]> Cypherpunks.ru repositories - pyderasn.git/blobdiff - pyderasn.py
Faster Set readiness determining during decode
[pyderasn.git] / pyderasn.py
index b28792c9e00e4c8459eff239210d0aaf9794c368..ed5b763ccef4123c790d52569d9b376ef2acf168 100755 (executable)
@@ -1,12 +1,12 @@
 #!/usr/bin/env python
 # coding: utf-8
+# cython: language_level=3
 # PyDERASN -- Python ASN.1 DER/BER codec with abstract structures
-# Copyright (C) 2017-2018 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2017-2020 Sergey Matveev <stargrave@stargrave.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Lesser General Public License as
-# published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
+# published by the Free Software Foundation, version 3 of the License.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -14,8 +14,7 @@
 # GNU Lesser General Public License for more details.
 #
 # You should have received a copy of the GNU Lesser General Public
-# License along with this program.  If not, see
-# <http://www.gnu.org/licenses/>.
+# License along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Python ASN.1 DER/BER codec with abstract structures
 
 This library allows you to marshal various structures in ASN.1 DER
@@ -23,7 +22,7 @@ format, unmarshal them in BER/CER/DER ones.
 
     >>> i = Integer(123)
     >>> raw = i.encode()
-    >>> Integer().decode(raw) == i
+    >>> Integer().decod(raw) == i
     True
 
 There are primitive types, holding single values
@@ -67,10 +66,11 @@ ____
 
 Most types in ASN.1 has specific tag for them. ``Obj.tag_default`` is
 the default tag used during coding process. You can override it with
-either ``IMPLICIT`` (using ``impl`` keyword argument), or
-``EXPLICIT`` one (using ``expl`` keyword argument). Both arguments take
-raw binary string, containing that tag. You can **not** set implicit and
-explicit tags simultaneously.
+either ``IMPLICIT`` (using either ``impl`` keyword argument or ``impl``
+class attribute), or ``EXPLICIT`` one (using either ``expl`` keyword
+argument or ``expl`` class attribute). Both arguments take raw binary
+string, containing that tag. You can **not** set implicit and explicit
+tags simultaneously.
 
 There are :py:func:`pyderasn.tag_ctxp` and :py:func:`pyderasn.tag_ctxc`
 functions, allowing you to easily create ``CONTEXT``
@@ -163,21 +163,27 @@ All objects have ``ready`` boolean property, that tells if object is
 ready to be encoded. If that kind of action is performed on unready
 object, then :py:exc:`pyderasn.ObjNotReady` exception will be raised.
 
-All objects have ``copy()`` method, that returns their copy, that can be
+All objects are friendly to ``copy.copy()`` and copied objects can be
 safely mutated.
 
+Also all objects can be safely ``pickle``-d, but pay attention that
+pickling among different PyDERASN versions is prohibited.
+
 .. _decoding:
 
 Decoding
 --------
 
-Decoding is performed using ``decode()`` method. ``offset`` optional
-argument could be used to set initial object's offset in the binary
-data, for convenience. It returns decoded object and remaining
-unmarshalled data (tail). Internally all work is done on
+Decoding is performed using :py:meth:`pyderasn.Obj.decode` method.
+``offset`` optional argument could be used to set initial object's
+offset in the binary data, for convenience. It returns decoded object
+and remaining unmarshalled data (tail). Internally all work is done on
 ``memoryview(data)``, and you can leave returning tail as a memoryview,
 by specifying ``leavemm=True`` argument.
 
+Also note convenient :py:meth:`pyderasn.Obj.decod` method, that
+immediately checks and raises if there is non-empty tail.
+
 When object is decoded, ``decoded`` property is true and you can safely
 use following properties:
 
@@ -189,9 +195,16 @@ use following properties:
 
 Pay attention that those values do **not** include anything related to
 explicit tag. If you want to know information about it, then use:
-``expled`` (to know if explicit tag is set), ``expl_offset`` (it is
-lesser than ``offset``), ``expl_tlen``, ``expl_llen``, ``expl_vlen``
-(that actually equals to ordinary ``tlvlen``).
+
+* ``expled`` -- to know if explicit tag is set
+* ``expl_offset`` (it is lesser than ``offset``)
+* ``expl_tlen``,
+* ``expl_llen``
+* ``expl_vlen`` (that actually equals to ordinary ``tlvlen``)
+* ``fulloffset`` -- it equals to ``expl_offset`` if explicit tag is set,
+  ``offset`` otherwise
+* ``fulllen`` -- it equals to ``expl_len`` if explicit tag is set,
+  ``tlvlen`` otherwise
 
 When error occurs, :py:exc:`pyderasn.DecodeError` is raised.
 
@@ -200,15 +213,17 @@ When error occurs, :py:exc:`pyderasn.DecodeError` is raised.
 Context
 _______
 
-You can specify so called context keyword argument during ``decode()``
-invocation. It is dictionary containing various options governing
-decoding process.
+You can specify so called context keyword argument during
+:py:meth:`pyderasn.Obj.decode` invocation. It is dictionary containing
+various options governing decoding process.
 
 Currently available context options:
 
+* :ref:`allow_default_values <allow_default_values_ctx>`
+* :ref:`allow_expl_oob <allow_expl_oob_ctx>`
+* :ref:`allow_unordered_set <allow_unordered_set_ctx>`
 * :ref:`bered <bered_ctx>`
 * :ref:`defines_by_path <defines_by_path_ctx>`
-* :ref:`strict_default_existence <strict_default_existence_ctx>`
 
 .. _pprinting:
 
@@ -230,6 +245,106 @@ all object ``repr``. But it is easy to write custom formatters.
     >>> print(pprint(obj))
         0   [1,1,   2] INTEGER -12345
 
+.. _pprint_example:
+
+Example certificate::
+
+    >>> print(pprint(crt))
+        0   [1,3,1604] Certificate SEQUENCE
+        4   [1,3,1453]  . tbsCertificate: TBSCertificate SEQUENCE
+       10-2 [1,1,   1]  . . version: [0] EXPLICIT Version INTEGER v3 OPTIONAL
+       13   [1,1,   3]  . . serialNumber: CertificateSerialNumber INTEGER 61595
+       18   [1,1,  13]  . . signature: AlgorithmIdentifier SEQUENCE
+       20   [1,1,   9]  . . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
+       31   [0,0,   2]  . . . parameters: [UNIV 5] ANY OPTIONAL
+                        . . . . 05:00
+       33   [0,0, 278]  . . issuer: Name CHOICE rdnSequence
+       33   [1,3, 274]  . . . rdnSequence: RDNSequence SEQUENCE OF
+       37   [1,1,  11]  . . . . 0: RelativeDistinguishedName SET OF
+       39   [1,1,   9]  . . . . . 0: AttributeTypeAndValue SEQUENCE
+       41   [1,1,   3]  . . . . . . type: AttributeType OBJECT IDENTIFIER 2.5.4.6
+       46   [0,0,   4]  . . . . . . value: [UNIV 19] AttributeValue ANY
+                        . . . . . . . 13:02:45:53
+    [...]
+     1461   [1,1,  13]  . signatureAlgorithm: AlgorithmIdentifier SEQUENCE
+     1463   [1,1,   9]  . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
+     1474   [0,0,   2]  . . parameters: [UNIV 5] ANY OPTIONAL
+                        . . . 05:00
+     1476   [1,2, 129]  . signatureValue: BIT STRING 1024 bits
+                        . . 68:EE:79:97:97:DD:3B:EF:16:6A:06:F2:14:9A:6E:CD
+                        . . 9E:12:F7:AA:83:10:BD:D1:7C:98:FA:C7:AE:D4:0E:2C
+     [...]
+
+    Trailing data: 0a
+
+Let's parse that output, human::
+
+       10-2 [1,1,   1]    . . version: [0] EXPLICIT Version INTEGER v3 OPTIONAL
+       ^  ^  ^ ^    ^     ^   ^        ^            ^       ^       ^  ^
+       0  1  2 3    4     5   6        7            8       9       10 11
+
+::
+
+       20   [1,1,   9]    . . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
+       ^     ^ ^    ^     ^     ^          ^                 ^
+       0     2 3    4     5     6          9                 10
+
+::
+
+       33   [0,0, 278]    . . issuer: Name CHOICE rdnSequence
+       ^     ^ ^    ^     ^   ^       ^    ^      ^
+       0     2 3    4     5   6       8    9      10
+
+::
+
+       52-2∞ B [1,1,1054]∞  . . . . eContent: [0] EXPLICIT BER OCTET STRING 1046 bytes
+             ^           ^                                 ^   ^            ^
+            12          13                                14   9            10
+
+:0:
+ Offset of the object, where its DER/BER encoding begins.
+ Pay attention that it does **not** include explicit tag.
+:1:
+ If explicit tag exists, then this is its length (tag + encoded length).
+:2:
+ Length of object's tag. For example CHOICE does not have its own tag,
+ so it is zero.
+:3:
+ Length of encoded length.
+:4:
+ Length of encoded value.
+:5:
+ Visual indentation to show the depth of object in the hierarchy.
+:6:
+ Object's name inside SEQUENCE/CHOICE.
+:7:
+ If either IMPLICIT or EXPLICIT tag is set, then it will be shown
+ here. "IMPLICIT" is omitted.
+:8:
+ Object's class name, if set. Omitted if it is just an ordinary simple
+ value (like with ``algorithm`` in example above).
+:9:
+ Object's ASN.1 type.
+:10:
+ Object's value, if set. Can consist of multiple words (like OCTET/BIT
+ STRINGs above). We see ``v3`` value in Version, because it is named.
+ ``rdnSequence`` is the choice of CHOICE type.
+:11:
+ Possible other flags like OPTIONAL and DEFAULT, if value equals to the
+ default one, specified in the schema.
+:12:
+ Shows does object contains any kind of BER encoded data (possibly
+ Sequence holding BER-encoded underlying value).
+:13:
+ Only applicable to BER encoded data. Indefinite length encoding mark.
+:14:
+ Only applicable to BER encoded data. If object has BER-specific
+ encoding, then ``BER`` will be shown. It does not depend on indefinite
+ length encoding. ``EOC``, ``BOOLEAN``, ``BIT STRING``, ``OCTET STRING``
+ (and its derivatives), ``SET``, ``SET OF``, ``UTCTime``, ``GeneralizedTime``
+ could be BERed.
+
+
 .. _definedby:
 
 DEFINED BY
@@ -240,6 +355,8 @@ DEFINED BY some previously met ObjectIdentifier. This library provides
 ability to specify mapping between some OID and field that must be
 decoded with specific specification.
 
+.. _defines:
+
 defines kwarg
 _____________
 
@@ -267,7 +384,7 @@ You can specify multiple fields, that will be autodecoded -- that is why
 ``defines`` kwarg is a sequence. You can specify defined field
 relatively or absolutely to current decode path. For example ``defines``
 for AlgorithmIdentifier of X.509's
-``tbsCertificate.subjectPublicKeyInfo.algorithm.algorithm``::
+``tbsCertificate:subjectPublicKeyInfo:algorithm:algorithm``::
 
         (
             (("parameters",), {
@@ -295,8 +412,7 @@ Following types can be automatically decoded (DEFINED BY):
 When any of those fields is automatically decoded, then ``.defined``
 attribute contains ``(OID, value)`` tuple. ``OID`` tells by which OID it
 was defined, ``value`` contains corresponding decoded value. For example
-above, ``content_info["content"].defined == (id_signedData,
-signed_data)``.
+above, ``content_info["content"].defined == (id_signedData, signed_data)``.
 
 .. _defines_by_path_ctx:
 
@@ -314,15 +430,15 @@ value must be sequence of following tuples::
 
 where ``decode_path`` is a tuple holding so-called decode path to the
 exact :py:class:`pyderasn.ObjectIdentifier` field you want to apply
-``defines``, holding exactly the same value as accepted in its keyword
-argument.
+``defines``, holding exactly the same value as accepted in its
+:ref:`keyword argument <defines>`.
 
 For example, again for CMS, you want to automatically decode
 ``SignedData`` and CMC's (:rfc:`5272`) ``PKIData`` and ``PKIResponse``
 structures it may hold. Also, automatically decode ``controlSequence``
 of ``PKIResponse``::
 
-    content_info, tail = ContentInfo().decode(data, defines_by_path=(
+    content_info = ContentInfo().decod(data, ctx={"defines_by_path": (
         (
             ("contentType",),
             ((("content",), {id_signedData: SignedData()}),),
@@ -357,7 +473,7 @@ of ``PKIResponse``::
                 id_cmc_transactionId: TransactionId(),
             })),
         ),
-    ))
+    )})
 
 Pay attention for :py:class:`pyderasn.DecodePathDefBy` and ``any``.
 First function is useful for path construction when some automatic
@@ -369,28 +485,52 @@ useful for SEQUENCE/SET OF-s.
 BER encoding
 ------------
 
-.. warning::
-
-   Currently BER support is not extensively tested.
-
 By default PyDERASN accepts only DER encoded data. It always encodes to
 DER. But you can optionally enable BER decoding with setting ``bered``
 :ref:`context <ctx>` argument to True. Indefinite lengths and
 constructed primitive types should be parsed successfully.
 
-* If object is encoded in BER form (not the DER one), then ``bered``
+* If object is encoded in BER form (not the DER one), then ``ber_encoded``
   attribute is set to True. Only ``BOOLEAN``, ``BIT STRING``, ``OCTET
-  STRING`` can contain it.
+  STRING``, ``OBJECT IDENTIFIER``, ``SEQUENCE``, ``SET``, ``SET OF``,
+  ``UTCTime``, ``GeneralizedTime`` can contain it.
 * If object has an indefinite length encoding, then its ``lenindef``
   attribute is set to True. Only ``BIT STRING``, ``OCTET STRING``,
   ``SEQUENCE``, ``SET``, ``SEQUENCE OF``, ``SET OF``, ``ANY`` can
   contain it.
 * If object has an indefinite length encoded explicit tag, then
   ``expl_lenindef`` is set to True.
+* If object has either any of BER-related encoding (explicit tag
+  indefinite length, object's indefinite length, BER-encoding) or any
+  underlying component has that kind of encoding, then ``bered``
+  attribute is set to True. For example SignedData CMS can have
+  ``ContentInfo:content:signerInfos:*`` ``bered`` value set to True, but
+  ``ContentInfo:content:signerInfos:*:signedAttrs`` won't.
 
 EOC (end-of-contents) token's length is taken in advance in object's
 value length.
 
