
+        r = self.__class__(self._componentType, tagSet, subtypeSpec, sizeSpec)
+        if cloneValueFlag:
+            self._cloneComponentValues(r, cloneValueFlag)
+        return r
+
+    def subtype(self, implicitTag=None, explicitTag=None, subtypeSpec=None,
+                sizeSpec=None, cloneValueFlag=None):
+        if implicitTag is not None:
+            tagSet = self._tagSet.tagImplicitly(implicitTag)
+        elif explicitTag is not None:
+            tagSet = self._tagSet.tagExplicitly(explicitTag)
+        else:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        else:
+            subtypeSpec = subtypeSpec + self._subtypeSpec
+        if sizeSpec is None:
+            sizeSpec = self._sizeSpec
+        else:
+            sizeSpec = sizeSpec + self._sizeSpec
+        r = self.__class__(self._componentType, tagSet, subtypeSpec, sizeSpec)
+        if cloneValueFlag:
+            self._cloneComponentValues(r, cloneValueFlag)
+        return r
+
+    def _verifyComponent(self, idx, value): pass
+
+    def verifySizeSpec(self): self._sizeSpec(self)
+
+    def getComponentByPosition(self, idx):
+        raise error.PyAsn1Error('Method not implemented')
+    def setComponentByPosition(self, idx, value, verifyConstraints=True):
+        raise error.PyAsn1Error('Method not implemented')
+
+    def getComponentType(self): return self._componentType
+
+    def __getitem__(self, idx): return self.getComponentByPosition(idx)
+    def __setitem__(self, idx, value): self.setComponentByPosition(idx, value)
+
+    def __len__(self): return len(self._componentValues)
+    
+    def clear(self):
+        self._componentValues = []
+        self._componentValuesSet = 0
+
+    def setDefaultComponents(self): pass
diff --git a/python/pyasn1/pyasn1/type/char.py b/python/pyasn1/pyasn1/type/char.py
new file mode 100644
index 000000000..ae112f8bd
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/char.py
@@ -0,0 +1,61 @@
+# ASN.1 "character string" types
+from pyasn1.type import univ, tag
+
+class UTF8String(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 12)
+        )
+    encoding = "utf-8"
+
+class NumericString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 18)
+        )
+
+class PrintableString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 19)
+        )
+
+class TeletexString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 20)
+        )
+    
+
+class VideotexString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 21)
+        )
+
+class IA5String(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 22)
+        )
+
+class GraphicString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 25)
+        )
+
+class VisibleString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 26)
+        )
+
+class GeneralString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 27)
+        )
+
+class UniversalString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 28)
+        )
+    encoding = "utf-32-be"
+
+class BMPString(univ.OctetString):
+    tagSet = univ.OctetString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 30)
+        )
+    encoding = "utf-16-be"
diff --git a/python/pyasn1/pyasn1/type/constraint.py b/python/pyasn1/pyasn1/type/constraint.py
new file mode 100644
index 000000000..66873937d
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/constraint.py
@@ -0,0 +1,200 @@
+#
+#   ASN.1 subtype constraints classes.
+#
+#   Constraints are relatively rare, but every ASN1 object
+#   is doing checks all the time for whether they have any
+#   constraints and whether they are applicable to the object.
+#
+#   What we're going to do is define objects/functions that
+#   can be called unconditionally if they are present, and that
+#   are simply not present if there are no constraints.
+#
+#   Original concept and code by Mike C. Fletcher.
+#
+import sys
+from pyasn1.type import error
+
+class AbstractConstraint:
+    """Abstract base-class for constraint objects
+
+       Constraints should be stored in a simple sequence in the
+       namespace of their client Asn1Item sub-classes.
+    """
+    def __init__(self, *values):
+        self._valueMap = {}
+        self._setValues(values)
+        self.__hashedValues = None
+    def __call__(self, value, idx=None):
+        try:
+            self._testValue(value, idx)
+        except error.ValueConstraintError:
+            raise error.ValueConstraintError(
+               '%s failed at: \"%s\"' % (self, sys.exc_info()[1])
+            )
+    def __repr__(self):
+        return '%s(%s)' % (
+            self.__class__.__name__,
+            ', '.join([repr(x) for x in self._values])
+        )
+    def __eq__(self, other):
+        return self is other and True or self._values == other
+    def __ne__(self, other): return self._values != other
+    def __lt__(self, other): return self._values < other
+    def __le__(self, other): return self._values <= other
+    def __gt__(self, other): return self._values > other
+    def __ge__(self, other): return self._values >= other
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(self._values)
+    else:
+        def __bool__(self): return bool(self._values)
+
+    def __hash__(self):
+        if self.__hashedValues is None:
+            self.__hashedValues = hash((self.__class__.__name__, self._values))
+        return self.__hashedValues
+
+    def _setValues(self, values): self._values = values
+    def _testValue(self, value, idx):
+        raise error.ValueConstraintError(value)
+
+    # Constraints derivation logic
+    def getValueMap(self): return self._valueMap
+    def isSuperTypeOf(self, otherConstraint):
+        return self in otherConstraint.getValueMap() or \
+               otherConstraint is self or otherConstraint == self
+    def isSubTypeOf(self, otherConstraint):
+        return otherConstraint in self._valueMap or \
+               otherConstraint is self or otherConstraint == self
+
+class SingleValueConstraint(AbstractConstraint):
+    """Value must be part of defined values constraint"""
+    def _testValue(self, value, idx):
+        # XXX index vals for performance?
+        if value not in self._values:
+            raise error.ValueConstraintError(value)
+
+class ContainedSubtypeConstraint(AbstractConstraint):
+    """Value must satisfy all of defined set of constraints"""
+    def _testValue(self, value, idx):
+        for c in self._values:
+            c(value, idx)
+
+class ValueRangeConstraint(AbstractConstraint):
+    """Value must be within start and stop values (inclusive)"""
+    def _testValue(self, value, idx):
+        if value < self.start or value > self.stop:
+            raise error.ValueConstraintError(value)
+
+    def _setValues(self, values):
+        if len(values) != 2:
+            raise error.PyAsn1Error(
+                '%s: bad constraint values' % (self.__class__.__name__,)
+                )
+        self.start, self.stop = values
+        if self.start > self.stop:
+            raise error.PyAsn1Error(
+                '%s: screwed constraint values (start > stop): %s > %s' % (
+                    self.__class__.__name__,
+                    self.start, self.stop
+                )
+            )
+        AbstractConstraint._setValues(self, values)
+        
+class ValueSizeConstraint(ValueRangeConstraint):
+    """len(value) must be within start and stop values (inclusive)"""
+    def _testValue(self, value, idx):
+        l = len(value)
+        if l < self.start or l > self.stop:
+            raise error.ValueConstraintError(value)
+
+class PermittedAlphabetConstraint(SingleValueConstraint):
+    def _setValues(self, values):
+        self._values = ()
+        for v in values:
+            self._values = self._values + tuple(v)
+
+    def _testValue(self, value, idx):
+        for v in value:
+            if v not in self._values:
+                raise error.ValueConstraintError(value)
+
+# This is a bit kludgy, meaning two op modes within a single constraing
+class InnerTypeConstraint(AbstractConstraint):
+    """Value must satisfy type and presense constraints"""
+    def _testValue(self, value, idx):
+        if self.__singleTypeConstraint:
+            self.__singleTypeConstraint(value)
+        elif self.__multipleTypeConstraint:
+            if idx not in self.__multipleTypeConstraint:
+                raise error.ValueConstraintError(value)
+            constraint, status = self.__multipleTypeConstraint[idx]
+            if status == 'ABSENT':   # XXX presense is not checked!
