From: Sergey Matveev <stargrave@stargrave.org>
Date: Sun, 20 May 2018 13:21:53 +0000 (+0300)
Subject: Note about BIT/OCTET STRING primitive/constructed encodings
X-Git-Tag: 3.7~5
X-Git-Url: http://www.git.cypherpunks.ru/?p=pyderasn.git;a=commitdiff_plain;h=9f6b6bbcf30cbbb605caa846d7d3de10615802f4

Note about BIT/OCTET STRING primitive/constructed encodings
---

diff --git a/pyderasn.py b/pyderasn.py
index b28792c..ee39e57 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -1927,6 +1927,14 @@ 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)
@@ -2357,6 +2365,14 @@ 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)