+.. _allow_expl_oob_ctx:
+
+Allow explicit tag out-of-bound
+-------------------------------
+
+Invalid BER encoding could contain ``EXPLICIT`` tag containing more than
+one value, more than one object. If you set ``allow_expl_oob`` context
+option to True, then no error will be raised and that invalid encoding
+will be silently further processed. But pay attention that offsets and
+lengths will be invalid in that case.
+
+.. warning::
+
+   This option should be used only for skipping some decode errors, just
+   to see the decoded structure somehow.
+
+Base Obj
+--------
+.. autoclass:: pyderasn.Obj
+   :members:
+
 Primitive types
 ---------------
 
@@ -436,6 +576,11 @@ NumericString
 _____________
 .. autoclass:: pyderasn.NumericString
 
+PrintableString
+_______________
+.. autoclass:: pyderasn.PrintableString
+   :members: __init__
+
 UTCTime
 _______
 .. autoclass:: pyderasn.UTCTime
@@ -489,16 +634,17 @@ Various
 -------
 
 .. autofunction:: pyderasn.abs_decode_path
+.. autofunction:: pyderasn.colonize_hex
 .. autofunction:: pyderasn.hexenc
 .. autofunction:: pyderasn.hexdec
 .. autofunction:: pyderasn.tag_encode
 .. autofunction:: pyderasn.tag_decode
 .. autofunction:: pyderasn.tag_ctxp
 .. autofunction:: pyderasn.tag_ctxc
-.. autoclass:: pyderasn.Obj
 .. autoclass:: pyderasn.DecodeError
    :members: __init__
 .. autoclass:: pyderasn.NotEnoughData
+.. autoclass:: pyderasn.ExceedingData
 .. autoclass:: pyderasn.LenIndefForm
 .. autoclass:: pyderasn.TagMismatch
 .. autoclass:: pyderasn.InvalidLength
@@ -513,10 +659,14 @@ from codecs import getdecoder
 from codecs import getencoder
 from collections import namedtuple
 from collections import OrderedDict
+from copy import copy
 from datetime import datetime
+from datetime import timedelta
 from math import ceil
 from os import environ
+from string import ascii_letters
 from string import digits
+from unicodedata import category as unicat
 
 from six import add_metaclass
 from six import binary_type
@@ -525,18 +675,22 @@ from six import indexbytes
 from six import int2byte
 from six import integer_types
 from six import iterbytes
+from six import iteritems
+from six import itervalues
 from six import PY2
 from six import string_types
 from six import text_type
+from six import unichr as six_unichr
 from six.moves import xrange as six_xrange
 
 
 try:
     from termcolor import colored
-except ImportError:
-    def colored(what, *args):
+except ImportError:  # pragma: no cover
+    def colored(what, *args, **kwargs):
         return what
 
+__version__ = "6.2"
 
 __all__ = (
     "Any",
@@ -548,6 +702,7 @@ __all__ = (
     "DecodeError",
     "DecodePathDefBy",
     "Enumerated",
+    "ExceedingData",
     "GeneralizedTime",
     "GeneralString",
     "GraphicString",
@@ -607,13 +762,33 @@ TagClassReprs = {
 }
 EOC = b"\x00\x00"
 EOC_LEN = len(EOC)
+LENINDEF = b"\x80"  # length indefinite mark
+LENINDEF_PP_CHAR = "I" if PY2 else "∞"
+NAMEDTUPLE_KWARGS = {} if PY2 else {"module": __name__}
+SET01 = frozenset("01")
+DECIMALS = frozenset(digits)
+DECIMAL_SIGNS = ".,"
+
+
+def pureint(value):
+    if not set(value) <= DECIMALS:
+        raise ValueError("non-pure integer")
+    return int(value)
+
+def fractions2float(fractions_raw):
+    pureint(fractions_raw)
+    return float("0." + fractions_raw)
 
 
 ########################################################################
 # Errors
 ########################################################################
 
-class DecodeError(Exception):
+class ASN1Error(ValueError):
+    pass
+
+
+class DecodeError(ASN1Error):
     def __init__(self, msg="", klass=None, decode_path=(), offset=0):
         """
         :param str msg: reason of decode failing
@@ -636,7 +811,7 @@ class DecodeError(Exception):
             c for c in (
                 "" if self.klass is None else self.klass.__name__,
                 (
-                    ("(%s)" % ".".join(str(dp) for dp in self.decode_path))
+                    ("(%s)" % ":".join(str(dp) for dp in self.decode_path))
                     if len(self.decode_path) > 0 else ""
                 ),
                 ("(at %d)" % self.offset) if self.offset > 0 else "",
@@ -652,6 +827,18 @@ class NotEnoughData(DecodeError):
     pass
 
 
+class ExceedingData(ASN1Error):
+    def __init__(self, nbytes):
+        super(ExceedingData, self).__init__()
+        self.nbytes = nbytes
+
+    def __str__(self):
+        return "%d trailing bytes" % self.nbytes
+
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, self)
+
+
 class LenIndefForm(DecodeError):
     pass
 
@@ -668,7 +855,7 @@ class InvalidOID(DecodeError):
     pass
 
 
-class ObjUnknown(ValueError):
+class ObjUnknown(ASN1Error):
     def __init__(self, name):
         super(ObjUnknown, self).__init__()
         self.name = name
@@ -680,7 +867,7 @@ class ObjUnknown(ValueError):
         return "%s(%s)" % (self.__class__.__name__, self)
 
 
-class ObjNotReady(ValueError):
+class ObjNotReady(ASN1Error):
     def __init__(self, name):
         super(ObjNotReady, self).__init__()
         self.name = name
@@ -692,7 +879,7 @@ class ObjNotReady(ValueError):
         return "%s(%s)" % (self.__class__.__name__, self)
 
 
-class InvalidValueType(ValueError):
+class InvalidValueType(ASN1Error):
     def __init__(self, expected_types):
         super(InvalidValueType, self).__init__()
         self.expected_types = expected_types
@@ -706,7 +893,7 @@ class InvalidValueType(ValueError):
         return "%s(%s)" % (self.__class__.__name__, self)
 
 
-class BoundsError(ValueError):
+class BoundsError(ASN1Error):
     def __init__(self, bound_min, value, bound_max):
         super(BoundsError, self).__init__()
         self.bound_min = bound_min
@@ -877,9 +1064,9 @@ def len_decode(data):
 ########################################################################
 
 class AutoAddSlots(type):
-    def __new__(mcs, name, bases, _dict):
+    def __new__(cls, name, bases, _dict):
         _dict["__slots__"] = _dict.get("__slots__", ())
-        return type.__new__(mcs, name, bases, _dict)
+        return type.__new__(cls, name, bases, _dict)
 
 
 @add_metaclass(AutoAddSlots)
@@ -900,7 +1087,7 @@ class Obj(object):
         "vlen",
         "expl_lenindef",
         "lenindef",
-        "bered",
+        "ber_encoded",
     )
 
     def __init__(
@@ -914,9 +1101,7 @@ class Obj(object):
         self.tag = getattr(self, "impl", self.tag_default) if impl is None else impl
         self._expl = getattr(self, "expl", None) if expl is None else expl
         if self.tag != self.tag_default and self._expl is not None:
-            raise ValueError(
-                "implicit and explicit tags can not be set simultaneously"
-            )
+            raise ValueError("implicit and explicit tags can not be set simultaneously")
         if default is not None:
             optional = True
         self.optional = optional
@@ -924,7 +1109,7 @@ class Obj(object):
         self.default = None
         self.expl_lenindef = False
         self.lenindef = False
-        self.bered = False
+        self.ber_encoded = False
 
     @property
     def ready(self):  # pragma: no cover
@@ -936,23 +1121,48 @@ class Obj(object):
         if not self.ready:
             raise ObjNotReady(self.__class__.__name__)
 
+    @property
+    def bered(self):
+        """Is either object or any elements inside is BER encoded?
+        """
+        return self.expl_lenindef or self.lenindef or self.ber_encoded
+
     @property
     def decoded(self):
         """Is object decoded?
         """
         return (self.llen + self.vlen) > 0
 
-    def copy(self):  # pragma: no cover
-        """Make a copy of object, safe to be mutated
+    def __getstate__(self):  # pragma: no cover
+        """Used for making safe to be mutable pickleable copies
         """
         raise NotImplementedError()
 
+    def __setstate__(self, state):
+        if state.version != __version__:
+            raise ValueError("data is pickled by different PyDERASN version")
+        self.tag = self.tag_default
+        self._value = None
+        self._expl = None
+        self.default = None
+        self.optional = False
+        self.offset = 0
+        self.llen = 0
+        self.vlen = 0
+        self.expl_lenindef = False
+        self.lenindef = False
+        self.ber_encoded = False
+
     @property
     def tlen(self):
+        """See :ref:`decoding`
+        """
         return len(self.tag)
 
     @property
     def tlvlen(self):
+        """See :ref:`decoding`
+        """
         return self.tlen + self.llen + self.vlen
 
     def __str__(self):  # pragma: no cover
@@ -977,11 +1187,20 @@ class Obj(object):
         raise NotImplementedError()
 
     def encode(self):
+        """Encode the structure
+
+        :returns: DER representation
+        """
         raw = self._encode()
         if self._expl is None:
             return raw
         return b"".join((self._expl, len_encode(len(raw)), raw))
 
+    def hexencode(self):
+        """Do hexadecimal encoded :py:meth:`pyderasn.Obj.encode`
+        """
+        return hexenc(self.encode())
+
     def decode(
             self,
             data,
@@ -990,6 +1209,7 @@ class Obj(object):
             decode_path=(),
             ctx=None,
             tag_only=False,
+            _ctx_immutable=True,
     ):
         """Decode the data
 
@@ -997,14 +1217,20 @@ class Obj(object):
         :param int offset: initial data's offset
         :param bool leavemm: do we need to leave memoryview of remaining
                     data as is, or convert it to bytes otherwise
-        :param ctx: optional :ref:`context <ctx>` governing decoding process.
+        :param ctx: optional :ref:`context <ctx>` governing decoding process
         :param tag_only: decode only the tag, without length and contents
                          (used only in Choice and Set structures, trying to
                          determine if tag satisfies the scheme)
+        :param _ctx_immutable: do we need to ``copy.copy()`` ``ctx``
+                               before using it?
         :returns: (Obj, remaining data)
+
+        .. seealso:: :ref:`decoding`
         """
         if ctx is None:
             ctx = {}
+        elif _ctx_immutable:
+            ctx = copy(ctx)
         tlv = memoryview(data)
         if self._expl is None:
             result = self._decode(
@@ -1015,7 +1241,7 @@ class Obj(object):
                 tag_only=tag_only,
             )
             if tag_only:
-                return
+                return None
             obj, tail = result
         else:
             try:
@@ -1052,13 +1278,14 @@ class Obj(object):
                     ctx=ctx,
                     tag_only=tag_only,
                 )
-                if tag_only:
-                    return
+                if tag_only:  # pragma: no cover
+                    return None
                 obj, tail = result
                 eoc_expected, tail = tail[:EOC_LEN], tail[EOC_LEN:]
                 if eoc_expected.tobytes() != EOC:
                     raise DecodeError(
-                        msg="no EOC",
+                        "no EOC",
+                        klass=self.__class__,
                         decode_path=decode_path,
                         offset=offset,
                     )
@@ -1086,41 +1313,136 @@ class Obj(object):
                     ctx=ctx,
                     tag_only=tag_only,
                 )
-                if tag_only:
-                    return
+                if tag_only:  # pragma: no cover
+                    return None
                 obj, tail = result
+                if obj.tlvlen < l and not ctx.get("allow_expl_oob", False):
+                    raise DecodeError(
+                        "explicit tag out-of-bound, longer than data",
+                        klass=self.__class__,
+                        decode_path=decode_path,
+                        offset=offset,
+                    )
         return obj, (tail if leavemm else tail.tobytes())
 
+    def decod(self, data, offset=0, decode_path=(), ctx=None):
+        """Decode the data, check that tail is empty
+
+        :raises ExceedingData: if tail is not empty
+
+        This is just a wrapper over :py:meth:`pyderasn.Obj.decode`
+        (decode without tail) that also checks that there is no
+        trailing data left.
+        """
+        obj, tail = self.decode(
+            data,
+            offset=offset,
+            decode_path=decode_path,
+            ctx=ctx,
+            leavemm=True,
+        )
+        if len(tail) > 0:
+            raise ExceedingData(len(tail))
+        return obj
+
+    def hexdecode(self, data, *args, **kwargs):
+        """Do :py:meth:`pyderasn.Obj.decode` with hexadecimal decoded data
+        """
+        return self.decode(hexdec(data), *args, **kwargs)
+
+    def hexdecod(self, data, *args, **kwargs):
+        """Do :py:meth:`pyderasn.Obj.decod` with hexadecimal decoded data
+        """
+        return self.decod(hexdec(data), *args, **kwargs)
+
     @property
     def expled(self):
+        """See :ref:`decoding`
+        """
         return self._expl is not None
 
     @property
     def expl_tag(self):
+        """See :ref:`decoding`
+        """
         return self._expl
 
     @property
     def expl_tlen(self):
+        """See :ref:`decoding`
+        """
         return len(self._expl)
 
     @property
     def expl_llen(self):
+        """See :ref:`decoding`
+        """
         if self.expl_lenindef:
             return 1
         return len(len_encode(self.tlvlen))
 
     @property
     def expl_offset(self):
+        """See :ref:`decoding`
+        """
         return self.offset - self.expl_tlen - self.expl_llen
 
     @property
     def expl_vlen(self):
+        """See :ref:`decoding`
+        """
         return self.tlvlen
 
     @property
     def expl_tlvlen(self):
+        """See :ref:`decoding`
+        """
         return self.expl_tlen + self.expl_llen + self.expl_vlen
 
+    @property
+    def fulloffset(self):
+        """See :ref:`decoding`
+        """
+        return self.expl_offset if self.expled else self.offset
+
+    @property
+    def fulllen(self):
+        """See :ref:`decoding`
+        """
+        return self.expl_tlvlen if self.expled else self.tlvlen
+
+    def pps_lenindef(self, decode_path):
+        if self.lenindef and not (
+                getattr(self, "defined", None) is not None and
+                self.defined[1].lenindef
+        ):
+            yield _pp(
+                asn1_type_name="EOC",
+                obj_name="",
+                decode_path=decode_path,
+                offset=(
+                    self.offset + self.tlvlen -
+                    (EOC_LEN * 2 if self.expl_lenindef else EOC_LEN)
+                ),
+                tlen=1,
+                llen=1,
+                vlen=0,
+                ber_encoded=True,
+                bered=True,
+            )
+        if self.expl_lenindef:
+            yield _pp(
+                asn1_type_name="EOC",
+                obj_name="EXPLICIT",
+                decode_path=decode_path,
+                offset=self.expl_offset + self.expl_tlvlen - EOC_LEN,
+                tlen=1,
+                llen=1,
+                vlen=0,
+                ber_encoded=True,
+                bered=True,
+            )
+
 
 class DecodePathDefBy(object):
     """DEFINED BY representation inside decode path
@@ -1150,6 +1472,7 @@ class DecodePathDefBy(object):
 ########################################################################
 
 PP = namedtuple("PP", (
+    "obj",
     "asn1_type_name",
     "obj_name",
     "decode_path",
@@ -1169,11 +1492,13 @@ PP = namedtuple("PP", (
     "expl_vlen",
     "expl_lenindef",
     "lenindef",
+    "ber_encoded",
     "bered",
-))
+), **NAMEDTUPLE_KWARGS)
 
 
 def _pp(
+        obj=None,
         asn1_type_name="unknown",
         obj_name="unknown",
         decode_path=(),
@@ -1193,9 +1518,11 @@ def _pp(
         expl_vlen=None,
         expl_lenindef=False,
         lenindef=False,
+        ber_encoded=False,
         bered=False,
 ):
     return PP(
+        obj,
         asn1_type_name,
         obj_name,
         decode_path,
@@ -1215,141 +1542,194 @@ def _pp(
         expl_vlen,
         expl_lenindef,
         lenindef,
+        ber_encoded,
         bered,
     )
 
 
-def _colorize(what, colour, with_colours, attrs=("bold",)):
+def _colourize(what, colour, with_colours, attrs=("bold",)):
     return colored(what, colour, attrs=attrs) if with_colours else what
 