+                raise error.ValueConstraintError(value)
+            constraint(value)
+
+    def _setValues(self, values):
+        self.__multipleTypeConstraint = {}
+        self.__singleTypeConstraint = None
+        for v in values:
+            if isinstance(v, tuple):
+                self.__multipleTypeConstraint[v[0]] = v[1], v[2]
+            else:
+                self.__singleTypeConstraint = v
+        AbstractConstraint._setValues(self, values)
+
+# Boolean ops on constraints 
+
+class ConstraintsExclusion(AbstractConstraint):
+    """Value must not fit the single constraint"""
+    def _testValue(self, value, idx):
+        try:
+            self._values[0](value, idx)
+        except error.ValueConstraintError:
+            return
+        else:
+            raise error.ValueConstraintError(value)
+
+    def _setValues(self, values):
+        if len(values) != 1:
+            raise error.PyAsn1Error('Single constraint expected')
+        AbstractConstraint._setValues(self, values)
+
+class AbstractConstraintSet(AbstractConstraint):
+    """Value must not satisfy the single constraint"""
+    def __getitem__(self, idx): return self._values[idx]
+
+    def __add__(self, value): return self.__class__(self, value)
+    def __radd__(self, value): return self.__class__(self, value)
+
+    def __len__(self): return len(self._values)
+
+    # Constraints inclusion in sets
+    
+    def _setValues(self, values):
+        self._values = values
+        for v in values:
+            self._valueMap[v] = 1
+            self._valueMap.update(v.getValueMap())
+
+class ConstraintsIntersection(AbstractConstraintSet):
+    """Value must satisfy all constraints"""
+    def _testValue(self, value, idx):
+        for v in self._values:
+            v(value, idx)
+
+class ConstraintsUnion(AbstractConstraintSet):
+    """Value must satisfy at least one constraint"""
+    def _testValue(self, value, idx):
+        for v in self._values:
+            try:
+                v(value, idx)
+            except error.ValueConstraintError:
+                pass
+            else:
+                return
+        raise error.ValueConstraintError(
+            'all of %s failed for \"%s\"' % (self._values, value)
+            )
+
+# XXX
+# add tests for type check
diff --git a/python/pyasn1/pyasn1/type/error.py b/python/pyasn1/pyasn1/type/error.py
new file mode 100644
index 000000000..3e6848447
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/error.py
@@ -0,0 +1,3 @@
+from pyasn1.error import PyAsn1Error
+
+class ValueConstraintError(PyAsn1Error): pass
diff --git a/python/pyasn1/pyasn1/type/namedtype.py b/python/pyasn1/pyasn1/type/namedtype.py
new file mode 100644
index 000000000..48967a5fe
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/namedtype.py
@@ -0,0 +1,132 @@
+# NamedType specification for constructed types
+import sys
+from pyasn1.type import tagmap
+from pyasn1 import error
+
+class NamedType:
+    isOptional = 0
+    isDefaulted = 0
+    def __init__(self, name, t):
+        self.__name = name; self.__type = t
+    def __repr__(self): return '%s(%s, %s)' % (
+        self.__class__.__name__, self.__name, self.__type
+        )
+    def getType(self): return self.__type
+    def getName(self): return self.__name
+    def __getitem__(self, idx):
+        if idx == 0: return self.__name
+        if idx == 1: return self.__type
+        raise IndexError()
+    
+class OptionalNamedType(NamedType):
+    isOptional = 1
+class DefaultedNamedType(NamedType):
+    isDefaulted = 1
+    
+class NamedTypes:
+    def __init__(self, *namedTypes):
+        self.__namedTypes = namedTypes
+        self.__namedTypesLen = len(self.__namedTypes)
+        self.__minTagSet = None
+        self.__tagToPosIdx = {}; self.__nameToPosIdx = {}
+        self.__tagMap = { False: None, True: None }
+        self.__ambigiousTypes = {}
+
+    def __repr__(self):
+        r = '%s(' % self.__class__.__name__
+        for n in self.__namedTypes:
+            r = r + '%r, ' % (n,)
+        return r + ')'
+    
+    def __getitem__(self, idx): return self.__namedTypes[idx]
+
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(self.__namedTypesLen)
+    else:
+        def __bool__(self): return bool(self.__namedTypesLen)
+    def __len__(self): return self.__namedTypesLen
+    
+    def getTypeByPosition(self, idx):
+        if idx < 0 or idx >= self.__namedTypesLen:
+            raise error.PyAsn1Error('Type position out of range')
+        else:
+            return self.__namedTypes[idx].getType()
+
+    def getPositionByType(self, tagSet):
+        if not self.__tagToPosIdx:
+            idx = self.__namedTypesLen
+            while idx > 0:
+                idx = idx - 1
+                tagMap = self.__namedTypes[idx].getType().getTagMap()
+                for t in tagMap.getPosMap():
+                    if t in self.__tagToPosIdx:
+                        raise error.PyAsn1Error('Duplicate type %s' % (t,))
+                    self.__tagToPosIdx[t] = idx
+        try:
+            return self.__tagToPosIdx[tagSet]
+        except KeyError:
+            raise error.PyAsn1Error('Type %s not found' % (tagSet,))
+        
+    def getNameByPosition(self, idx):
+        try:
+            return self.__namedTypes[idx].getName()
+        except IndexError:
+            raise error.PyAsn1Error('Type position out of range')
+    def getPositionByName(self, name):
+        if not self.__nameToPosIdx:
+            idx = self.__namedTypesLen
+            while idx > 0:
+                idx = idx - 1
+                n = self.__namedTypes[idx].getName()
+                if n in self.__nameToPosIdx:
+                    raise error.PyAsn1Error('Duplicate name %s' % (n,))
+                self.__nameToPosIdx[n] = idx
+        try:
+            return self.__nameToPosIdx[name]
+        except KeyError:
+            raise error.PyAsn1Error('Name %s not found' % (name,))
+
+    def __buildAmbigiousTagMap(self):
+        ambigiousTypes = ()
+        idx = self.__namedTypesLen
+        while idx > 0:
+            idx = idx - 1
+            t = self.__namedTypes[idx]
+            if t.isOptional or t.isDefaulted:
+                ambigiousTypes = (t, ) + ambigiousTypes
+            else:
+                ambigiousTypes = (t, )
+            self.__ambigiousTypes[idx] = NamedTypes(*ambigiousTypes)
+        
+    def getTagMapNearPosition(self, idx):
+        if not self.__ambigiousTypes: self.__buildAmbigiousTagMap()
+        try:
+            return self.__ambigiousTypes[idx].getTagMap()
+        except KeyError:
+            raise error.PyAsn1Error('Type position out of range')
+
+    def getPositionNearType(self, tagSet, idx):
+        if not self.__ambigiousTypes: self.__buildAmbigiousTagMap()
+        try:
+            return idx+self.__ambigiousTypes[idx].getPositionByType(tagSet)
+        except KeyError:
+            raise error.PyAsn1Error('Type position out of range')
+
+    def genMinTagSet(self):
+        if self.__minTagSet is None:
+            for t in self.__namedTypes:
+                __type = t.getType()
+                tagSet = getattr(__type,'getMinTagSet',__type.getTagSet)()
+                if self.__minTagSet is None or tagSet < self.__minTagSet:
+                    self.__minTagSet = tagSet
+        return self.__minTagSet
+    
+    def getTagMap(self, uniq=False):
+        if self.__tagMap[uniq] is None:
+            tagMap = tagmap.TagMap()
+            for nt in self.__namedTypes:
+                tagMap = tagMap.clone(
+                    nt.getType(), nt.getType().getTagMap(), uniq
+                    )
+            self.__tagMap[uniq] = tagMap
+        return self.__tagMap[uniq]
diff --git a/python/pyasn1/pyasn1/type/namedval.py b/python/pyasn1/pyasn1/type/namedval.py
new file mode 100644
index 000000000..d0fea7cc7
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/namedval.py
@@ -0,0 +1,46 @@
+# ASN.1 named integers
+from pyasn1 import error
+
+__all__ = [ 'NamedValues' ]
+
+class NamedValues:
+    def __init__(self, *namedValues):
+        self.nameToValIdx = {}; self.valToNameIdx = {}
+        self.namedValues = ()        
+        automaticVal = 1
+        for namedValue in namedValues:
+            if isinstance(namedValue, tuple):
+                name, val = namedValue
+            else:
+                name = namedValue
+                val = automaticVal
+            if name in self.nameToValIdx:
+                raise error.PyAsn1Error('Duplicate name %s' % (name,))
+            self.nameToValIdx[name] = val
+            if val in self.valToNameIdx:
+                raise error.PyAsn1Error('Duplicate value %s=%s' % (name, val))
+            self.valToNameIdx[val] = name
+            self.namedValues = self.namedValues + ((name, val),)
+            automaticVal = automaticVal + 1
+    def __str__(self): return str(self.namedValues)
+    
+    def getName(self, value):
+        if value in self.valToNameIdx:
+            return self.valToNameIdx[value]
+
+    def getValue(self, name):
+        if name in self.nameToValIdx:
+            return self.nameToValIdx[name]
+    
+    def __getitem__(self, i): return self.namedValues[i]
+    def __len__(self): return len(self.namedValues)
+
+    def __add__(self, namedValues):
+        return self.__class__(*self.namedValues + namedValues)
+    def __radd__(self, namedValues):
+        return self.__class__(*namedValues + tuple(self))
+        
+    def clone(self, *namedValues):
+        return self.__class__(*tuple(self) + namedValues)
+
+# XXX clone/subtype?