 
+def colonize_hex(hexed):
+    """Separate hexadecimal string with colons
+    """
+    return ":".join(hexed[i:i + 2] for i in six_xrange(0, len(hexed), 2))
+
+
 def pp_console_row(
         pp,
-        oids=None,
+        oid_maps=(),
         with_offsets=False,
         with_blob=True,
         with_colours=False,
+        with_decode_path=False,
+        decode_path_len_decrease=0,
 ):
     cols = []
     if with_offsets:
-        col = "%5d%s" % (
+        col = "%5d%s%s" % (
             pp.offset,
             (
                 "  " if pp.expl_offset is None else
                 ("-%d" % (pp.offset - pp.expl_offset))
             ),
+            LENINDEF_PP_CHAR if pp.expl_lenindef else " ",
         )
-        cols.append(_colorize(col, "red", with_colours, ()))
-        col = "[%d,%d,%4d]" % (pp.tlen, pp.llen, pp.vlen)
-        col = _colorize(col, "green", with_colours, ())
-        ber_deoffset = 0
-        if pp.expl_lenindef:
-            ber_deoffset += 2
-        if pp.lenindef:
-            ber_deoffset += 2
-        col += (
-            "  " if ber_deoffset == 0 else
-            _colorize(("-%d" % ber_deoffset), "red", with_colours)
+        col = _colourize(col, "red", with_colours, ())
+        col += _colourize("B", "red", with_colours) if pp.bered else " "
+        cols.append(col)
+        col = "[%d,%d,%4d]%s" % (
+            pp.tlen,
+            pp.llen,
+            pp.vlen,
+            LENINDEF_PP_CHAR if pp.lenindef else " "
         )
+        col = _colourize(col, "green", with_colours, ())
         cols.append(col)
-    if len(pp.decode_path) > 0:
-        cols.append(" ." * (len(pp.decode_path)))
+    decode_path_len = len(pp.decode_path) - decode_path_len_decrease
+    if decode_path_len > 0:
+        cols.append(" ." * decode_path_len)
         ent = pp.decode_path[-1]
         if isinstance(ent, DecodePathDefBy):
-            cols.append(_colorize("DEFINED BY", "red", with_colours, ("reverse",)))
+            cols.append(_colourize("DEFINED BY", "red", with_colours, ("reverse",)))
             value = str(ent.defined_by)
+            oid_name = None
             if (
-                    oids is not None and
+                    len(oid_maps) > 0 and
                     ent.defined_by.asn1_type_name ==
-                    ObjectIdentifier.asn1_type_name and
-                    value in oids
+                    ObjectIdentifier.asn1_type_name
             ):
-                cols.append(_colorize("%s:" % oids[value], "green", with_colours))
-            else:
-                cols.append(_colorize("%s:" % value, "white", with_colours, ("reverse",)))
+                for oid_map in oid_maps:
+                    oid_name = oid_map.get(value)
+                    if oid_name is not None:
+                        cols.append(_colourize("%s:" % oid_name, "green", with_colours))
+                        break
+            if oid_name is None:
+                cols.append(_colourize("%s:" % value, "white", with_colours, ("reverse",)))
         else:
-            cols.append(_colorize("%s:" % ent, "yellow", with_colours, ("reverse",)))
+            cols.append(_colourize("%s:" % ent, "yellow", with_colours, ("reverse",)))
     if pp.expl is not None:
         klass, _, num = pp.expl
         col = "[%s%d] EXPLICIT" % (TagClassReprs[klass], num)
-        cols.append(_colorize(col, "blue", with_colours))
+        cols.append(_colourize(col, "blue", with_colours))
     if pp.impl is not None:
         klass, _, num = pp.impl
         col = "[%s%d]" % (TagClassReprs[klass], num)
-        cols.append(_colorize(col, "blue", with_colours))
+        cols.append(_colourize(col, "blue", with_colours))
     if pp.asn1_type_name.replace(" ", "") != pp.obj_name.upper():
-        cols.append(_colorize(pp.obj_name, "magenta", with_colours))
-    if pp.bered:
-        cols.append(_colorize("BER", "red", with_colours))
-    cols.append(_colorize(pp.asn1_type_name, "cyan", with_colours))
+        cols.append(_colourize(pp.obj_name, "magenta", with_colours))
+    if pp.ber_encoded:
+        cols.append(_colourize("BER", "red", with_colours))
+    cols.append(_colourize(pp.asn1_type_name, "cyan", with_colours))
     if pp.value is not None:
         value = pp.value
-        cols.append(_colorize(value, "white", with_colours, ("reverse",)))
+        cols.append(_colourize(value, "white", with_colours, ("reverse",)))
         if (
-                oids is not None and
-                pp.asn1_type_name == ObjectIdentifier.asn1_type_name and
-                value in oids
+                len(oid_maps) > 0 and
+                pp.asn1_type_name == ObjectIdentifier.asn1_type_name
         ):
-            cols.append(_colorize("(%s)" % oids[value], "green", with_colours))
+            for oid_map in oid_maps:
+                oid_name = oid_map.get(value)
+                if oid_name is not None:
+                    cols.append(_colourize("(%s)" % oid_name, "green", with_colours))
+                    break
+        if pp.asn1_type_name == Integer.asn1_type_name:
+            hex_repr = hex(int(pp.obj._value))[2:].upper()
+            if len(hex_repr) % 2 != 0:
+                hex_repr = "0" + hex_repr
+            cols.append(_colourize(
+                "(%s)" % colonize_hex(hex_repr),
+                "green",
+                with_colours,
+            ))
     if with_blob:
-        if isinstance(pp.blob, binary_type):
+        if pp.blob.__class__ == binary_type:
             cols.append(hexenc(pp.blob))
-        elif isinstance(pp.blob, tuple):
+        elif pp.blob.__class__ == tuple:
             cols.append(", ".join(pp.blob))
     if pp.optional:
-        cols.append(_colorize("OPTIONAL", "red", with_colours))
+        cols.append(_colourize("OPTIONAL", "red", with_colours))
     if pp.default:
-        cols.append(_colorize("DEFAULT", "red", with_colours))
+        cols.append(_colourize("DEFAULT", "red", with_colours))
+    if with_decode_path:
+        cols.append(_colourize(
+            "[%s]" % ":".join(str(p) for p in pp.decode_path),
+            "grey",
+            with_colours,
+        ))
     return " ".join(cols)
 
 
-def pp_console_blob(pp):
-    cols = [" " * len("XXXXXYY [X,X,XXXX]YY")]
-    if len(pp.decode_path) > 0:
-        cols.append(" ." * (len(pp.decode_path) + 1))
-    if isinstance(pp.blob, binary_type):
+def pp_console_blob(pp, decode_path_len_decrease=0):
+    cols = [" " * len("XXXXXYYZZ [X,X,XXXX]Z")]
+    decode_path_len = len(pp.decode_path) - decode_path_len_decrease
+    if decode_path_len > 0:
+        cols.append(" ." * (decode_path_len + 1))
+    if pp.blob.__class__ == binary_type:
         blob = hexenc(pp.blob).upper()
-        for i in range(0, len(blob), 32):
+        for i in six_xrange(0, len(blob), 32):
             chunk = blob[i:i + 32]
-            yield " ".join(cols + [":".join(
-                chunk[j:j + 2] for j in range(0, len(chunk), 2)
-            )])
-    elif isinstance(pp.blob, tuple):
+            yield " ".join(cols + [colonize_hex(chunk)])
+    elif pp.blob.__class__ == tuple:
         yield " ".join(cols + [", ".join(pp.blob)])
 
 
-def pprint(obj, oids=None, big_blobs=False, with_colours=False):
+def pprint(
+        obj,
+        oid_maps=(),
+        big_blobs=False,
+        with_colours=False,
+        with_decode_path=False,
+        decode_path_only=(),
+):
     """Pretty print object
 
     :param Obj obj: object you want to pretty print
-    :param oids: ``OID <-> humand readable string`` dictionary. When OID
-                 from it is met, then its humand readable form is printed
+    :param oid_maps: list of ``str(OID) <-> human readable string`` dictionary.
+                     Its human readable form is printed when OID is met
     :param big_blobs: if large binary objects are met (like OctetString
                       values), do we need to print them too, on separate
                       lines
     :param with_colours: colourize output, if ``termcolor`` library
                          is available
+    :param with_decode_path: print decode path
+    :param decode_path_only: print only that specified decode path
     """
     def _pprint_pps(pps):
         for pp in pps:
             if hasattr(pp, "_fields"):
+                if (
+                        decode_path_only != () and
+                        tuple(
+                            str(p) for p in pp.decode_path[:len(decode_path_only)]
+                        ) != decode_path_only
+                ):
+                    continue
                 if big_blobs:
                     yield pp_console_row(
                         pp,
-                        oids=oids,
+                        oid_maps=oid_maps,
                         with_offsets=True,
                         with_blob=False,
                         with_colours=with_colours,
+                        with_decode_path=with_decode_path,
+                        decode_path_len_decrease=len(decode_path_only),
                     )
-                    for row in pp_console_blob(pp):
+                    for row in pp_console_blob(
+                            pp,
+                            decode_path_len_decrease=len(decode_path_only),
+                    ):
                         yield row
                 else:
                     yield pp_console_row(
                         pp,
-                        oids=oids,
+                        oid_maps=oid_maps,
                         with_offsets=True,
                         with_blob=True,
                         with_colours=with_colours,
+                        with_decode_path=with_decode_path,
+                        decode_path_len_decrease=len(decode_path_only),
                     )
             else:
                 for row in _pprint_pps(pp):
@@ -1361,6 +1741,22 @@ def pprint(obj, oids=None, big_blobs=False, with_colours=False):
 # ASN.1 primitive types
 ########################################################################
 
+BooleanState = namedtuple("BooleanState", (
+    "version",
+    "value",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
+
+
 class Boolean(Obj):
     """``BOOLEAN`` boolean type
 
@@ -1405,27 +1801,45 @@ class Boolean(Obj):
                 self._value = default
 
     def _value_sanitize(self, value):
+        if value.__class__ == bool:
+            return value
         if issubclass(value.__class__, Boolean):
             return value._value
-        if isinstance(value, bool):
-            return value
         raise InvalidValueType((self.__class__, bool))
 
     @property
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__()
-        obj._value = self._value
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return BooleanState(
+            __version__,
+            self._value,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(Boolean, self).__setstate__(state)
+        self._value = state.value
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __nonzero__(self):
         self._assert_ready()
@@ -1436,7 +1850,7 @@ class Boolean(Obj):
         return self._value
 
     def __eq__(self, their):
-        if isinstance(their, bool):
+        if their.__class__ == bool:
             return self._value == their
         if not issubclass(their.__class__, Boolean):
             return False
@@ -1487,7 +1901,7 @@ class Boolean(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         try:
             l, _, v = len_decode(lv)
         except DecodeError as err:
@@ -1512,14 +1926,14 @@ class Boolean(Obj):
                 offset=offset,
             )
         first_octet = byte2int(v)
-        bered = False
+        ber_encoded = False
         if first_octet == 0:
             value = False
         elif first_octet == 0xFF:
             value = True
         elif ctx.get("bered", False):
             value = True
-            bered = True
+            ber_encoded = True
         else:
             raise DecodeError(
                 "unacceptable Boolean value",
@@ -1535,7 +1949,7 @@ class Boolean(Obj):
             optional=self.optional,
             _decoded=(offset, 1, 1),
         )
-        obj.bered = bered
+        obj.ber_encoded = ber_encoded
         return obj, v[1:]
 
     def __repr__(self):
@@ -1543,6 +1957,7 @@ class Boolean(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -1560,8 +1975,30 @@ class Boolean(Obj):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            ber_encoded=self.ber_encoded,
             bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
+
+
+IntegerState = namedtuple("IntegerState", (
+    "version",
+    "specs",
+    "value",
+    "bound_min",
+    "bound_max",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
 
 
 class Integer(Obj):
@@ -1627,7 +2064,7 @@ class Integer(Obj):
         super(Integer, self).__init__(impl, expl, default, optional, _decoded)
         self._value = value
         specs = getattr(self, "schema", {}) if _specs is None else _specs
-        self.specs = specs if isinstance(specs, dict) else dict(specs)
+        self.specs = specs if specs.__class__ == dict else dict(specs)
         self._bound_min, self._bound_max = getattr(
             self,
             "bounds",
@@ -1647,11 +2084,11 @@ class Integer(Obj):
                 self._value = default
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, Integer):
-            value = value._value
-        elif isinstance(value, integer_types):
+        if isinstance(value, integer_types):
             pass
-        elif isinstance(value, str):
+        elif issubclass(value.__class__, Integer):
+            value = value._value
+        elif value.__class__ == str:
             value = self.specs.get(value)
             if value is None:
                 raise ObjUnknown("integer value: %s" % value)
@@ -1665,19 +2102,41 @@ class Integer(Obj):
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__(_specs=self.specs)
-        obj._value = self._value
-        obj._bound_min = self._bound_min
-        obj._bound_max = self._bound_max
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return IntegerState(
+            __version__,
+            self.specs,
+            self._value,
+            self._bound_min,
+            self._bound_max,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(Integer, self).__setstate__(state)
+        self.specs = state.specs
+        self._value = state.value
+        self._bound_min = state.bound_min
+        self._bound_max = state.bound_max
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __int__(self):
         self._assert_ready()
@@ -1707,9 +2166,10 @@ class Integer(Obj):
 
     @property
     def named(self):
-        for name, value in self.specs.items():
+        for name, value in iteritems(self.specs):
             if value == self._value:
                 return name
+        return None
 
     def __call__(
             self,
@@ -1789,7 +2249,7 @@ class Integer(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -1867,6 +2327,7 @@ class Integer(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -1884,7 +2345,29 @@ class Integer(Obj):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
+
+
+BitStringState = namedtuple("BitStringState", (
+    "version",
+    "specs",
+    "value",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+    "tag_constructed",
+    "defined",
+), **NAMEDTUPLE_KWARGS)
 
 
 class BitString(Obj):
@@ -1927,6 +2410,14 @@ class BitString(Obj):
     ['nonRepudiation', 'keyEncipherment']
     >>> b.specs
     {'nonRepudiation': 1, 'digitalSignature': 0, 'keyEncipherment': 2}
+
+    .. note::
+
+       Pay attention that BIT STRING can be encoded both in primitive
+       and constructed forms. Decoder always checks constructed form tag
+       additionally to specified primitive one. If BER decoding is
+       :ref:`not enabled <bered_ctx>`, then decoder will fail, because
+       of DER restrictions.
     """
     __slots__ = ("tag_constructed", "specs", "defined")
     tag_default = tag_encode(3)
@@ -1954,7 +2445,7 @@ class BitString(Obj):
         """
         super(BitString, self).__init__(impl, expl, default, optional, _decoded)
         specs = getattr(self, "schema", {}) if _specs is None else _specs
-        self.specs = specs if isinstance(specs, dict) else dict(specs)
+        self.specs = specs if specs.__class__ == dict else dict(specs)
         self._value = None if value is None else self._value_sanitize(value)
         if default is not None:
             default = self._value_sanitize(default)
@@ -1984,8 +2475,6 @@ class BitString(Obj):
         return bit_len, bytes(octets)
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, BitString):
-            return value._value
         if isinstance(value, (string_types, binary_type)):
             if (
                     isinstance(value, string_types) and
@@ -1993,26 +2482,23 @@ class BitString(Obj):
             ):
                 if value.endswith("'B"):
                     value = value[1:-2]
-                    if not set(value) <= set(("0", "1")):
+                    if not frozenset(value) <= SET01:
                         raise ValueError("B's coding contains unacceptable chars")
                     return self._bits2octets(value)
-                elif value.endswith("'H"):
+                if value.endswith("'H"):
                     value = value[1:-2]
                     return (
                         len(value) * 4,
                         hexdec(value + ("" if len(value) % 2 == 0 else "0")),
                     )
-                else:
-                    raise InvalidValueType((self.__class__, string_types, binary_type))
-            elif isinstance(value, binary_type):
+            if value.__class__ == binary_type:
                 return (len(value) * 8, value)
-            else:
-                raise InvalidValueType((self.__class__, string_types, binary_type))
-        if isinstance(value, tuple):
+            raise InvalidValueType((self.__class__, string_types, binary_type))
+        if value.__class__ == tuple:
             if (
                     len(value) == 2 and
                     isinstance(value[0], integer_types) and
-                    isinstance(value[1], binary_type)
+                    value[1].__class__ == binary_type
             ):
                 return value
             bits = []
@@ -2023,31 +2509,54 @@ class BitString(Obj):
                 bits.append(bit)
             if len(bits) == 0:
                 return self._bits2octets("")
-            bits = set(bits)
+            bits = frozenset(bits)
             return self._bits2octets("".join(
                 ("1" if bit in bits else "0")
                 for bit in six_xrange(max(bits) + 1)
             ))
+        if issubclass(value.__class__, BitString):
+            return value._value
         raise InvalidValueType((self.__class__, binary_type, string_types))
 
     @property
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__(_specs=self.specs)
-        value = self._value
-        if value is not None:
-            value = (value[0], value[1])
-        obj._value = value
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return BitStringState(
+            __version__,
+            self.specs,
+            self._value,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+            self.tag_constructed,
+            self.defined,
+        )
+
+    def __setstate__(self, state):
+        super(BitString, self).__setstate__(state)
+        self.specs = state.specs
+        self._value = state.value
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
+        self.tag_constructed = state.tag_constructed
+        self.defined = state.defined
 
     def __iter__(self):
         self._assert_ready()
@@ -2064,7 +2573,7 @@ class BitString(Obj):
         return self._value[1]
 
     def __eq__(self, their):
-        if isinstance(their, bytes):
+        if their.__class__ == bytes:
             return self._value[1] == their
         if not issubclass(their.__class__, BitString):
             return False
@@ -2076,7 +2585,7 @@ class BitString(Obj):
 
     @property
     def named(self):
-        return [name for name, bit in self.specs.items() if self[bit]]
+        return [name for name, bit in iteritems(self.specs) if self[bit]]
 
     def __call__(
             self,
@@ -2096,7 +2605,7 @@ class BitString(Obj):
         )
 
     def __getitem__(self, key):
-        if isinstance(key, int):
+        if key.__class__ == int:
             bit_len, octets = self._value
             if key >= bit_len:
                 return False
@@ -2121,64 +2630,6 @@ class BitString(Obj):
             octets,
         ))
 
-    def _decode_chunk(self, lv, offset, decode_path, ctx):
-        try:
-            l, llen, v = len_decode(lv)
-        except DecodeError as err:
-            raise err.__class__(
-                msg=err.msg,
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        if l > len(v):
-            raise NotEnoughData(
-                "encoded length is longer than data",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        if l == 0:
-            raise NotEnoughData(
-                "zero length",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        pad_size = byte2int(v)
-        if l == 1 and pad_size != 0:
-            raise DecodeError(
-                "invalid empty value",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        if pad_size > 7:
-            raise DecodeError(
-                "too big pad",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        if byte2int(v[l - 1:l]) & ((1 << pad_size) - 1) != 0:
-            raise DecodeError(
-                "invalid pad",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        v, tail = v[:l], v[l:]
-        obj = self.__class__(
-            value=((len(v) - 1) * 8 - pad_size, v[1:].tobytes()),
-            impl=self.tag,
-            expl=self._expl,
-            default=self.default,
-            optional=self.optional,
-            _specs=self.specs,
-            _decoded=(offset, llen, l),
-        )
-        return obj, tail
-
     def _decode(self, tlv, offset, decode_path, ctx, tag_only):
         try:
             t, tlen, lv = tag_strip(tlv)
@@ -2190,24 +2641,10 @@ class BitString(Obj):
                 offset=offset,
             )
         if t == self.tag:
-            if tag_only:
-                return
-            return self._decode_chunk(lv, offset, decode_path, ctx)
-        if t == self.tag_constructed:
-            if not ctx.get("bered", False):
-                raise DecodeError(
-                    msg="unallowed BER constructed encoding",
-                    decode_path=decode_path,
-                    offset=offset,
-                )
-            if tag_only:
-                return
-            lenindef = False
+            if tag_only:  # pragma: no cover
+                return None
             try:
                 l, llen, v = len_decode(lv)
-            except LenIndefForm:
-                llen, l, v = 1, 0, lv[1:]
-                lenindef = True
             except DecodeError as err:
                 raise err.__class__(
                     msg=err.msg,
@@ -2215,92 +2652,167 @@ class BitString(Obj):
                     decode_path=decode_path,
                     offset=offset,
                 )
-            if l > 0 and l > len(v):
+            if l > len(v):
                 raise NotEnoughData(
                     "encoded length is longer than data",
                     klass=self.__class__,
                     decode_path=decode_path,
                     offset=offset,
                 )
-            if not lenindef and l == 0:
+            if l == 0:
                 raise NotEnoughData(
                     "zero length",
                     klass=self.__class__,
                     decode_path=decode_path,
                     offset=offset,
                 )
-            chunks = []
-            sub_offset = offset + tlen + llen
-            vlen = 0
-            while True:
-                if lenindef:
-                    if v[:EOC_LEN].tobytes() == EOC:
-                        break
-                else:
-                    if vlen == l:
-                        break
-                    if vlen > l:
-                        raise DecodeError(
-                            msg="chunk out of bounds",
-                            decode_path=len(chunks) - 1,
-                            offset=chunks[-1].offset,
-                        )
-                sub_decode_path = decode_path + (str(len(chunks)),)
-                try:
-                    chunk, v_tail = BitString().decode(
-                        v,
-                        offset=sub_offset,
-                        decode_path=sub_decode_path,
-                        leavemm=True,
-                        ctx=ctx,
-                    )
-                except TagMismatch:
-                    raise DecodeError(
-                        msg="expected BitString encoded chunk",
-                        decode_path=sub_decode_path,
-                        offset=sub_offset,
-                    )
-                chunks.append(chunk)
-                sub_offset += chunk.tlvlen
-                vlen += chunk.tlvlen
-                v = v_tail
-            if len(chunks) == 0:
+            pad_size = byte2int(v)
+            if l == 1 and pad_size != 0:
                 raise DecodeError(
-                    msg="no chunks",
+                    "invalid empty value",
+                    klass=self.__class__,
                     decode_path=decode_path,
                     offset=offset,
                 )
-            values = []
-            bit_len = 0
-            for chunk_i, chunk in enumerate(chunks[:-1]):
-                if chunk.bit_len % 8 != 0:
-                    raise DecodeError(
-                        msg="BitString chunk is not multiple of 8 bit",
-                        decode_path=decode_path + (str(chunk_i),),
-                        offset=chunk.offset,
-                    )
-                values.append(bytes(chunk))
-                bit_len += chunk.bit_len
-            chunk_last = chunks[-1]
-            values.append(bytes(chunk_last))
-            bit_len += chunk_last.bit_len
+            if pad_size > 7:
+                raise DecodeError(
+                    "too big pad",
+                    klass=self.__class__,
+                    decode_path=decode_path,
+                    offset=offset,
+                )
+            if byte2int(v[l - 1:l]) & ((1 << pad_size) - 1) != 0:
+                raise DecodeError(
+                    "invalid pad",
+                    klass=self.__class__,
+                    decode_path=decode_path,
+                    offset=offset,
+                )
+            v, tail = v[:l], v[l:]
             obj = self.__class__(
-                value=(bit_len, b"".join(values)),
+                value=((len(v) - 1) * 8 - pad_size, v[1:].tobytes()),
                 impl=self.tag,
                 expl=self._expl,
                 default=self.default,
                 optional=self.optional,
                 _specs=self.specs,
-                _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
+                _decoded=(offset, llen, l),
             )
-            obj.lenindef = lenindef
-            obj.bered = True
-            return obj, (v[EOC_LEN:] if lenindef else v)
-        raise TagMismatch(
-            klass=self.__class__,
-            decode_path=decode_path,
-            offset=offset,
+            return obj, tail
+        if t != self.tag_constructed:
+            raise TagMismatch(
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if not ctx.get("bered", False):
+            raise DecodeError(
+                "unallowed BER constructed encoding",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if tag_only:  # pragma: no cover
+            return None
+        lenindef = False
+        try:
+            l, llen, v = len_decode(lv)
+        except LenIndefForm:
+            llen, l, v = 1, 0, lv[1:]
+            lenindef = True
+        except DecodeError as err:
+            raise err.__class__(
+                msg=err.msg,
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if l > len(v):
+            raise NotEnoughData(
+                "encoded length is longer than data",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if not lenindef and l == 0:
+            raise NotEnoughData(
+                "zero length",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        chunks = []
+        sub_offset = offset + tlen + llen
+        vlen = 0
+        while True:
+            if lenindef:
+                if v[:EOC_LEN].tobytes() == EOC:
+                    break
+            else:
+                if vlen == l:
+                    break
+                if vlen > l:
+                    raise DecodeError(
+                        "chunk out of bounds",
+                        klass=self.__class__,
+                        decode_path=decode_path + (str(len(chunks) - 1),),
+                        offset=chunks[-1].offset,
+                    )
+            sub_decode_path = decode_path + (str(len(chunks)),)
+            try:
+                chunk, v_tail = BitString().decode(
+                    v,
+                    offset=sub_offset,
+                    decode_path=sub_decode_path,
+                    leavemm=True,
+                    ctx=ctx,
+                    _ctx_immutable=False,
+                )
+            except TagMismatch:
+                raise DecodeError(
+                    "expected BitString encoded chunk",
+                    klass=self.__class__,
+                    decode_path=sub_decode_path,
+                    offset=sub_offset,
+                )
+            chunks.append(chunk)
+            sub_offset += chunk.tlvlen
+            vlen += chunk.tlvlen
+            v = v_tail
+        if len(chunks) == 0:
+            raise DecodeError(
+                "no chunks",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        values = []
+        bit_len = 0
+        for chunk_i, chunk in enumerate(chunks[:-1]):
+            if chunk.bit_len % 8 != 0:
+                raise DecodeError(
+                    "BitString chunk is not multiple of 8 bits",
+                    klass=self.__class__,
+                    decode_path=decode_path + (str(chunk_i),),
+                    offset=chunk.offset,
+                )
+            values.append(bytes(chunk))
+            bit_len += chunk.bit_len
+        chunk_last = chunks[-1]
+        values.append(bytes(chunk_last))
+        bit_len += chunk_last.bit_len
+        obj = self.__class__(
+            value=(bit_len, b"".join(values)),
+            impl=self.tag,
+            expl=self._expl,
+            default=self.default,
+            optional=self.optional,
+            _specs=self.specs,
+            _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
         )
+        obj.lenindef = lenindef
+        obj.ber_encoded = True
+        return obj, (v[EOC_LEN:] if lenindef else v)
 
     def __repr__(self):
         return pp_console_row(next(self.pps()))
@@ -2314,6 +2826,7 @@ class BitString(Obj):
             if len(self.specs) > 0:
                 blob = tuple(self.named)
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -2333,6 +2846,7 @@ class BitString(Obj):
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
             lenindef=self.lenindef,
+            ber_encoded=self.ber_encoded,
             bered=self.bered,
         )
         defined_by, defined = self.defined or (None, None)
@@ -2340,6 +2854,28 @@ class BitString(Obj):
             yield defined.pps(
                 decode_path=decode_path + (DecodePathDefBy(defined_by),)
             )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
+
+
+OctetStringState = namedtuple("OctetStringState", (
+    "version",
+    "value",
+    "bound_min",
+    "bound_max",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+    "tag_constructed",
+    "defined",
+), **NAMEDTUPLE_KWARGS)
 
 
 class OctetString(Obj):
@@ -2357,6 +2893,14 @@ class OctetString(Obj):
     pyderasn.BoundsError: unsatisfied bounds: 4 <= 5 <= 4
     >>> OctetString(b"hell", bounds=(4, 4))
     OCTET STRING 4 bytes 68656c6c
+
+    .. note::
+
+       Pay attention that OCTET STRING can be encoded both in primitive
+       and constructed forms. Decoder always checks constructed form tag
+       additionally to specified primitive one. If BER decoding is
+       :ref:`not enabled <bered_ctx>`, then decoder will fail, because
+       of DER restrictions.
     """
     __slots__ = ("tag_constructed", "_bound_min", "_bound_max", "defined")
     tag_default = tag_encode(4)
@@ -2371,6 +2915,7 @@ class OctetString(Obj):
             default=None,
             optional=False,
             _decoded=(0, 0, 0),
+            ctx=None,
     ):
         """
         :param value: set the value. Either binary type, or
@@ -2382,13 +2927,7 @@ class OctetString(Obj):
         :param default: set default value. Type same as in ``value``
         :param bool optional: is object ``OPTIONAL`` in sequence
         """
-        super(OctetString, self).__init__(
-            impl,
-            expl,
-            default,
-            optional,
-            _decoded,
-        )
+        super(OctetString, self).__init__(impl, expl, default, optional, _decoded)
         self._value = value
         self._bound_min, self._bound_max = getattr(
             self,
@@ -2415,10 +2954,10 @@ class OctetString(Obj):
         )
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, OctetString):
-            value = value._value
-        elif isinstance(value, binary_type):
+        if value.__class__ == binary_type:
             pass
+        elif issubclass(value.__class__, OctetString):
+            value = value._value
         else:
             raise InvalidValueType((self.__class__, bytes))
         if not self._bound_min <= len(value) <= self._bound_max:
@@ -2429,26 +2968,50 @@ class OctetString(Obj):
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__()
-        obj._value = self._value
-        obj._bound_min = self._bound_min
-        obj._bound_max = self._bound_max
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return OctetStringState(
+            __version__,
+            self._value,
+            self._bound_min,
+            self._bound_max,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+            self.tag_constructed,
+            self.defined,
+        )
+
+    def __setstate__(self, state):
+        super(OctetString, self).__setstate__(state)
+        self._value = state.value
+        self._bound_min = state.bound_min
+        self._bound_max = state.bound_max
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
+        self.tag_constructed = state.tag_constructed
+        self.defined = state.defined
 
     def __bytes__(self):
         self._assert_ready()
         return self._value
 
     def __eq__(self, their):
-        if isinstance(their, binary_type):
+        if their.__class__ == binary_type:
             return self._value == their
         if not issubclass(their.__class__, OctetString):
             return False
@@ -2490,50 +3053,6 @@ class OctetString(Obj):
             self._value,
         ))
 
-    def _decode_chunk(self, lv, offset, decode_path, ctx):
-        try:
-            l, llen, v = len_decode(lv)
-        except DecodeError as err:
-            raise err.__class__(
-                msg=err.msg,
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        if l > len(v):
-            raise NotEnoughData(
-                "encoded length is longer than data",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        v, tail = v[:l], v[l:]
-        try:
-            obj = self.__class__(
-                value=v.tobytes(),
-                bounds=(self._bound_min, self._bound_max),
-                impl=self.tag,
-                expl=self._expl,
-                default=self.default,
-                optional=self.optional,
-                _decoded=(offset, llen, l),
-            )
-        except DecodeError as err:
-            raise DecodeError(
-                msg=err.msg,
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        except BoundsError as err:
-            raise DecodeError(
-                msg=str(err),
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        return obj, tail
-
     def _decode(self, tlv, offset, decode_path, ctx, tag_only):
         try:
             t, tlen, lv = tag_strip(tlv)
@@ -2546,23 +3065,9 @@ class OctetString(Obj):
             )
         if t == self.tag:
             if tag_only:
-                return
-            return self._decode_chunk(lv, offset, decode_path, ctx)
-        if t == self.tag_constructed:
-            if not ctx.get("bered", False):
-                raise DecodeError(
-                    msg="unallowed BER constructed encoding",
-                    decode_path=decode_path,
-                    offset=offset,
-                )
-            if tag_only:
-                return
-            lenindef = False
+                return None
             try:
                 l, llen, v = len_decode(lv)
-            except LenIndefForm:
-                llen, l, v = 1, 0, lv[1:]
-                lenindef = True
             except DecodeError as err:
                 raise err.__class__(
                     msg=err.msg,
@@ -2570,70 +3075,24 @@ class OctetString(Obj):
                     decode_path=decode_path,
                     offset=offset,
                 )
-            if l > 0 and l > len(v):
+            if l > len(v):
                 raise NotEnoughData(
                     "encoded length is longer than data",
                     klass=self.__class__,
                     decode_path=decode_path,
                     offset=offset,
                 )
-            if not lenindef and l == 0:
-                raise NotEnoughData(
-                    "zero length",
-                    klass=self.__class__,
-                    decode_path=decode_path,
-                    offset=offset,
-                )
-            chunks = []
-            sub_offset = offset + tlen + llen
-            vlen = 0
-            while True:
-                if lenindef:
-                    if v[:EOC_LEN].tobytes() == EOC:
-                        break
-                else:
-                    if vlen == l:
-                        break
-                    if vlen > l:
-                        raise DecodeError(
-                            msg="chunk out of bounds",
-                            decode_path=len(chunks) - 1,
-                            offset=chunks[-1].offset,
-                        )
-                sub_decode_path = decode_path + (str(len(chunks)),)
-                try:
-                    chunk, v_tail = OctetString().decode(
-                        v,
-                        offset=sub_offset,
-                        decode_path=sub_decode_path,
-                        leavemm=True,
-                        ctx=ctx,
-                    )
-                except TagMismatch:
-                    raise DecodeError(
-                        msg="expected OctetString encoded chunk",
-                        decode_path=sub_decode_path,
-                        offset=sub_offset,
-                    )
-                chunks.append(chunk)
-                sub_offset += chunk.tlvlen
-                vlen += chunk.tlvlen
-                v = v_tail
-            if len(chunks) == 0:
-                raise DecodeError(
-                    msg="no chunks",
-                    decode_path=decode_path,
-                    offset=offset,
-                )
+            v, tail = v[:l], v[l:]
             try:
                 obj = self.__class__(
-                    value=b"".join(bytes(chunk) for chunk in chunks),
+                    value=v.tobytes(),
                     bounds=(self._bound_min, self._bound_max),
                     impl=self.tag,
                     expl=self._expl,
                     default=self.default,
                     optional=self.optional,
-                    _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
+                    _decoded=(offset, llen, l),
+                    ctx=ctx,
                 )
             except DecodeError as err:
                 raise DecodeError(
@@ -2649,20 +3108,115 @@ class OctetString(Obj):
                     decode_path=decode_path,
                     offset=offset,
                 )
-            obj.lenindef = lenindef
-            obj.bered = True
-            return obj, (v[EOC_LEN:] if lenindef else v)
-        raise TagMismatch(
-            klass=self.__class__,
-            decode_path=decode_path,
-            offset=offset,
-        )
+            return obj, tail
+        if t != self.tag_constructed:
+            raise TagMismatch(
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if not ctx.get("bered", False):
+            raise DecodeError(
+                "unallowed BER constructed encoding",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if tag_only:
+            return None
+        lenindef = False
+        try:
+            l, llen, v = len_decode(lv)
+        except LenIndefForm:
+            llen, l, v = 1, 0, lv[1:]
+            lenindef = True
+        except DecodeError as err:
+            raise err.__class__(
+                msg=err.msg,
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if l > len(v):
+            raise NotEnoughData(
+                "encoded length is longer than data",
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        chunks = []
+        sub_offset = offset + tlen + llen
+        vlen = 0
+        while True:
+            if lenindef:
+                if v[:EOC_LEN].tobytes() == EOC:
+                    break
+            else:
+                if vlen == l:
+                    break
+                if vlen > l:
+                    raise DecodeError(
+                        "chunk out of bounds",
+                        klass=self.__class__,
+                        decode_path=decode_path + (str(len(chunks) - 1),),
+                        offset=chunks[-1].offset,
+                    )
+            sub_decode_path = decode_path + (str(len(chunks)),)
+            try:
+                chunk, v_tail = OctetString().decode(
+                    v,
+                    offset=sub_offset,
+                    decode_path=sub_decode_path,
+                    leavemm=True,
+                    ctx=ctx,
+                    _ctx_immutable=False,
+                )
+            except TagMismatch:
+                raise DecodeError(
+                    "expected OctetString encoded chunk",
+                    klass=self.__class__,
+                    decode_path=sub_decode_path,
+                    offset=sub_offset,
+                )
+            chunks.append(chunk)
+            sub_offset += chunk.tlvlen
+            vlen += chunk.tlvlen
+            v = v_tail
+        try:
+            obj = self.__class__(
+                value=b"".join(bytes(chunk) for chunk in chunks),
+                bounds=(self._bound_min, self._bound_max),
+                impl=self.tag,
+                expl=self._expl,
+                default=self.default,
+                optional=self.optional,
+                _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
+                ctx=ctx,
+            )
+        except DecodeError as err:
+            raise DecodeError(
+                msg=err.msg,
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        except BoundsError as err:
+            raise DecodeError(
+                msg=str(err),
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        obj.lenindef = lenindef
+        obj.ber_encoded = True
+        return obj, (v[EOC_LEN:] if lenindef else v)
 