diff --git a/python/pyasn1/pyasn1/type/tag.py b/python/pyasn1/pyasn1/type/tag.py
new file mode 100644
index 000000000..1144907fa
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/tag.py
@@ -0,0 +1,122 @@
+# ASN.1 types tags
+from operator import getitem
+from pyasn1 import error
+
+tagClassUniversal = 0x00
+tagClassApplication = 0x40
+tagClassContext = 0x80
+tagClassPrivate = 0xC0
+
+tagFormatSimple = 0x00
+tagFormatConstructed = 0x20
+
+tagCategoryImplicit = 0x01
+tagCategoryExplicit = 0x02
+tagCategoryUntagged = 0x04
+
+class Tag:
+    def __init__(self, tagClass, tagFormat, tagId):
+        if tagId < 0:
+            raise error.PyAsn1Error(
+                'Negative tag ID (%s) not allowed' % (tagId,)
+                )
+        self.__tag = (tagClass, tagFormat, tagId)
+        self.uniq = (tagClass, tagId)
+        self.__hashedUniqTag = hash(self.uniq)
+
+    def __repr__(self):
+        return '%s(tagClass=%s, tagFormat=%s, tagId=%s)' % (
+            (self.__class__.__name__,) + self.__tag
+            )
+    # These is really a hotspot -- expose public "uniq" attribute to save on
+    # function calls
+    def __eq__(self, other): return self.uniq == other.uniq
+    def __ne__(self, other): return self.uniq != other.uniq
+    def __lt__(self, other): return self.uniq < other.uniq
+    def __le__(self, other): return self.uniq <= other.uniq
+    def __gt__(self, other): return self.uniq > other.uniq
+    def __ge__(self, other): return self.uniq >= other.uniq
+    def __hash__(self): return self.__hashedUniqTag
+    def __getitem__(self, idx): return self.__tag[idx]
+    def __and__(self, otherTag):
+        (tagClass, tagFormat, tagId) = otherTag
+        return self.__class__(
+            self.__tag&tagClass, self.__tag&tagFormat, self.__tag&tagId
+            )
+    def __or__(self, otherTag):
+        (tagClass, tagFormat, tagId) = otherTag
+        return self.__class__(
+            self.__tag[0]|tagClass,
+            self.__tag[1]|tagFormat,
+            self.__tag[2]|tagId
+            )
+    def asTuple(self): return self.__tag  # __getitem__() is slow
+    
+class TagSet:
+    def __init__(self, baseTag=(), *superTags):
+        self.__baseTag = baseTag
+        self.__superTags = superTags
+        self.__hashedSuperTags = hash(superTags)
+        _uniq = ()
+        for t in superTags:
+            _uniq = _uniq + t.uniq
+        self.uniq = _uniq
+        self.__lenOfSuperTags = len(superTags)
+        
+    def __repr__(self):
+        return '%s(%s)' % (
+            self.__class__.__name__,
+            ', '.join([repr(x) for x in self.__superTags])
+            )
+
+    def __add__(self, superTag):
+        return self.__class__(
+            self.__baseTag, *self.__superTags + (superTag,)
+            )
+    def __radd__(self, superTag):
+        return self.__class__(
+            self.__baseTag, *(superTag,) + self.__superTags
+            )
+
+    def tagExplicitly(self, superTag):
+        tagClass, tagFormat, tagId = superTag
+        if tagClass == tagClassUniversal:
+            raise error.PyAsn1Error(
+                'Can\'t tag with UNIVERSAL-class tag'
+                )
+        if tagFormat != tagFormatConstructed:
+            superTag = Tag(tagClass, tagFormatConstructed, tagId)
+        return self + superTag
+
+    def tagImplicitly(self, superTag):
+        tagClass, tagFormat, tagId = superTag
+        if self.__superTags:
+            superTag = Tag(tagClass, self.__superTags[-1][1], tagId)
+        return self[:-1] + superTag
+
+    def getBaseTag(self): return self.__baseTag
+    def __getitem__(self, idx):
+        if isinstance(idx, slice):
+            return self.__class__(
+               self.__baseTag, *getitem(self.__superTags, idx)
+            )
+        return self.__superTags[idx]
+    def __eq__(self, other): return self.uniq == other.uniq
+    def __ne__(self, other): return self.uniq != other.uniq
+    def __lt__(self, other): return self.uniq < other.uniq
+    def __le__(self, other): return self.uniq <= other.uniq
+    def __gt__(self, other): return self.uniq > other.uniq
+    def __ge__(self, other): return self.uniq >= other.uniq
+    def __hash__(self): return self.__hashedSuperTags
+    def __len__(self): return self.__lenOfSuperTags
+    def isSuperTagSetOf(self, tagSet):
+        if len(tagSet) < self.__lenOfSuperTags:
+            return
+        idx = self.__lenOfSuperTags - 1
+        while idx >= 0:
+            if self.__superTags[idx] != tagSet[idx]:
+                return
+            idx = idx - 1
+        return 1
+    
+def initTagSet(tag): return TagSet(tag, tag)
diff --git a/python/pyasn1/pyasn1/type/tagmap.py b/python/pyasn1/pyasn1/type/tagmap.py
new file mode 100644
index 000000000..7cec3a10e
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/tagmap.py
@@ -0,0 +1,52 @@
+from pyasn1 import error
+
+class TagMap:
+    def __init__(self, posMap={}, negMap={}, defType=None):
+        self.__posMap = posMap.copy()
+        self.__negMap = negMap.copy()
+        self.__defType = defType
+        
+    def __contains__(self, tagSet):
+        return tagSet in self.__posMap or \
+               self.__defType is not None and tagSet not in self.__negMap
+
+    def __getitem__(self, tagSet):
+        if tagSet in self.__posMap:
+            return self.__posMap[tagSet]
+        elif tagSet in self.__negMap:
+            raise error.PyAsn1Error('Key in negative map')
+        elif self.__defType is not None:
+            return self.__defType
+        else:
+            raise KeyError()
+
+    def __repr__(self):
+        s = '%r/%r' % (self.__posMap, self.__negMap)
+        if self.__defType is not None:
+            s = s + '/%r' % (self.__defType,)
+        return s
+
+    def clone(self, parentType, tagMap, uniq=False):
+        if self.__defType is not None and tagMap.getDef() is not None:
+            raise error.PyAsn1Error('Duplicate default value at %s' % (self,))
+        if tagMap.getDef() is not None:
+            defType = tagMap.getDef()
+        else:
+            defType = self.__defType
+            
+        posMap = self.__posMap.copy()
+        for k in tagMap.getPosMap():
+            if uniq and k in posMap:
+                raise error.PyAsn1Error('Duplicate positive key %s' % (k,))
+            posMap[k] = parentType
+
+        negMap = self.__negMap.copy()
+        negMap.update(tagMap.getNegMap())
+        
+        return self.__class__(
+            posMap, negMap, defType,
+            )
+
+    def getPosMap(self): return self.__posMap.copy()
+    def getNegMap(self): return self.__negMap.copy()
+    def getDef(self): return self.__defType
diff --git a/python/pyasn1/pyasn1/type/univ.py b/python/pyasn1/pyasn1/type/univ.py
new file mode 100644
index 000000000..9cd16f8a2
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/univ.py
@@ -0,0 +1,1042 @@
+# ASN.1 "universal" data types
+import operator, sys
+from pyasn1.type import base, tag, constraint, namedtype, namedval, tagmap
+from pyasn1.codec.ber import eoo
+from pyasn1.compat import octets
+from pyasn1 import error
+
+# "Simple" ASN.1 types (yet incomplete)
+
+class Integer(base.AbstractSimpleAsn1Item):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x02)
+        )
+    namedValues = namedval.NamedValues()
+    def __init__(self, value=None, tagSet=None, subtypeSpec=None,
+                 namedValues=None):
+        if namedValues is None:
+            self.__namedValues = self.namedValues
+        else:
+            self.__namedValues = namedValues
+        base.AbstractSimpleAsn1Item.__init__(
+            self, value, tagSet, subtypeSpec
+            )
+
+    def __and__(self, value): return self.clone(self._value & value)
+    def __rand__(self, value): return self.clone(value & self._value)
+    def __or__(self, value): return self.clone(self._value | value)