     def __repr__(self):
         return pp_console_row(next(self.pps()))
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -2682,6 +3236,7 @@ class OctetString(Obj):
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
             lenindef=self.lenindef,
+            ber_encoded=self.ber_encoded,
             bered=self.bered,
         )
         defined_by, defined = self.defined or (None, None)
@@ -2689,6 +3244,23 @@ class OctetString(Obj):
             yield defined.pps(
                 decode_path=decode_path + (DecodePathDefBy(defined_by),)
             )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
+
+
+NullState = namedtuple("NullState", (
+    "version",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
 
 
 class Null(Obj):
@@ -2723,16 +3295,33 @@ class Null(Obj):
     def ready(self):
         return True
 
-    def copy(self):
-        obj = self.__class__()
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return NullState(
+            __version__,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(Null, self).__setstate__(state)
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __eq__(self, their):
         if not issubclass(their.__class__, Null):
@@ -2774,8 +3363,8 @@ class Null(Obj):
                 decode_path=decode_path,
                 offset=offset,
             )
-        if tag_only:
-            return
+        if tag_only:  # pragma: no cover
+            return None
         try:
             l, _, v = len_decode(lv)
         except DecodeError as err:
@@ -2805,6 +3394,7 @@ class Null(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -2820,7 +3410,27 @@ class Null(Obj):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
+
+
+ObjectIdentifierState = namedtuple("ObjectIdentifierState", (
+    "version",
+    "value",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+    "defines",
+), **NAMEDTUPLE_KWARGS)
 
 
 class ObjectIdentifier(Obj):
@@ -2873,13 +3483,7 @@ class ObjectIdentifier(Obj):
         :param default: set default value. Type same as in ``value``
         :param bool optional: is object ``OPTIONAL`` in sequence
         """
-        super(ObjectIdentifier, self).__init__(
-            impl,
-            expl,
-            default,
-            optional,
-            _decoded,
-        )
+        super(ObjectIdentifier, self).__init__(impl, expl, default, optional, _decoded)
         self._value = value
         if value is not None:
             self._value = self._value_sanitize(value)
@@ -2895,10 +3499,10 @@ class ObjectIdentifier(Obj):
         self.defines = defines
 
     def __add__(self, their):
+        if their.__class__ == tuple:
+            return self.__class__(self._value + their)
         if isinstance(their, self.__class__):
             return self.__class__(self._value + their._value)
-        if isinstance(their, tuple):
-            return self.__class__(self._value + their)
         raise InvalidValueType((self.__class__, tuple))
 
     def _value_sanitize(self, value):
@@ -2906,10 +3510,10 @@ class ObjectIdentifier(Obj):
             return value._value
         if isinstance(value, string_types):
             try:
-                value = tuple(int(arc) for arc in value.split("."))
+                value = tuple(pureint(arc) for arc in value.split("."))
             except ValueError:
                 raise InvalidOID("unacceptable arcs values")
-        if isinstance(value, tuple):
+        if value.__class__ == tuple:
             if len(value) < 2:
                 raise InvalidOID("less than 2 arcs")
             first_arc = value[0]
@@ -2920,6 +3524,8 @@ class ObjectIdentifier(Obj):
                 pass
             else:
                 raise InvalidOID("unacceptable first arc value")
+            if not all(arc >= 0 for arc in value):
+                raise InvalidOID("negative arc value")
             return value
         raise InvalidValueType((self.__class__, str, tuple))
 
@@ -2927,18 +3533,37 @@ class ObjectIdentifier(Obj):
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__()
-        obj._value = self._value
-        obj.defines = self.defines
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    def __getstate__(self):
+        return ObjectIdentifierState(
+            __version__,
+            self._value,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+            self.defines,
+        )
+
+    def __setstate__(self, state):
+        super(ObjectIdentifier, self).__setstate__(state)
+        self._value = state.value
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
+        self.defines = state.defines
 
     def __iter__(self):
         self._assert_ready()
@@ -2956,7 +3581,7 @@ class ObjectIdentifier(Obj):
         )
 
     def __eq__(self, their):
-        if isinstance(their, tuple):
+        if their.__class__ == tuple:
             return self._value == their
         if not issubclass(their.__class__, ObjectIdentifier):
             return False
@@ -3022,8 +3647,8 @@ class ObjectIdentifier(Obj):
                 decode_path=decode_path,
                 offset=offset,
             )
-        if tag_only:
-            return
+        if tag_only:  # pragma: no cover
+            return None
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -3049,11 +3674,17 @@ class ObjectIdentifier(Obj):
             )
         v, tail = v[:l], v[l:]
         arcs = []
+        ber_encoded = False
         while len(v) > 0:
             i = 0
             arc = 0
             while True:
                 octet = indexbytes(v, i)
+                if i == 0 and octet == 0x80:
+                    if ctx.get("bered", False):
+                        ber_encoded = True
+                    else:
+                        raise DecodeError("non normalized arc encoding")
                 arc = (arc << 7) | (octet & 0x7F)
                 if octet & 0x80 == 0:
                     arcs.append(arc)
@@ -3085,6 +3716,8 @@ class ObjectIdentifier(Obj):
             optional=self.optional,
             _decoded=(offset, llen, l),
         )
+        if ber_encoded:
+            obj.ber_encoded = True
         return obj, tail
 
     def __repr__(self):
@@ -3092,6 +3725,7 @@ class ObjectIdentifier(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -3109,7 +3743,11 @@ class ObjectIdentifier(Obj):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            ber_encoded=self.ber_encoded,
+            bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class Enumerated(Integer):
@@ -3134,13 +3772,7 @@ class Enumerated(Integer):
             bounds=None,  # dummy argument, workability for Integer.decode
     ):
         super(Enumerated, self).__init__(
-            value=value,
-            impl=impl,
-            expl=expl,
-            default=default,
-            optional=optional,
-            _specs=_specs,
-            _decoded=_decoded,
+            value, bounds, impl, expl, default, optional, _specs, _decoded,
         )
         if len(self.specs) == 0:
             raise ValueError("schema must be specified")
@@ -3149,7 +3781,10 @@ class Enumerated(Integer):
         if isinstance(value, self.__class__):
             value = value._value
         elif isinstance(value, integer_types):
-            if value not in list(self.specs.values()):
+            for _value in itervalues(self.specs):
+                if _value == value:
+                    break
+            else:
                 raise DecodeError(
                     "unknown integer value: %s" % value,
                     klass=self.__class__,
@@ -3162,20 +3797,6 @@ class Enumerated(Integer):
             raise InvalidValueType((self.__class__, int, str))
         return value
 
-    def copy(self):
-        obj = self.__class__(_specs=self.specs)
-        obj._value = self._value
-        obj._bound_min = self._bound_min
-        obj._bound_max = self._bound_max
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
-
     def __call__(
             self,
             value=None,
@@ -3195,6 +3816,12 @@ class Enumerated(Integer):
         )
 
 
+def escape_control_unicode(c):
+    if unicat(c)[0] == "C":
+        c = repr(c).lstrip("u").strip("'")
+    return c
+
+
 class CommonString(OctetString):
     """Common class for all strings
 
@@ -3257,16 +3884,16 @@ class CommonString(OctetString):
        * - :py:class:`pyderasn.BMPString`
          - utf-16-be
     """
-    __slots__ = ("encoding",)
+    __slots__ = ()
 
     def _value_sanitize(self, value):
         value_raw = None
         value_decoded = None
         if isinstance(value, self.__class__):
             value_raw = value._value
-        elif isinstance(value, text_type):
+        elif value.__class__ == text_type:
             value_decoded = value
-        elif isinstance(value, binary_type):
+        elif value.__class__ == binary_type:
             value_raw = value
         else:
             raise InvalidValueType((self.__class__, text_type, binary_type))
@@ -3290,9 +3917,9 @@ class CommonString(OctetString):
         return value_raw
 
     def __eq__(self, their):
-        if isinstance(their, binary_type):
+        if their.__class__ == binary_type:
             return self._value == their
-        if isinstance(their, text_type):
+        if their.__class__ == text_type:
             return self._value == their.encode(self.encoding)
         if not isinstance(their, self.__class__):
             return False
@@ -3313,8 +3940,12 @@ class CommonString(OctetString):
     def pps(self, decode_path=(), no_unicode=False):
         value = None
         if self.ready:
-            value = hexenc(bytes(self)) if no_unicode else self.__unicode__()
+            value = (
+                hexenc(bytes(self)) if no_unicode else
+                "".join(escape_control_unicode(c) for c in self.__unicode__())
+            )
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -3332,7 +3963,11 @@ class CommonString(OctetString):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            ber_encoded=self.ber_encoded,
+            bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class UTF8String(CommonString):
@@ -3342,29 +3977,140 @@ class UTF8String(CommonString):
     asn1_type_name = "UTF8String"
 
 
-class NumericString(CommonString):
+class AllowableCharsMixin(object):
+    @property
+    def allowable_chars(self):
+        if PY2:
+            return self._allowable_chars
+        return frozenset(six_unichr(c) for c in self._allowable_chars)
+
+
+class NumericString(AllowableCharsMixin, CommonString):
     """Numeric string
 
-    Its value is properly sanitized: only ASCII digits can be stored.
+    Its value is properly sanitized: only ASCII digits with spaces can
+    be stored.
+
+    >>> NumericString().allowable_chars
+    frozenset(['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ' '])
     """
     __slots__ = ()
     tag_default = tag_encode(18)
     encoding = "ascii"
     asn1_type_name = "NumericString"
-    allowable_chars = set(digits.encode("ascii"))
+    _allowable_chars = frozenset(digits.encode("ascii") + b" ")
 
     def _value_sanitize(self, value):
         value = super(NumericString, self)._value_sanitize(value)
-        if not set(value) <= self.allowable_chars:
+        if not frozenset(value) <= self._allowable_chars:
             raise DecodeError("non-numeric value")
         return value
 
 
-class PrintableString(CommonString):
+PrintableStringState = namedtuple(
+    "PrintableStringState",
+    OctetStringState._fields + ("allowable_chars",),
+    **NAMEDTUPLE_KWARGS
+)
+
+
+class PrintableString(AllowableCharsMixin, CommonString):
+    """Printable string
+
+    Its value is properly sanitized: see X.680 41.4 table 10.
+
+    >>> PrintableString().allowable_chars
+    frozenset([' ', "'", ..., 'z'])
+    >>> obj = PrintableString("foo*bar", allow_asterisk=True)
+    PrintableString PrintableString foo*bar
+    >>> obj.allow_asterisk, obj.allow_ampersand
+    (True, False)
+    """
     __slots__ = ()
     tag_default = tag_encode(19)
     encoding = "ascii"
     asn1_type_name = "PrintableString"
+    _allowable_chars = frozenset(
+        (ascii_letters + digits + " '()+,-./:=?").encode("ascii")
+    )
+    _asterisk = frozenset("*".encode("ascii"))
+    _ampersand = frozenset("&".encode("ascii"))
+
+    def __init__(
+            self,
+            value=None,
+            bounds=None,
+            impl=None,
+            expl=None,
+            default=None,
+            optional=False,
+            _decoded=(0, 0, 0),
+            ctx=None,
+            allow_asterisk=False,
+            allow_ampersand=False,
+    ):
+        """
+        :param allow_asterisk: allow asterisk character
+        :param allow_ampersand: allow ampersand character
+        """
+        if allow_asterisk:
+            self._allowable_chars |= self._asterisk
+        if allow_ampersand:
+            self._allowable_chars |= self._ampersand
+        super(PrintableString, self).__init__(
+            value, bounds, impl, expl, default, optional, _decoded, ctx,
+        )
+
+    @property
+    def allow_asterisk(self):
+        """Is asterisk character allowed?
+        """
+        return self._asterisk <= self._allowable_chars
+
+    @property
+    def allow_ampersand(self):
+        """Is ampersand character allowed?
+        """
+        return self._ampersand <= self._allowable_chars
+
+    def _value_sanitize(self, value):
+        value = super(PrintableString, self)._value_sanitize(value)
+        if not frozenset(value) <= self._allowable_chars:
+            raise DecodeError("non-printable value")
+        return value
+
+    def __getstate__(self):
+        return PrintableStringState(
+            *super(PrintableString, self).__getstate__(),
+            **{"allowable_chars": self._allowable_chars}
+        )
+
+    def __setstate__(self, state):
+        super(PrintableString, self).__setstate__(state)
+        self._allowable_chars = state.allowable_chars
+
+    def __call__(
+            self,
+            value=None,
+            bounds=None,
+            impl=None,
+            expl=None,
+            default=None,
+            optional=None,
+    ):
+        return self.__class__(
+            value=value,
+            bounds=(
+                (self._bound_min, self._bound_max)
+                if bounds is None else bounds
+            ),
+            impl=self.tag if impl is None else impl,
+            expl=self._expl if expl is None else expl,
+            default=self.default if default is None else default,
+            optional=self.optional if optional is None else optional,
+            allow_asterisk=self.allow_asterisk,
+            allow_ampersand=self.allow_ampersand,
+        )
 
 
 class TeletexString(CommonString):
@@ -3398,7 +4144,31 @@ LEN_YYYYMMDDHHMMSSDMZ = len("YYYYMMDDHHMMSSDMZ")
 LEN_YYYYMMDDHHMMSSZ = len("YYYYMMDDHHMMSSZ")
 
 
-class UTCTime(CommonString):
+class VisibleString(CommonString):
+    __slots__ = ()
+    tag_default = tag_encode(26)
+    encoding = "ascii"
+    asn1_type_name = "VisibleString"
+
+
+UTCTimeState = namedtuple(
+    "UTCTimeState",
+    OctetStringState._fields + ("ber_raw",),
+    **NAMEDTUPLE_KWARGS
+)
+
+
+def str_to_time_fractions(value):
+    v = pureint(value)
+    year, v = (v // 10**10), (v % 10**10)
+    month, v = (v // 10**8), (v % 10**8)
+    day, v = (v // 10**6), (v % 10**6)
+    hour, v = (v // 10**4), (v % 10**4)
+    minute, second = (v // 100), (v % 100)
+    return year, month, day, hour, minute, second
+
+
+class UTCTime(VisibleString):
     """``UTCTime`` datetime type
 
     >>> t = UTCTime(datetime(2017, 9, 30, 22, 7, 50, 123))
@@ -3411,14 +4181,28 @@ class UTCTime(CommonString):
     datetime.datetime(2017, 9, 30, 22, 7, 50)
     >>> UTCTime(datetime(2057, 9, 30, 22, 7, 50)).todatetime()
     datetime.datetime(1957, 9, 30, 22, 7, 50)
+
+    If BER encoded value was met, then ``ber_raw`` attribute will hold
+    its raw representation.
+
+    .. warning::
+
+       Pay attention that UTCTime can not hold full year, so all years
+       having < 50 years are treated as 20xx, 19xx otherwise, according
+       to X.509 recommendation.
+
+    .. warning::
+
+       No strict validation of UTC offsets are made, but very crude:
+
+       * minutes are not exceeding 60
+       * offset value is not exceeding 14 hours
     """
-    __slots__ = ()
+    __slots__ = ("ber_raw",)
     tag_default = tag_encode(23)
     encoding = "ascii"
     asn1_type_name = "UTCTime"
 
-    fmt = "%y%m%d%H%M%SZ"
-
     def __init__(
             self,
             value=None,
@@ -3428,6 +4212,7 @@ class UTCTime(CommonString):
             optional=False,
             _decoded=(0, 0, 0),
             bounds=None,  # dummy argument, workability for OctetString.decode
+            ctx=None,
     ):
         """
         :param value: set the value. Either datetime type, or
@@ -3438,17 +4223,15 @@ class UTCTime(CommonString):
         :param bool optional: is object ``OPTIONAL`` in sequence
         """
         super(UTCTime, self).__init__(
-            impl=impl,
-            expl=expl,
-            default=default,
-            optional=optional,
-            _decoded=_decoded,
+            None, None, impl, expl, None, optional, _decoded, ctx,
         )
         self._value = value
+        self.ber_raw = None
         if value is not None:
-            self._value = self._value_sanitize(value)
+            self._value, self.ber_raw = self._value_sanitize(value, ctx)
+            self.ber_encoded = self.ber_raw is not None
         if default is not None:
-            default = self._value_sanitize(default)
+            default, _ = self._value_sanitize(default)
             self.default = self.__class__(
                 value=default,
                 impl=self.tag,
@@ -3456,28 +4239,122 @@ class UTCTime(CommonString):
             )
             if self._value is None:
                 self._value = default
+            optional = True
+        self.optional = optional
 
-    def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
-        if isinstance(value, datetime):
-            return value.strftime(self.fmt).encode("ascii")
-        if isinstance(value, binary_type):
-            value_decoded = value.decode("ascii")
-            if len(value_decoded) == LEN_YYMMDDHHMMSSZ:
-                try:
-                    datetime.strptime(value_decoded, self.fmt)
-                except ValueError:
-                    raise DecodeError("invalid UTCTime format")
-                return value
+    def _strptime_bered(self, value):
+        year, month, day, hour, minute, _ = str_to_time_fractions(value[:10] + "00")
+        value = value[10:]
+        if len(value) == 0:
+            raise ValueError("no timezone")
+        year += 2000 if year < 50 else 1900
+        decoded = datetime(year, month, day, hour, minute)
+        offset = 0
+        if value[-1] == "Z":
+            value = value[:-1]
+        else:
+            if len(value) < 5:
+                raise ValueError("invalid UTC offset")
+            if value[-5] == "-":
+                sign = -1
+            elif value[-5] == "+":
+                sign = 1
             else:
-                raise DecodeError("invalid UTCTime length")
+                raise ValueError("invalid UTC offset")
+            v = pureint(value[-4:])
+            offset, v = (60 * (v % 100)), v // 100
+            if offset >= 3600:
+                raise ValueError("invalid UTC offset minutes")
+            offset += 3600 * v
+            if offset > 14 * 3600:
+                raise ValueError("too big UTC offset")
+            offset *= sign
+            value = value[:-5]
+        if len(value) == 0:
+            return offset, decoded
+        if len(value) != 2:
+            raise ValueError("invalid UTC offset seconds")
+        seconds = pureint(value)
+        if seconds >= 60:
+            raise ValueError("invalid seconds value")
+        return offset, decoded + timedelta(seconds=seconds)
+
+    def _strptime(self, value):
+        # datetime.strptime's format: %y%m%d%H%M%SZ
+        if len(value) != LEN_YYMMDDHHMMSSZ:
+            raise ValueError("invalid UTCTime length")
+        if value[-1] != "Z":
+            raise ValueError("non UTC timezone")
+        year, month, day, hour, minute, second = str_to_time_fractions(value[:-1])
+        year += 2000 if year < 50 else 1900
+        return datetime(year, month, day, hour, minute, second)
+
+    def _dt_sanitize(self, value):
+        if value.year < 1950 or value.year > 2049:
+            raise ValueError("UTCTime can hold only 1950-2049 years")
+        return value.replace(microsecond=0)
+
+    def _value_sanitize(self, value, ctx=None):
+        if value.__class__ == binary_type:
+            try:
+                value_decoded = value.decode("ascii")
+            except (UnicodeEncodeError, UnicodeDecodeError) as err:
+                raise DecodeError("invalid UTCTime encoding: %r" % err)
+            err = None
+            try:
+                return self._strptime(value_decoded), None
+            except (TypeError, ValueError) as _err:
+                err = _err
+                if (ctx is not None) and ctx.get("bered", False):
+                    try:
+                        offset, _value = self._strptime_bered(value_decoded)
+                        _value = _value - timedelta(seconds=offset)
+                        return self._dt_sanitize(_value), value
+                    except (TypeError, ValueError, OverflowError) as _err:
+                        err = _err
+            raise DecodeError(
+                "invalid %s format: %r" % (self.asn1_type_name, err),
+                klass=self.__class__,
+            )
+        if isinstance(value, self.__class__):
+            return value._value, None
+        if value.__class__ == datetime:
+            return self._dt_sanitize(value), None
         raise InvalidValueType((self.__class__, datetime))
 
+    def _pp_value(self):
+        if self.ready:
+            value = self._value.isoformat()
+            if self.ber_encoded:
+                value += " (%s)" % self.ber_raw
+            return value
+
+    def __unicode__(self):
+        if self.ready:
+            value = self._value.isoformat()
+            if self.ber_encoded:
+                value += " (%s)" % self.ber_raw
+            return value
+        return text_type(self._pp_value())
+
+    def __getstate__(self):
+        return UTCTimeState(
+            *super(UTCTime, self).__getstate__(),
+            **{"ber_raw": self.ber_raw}
+        )
+
+    def __setstate__(self, state):
+        super(UTCTime, self).__setstate__(state)
+        self.ber_raw = state.ber_raw
+
+    def __bytes__(self):
+        self._assert_ready()
+        return self._encode_time()
+
     def __eq__(self, their):
-        if isinstance(their, binary_type):
-            return self._value == their
-        if isinstance(their, datetime):
+        if their.__class__ == binary_type:
+            return self._encode_time() == their
+        if their.__class__ == datetime:
             return self.todatetime() == their
         if not isinstance(their, self.__class__):
             return False
@@ -3487,35 +4364,27 @@ class UTCTime(CommonString):
             self._expl == their._expl
         )
 
-    def todatetime(self):
-        """Convert to datetime
+    def _encode_time(self):
+        return self._value.strftime("%y%m%d%H%M%SZ").encode("ascii")
 
-        :returns: datetime
+    def _encode(self):
+        self._assert_ready()
+        value = self._encode_time()
+        return b"".join((self.tag, len_encode(len(value)), value))
 
-        Pay attention that UTCTime can not hold full year, so all years
-        having < 50 years are treated as 20xx, 19xx otherwise, according
-        to X.509 recomendation.
-        """
-        value = datetime.strptime(self._value.decode("ascii"), self.fmt)
-        year = value.year % 100
-        return datetime(
-            year=(2000 + year) if year < 50 else (1900 + year),
-            month=value.month,
-            day=value.day,
-            hour=value.hour,
-            minute=value.minute,
-            second=value.second,
-        )
+    def todatetime(self):
+        return self._value
 
     def __repr__(self):
         return pp_console_row(next(self.pps()))
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
-            value=self.todatetime().isoformat() if self.ready else None,
+            value=self._pp_value(),
             optional=self.optional,
             default=self == self.default,
             impl=None if self.tag == self.tag_default else tag_decode(self.tag),
@@ -3529,65 +4398,140 @@ class UTCTime(CommonString):
             expl_llen=self.expl_llen if self.expled else None,
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
+            ber_encoded=self.ber_encoded,
+            bered=self.bered,
         )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class GeneralizedTime(UTCTime):
     """``GeneralizedTime`` datetime type
 
-    This type is similar to :py:class:`pyderasn.UTCTime`.
+    This type is similar to :py:class:`pyderasn.UTCTime`.
+
+    >>> t = GeneralizedTime(datetime(2017, 9, 30, 22, 7, 50, 123))
+    GeneralizedTime GeneralizedTime 2017-09-30T22:07:50.000123
+    >>> str(t)
+    '20170930220750.000123Z'
+    >>> t = GeneralizedTime(datetime(2057, 9, 30, 22, 7, 50))
+    GeneralizedTime GeneralizedTime 2057-09-30T22:07:50
+
+    .. warning::
+
+       Only microsecond fractions are supported in DER encoding.
+       :py:exc:`pyderasn.DecodeError` will be raised during decoding of
+       higher precision values.
+
+    .. warning::
+
+       BER encoded data can loss information (accuracy) during decoding
+       because of float transformations.
+
+    .. warning::
+
+       Local times (without explicit timezone specification) are treated
+       as UTC one, no transformations are made.
+
+    .. warning::
 
-    >>> t = GeneralizedTime(datetime(2017, 9, 30, 22, 7, 50, 123))
-    GeneralizedTime GeneralizedTime 2017-09-30T22:07:50.000123
-    >>> str(t)
-    '20170930220750.000123Z'
-    >>> t = GeneralizedTime(datetime(2057, 9, 30, 22, 7, 50))
-    GeneralizedTime GeneralizedTime 2057-09-30T22:07:50
+       Zero year is unsupported.
     """
     __slots__ = ()
     tag_default = tag_encode(24)
     asn1_type_name = "GeneralizedTime"
 
-    fmt = "%Y%m%d%H%M%SZ"
-    fmt_ms = "%Y%m%d%H%M%S.%fZ"
+    def _dt_sanitize(self, value):
+        return value
 
-    def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
-        if isinstance(value, datetime):
-            return value.strftime(
-                self.fmt_ms if value.microsecond > 0 else self.fmt
-            ).encode("ascii")
-        if isinstance(value, binary_type):
-            value_decoded = value.decode("ascii")
-            if len(value_decoded) == LEN_YYYYMMDDHHMMSSZ:
-                try:
-                    datetime.strptime(value_decoded, self.fmt)
-                except ValueError:
-                    raise DecodeError(
-                        "invalid GeneralizedTime (without ms) format",
-                    )
-                return value
-            elif len(value_decoded) >= LEN_YYYYMMDDHHMMSSDMZ:
-                try:
-                    datetime.strptime(value_decoded, self.fmt_ms)
-                except ValueError:
-                    raise DecodeError(
-                        "invalid GeneralizedTime (with ms) format",
-                    )
-                return value
-            else:
-                raise DecodeError(
-                    "invalid GeneralizedTime length",
-                    klass=self.__class__,
-                )
-        raise InvalidValueType((self.__class__, datetime))
+    def _strptime_bered(self, value):
+        if len(value) < 4 + 3 * 2:
+            raise ValueError("invalid GeneralizedTime")
+        year, month, day, hour, _, _ = str_to_time_fractions(value[:10] + "0000")
+        decoded = datetime(year, month, day, hour)
+        offset, value = 0, value[10:]
+        if len(value) == 0:
+            return offset, decoded
+        if value[-1] == "Z":
+            value = value[:-1]
+        else:
+            for char, sign in (("-", -1), ("+", 1)):
+                idx = value.rfind(char)
+                if idx == -1:
+                    continue
+                offset_raw, value = value[idx + 1:].replace(":", ""), value[:idx]
+                v = pureint(offset_raw)
+                if len(offset_raw) == 4:
+                    offset, v = (60 * (v % 100)), v // 100
+                    if offset >= 3600:
+                        raise ValueError("invalid UTC offset minutes")
+                elif len(offset_raw) == 2:
+                    pass
+                else:
+                    raise ValueError("invalid UTC offset")
+                offset += 3600 * v
+                if offset > 14 * 3600:
+                    raise ValueError("too big UTC offset")
+                offset *= sign
+                break
+        if len(value) == 0:
+            return offset, decoded
+        if value[0] in DECIMAL_SIGNS:
+            return offset, (
+                decoded + timedelta(seconds=3600 * fractions2float(value[1:]))
+            )
+        if len(value) < 2:
+            raise ValueError("stripped minutes")
+        decoded += timedelta(seconds=60 * pureint(value[:2]))
+        value = value[2:]
+        if len(value) == 0:
+            return offset, decoded
+        if value[0] in DECIMAL_SIGNS:
+            return offset, (
+                decoded + timedelta(seconds=60 * fractions2float(value[1:]))
+            )
+        if len(value) < 2:
+            raise ValueError("stripped seconds")
+        decoded += timedelta(seconds=pureint(value[:2]))
+        value = value[2:]
+        if len(value) == 0:
+            return offset, decoded
+        if value[0] not in DECIMAL_SIGNS:
+            raise ValueError("invalid format after seconds")
+        return offset, (
+            decoded + timedelta(microseconds=10**6 * fractions2float(value[1:]))
+        )
 
-    def todatetime(self):
-        value = self._value.decode("ascii")
-        if len(value) == LEN_YYYYMMDDHHMMSSZ:
-            return datetime.strptime(value, self.fmt)
-        return datetime.strptime(value, self.fmt_ms)
+    def _strptime(self, value):
+        l = len(value)
+        if l == LEN_YYYYMMDDHHMMSSZ:
+            # datetime.strptime's format: %Y%m%d%H%M%SZ
+            if value[-1] != "Z":
+                raise ValueError("non UTC timezone")
+            return datetime(*str_to_time_fractions(value[:-1]))
+        if l >= LEN_YYYYMMDDHHMMSSDMZ:
+            # datetime.strptime's format: %Y%m%d%H%M%S.%fZ
+            if value[-1] != "Z":
+                raise ValueError("non UTC timezone")
+            if value[14] != ".":
+                raise ValueError("no fractions separator")
+            us = value[15:-1]
+            if us[-1] == "0":
+                raise ValueError("trailing zero")
+            us_len = len(us)
+            if us_len > 6:
+                raise ValueError("only microsecond fractions are supported")
+            us = pureint(us + ("0" * (6 - us_len)))
+            year, month, day, hour, minute, second = str_to_time_fractions(value[:14])
+            return datetime(year, month, day, hour, minute, second, us)
+        raise ValueError("invalid GeneralizedTime length")
+
+    def _encode_time(self):
+        value = self._value
+        encoded = value.strftime("%Y%m%d%H%M%S")
+        if value.microsecond > 0:
+            encoded += (".%06d" % value.microsecond).rstrip("0")
+        return (encoded + "Z").encode("ascii")
 
 
 class GraphicString(CommonString):
@@ -3597,13 +4541,6 @@ class GraphicString(CommonString):
     asn1_type_name = "GraphicString"
 
 
-class VisibleString(CommonString):
-    __slots__ = ()
-    tag_default = tag_encode(26)
-    encoding = "ascii"
-    asn1_type_name = "VisibleString"
-
-
 class ISO646String(VisibleString):
     __slots__ = ()
     asn1_type_name = "ISO646String"
@@ -3630,6 +4567,23 @@ class BMPString(CommonString):
     asn1_type_name = "BMPString"
 
 
+ChoiceState = namedtuple("ChoiceState", (
+    "version",
+    "specs",
+    "value",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
+
+
 class Choice(Obj):
     """``CHOICE`` special type
 
@@ -3691,7 +4645,7 @@ class Choice(Obj):
         if len(schema) == 0:
             raise ValueError("schema must be specified")
         self.specs = (
-            schema if isinstance(schema, OrderedDict) else OrderedDict(schema)
+            schema if schema.__class__ == OrderedDict else OrderedDict(schema)
         )
         self._value = None
         if value is not None:
@@ -3703,12 +4657,10 @@ class Choice(Obj):
             default_obj._value = default_value
             self.default = default_obj
             if value is None:
-                self._value = default_obj.copy()._value
+                self._value = copy(default_obj._value)
 
     def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
-        if isinstance(value, tuple) and len(value) == 2:
+        if (value.__class__ == tuple) and len(value) == 2:
             choice, obj = value
             spec = self.specs.get(choice)
             if spec is None:
@@ -3716,27 +4668,54 @@ class Choice(Obj):
             if not isinstance(obj, spec.__class__):
                 raise InvalidValueType((spec,))
             return (choice, spec(obj))
+        if isinstance(value, self.__class__):
+            return value._value
         raise InvalidValueType((self.__class__, tuple))
 