+    def __ror__(self, value): return self.clone(value | self._value)
+    def __xor__(self, value): return self.clone(self._value ^ value)
+    def __rxor__(self, value): return self.clone(value ^ self._value)
+    def __lshift__(self, value): return self.clone(self._value << value)
+    def __rshift__(self, value): return self.clone(self._value >> value)
+
+    def __add__(self, value): return self.clone(self._value + value)
+    def __radd__(self, value): return self.clone(value + self._value)
+    def __sub__(self, value): return self.clone(self._value - value)
+    def __rsub__(self, value): return self.clone(value - self._value)
+    def __mul__(self, value): return self.clone(self._value * value)
+    def __rmul__(self, value): return self.clone(value * self._value)
+    def __mod__(self, value): return self.clone(self._value % value)
+    def __rmod__(self, value): return self.clone(value % self._value)
+    def __pow__(self, value, modulo=None): return self.clone(pow(self._value, value, modulo))
+    def __rpow__(self, value): return self.clone(pow(value, self._value))
+
+    if sys.version_info[0] <= 2:
+        def __div__(self, value):  return self.clone(self._value // value)
+        def __rdiv__(self, value):  return self.clone(value // self._value)
+    else:
+        def __truediv__(self, value):  return self.clone(self._value / value)
+        def __rtruediv__(self, value):  return self.clone(value / self._value)
+        def __divmod__(self, value):  return self.clone(self._value // value)
+        def __rdivmod__(self, value):  return self.clone(value // self._value)
+
+        __hash__ = base.AbstractSimpleAsn1Item.__hash__
+
+    def __int__(self): return int(self._value)
+    if sys.version_info[0] <= 2:
+        def __long__(self): return long(self._value)
+    def __float__(self): return float(self._value)    
+    def __abs__(self): return abs(self._value)
+    def __index__(self): return int(self._value)
+
+    def __lt__(self, value): return self._value < value
+    def __le__(self, value): return self._value <= value
+    def __eq__(self, value): return self._value == value
+    def __ne__(self, value): return self._value != value
+    def __gt__(self, value): return self._value > value
+    def __ge__(self, value): return self._value >= value
+
+    def prettyIn(self, value):
+        if not isinstance(value, str):
+            try:
+                return int(value)
+            except:
+                raise error.PyAsn1Error(
+                    'Can\'t coerce %s into integer: %s' % (value, sys.exc_info()[1])
+                    )
+        r = self.__namedValues.getValue(value)
+        if r is not None:
+            return r
+        try:
+            return int(value)
+        except:
+            raise error.PyAsn1Error(
+                'Can\'t coerce %s into integer: %s' % (value, sys.exc_info()[1])
+                )
+
+    def prettyOut(self, value):
+        r = self.__namedValues.getName(value)
+        return r is None and str(value) or repr(r)
+
+    def getNamedValues(self): return self.__namedValues
+
+    def clone(self, value=None, tagSet=None, subtypeSpec=None,
+              namedValues=None):
+        if value is None and tagSet is None and subtypeSpec is None \
+               and namedValues is None:
+            return self
+        if value is None:
+            value = self._value
+        if tagSet is None:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        if namedValues is None:
+            namedValues = self.__namedValues
+        return self.__class__(value, tagSet, subtypeSpec, namedValues)
+
+    def subtype(self, value=None, implicitTag=None, explicitTag=None,
+                subtypeSpec=None, namedValues=None):
+        if value is None:
+            value = self._value
+        if implicitTag is not None:
+            tagSet = self._tagSet.tagImplicitly(implicitTag)
+        elif explicitTag is not None:
+            tagSet = self._tagSet.tagExplicitly(explicitTag)
+        else:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        else:
+            subtypeSpec = subtypeSpec + self._subtypeSpec
+        if namedValues is None:
+            namedValues = self.__namedValues
+        else:
+            namedValues = namedValues + self.__namedValues
+        return self.__class__(value, tagSet, subtypeSpec, namedValues)
+
+class Boolean(Integer):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x01),
+        )
+    subtypeSpec = Integer.subtypeSpec+constraint.SingleValueConstraint(0,1)
+    namedValues = Integer.namedValues.clone(('False', 0), ('True', 1))
+
+class BitString(base.AbstractSimpleAsn1Item):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x03)
+        )
+    namedValues = namedval.NamedValues()
+    def __init__(self, value=None, tagSet=None, subtypeSpec=None,
+                 namedValues=None):
+        if namedValues is None:
+            self.__namedValues = self.namedValues
+        else:
+            self.__namedValues = namedValues
+        base.AbstractSimpleAsn1Item.__init__(
+            self, value, tagSet, subtypeSpec
+            )
+
+    def clone(self, value=None, tagSet=None, subtypeSpec=None,
+              namedValues=None):
+        if value is None and tagSet is None and subtypeSpec is None \
+               and namedValues is None:
+            return self
+        if value is None:
+            value = self._value
+        if tagSet is None:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        if namedValues is None:
+            namedValues = self.__namedValues
+        return self.__class__(value, tagSet, subtypeSpec, namedValues)
+
+    def subtype(self, value=None, implicitTag=None, explicitTag=None,
+                subtypeSpec=None, namedValues=None):
+        if value is None:
+            value = self._value
+        if implicitTag is not None:
+            tagSet = self._tagSet.tagImplicitly(implicitTag)
+        elif explicitTag is not None:
+            tagSet = self._tagSet.tagExplicitly(explicitTag)
+        else:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        else:
+            subtypeSpec = subtypeSpec + self._subtypeSpec
+        if namedValues is None:
+            namedValues = self.__namedValues
+        else:
+            namedValues = namedValues + self.__namedValues
+        return self.__class__(value, tagSet, subtypeSpec, namedValues)
+
+    def __str__(self): return str(tuple(self))
+
+    # Immutable sequence object protocol
+
+    def __len__(self):
+        if self._len is None:
+            self._len = len(self._value)
+        return self._len
+    def __getitem__(self, i):
+        if isinstance(i, slice):
+            return self.clone(operator.getitem(self._value, i))
+        else:
+            return self._value[i]
+
+    def __add__(self, value): return self.clone(self._value + value)
+    def __radd__(self, value): return self.clone(value + self._value)
+    def __mul__(self, value): return self.clone(self._value * value)
+    def __rmul__(self, value): return self * value
+
+    def prettyIn(self, value):
+        r = []
+        if not value:
+            return ()
+        elif isinstance(value, str):
+            if value[0] == '\'':
+                if value[-2:] == '\'B':
+                    for v in value[1:-2]:
+                        if v == '0':
+                            r.append(0)
+                        elif v == '1':
+                            r.append(1)
+                        else:
+                            raise error.PyAsn1Error(
+                                'Non-binary BIT STRING initializer %s' % (v,)
+                                )
+                    return tuple(r)
+                elif value[-2:] == '\'H':
+                    for v in value[1:-2]:
+                        i = 4
+                        v = int(v, 16)
+                        while i:
+                            i = i - 1
+                            r.append((v>>i)&0x01)
+                    return tuple(r)
+                else:
+                    raise error.PyAsn1Error(
+                        'Bad BIT STRING value notation %s' % (value,)
+                        )                
+            else:
+                for i in value.split(','):
+                    j = self.__namedValues.getValue(i)
+                    if j is None:
+                        raise error.PyAsn1Error(
+                            'Unknown bit identifier \'%s\'' % (i,)
+                            )
+                    if j >= len(r):
+                        r.extend([0]*(j-len(r)+1))
+                    r[j] = 1
+                return tuple(r)
+        elif isinstance(value, (tuple, list)):
+            r = tuple(value)
+            for b in r:
+                if b and b != 1:
+                    raise error.PyAsn1Error(
+                        'Non-binary BitString initializer \'%s\'' % (r,)
+                        )
+            return r
+        elif isinstance(value, BitString):
+            return tuple(value)
+        else:
+            raise error.PyAsn1Error(
+                'Bad BitString initializer type \'%s\'' % (value,)
+                )
+
+    def prettyOut(self, value):
+        return '\"\'%s\'B\"' % ''.join([str(x) for x in value])
+
+class OctetString(base.AbstractSimpleAsn1Item):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x04)
+        )
+    defaultBinValue = defaultHexValue = base.noValue
+    encoding = 'us-ascii'
+    def __init__(self, value=None, tagSet=None, subtypeSpec=None,
+                 encoding=None, binValue=None, hexValue=None):
+        if encoding is None:
+            self._encoding = self.encoding
+        else:
+            self._encoding = encoding
+        if binValue is not None:
+            value = self.fromBinaryString(binValue)
+        if hexValue is not None:
+            value = self.fromHexString(hexValue)
+        if value is None or value is base.noValue:
+            value = self.defaultHexValue
+        if value is None or value is base.noValue:
+            value = self.defaultBinValue
+        self.__intValue = None
+        base.AbstractSimpleAsn1Item.__init__(self, value, tagSet, subtypeSpec)
+
+    def clone(self, value=None, tagSet=None, subtypeSpec=None,
+              encoding=None, binValue=None, hexValue=None):
+        if value is None and tagSet is None and subtypeSpec is None and \
+               encoding is None and binValue is None and hexValue is None:
+            return self
+        if value is None and binValue is None and hexValue is None:
+            value = self._value
+        if tagSet is None:
+            tagSet = self._tagSet
+        if subtypeSpec is None:
+            subtypeSpec = self._subtypeSpec
+        if encoding is None:
+            encoding = self._encoding
+        return self.__class__(
+            value, tagSet, subtypeSpec, encoding, binValue, hexValue
+            )
+   
+    if sys.version_info[0] <= 2:
+        def prettyIn(self, value):
+            if isinstance(value, str):
+                return value
+            elif isinstance(value, (tuple, list)):
+                try:
+                    return ''.join([ chr(x) for x in value ])
+                except ValueError:
+                    raise error.PyAsn1Error(
+                        'Bad OctetString initializer \'%s\'' % (value,)
+                        )                
+            else:
+                return str(value)
+    else:
+        def prettyIn(self, value):
+            if isinstance(value, bytes):
+                return value
+            elif isinstance(value, OctetString):
+                return value.asOctets()
+            elif isinstance(value, (tuple, list, map)):
+                try:
+                    return bytes(value)
+                except ValueError:
+                    raise error.PyAsn1Error(
+                        'Bad OctetString initializer \'%s\'' % (value,)
+                        )
+            else:
+                try:
+                    return str(value).encode(self._encoding)
+                except UnicodeEncodeError:
+                    raise error.PyAsn1Error(
+                        'Can\'t encode string \'%s\' with \'%s\' codec' % (value, self._encoding)
+                        )
+                        
+
+    def fromBinaryString(self, value):
+        bitNo = 8; byte = 0; r = ()
+        for v in value:
+            if bitNo:
+                bitNo = bitNo - 1
+            else:
+                bitNo = 7
+                r = r + (byte,)
+                byte = 0
+            if v == '0':
+                v = 0
+            elif v == '1':
+                v = 1
+            else:
+                raise error.PyAsn1Error(
+                    'Non-binary OCTET STRING initializer %s' % (v,)
+                    )
+            byte = byte | (v << bitNo)
+        return octets.ints2octs(r + (byte,))
+        
+    def fromHexString(self, value):            
+        r = p = ()
+        for v in value:
+            if p:
+                r = r + (int(p+v, 16),)
+                p = ()
+            else:
+                p = v
+        if p:
+            r = r + (int(p+'0', 16),)
+        return octets.ints2octs(r)
+
+    def prettyOut(self, value):
+        if sys.version_info[0] <= 2:
+            numbers = tuple([ ord(x) for x in value ])
+        else:
+            numbers = tuple(value)
+        if [ x for x in numbers if x < 32 or x > 126 ]:
+            return '0x' + ''.join([ '%.2x' % x for x in numbers ])
+        else:
+            return str(value)
+
+    def __repr__(self):
+        if self._value is base.noValue:
+            return self.__class__.__name__ + '()'
+        if [ x for x in self.asNumbers() if x < 32 or x > 126 ]:
+            return self.__class__.__name__ + '(hexValue=\'' + ''.join([ '%.2x' % x for x in self.asNumbers() ])+'\')'
+        else:
+            return self.__class__.__name__ + '(\'' + self.prettyOut(self._value) + '\')'
+                                
+    if sys.version_info[0] <= 2:
+        def __str__(self): return str(self._value)
+        def __unicode__(self):
+            return self._value.decode(self._encoding, 'ignore')
+        def asOctets(self): return self._value
+        def asNumbers(self):
+            if self.__intValue is None:
+                self.__intValue = tuple([ ord(x) for x in self._value ])
+            return self.__intValue
+    else:
+        def __str__(self): return self._value.decode(self._encoding, 'ignore')
+        def __bytes__(self): return self._value
+        def asOctets(self): return self._value
+        def asNumbers(self):
+            if self.__intValue is None:
+                self.__intValue = tuple(self._value)
+            return self.__intValue
+ 
+    # Immutable sequence object protocol
+    
+    def __len__(self):
+        if self._len is None:
+            self._len = len(self._value)
+        return self._len
+    def __getitem__(self, i):
+        if isinstance(i, slice):
+            return self.clone(operator.getitem(self._value, i))
+        else:
+            return self._value[i]
+
+    def __add__(self, value): return self.clone(self._value + self.prettyIn(value))
+    def __radd__(self, value): return self.clone(self.prettyIn(value) + self._value)
+    def __mul__(self, value): return self.clone(self._value * value)
+    def __rmul__(self, value): return self * value
+
+class Null(OctetString):
+    defaultValue = ''.encode()  # This is tightly constrained
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x05)
+        )