     @property
     def ready(self):
         return self._value is not None and self._value[1].ready
 
-    def copy(self):
-        obj = self.__class__(schema=self.specs)
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        value = self._value
-        if value is not None:
-            obj._value = (value[0], value[1].copy())
-        return obj
+    @property
+    def bered(self):
+        return self.expl_lenindef or (
+            (self._value is not None) and
+            self._value[1].bered
+        )
+
+    def __getstate__(self):
+        return ChoiceState(
+            __version__,
+            self.specs,
+            copy(self._value),
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(Choice, self).__setstate__(state)
+        self.specs = state.specs
+        self._value = state.value
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __eq__(self, their):
-        if isinstance(their, tuple) and len(their) == 2:
+        if (their.__class__ == tuple) and len(their) == 2:
             return self._value == their
         if not isinstance(their, self.__class__):
             return False
@@ -3801,7 +4780,7 @@ class Choice(Obj):
         return self._value[1].encode()
 
     def _decode(self, tlv, offset, decode_path, ctx, tag_only):
-        for choice, spec in self.specs.items():
+        for choice, spec in iteritems(self.specs):
             sub_decode_path = decode_path + (choice,)
             try:
                 spec.decode(
@@ -3811,6 +4790,7 @@ class Choice(Obj):
                     decode_path=sub_decode_path,
                     ctx=ctx,
                     tag_only=True,
+                    _ctx_immutable=False,
                 )
             except TagMismatch:
                 continue
@@ -3821,21 +4801,22 @@ class Choice(Obj):
                 decode_path=decode_path,
                 offset=offset,
             )
-        if tag_only:
-            return
+        if tag_only:  # pragma: no cover
+            return None
         value, tail = spec.decode(
             tlv,
             offset=offset,
             leavemm=True,
             decode_path=sub_decode_path,
             ctx=ctx,
+            _ctx_immutable=False,
         )
         obj = self.__class__(
             schema=self.specs,
             expl=self._expl,
             default=self.default,
             optional=self.optional,
-            _decoded=(offset, 0, value.tlvlen),
+            _decoded=(offset, 0, value.fulllen),
         )
         obj._value = (choice, value)
         return obj, tail
@@ -3848,6 +4829,7 @@ class Choice(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -3861,9 +4843,12 @@ class Choice(Obj):
             llen=self.llen,
             vlen=self.vlen,
             expl_lenindef=self.expl_lenindef,
+            bered=self.bered,
         )
         if self.ready:
             yield self.value.pps(decode_path=decode_path + (self.choice,))
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class PrimitiveTypes(Choice):
@@ -3871,9 +4856,9 @@ class PrimitiveTypes(Choice):
 
     It could be useful for general decoding of some unspecified values:
 
-    >>> PrimitiveTypes().decode(hexdec("0403666f6f"))[0].value
+    >>> PrimitiveTypes().decod(hexdec("0403666f6f")).value
     OCTET STRING 3 bytes 666f6f
-    >>> PrimitiveTypes().decode(hexdec("0203123456"))[0].value
+    >>> PrimitiveTypes().decod(hexdec("0203123456")).value
     INTEGER 1193046
     """
     __slots__ = ()
@@ -3901,6 +4886,22 @@ class PrimitiveTypes(Choice):
     ))
 
 
+AnyState = namedtuple("AnyState", (
+    "version",
+    "value",
+    "tag",
+    "expl",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+    "defined",
+), **NAMEDTUPLE_KWARGS)
+
+
 class Any(Obj):
     """``ANY`` special type
 
@@ -3935,31 +4936,58 @@ class Any(Obj):
         self.defined = None
 
     def _value_sanitize(self, value):
+        if value.__class__ == binary_type:
+            return value
         if isinstance(value, self.__class__):
             return value._value
         if isinstance(value, Obj):
             return value.encode()
-        if isinstance(value, binary_type):
-            return value
         raise InvalidValueType((self.__class__, Obj, binary_type))
 
     @property
     def ready(self):
         return self._value is not None
 
-    def copy(self):
-        obj = self.__class__()
-        obj._value = self._value
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        return obj
+    @property
+    def bered(self):
+        if self.expl_lenindef or self.lenindef:
+            return True
+        if self.defined is None:
+            return False
+        return self.defined[1].bered
+
+    def __getstate__(self):
+        return AnyState(
+            __version__,
+            self._value,
+            self.tag,
+            self._expl,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+            self.defined,
+        )
+
+    def __setstate__(self, state):
+        super(Any, self).__setstate__(state)
+        self._value = state.value
+        self.tag = state.tag
+        self._expl = state.expl
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
+        self.defined = state.defined
 
     def __eq__(self, their):
-        if isinstance(their, binary_type):
+        if their.__class__ == binary_type:
             return self._value == their
         if issubclass(their.__class__, Any):
             return self._value == their._value
@@ -4012,29 +5040,28 @@ class Any(Obj):
             llen, vlen, v = 1, 0, lv[1:]
             sub_offset = offset + tlen + llen
             chunk_i = 0
-            while True:
-                if v[:EOC_LEN].tobytes() == EOC:
-                    tlvlen = tlen + llen + vlen + EOC_LEN
-                    obj = self.__class__(
-                        value=tlv[:tlvlen].tobytes(),
-                        expl=self._expl,
-                        optional=self.optional,
-                        _decoded=(offset, 0, tlvlen),
-                    )
-                    obj.lenindef = True
-                    obj.tag = t
-                    return obj, v[EOC_LEN:]
-                else:
-                    chunk, v = Any().decode(
-                        v,
-                        offset=sub_offset,
-                        decode_path=decode_path + (str(chunk_i),),
-                        leavemm=True,
-                        ctx=ctx,
-                    )
-                    vlen += chunk.tlvlen
-                    sub_offset += chunk.tlvlen
-                    chunk_i += 1
+            while v[:EOC_LEN].tobytes() != EOC:
+                chunk, v = Any().decode(
+                    v,
+                    offset=sub_offset,
+                    decode_path=decode_path + (str(chunk_i),),
+                    leavemm=True,
+                    ctx=ctx,
+                    _ctx_immutable=False,
+                )
+                vlen += chunk.tlvlen
+                sub_offset += chunk.tlvlen
+                chunk_i += 1
+            tlvlen = tlen + llen + vlen + EOC_LEN
+            obj = self.__class__(
+                value=tlv[:tlvlen].tobytes(),
+                expl=self._expl,
+                optional=self.optional,
+                _decoded=(offset, 0, tlvlen),
+            )
+            obj.lenindef = True
+            obj.tag = t.tobytes()
+            return obj, v[EOC_LEN:]
         except DecodeError as err:
             raise err.__class__(
                 msg=err.msg,
@@ -4057,7 +5084,7 @@ class Any(Obj):
             optional=self.optional,
             _decoded=(offset, 0, tlvlen),
         )
-        obj.tag = t
+        obj.tag = t.tobytes()
         return obj, tail
 
     def __repr__(self):
@@ -4065,6 +5092,7 @@ class Any(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -4083,12 +5111,15 @@ class Any(Obj):
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
             lenindef=self.lenindef,
+            bered=self.bered,
         )
         defined_by, defined = self.defined or (None, None)
         if defined_by is not None:
             yield defined.pps(
                 decode_path=decode_path + (DecodePathDefBy(defined_by),)
             )
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 ########################################################################
@@ -4111,8 +5142,7 @@ def get_def_by_path(defines_by_path, sub_decode_path):
 def abs_decode_path(decode_path, rel_path):
     """Create an absolute decode path from current and relative ones
 
-    :param decode_path: current decode path, starting point.
-                        Tuple of strings
+    :param decode_path: current decode path, starting point. Tuple of strings
     :param rel_path: relative path to ``decode_path``. Tuple of strings.
                      If first tuple's element is "/", then treat it as
                      an absolute path, ignoring ``decode_path`` as
@@ -4134,6 +5164,23 @@ def abs_decode_path(decode_path, rel_path):
     return decode_path + rel_path
 
 
+SequenceState = namedtuple("SequenceState", (
+    "version",
+    "specs",
+    "value",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
+
+
 class Sequence(Obj):
     """``SEQUENCE`` structure type
 
@@ -4192,7 +5239,7 @@ class Sequence(Obj):
         ("algorithm", ObjectIdentifier("1.2.3")),
         ("parameters", Any(Null()))
     ))
-    AlgorithmIdentifier SEQUENCE[OBJECT IDENTIFIER 1.2.3, ANY 0500 OPTIONAL]
+    AlgorithmIdentifier SEQUENCE[algorithm: OBJECT IDENTIFIER 1.2.3; parameters: ANY 0500 OPTIONAL]
 
     You can determine if value exists/set in the sequence and take its value:
 
@@ -4213,18 +5260,14 @@ class Sequence(Obj):
 
     All defaulted values are always optional.
 
-    .. _strict_default_existence_ctx:
+    .. _allow_default_values_ctx:
 
-    .. warning::
-
-       When decoded DER contains defaulted value inside, then
-       technically this is not valid DER encoding. But we allow and pass
-       it **by default**. Of course reencoding of that kind of DER will
-       result in different binary representation (validly without
-       defaulted value inside). You can enable strict defaulted values
-       existence validation by setting ``"strict_default_existence":
-       True`` :ref:`context <ctx>` option -- decoding process will raise
-       an exception if defaulted value is met.
+    DER prohibits default value encoding and will raise an error if
+    default value is unexpectedly met during decode.
+    If :ref:`bered <bered_ctx>` context option is set, then no error
+    will be raised, but ``bered`` attribute set. You can disable strict
+    defaulted values existence validation by setting
+    ``"allow_default_values": True`` :ref:`context <ctx>` option.
 
     Two sequences are equal if they have equal specification (schema),
     implicit/explicit tagging and the same values.
@@ -4247,7 +5290,7 @@ class Sequence(Obj):
         if schema is None:
             schema = getattr(self, "schema", ())
         self.specs = (
-            schema if isinstance(schema, OrderedDict) else OrderedDict(schema)
+            schema if schema.__class__ == OrderedDict else OrderedDict(schema)
         )
         self._value = {}
         if value is not None:
@@ -4267,32 +5310,57 @@ class Sequence(Obj):
             default_obj._value = default_value
             self.default = default_obj
             if value is None:
-                self._value = default_obj.copy()._value
+                self._value = copy(default_obj._value)
 
     @property
     def ready(self):
-        for name, spec in self.specs.items():
+        for name, spec in iteritems(self.specs):
             value = self._value.get(name)
             if value is None:
                 if spec.optional:
                     continue
                 return False
-            else:
-                if not value.ready:
-                    return False
+            if not value.ready:
+                return False
         return True
 
-    def copy(self):
-        obj = self.__class__(schema=self.specs)
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        obj._value = {k: v.copy() for k, v in self._value.items()}
-        return obj
+    @property
+    def bered(self):
+        if self.expl_lenindef or self.lenindef or self.ber_encoded:
+            return True
+        return any(value.bered for value in itervalues(self._value))
+
+    def __getstate__(self):
+        return SequenceState(
+            __version__,
+            self.specs,
+            {k: copy(v) for k, v in iteritems(self._value)},
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(Sequence, self).__setstate__(state)
+        self.specs = state.specs
+        self._value = state.value
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __eq__(self, their):
         if not isinstance(their, self.__class__):
@@ -4352,7 +5420,7 @@ class Sequence(Obj):
 
     def _encoded_values(self):
         raws = []
-        for name, spec in self.specs.items():
+        for name, spec in iteritems(self.specs):
             value = self._value.get(name)
             if value is None:
                 if spec.optional:
@@ -4381,13 +5449,14 @@ class Sequence(Obj):
                 decode_path=decode_path,
                 offset=offset,
             )
-        if tag_only:
-            return
+        if tag_only:  # pragma: no cover
+            return None
         lenindef = False
+        ctx_bered = ctx.get("bered", False)
         try:
             l, llen, v = len_decode(lv)
         except LenIndefForm as err:
-            if not ctx.get("bered", False):
+            if not ctx_bered:
                 raise err.__class__(
                     msg=err.msg,
                     klass=self.__class__,
@@ -4415,7 +5484,9 @@ class Sequence(Obj):
         vlen = 0
         sub_offset = offset + tlen + llen
         values = {}
-        for name, spec in self.specs.items():
+        ber_encoded = False
+        ctx_allow_default_values = ctx.get("allow_default_values", False)
+        for name, spec in iteritems(self.specs):
             if spec.optional and (
                     (lenindef and v[:EOC_LEN].tobytes() == EOC) or
                     len(v) == 0
@@ -4429,13 +5500,14 @@ class Sequence(Obj):
                     leavemm=True,
                     decode_path=sub_decode_path,
                     ctx=ctx,
+                    _ctx_immutable=False,
                 )
-            except TagMismatch:
-                if spec.optional:
+            except TagMismatch as err:
+                if (len(err.decode_path) == len(decode_path) + 1) and spec.optional:
                     continue
                 raise
 
-            defined = get_def_by_path(ctx.get("defines", ()), sub_decode_path)
+            defined = get_def_by_path(ctx.get("_defines", ()), sub_decode_path)
             if defined is not None:
                 defined_by, defined_spec = defined
                 if issubclass(value.__class__, SequenceOf):
@@ -4453,6 +5525,7 @@ class Sequence(Obj):
                             leavemm=True,
                             decode_path=sub_sub_decode_path,
                             ctx=ctx,
+                            _ctx_immutable=False,
                         )
                         if len(defined_tail) > 0:
                             raise DecodeError(
@@ -4472,6 +5545,7 @@ class Sequence(Obj):
                         leavemm=True,
                         decode_path=sub_decode_path + (DecodePathDefBy(defined_by),),
                         ctx=ctx,
+                        _ctx_immutable=False,
                     )
                     if len(defined_tail) > 0:
                         raise DecodeError(
@@ -4482,20 +5556,20 @@ class Sequence(Obj):
                         )
                     value.defined = (defined_by, defined_value)
 
-            value_len = value.expl_tlvlen if value.expled else value.tlvlen
+            value_len = value.fulllen
             vlen += value_len
             sub_offset += value_len
             v = v_tail
             if spec.default is not None and value == spec.default:
-                if ctx.get("strict_default_existence", False):
+                if ctx_bered or ctx_allow_default_values:
+                    ber_encoded = True
+                else:
                     raise DecodeError(
                         "DEFAULT value met",
                         klass=self.__class__,
                         decode_path=sub_decode_path,
                         offset=sub_offset,
                     )
-                else:
-                    continue
             values[name] = value
 
             spec_defines = getattr(spec, "defines", ())
@@ -4507,7 +5581,7 @@ class Sequence(Obj):
                 for rel_path, schema in spec_defines:
                     defined = schema.get(value, None)
                     if defined is not None:
-                        ctx.setdefault("defines", []).append((
+                        ctx.setdefault("_defines", []).append((
                             abs_decode_path(sub_decode_path[:-1], rel_path),
                             (value, defined),
                         ))
@@ -4538,6 +5612,7 @@ class Sequence(Obj):
         )
         obj._value = values
         obj.lenindef = lenindef
+        obj.ber_encoded = ber_encoded
         return obj, tail
 
     def __repr__(self):
@@ -4547,11 +5622,12 @@ class Sequence(Obj):
             _value = self._value.get(name)
             if _value is None:
                 continue
-            cols.append(repr(_value))
-        return "%s[%s]" % (value, ", ".join(cols))
+            cols.append("%s: %s" % (name, repr(_value)))
+        return "%s[%s]" % (value, "; ".join(cols))
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -4569,18 +5645,30 @@ class Sequence(Obj):
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
             lenindef=self.lenindef,
+            ber_encoded=self.ber_encoded,
+            bered=self.bered,
         )
         for name in self.specs:
             value = self._value.get(name)
             if value is None:
                 continue
             yield value.pps(decode_path=decode_path + (name,))
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class Set(Sequence):
     """``SET`` structure type
 