+    subtypeSpec = OctetString.subtypeSpec+constraint.SingleValueConstraint(''.encode())
+    
+if sys.version_info[0] <= 2:
+    intTypes = (int, long)
+else:
+    intTypes = int
+
+class ObjectIdentifier(base.AbstractSimpleAsn1Item):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x06)
+        )
+    def __add__(self, other): return self.clone(self._value + other)
+    def __radd__(self, other): return self.clone(other + self._value)
+
+    def asTuple(self): return self._value
+    
+    # Sequence object protocol
+    
+    def __len__(self):
+        if self._len is None:
+            self._len = len(self._value)
+        return self._len
+    def __getitem__(self, i):
+        if isinstance(i, slice):
+            return self.clone(
+                operator.getitem(self._value, i)
+                )
+        else:
+            return self._value[i]
+
+    def __str__(self): return self.prettyPrint()
+    
+    def index(self, suboid): return self._value.index(suboid)
+
+    def isPrefixOf(self, value):
+        """Returns true if argument OID resides deeper in the OID tree"""
+        l = len(self)
+        if l <= len(value):
+            if self._value[:l] == value[:l]:
+                return 1
+        return 0
+
+    def prettyIn(self, value):
+        """Dotted -> tuple of numerics OID converter"""
+        if isinstance(value, tuple):
+            pass
+        elif isinstance(value, ObjectIdentifier):
+            return tuple(value)        
+        elif isinstance(value, str):
+            r = []
+            for element in [ x for x in value.split('.') if x != '' ]:
+                try:
+                    r.append(int(element, 0))
+                except ValueError:
+                    raise error.PyAsn1Error(
+                        'Malformed Object ID %s at %s: %s' %
+                        (str(value), self.__class__.__name__, sys.exc_info()[1])
+                        )
+            value = tuple(r)
+        else:
+            try:
+                value = tuple(value)
+            except TypeError:
+                raise error.PyAsn1Error(
+                        'Malformed Object ID %s at %s: %s' %
+                        (str(value), self.__class__.__name__,sys.exc_info()[1])
+                        )
+
+        for x in value:
+            if not isinstance(x, intTypes) or x < 0:
+                raise error.PyAsn1Error(
+                    'Invalid sub-ID in %s at %s' % (value, self.__class__.__name__)
+                    )
+    
+        return value
+
+    def prettyOut(self, value): return '.'.join([ str(x) for x in value ])
+    
+class Real(base.AbstractSimpleAsn1Item):
+    try:
+        _plusInf = float('inf')
+        _minusInf = float('-inf')
+        _inf = (_plusInf, _minusInf)
+    except ValueError:
+        # Infinity support is platform and Python dependent
+        _plusInf = _minusInf = None
+        _inf = ()
+
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x09)
+        )
+
+    def __normalizeBase10(self, value):
+        m, b, e = value
+        while m and m % 10 == 0:
+            m = m / 10
+            e = e + 1
+        return m, b, e
+
+    def prettyIn(self, value):
+        if isinstance(value, tuple) and len(value) == 3:
+            for d in value:
+                if not isinstance(d, intTypes):
+                    raise error.PyAsn1Error(
+                        'Lame Real value syntax: %s' % (value,)
+                        )
+            if value[1] not in (2, 10):
+                raise error.PyAsn1Error(
+                    'Prohibited base for Real value: %s' % (value[1],)
+                    )
+            if value[1] == 10:
+                value = self.__normalizeBase10(value)
+            return value
+        elif isinstance(value, intTypes):
+            return self.__normalizeBase10((value, 10, 0))
+        elif isinstance(value, float):
+            if self._inf and value in self._inf:
+                return value
+            else:
+                e = 0
+                while int(value) != value:
+                    value = value * 10
+                    e = e - 1
+                return self.__normalizeBase10((int(value), 10, e))
+        elif isinstance(value, Real):
+            return tuple(value)
+        elif isinstance(value, str):  # handle infinite literal
+            try:
+                return float(value)
+            except ValueError:
+                pass
+        raise error.PyAsn1Error(
+            'Bad real value syntax: %s' % (value,)
+            )
+        
+    def prettyOut(self, value):
+        if value in self._inf:
+            return '\'%s\'' % value
+        else:
+            return str(value)
+
+    def isPlusInfinity(self): return self._value == self._plusInf
+    def isMinusInfinity(self): return self._value == self._minusInf
+    def isInfinity(self): return self._value in self._inf
+    
+    def __str__(self): return str(float(self))
+    
+    def __add__(self, value): return self.clone(float(self) + value)
+    def __radd__(self, value): return self + value
+    def __mul__(self, value): return self.clone(float(self) * value)
+    def __rmul__(self, value): return self * value
+    def __sub__(self, value): return self.clone(float(self) - value)
+    def __rsub__(self, value): return self.clone(value - float(self))
+    def __mod__(self, value): return self.clone(float(self) % value)
+    def __rmod__(self, value): return self.clone(value % float(self))
+    def __pow__(self, value, modulo=None): return self.clone(pow(float(self), value, modulo))
+    def __rpow__(self, value): return self.clone(pow(value, float(self)))
+
+    if sys.version_info[0] <= 2:
+        def __div__(self, value): return self.clone(float(self) / value)
+        def __rdiv__(self, value): return self.clone(value / float(self))
+    else:
+        def __truediv__(self, value): return self.clone(float(self) / value)
+        def __rtruediv__(self, value): return self.clone(value / float(self))
+        def __divmod__(self, value): return self.clone(float(self) // value)
+        def __rdivmod__(self, value): return self.clone(value // float(self))
+
+    def __int__(self): return int(float(self))
+    if sys.version_info[0] <= 2:
+        def __long__(self): return long(float(self))
+    def __float__(self):
+        if self._value in self._inf:
+            return self._value
+        else:
+            return float(
+                self._value[0] * pow(self._value[1], self._value[2])
+                )
+    def __abs__(self): return abs(float(self))
+
+    def __lt__(self, value): return float(self) < value
+    def __le__(self, value): return float(self) <= value
+    def __eq__(self, value): return float(self) == value
+    def __ne__(self, value): return float(self) != value
+    def __gt__(self, value): return float(self) > value
+    def __ge__(self, value): return float(self) >= value
+
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(float(self))
+    else:
+        def __bool__(self): return bool(float(self))
+        __hash__ = base.AbstractSimpleAsn1Item.__hash__
+
+    def __getitem__(self, idx):
+        if self._value in self._inf:
+            raise error.PyAsn1Error('Invalid infinite value operation')
+        else:
+            return self._value[idx]
+    
+class Enumerated(Integer):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 0x0A)
+        )
+
+# "Structured" ASN.1 types
+
+class SetOf(base.AbstractConstructedAsn1Item):
+    componentType = None
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatConstructed, 0x11)
+        )
+    typeId = 1
+
+    def _cloneComponentValues(self, myClone, cloneValueFlag):
+        idx = 0; l = len(self._componentValues)
+        while idx < l:
+            c = self._componentValues[idx]
+            if c is not None:
+                if isinstance(c, base.AbstractConstructedAsn1Item):
+                    myClone.setComponentByPosition(
+                        idx, c.clone(cloneValueFlag=cloneValueFlag)
+                        )
+                else:
+                    myClone.setComponentByPosition(idx, c.clone())
+            idx = idx + 1
+        
+    def _verifyComponent(self, idx, value):
+        if self._componentType is not None and \
+               not self._componentType.isSuperTypeOf(value):
+            raise error.PyAsn1Error('Component type error %s' % (value,))
+
+    def getComponentByPosition(self, idx): return self._componentValues[idx]
+    def setComponentByPosition(self, idx, value=None, verifyConstraints=True):
+        l = len(self._componentValues)
+        if idx >= l:
+            self._componentValues = self._componentValues + (idx-l+1)*[None]
+        if value is None:
+            if self._componentValues[idx] is None:
+                if self._componentType is None:
+                    raise error.PyAsn1Error('Component type not defined')
+                self._componentValues[idx] = self._componentType.clone()
+                self._componentValuesSet = self._componentValuesSet + 1
+            return self
+        elif not isinstance(value, base.Asn1Item):
+            if self._componentType is None:
+                raise error.PyAsn1Error('Component type not defined')
+            if isinstance(self._componentType, base.AbstractSimpleAsn1Item):
+                value = self._componentType.clone(value=value)
+            else:
+                raise error.PyAsn1Error('Instance value required')
+        if verifyConstraints:
+            if self._componentType is not None:
+                self._verifyComponent(idx, value)
+            self._verifySubtypeSpec(value, idx)            
+        if self._componentValues[idx] is None:
+            self._componentValuesSet = self._componentValuesSet + 1
+        self._componentValues[idx] = value
+        return self
+
+    def getComponentTagMap(self):
+        if self._componentType is not None:
+            return self._componentType.getTagMap()
+
+    def prettyPrint(self, scope=0):
+        scope = scope + 1
+        r = self.__class__.__name__ + ':\n'        
+        for idx in range(len(self._componentValues)):
+            r = r + ' '*scope
+            if self._componentValues[idx] is None:
+                r = r + '<empty>'
+            else:
+                r = r + self._componentValues[idx].prettyPrint(scope)
+        return r
+
+class SequenceOf(SetOf):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatConstructed, 0x10)
+        )
+    typeId = 2
+
+class SequenceAndSetBase(base.AbstractConstructedAsn1Item):
+    componentType = namedtype.NamedTypes()
+    def __init__(self, componentType=None, tagSet=None,
+                 subtypeSpec=None, sizeSpec=None):
+        base.AbstractConstructedAsn1Item.__init__(
+            self, componentType, tagSet, subtypeSpec, sizeSpec
+            )
+        if self._componentType is None:
+            self._componentTypeLen = 0
+        else:
+            self._componentTypeLen = len(self._componentType)
+
+    def __getitem__(self, idx):
+        if isinstance(idx, str):
+            return self.getComponentByName(idx)
+        else:
+            return base.AbstractConstructedAsn1Item.__getitem__(self, idx)
+
+    def __setitem__(self, idx, value):
+        if isinstance(idx, str):
+            self.setComponentByName(idx, value)
+        else:
+            base.AbstractConstructedAsn1Item.__setitem__(self, idx, value)
+        
+    def _cloneComponentValues(self, myClone, cloneValueFlag):
+        idx = 0; l = len(self._componentValues)
+        while idx < l:
+            c = self._componentValues[idx]
+            if c is not None:
+                if isinstance(c, base.AbstractConstructedAsn1Item):
+                    myClone.setComponentByPosition(
+                        idx, c.clone(cloneValueFlag=cloneValueFlag)
+                        )
+                else:
+                    myClone.setComponentByPosition(idx, c.clone())
+            idx = idx + 1
+
+    def _verifyComponent(self, idx, value):
+        if idx >= self._componentTypeLen:
+            raise error.PyAsn1Error(
+                'Component type error out of range'
+                )
+        t = self._componentType[idx].getType()
+        if not t.isSuperTypeOf(value):
+            raise error.PyAsn1Error('Component type error %r vs %r' % (t, value))
+
+    def getComponentByName(self, name):
+        return self.getComponentByPosition(
+            self._componentType.getPositionByName(name)
+            )
+    def setComponentByName(self, name, value=None, verifyConstraints=True):
+        return self.setComponentByPosition(
+            self._componentType.getPositionByName(name), value,
+            verifyConstraints
+            )
+
+    def getComponentByPosition(self, idx):
+        try:
+            return self._componentValues[idx]
+        except IndexError:
+            if idx < self._componentTypeLen:
+                return
+            raise
+    def setComponentByPosition(self, idx, value=None, verifyConstraints=True):
+        l = len(self._componentValues)
+        if idx >= l:
+            self._componentValues = self._componentValues + (idx-l+1)*[None]
+        if value is None:
+            if self._componentValues[idx] is None:
+                self._componentValues[idx] = self._componentType.getTypeByPosition(idx).clone()
+                self._componentValuesSet = self._componentValuesSet + 1
+            return self
+        elif not isinstance(value, base.Asn1Item):
+            t = self._componentType.getTypeByPosition(idx)
+            if isinstance(t, base.AbstractSimpleAsn1Item):
+                value = t.clone(value=value)
+            else:
+                raise error.PyAsn1Error('Instance value required')
+        if verifyConstraints:
+            if self._componentTypeLen:
+                self._verifyComponent(idx, value)
+            self._verifySubtypeSpec(value, idx)            
+        if self._componentValues[idx] is None:
+            self._componentValuesSet = self._componentValuesSet + 1
+        self._componentValues[idx] = value
+        return self
+
+    def getNameByPosition(self, idx):
+        if self._componentTypeLen:
+            return self._componentType.getNameByPosition(idx)
+
+    def getDefaultComponentByPosition(self, idx):
+        if self._componentTypeLen and self._componentType[idx].isDefaulted:
+            return self._componentType[idx].getType()
+
+    def getComponentType(self):
+        if self._componentTypeLen:
+            return self._componentType
+    
+    def setDefaultComponents(self):
+        if self._componentTypeLen == self._componentValuesSet:
+            return
+        idx = self._componentTypeLen
+        while idx:
+            idx = idx - 1
+            if self._componentType[idx].isDefaulted:
+                if self.getComponentByPosition(idx) is None:
+                    self.setComponentByPosition(idx)
+            elif not self._componentType[idx].isOptional:
+                if self.getComponentByPosition(idx) is None:
+                    raise error.PyAsn1Error(
+                        'Uninitialized component #%s at %r' % (idx, self)
+                        )
+
+    def prettyPrint(self, scope=0):
+        scope = scope + 1
+        r = self.__class__.__name__ + ':\n'
+        for idx in range(len(self._componentValues)):
+            if self._componentValues[idx] is not None:
+                r = r + ' '*scope
+                componentType = self.getComponentType()
+                if componentType is None:
+                    r = r + '<no-name>'
+                else:
+                    r = r + componentType.getNameByPosition(idx)