     Its usage is identical to :py:class:`pyderasn.Sequence`.
+
+    .. _allow_unordered_set_ctx:
+
+    DER prohibits unordered values encoding and will raise an error
+    during decode. If If :ref:`bered <bered_ctx>` context option is set,
+    then no error will occure. Also you can disable strict values
+    ordering check by setting ``"allow_unordered_set": True``
+    :ref:`context <ctx>` option.
     """
     __slots__ = ()
     tag_default = tag_encode(form=TagFormConstructed, num=17)
@@ -4592,6 +5680,9 @@ class Set(Sequence):
         v = b"".join(raws)
         return b"".join((self.tag, len_encode(len(v)), v))
 
+    def _specs_items(self):
+        return iteritems(self.specs)
+
     def _decode(self, tlv, offset, decode_path, ctx, tag_only):
         try:
             t, tlen, lv = tag_strip(tlv)
@@ -4609,12 +5700,13 @@ class Set(Sequence):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         lenindef = False
+        ctx_bered = ctx.get("bered", False)
         try:
             l, llen, v = len_decode(lv)
         except LenIndefForm as err:
-            if not ctx.get("bered", False):
+            if not ctx_bered:
                 raise err.__class__(
                     msg=err.msg,
                     klass=self.__class__,
@@ -4641,11 +5733,15 @@ class Set(Sequence):
         vlen = 0
         sub_offset = offset + tlen + llen
         values = {}
-        specs_items = self.specs.items
+        ber_encoded = False
+        ctx_allow_default_values = ctx.get("allow_default_values", False)
+        ctx_allow_unordered_set = ctx.get("allow_unordered_set", False)
+        value_prev = memoryview(v[:0])
+
         while len(v) > 0:
             if lenindef and v[:EOC_LEN].tobytes() == EOC:
                 break
-            for name, spec in specs_items():
+            for name, spec in self._specs_items():
                 sub_decode_path = decode_path + (name,)
                 try:
                     spec.decode(
@@ -4655,6 +5751,7 @@ class Set(Sequence):
                         decode_path=sub_decode_path,
                         ctx=ctx,
                         tag_only=True,
+                        _ctx_immutable=False,
                     )
                 except TagMismatch:
                     continue
@@ -4671,14 +5768,35 @@ class Set(Sequence):
                 leavemm=True,
                 decode_path=sub_decode_path,
                 ctx=ctx,
+                _ctx_immutable=False,
             )
-            value_len = value.expl_tlvlen if value.expled else value.tlvlen
+            value_len = value.fulllen
+            if value_prev.tobytes() > v[:value_len].tobytes():
+                if ctx_bered or ctx_allow_unordered_set:
+                    ber_encoded = True
+                else:
+                    raise DecodeError(
+                        "unordered " + self.asn1_type_name,
+                        klass=self.__class__,
+                        decode_path=sub_decode_path,
+                        offset=sub_offset,
+                    )
+            if spec.default is None or value != spec.default:
+                pass
+            elif ctx_bered or ctx_allow_default_values:
+                ber_encoded = True
+            else:
+                raise DecodeError(
+                    "DEFAULT value met",
+                    klass=self.__class__,
+                    decode_path=sub_decode_path,
+                    offset=sub_offset,
+                )
+            values[name] = value
+            value_prev = v[:value_len]
             sub_offset += value_len
             vlen += value_len
             v = v_tail
-            if spec.default is None or value != spec.default:  # pragma: no cover
-                # SeqMixing.test_encoded_default_accepted covers that place
-                values[name] = value
         obj = self.__class__(
             schema=self.specs,
             impl=self.tag,
@@ -4687,16 +5805,46 @@ class Set(Sequence):
             optional=self.optional,
             _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
         )
+        if lenindef:
+            if v[:EOC_LEN].tobytes() != EOC:
+                raise DecodeError(
+                    "no EOC",
+                    klass=self.__class__,
+                    decode_path=decode_path,
+                    offset=offset,
+                )
+            tail = v[EOC_LEN:]
+            obj.lenindef = True
         obj._value = values
-        if not obj.ready:
-            raise DecodeError(
-                msg="not all values are ready",
-                klass=self.__class__,
-                decode_path=decode_path,
-                offset=offset,
-            )
-        obj.lenindef = lenindef
-        return obj, (v[EOC_LEN:] if lenindef else tail)
+        for name, spec in iteritems(self.specs):
+            if name not in values and not spec.optional:
+                raise DecodeError(
+                    "%s value is not ready" % name,
+                    klass=self.__class__,
+                    decode_path=decode_path,
+                    offset=offset,
+                )
+        obj.ber_encoded = ber_encoded
+        return obj, tail
+
+
+SequenceOfState = namedtuple("SequenceOfState", (
+    "version",
+    "spec",
+    "value",
+    "bound_min",
+    "bound_max",
+    "tag",
+    "expl",
+    "default",
+    "optional",
+    "offset",
+    "llen",
+    "vlen",
+    "expl_lenindef",
+    "lenindef",
+    "ber_encoded",
+), **NAMEDTUPLE_KWARGS)
 
 
 class SequenceOf(Obj):
@@ -4744,13 +5892,7 @@ class SequenceOf(Obj):
             optional=False,
             _decoded=(0, 0, 0),
     ):
-        super(SequenceOf, self).__init__(
-            impl,
-            expl,
-            default,
-            optional,
-            _decoded,
-        )
+        super(SequenceOf, self).__init__(impl, expl, default, optional, _decoded)
         if schema is None:
             schema = getattr(self, "schema", None)
         if schema is None:
@@ -4774,7 +5916,7 @@ class SequenceOf(Obj):
             default_obj._value = default_value
             self.default = default_obj
             if value is None:
-                self._value = default_obj.copy()._value
+                self._value = copy(default_obj._value)
 
     def _value_sanitize(self, value):
         if issubclass(value.__class__, SequenceOf):
@@ -4794,19 +5936,47 @@ class SequenceOf(Obj):
     def ready(self):
         return all(v.ready for v in self._value)
 
-    def copy(self):
-        obj = self.__class__(schema=self.spec)
-        obj._bound_min = self._bound_min
-        obj._bound_max = self._bound_max
-        obj.tag = self.tag
-        obj._expl = self._expl
-        obj.default = self.default
-        obj.optional = self.optional
-        obj.offset = self.offset
-        obj.llen = self.llen
-        obj.vlen = self.vlen
-        obj._value = [v.copy() for v in self._value]
-        return obj
+    @property
+    def bered(self):
+        if self.expl_lenindef or self.lenindef or self.ber_encoded:
+            return True
+        return any(v.bered for v in self._value)
+
+    def __getstate__(self):
+        return SequenceOfState(
+            __version__,
+            self.spec,
+            [copy(v) for v in self._value],
+            self._bound_min,
+            self._bound_max,
+            self.tag,
+            self._expl,
+            self.default,
+            self.optional,
+            self.offset,
+            self.llen,
+            self.vlen,
+            self.expl_lenindef,
+            self.lenindef,
+            self.ber_encoded,
+        )
+
+    def __setstate__(self, state):
+        super(SequenceOf, self).__setstate__(state)
+        self.spec = state.spec
+        self._value = state.value
+        self._bound_min = state.bound_min
+        self._bound_max = state.bound_max
+        self.tag = state.tag
+        self._expl = state.expl
+        self.default = state.default
+        self.optional = state.optional
+        self.offset = state.offset
+        self.llen = state.llen
+        self.vlen = state.vlen
+        self.expl_lenindef = state.expl_lenindef
+        self.lenindef = state.lenindef
+        self.ber_encoded = state.ber_encoded
 
     def __eq__(self, their):
         if isinstance(their, self.__class__):
@@ -4879,7 +6049,7 @@ class SequenceOf(Obj):
         v = b"".join(self._encoded_values())
         return b"".join((self.tag, len_encode(len(v)), v))
 
-    def _decode(self, tlv, offset, decode_path, ctx, tag_only):
+    def _decode(self, tlv, offset, decode_path, ctx, tag_only, ordering_check=False):
         try:
             t, tlen, lv = tag_strip(tlv)
         except DecodeError as err:
@@ -4896,12 +6066,13 @@ class SequenceOf(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         lenindef = False
+        ctx_bered = ctx.get("bered", False)
         try:
             l, llen, v = len_decode(lv)
         except LenIndefForm as err:
-            if not ctx.get("bered", False):
+            if not ctx_bered:
                 raise err.__class__(
                     msg=err.msg,
                     klass=self.__class__,
@@ -4929,34 +6100,69 @@ class SequenceOf(Obj):
         vlen = 0
         sub_offset = offset + tlen + llen
         _value = []
+        ctx_allow_unordered_set = ctx.get("allow_unordered_set", False)
+        value_prev = memoryview(v[:0])
+        ber_encoded = False
         spec = self.spec
         while len(v) > 0:
             if lenindef and v[:EOC_LEN].tobytes() == EOC:
                 break
+            sub_decode_path = decode_path + (str(len(_value)),)
             value, v_tail = spec.decode(
                 v,
                 sub_offset,
                 leavemm=True,
-                decode_path=decode_path + (str(len(_value)),),
+                decode_path=sub_decode_path,
                 ctx=ctx,
+                _ctx_immutable=False,
             )
-            value_len = value.expl_tlvlen if value.expled else value.tlvlen
+            value_len = value.fulllen
+            if ordering_check:
+                if value_prev.tobytes() > v[:value_len].tobytes():
+                    if ctx_bered or ctx_allow_unordered_set:
+                        ber_encoded = True
+                    else:
+                        raise DecodeError(
+                            "unordered " + self.asn1_type_name,
+                            klass=self.__class__,
+                            decode_path=sub_decode_path,
+                            offset=sub_offset,
+                        )
+                value_prev = v[:value_len]
+            _value.append(value)
             sub_offset += value_len
             vlen += value_len
             v = v_tail
-            _value.append(value)
-        obj = self.__class__(
-            value=_value,
-            schema=spec,
-            bounds=(self._bound_min, self._bound_max),
-            impl=self.tag,
-            expl=self._expl,
-            default=self.default,
-            optional=self.optional,
-            _decoded=(offset, llen, vlen),
-        )
-        obj.lenindef = lenindef
-        return obj, (v[EOC_LEN:] if lenindef else tail)
+        try:
+            obj = self.__class__(
+                value=_value,
+                schema=spec,
+                bounds=(self._bound_min, self._bound_max),
+                impl=self.tag,
+                expl=self._expl,
+                default=self.default,
+                optional=self.optional,
+                _decoded=(offset, llen, vlen + (EOC_LEN if lenindef else 0)),
+            )
+        except BoundsError as err:
+            raise DecodeError(
+                msg=str(err),
+                klass=self.__class__,
+                decode_path=decode_path,
+                offset=offset,
+            )
+        if lenindef:
+            if v[:EOC_LEN].tobytes() != EOC:
+                raise DecodeError(
+                    "no EOC",
+                    klass=self.__class__,
+                    decode_path=decode_path,
+                    offset=offset,
+                )
+            obj.lenindef = True
+            tail = v[EOC_LEN:]
+        obj.ber_encoded = ber_encoded
+        return obj, tail
 
     def __repr__(self):
         return "%s[%s]" % (
@@ -4966,6 +6172,7 @@ class SequenceOf(Obj):
 
     def pps(self, decode_path=()):
         yield _pp(
+            obj=self,
             asn1_type_name=self.asn1_type_name,
             obj_name=self.__class__.__name__,
             decode_path=decode_path,
@@ -4983,9 +6190,13 @@ class SequenceOf(Obj):
             expl_vlen=self.expl_vlen if self.expled else None,
             expl_lenindef=self.expl_lenindef,
             lenindef=self.lenindef,
+            ber_encoded=self.ber_encoded,
+            bered=self.bered,
         )
         for i, value in enumerate(self._value):
             yield value.pps(decode_path=decode_path + (str(i),))
+        for pp in self.pps_lenindef(decode_path):
+            yield pp
 
 
 class SetOf(SequenceOf):
@@ -5003,6 +6214,16 @@ class SetOf(SequenceOf):
         v = b"".join(raws)
         return b"".join((self.tag, len_encode(len(v)), v))
 
+    def _decode(self, tlv, offset, decode_path, ctx, tag_only):
+        return super(SetOf, self)._decode(
+            tlv,
+            offset,
+            decode_path,
+            ctx,
+            tag_only,
+            ordering_check=True,
+        )
+
 
 def obj_by_path(pypath):  # pragma: no cover
     """Import object specified as string Python path
@@ -5027,7 +6248,7 @@ def generic_decoder():  # pragma: no cover
     choice = PrimitiveTypes()
     choice.specs["SequenceOf"] = SequenceOf(schema=choice)
     choice.specs["SetOf"] = SetOf(schema=choice)
-    for i in range(31):
+    for i in six_xrange(31):
         choice.specs["SequenceOf%d" % i] = SequenceOf(
             schema=choice,
             expl=tag_ctxc(i),
@@ -5039,10 +6260,21 @@ def generic_decoder():  # pragma: no cover
         __slots__ = ()
         schema = choice
 
-    def pprint_any(obj, oids=None, with_colours=False):
+    def pprint_any(
+            obj,
+            oid_maps=(),
+            with_colours=False,
+            with_decode_path=False,
+            decode_path_only=(),
+    ):
         def _pprint_pps(pps):
             for pp in pps:
                 if hasattr(pp, "_fields"):
+                    if (
+                            decode_path_only != () and
+                            pp.decode_path[:len(decode_path_only)] != decode_path_only
+                    ):
+                        continue
                     if pp.asn1_type_name == Choice.asn1_type_name:
                         continue
                     pp_kwargs = pp._asdict()
@@ -5050,12 +6282,17 @@ def generic_decoder():  # pragma: no cover
                     pp = _pp(**pp_kwargs)
                     yield pp_console_row(
                         pp,
-                        oids=oids,
+                        oid_maps=oid_maps,
                         with_offsets=True,
                         with_blob=False,
                         with_colours=with_colours,
+                        with_decode_path=with_decode_path,
+                        decode_path_len_decrease=len(decode_path_only),
                     )
-                    for row in pp_console_blob(pp):
+                    for row in pp_console_blob(
+                            pp,
+                            decode_path_len_decrease=len(decode_path_only),
+                    ):
                         yield row
                 else:
                     for row in _pprint_pps(pp):
@@ -5075,7 +6312,7 @@ def main():  # pragma: no cover
     )
     parser.add_argument(
         "--oids",
-        help="Python path to dictionary with OIDs",
+        help="Python paths to dictionary with OIDs, comma separated",
     )
     parser.add_argument(
         "--schema",
@@ -5087,9 +6324,23 @@ def main():  # pragma: no cover
     )
     parser.add_argument(
         "--nobered",
-        action='store_true',
+        action="store_true",
         help="Disallow BER encoding",
     )
+    parser.add_argument(
+        "--print-decode-path",
+        action="store_true",
+        help="Print decode paths",
+    )
+    parser.add_argument(
+        "--decode-path-only",
+        help="Print only specified decode path",
+    )
+    parser.add_argument(
+        "--allow-expl-oob",
+        action="store_true",
+        help="Allow explicit tag out-of-bound",
+    )
     parser.add_argument(
         "DERFile",
         type=argparse.FileType("rb"),
@@ -5099,21 +6350,32 @@ def main():  # pragma: no cover
     args.DERFile.seek(args.skip)
     der = memoryview(args.DERFile.read())
     args.DERFile.close()
-    oids = obj_by_path(args.oids) if args.oids else {}
+    oid_maps = (
+        [obj_by_path(_path) for _path in (args.oids or "").split(",")]
+        if args.oids else ()
+    )
     if args.schema:
         schema = obj_by_path(args.schema)
         from functools import partial
         pprinter = partial(pprint, big_blobs=True)
     else:
         schema, pprinter = generic_decoder()
-    ctx = {"bered": not args.nobered}
+    ctx = {
+        "bered": not args.nobered,
+        "allow_expl_oob": args.allow_expl_oob,
+    }
     if args.defines_by_path is not None:
         ctx["defines_by_path"] = obj_by_path(args.defines_by_path)
     obj, tail = schema().decode(der, ctx=ctx)
     print(pprinter(
         obj,
-        oids=oids,
-        with_colours=True if environ.get("NO_COLOR") is None else False,
+        oid_maps=oid_maps,
+        with_colours=environ.get("NO_COLOR") is None,
+        with_decode_path=args.print_decode_path,
+        decode_path_only=(
+            () if args.decode_path_only is None else
+            tuple(args.decode_path_only.split(":"))
+        ),
     ))
     if tail != b"":
         print("\nTrailing data: %s" % hexenc(tail))