+                r = '%s=%s\n' % (
+                    r, self._componentValues[idx].prettyPrint(scope)
+                    )
+        return r
+
+class Sequence(SequenceAndSetBase):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatConstructed, 0x10)
+        )
+    typeId = 3
+
+    def getComponentTagMapNearPosition(self, idx):
+        if self._componentType:
+            return self._componentType.getTagMapNearPosition(idx)
+    
+    def getComponentPositionNearType(self, tagSet, idx):
+        if self._componentType:
+            return self._componentType.getPositionNearType(tagSet, idx)
+        else:
+            return idx
+    
+class Set(SequenceAndSetBase):
+    tagSet = baseTagSet = tag.initTagSet(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatConstructed, 0x11)
+        )
+    typeId = 4
+
+    def getComponent(self, innerFlag=0): return self
+    
+    def getComponentByType(self, tagSet, innerFlag=0):
+        c = self.getComponentByPosition(
+            self._componentType.getPositionByType(tagSet)
+            )
+        if innerFlag and isinstance(c, Set):
+            # get inner component by inner tagSet
+            return c.getComponent(1)
+        else:
+            # get outer component by inner tagSet
+            return c
+        
+    def setComponentByType(self, tagSet, value=None, innerFlag=0,
+                           verifyConstraints=True):
+        idx = self._componentType.getPositionByType(tagSet)
+        t = self._componentType.getTypeByPosition(idx)
+        if innerFlag:  # set inner component by inner tagSet
+            if t.getTagSet():
+                return self.setComponentByPosition(
+                    idx, value, verifyConstraints
+                    )
+            else:
+                t = self.setComponentByPosition(idx).getComponentByPosition(idx)
+                return t.setComponentByType(
+                    tagSet, value, innerFlag, verifyConstraints
+                    )
+        else:  # set outer component by inner tagSet
+            return self.setComponentByPosition(
+                idx, value, verifyConstraints
+                )
+            
+    def getComponentTagMap(self):
+        if self._componentType:
+            return self._componentType.getTagMap(True)
+
+    def getComponentPositionByType(self, tagSet):
+        if self._componentType:
+            return self._componentType.getPositionByType(tagSet)
+
+class Choice(Set):
+    tagSet = baseTagSet = tag.TagSet()  # untagged
+    sizeSpec = constraint.ConstraintsIntersection(
+        constraint.ValueSizeConstraint(1, 1)
+        )
+    typeId = 5
+    _currentIdx = None
+
+    def __eq__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] == other
+        return NotImplemented
+    def __ne__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] != other
+        return NotImplemented
+    def __lt__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] < other
+        return NotImplemented
+    def __le__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] <= other
+        return NotImplemented
+    def __gt__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] > other
+        return NotImplemented
+    def __ge__(self, other):
+        if self._componentValues:
+            return self._componentValues[self._currentIdx] >= other
+        return NotImplemented
+    if sys.version_info[0] <= 2:
+        def __nonzero__(self): return bool(self._componentValues)
+    else:
+        def __bool__(self): return bool(self._componentValues)
+
+    def __len__(self): return self._currentIdx is not None and 1 or 0
+    
+    def verifySizeSpec(self):
+        if self._currentIdx is None:
+            raise error.PyAsn1Error('Component not chosen')
+        else:
+            self._sizeSpec(' ')
+
+    def _cloneComponentValues(self, myClone, cloneValueFlag):
+        try:
+            c = self.getComponent()
+        except error.PyAsn1Error:
+            pass
+        else:
+            if isinstance(c, Choice):
+                tagSet = c.getEffectiveTagSet()
+            else:
+                tagSet = c.getTagSet()
+            if isinstance(c, base.AbstractConstructedAsn1Item):
+                myClone.setComponentByType(
+                    tagSet, c.clone(cloneValueFlag=cloneValueFlag)
+                    )
+            else:
+                myClone.setComponentByType(tagSet, c.clone())
+
+    def setComponentByPosition(self, idx, value=None, verifyConstraints=True):
+        l = len(self._componentValues)
+        if idx >= l:
+            self._componentValues = self._componentValues + (idx-l+1)*[None]
+        if self._currentIdx is not None:
+            self._componentValues[self._currentIdx] = None
+        if value is None:
+            if self._componentValues[idx] is None:
+                self._componentValues[idx] = self._componentType.getTypeByPosition(idx).clone()
+                self._componentValuesSet = 1
+                self._currentIdx = idx
+            return self
+        elif not isinstance(value, base.Asn1Item):
+            value = self._componentType.getTypeByPosition(idx).clone(
+                value=value
+                )
+        if verifyConstraints:
+            if self._componentTypeLen:
+                self._verifyComponent(idx, value)
+            self._verifySubtypeSpec(value, idx)            
+        self._componentValues[idx] = value
+        self._currentIdx = idx
+        self._componentValuesSet = 1
+        return self
+
+    def getMinTagSet(self):
+        if self._tagSet:
+            return self._tagSet
+        else:
+            return self._componentType.genMinTagSet()
+
+    def getEffectiveTagSet(self):
+        if self._tagSet:
+            return self._tagSet
+        else:
+            c = self.getComponent()
+            if isinstance(c, Choice):
+                return c.getEffectiveTagSet()
+            else:
+                return c.getTagSet()
+
+    def getTagMap(self):
+        if self._tagSet:
+            return Set.getTagMap(self)
+        else:
+            return Set.getComponentTagMap(self)
+
+    def getComponent(self, innerFlag=0):
+        if self._currentIdx is None:
+            raise error.PyAsn1Error('Component not chosen')
+        else:
+            c = self._componentValues[self._currentIdx]
+            if innerFlag and isinstance(c, Choice):
+                return c.getComponent(innerFlag)
+            else:
+                return c
+
+    def getName(self, innerFlag=0):
+        if self._currentIdx is None:
+            raise error.PyAsn1Error('Component not chosen')
+        else:
+            if innerFlag:
+                c = self._componentValues[self._currentIdx]
+                if isinstance(c, Choice):
+                    return c.getName(innerFlag)
+            return self._componentType.getNameByPosition(self._currentIdx)
+
+    def setDefaultComponents(self): pass
+
+class Any(OctetString):
+    tagSet = baseTagSet = tag.TagSet()  # untagged
+    typeId = 6
+
+    def getTagMap(self):
+        return tagmap.TagMap(
+            { self.getTagSet(): self },
+            { eoo.endOfOctets.getTagSet(): eoo.endOfOctets },
+            self
+            )
+
+# XXX
+# coercion rules?
diff --git a/python/pyasn1/pyasn1/type/useful.py b/python/pyasn1/pyasn1/type/useful.py
new file mode 100644
index 000000000..a7139c22c
--- /dev/null
+++ b/python/pyasn1/pyasn1/type/useful.py
@@ -0,0 +1,12 @@
+# ASN.1 "useful" types
+from pyasn1.type import char, tag
+
+class GeneralizedTime(char.VisibleString):
+    tagSet = char.VisibleString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 24)
+        )
+
+class UTCTime(char.VisibleString):
+    tagSet = char.VisibleString.tagSet.tagImplicitly(
+        tag.Tag(tag.tagClassUniversal, tag.tagFormatSimple, 23)
+        )