catch inappropriate substrate type passed to decoder

4 files changed, 9 insertions, 3 deletions

diff --git a/CHANGES b/CHANGES
index 3d75f97..8a1fdbe 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,7 +4,8 @@ Revision 0.1.4
 - built-in codec debugging facility added
 - Added some more checks to ObjectIdentifier BER encoder catching
   posible 2^8 overflow condition by two leading sub-OIDs
-- Fix in Boolean truth testting built-in methods
+- Catch inappropriate substrate type passed to decoder.
+- Fix in Boolean truth testing built-in methods
 - Fix to substrate underrun error handling at ObjectIdentifier BER decoder
 - Fix to BER Boolean decoder that allows other pre-computed
   values besides 0 and 1
diff --git a/pyasn1/codec/ber/decoder.py b/pyasn1/codec/ber/decoder.py
index db3e00a..bc4ae43 100644
--- a/pyasn1/codec/ber/decoder.py
+++ b/pyasn1/codec/ber/decoder.py
@@ -1,7 +1,7 @@
 # BER decoder
 from pyasn1.type import tag, base, univ, char, useful, tagmap
 from pyasn1.codec.ber import eoo
-from pyasn1.compat.octets import oct2int, octs2ints
+from pyasn1.compat.octets import oct2int, octs2ints, isOctetsType
 from pyasn1 import debug, error
 
 class AbstractDecoder:
@@ -547,6 +547,9 @@ class Decoder:
                     raise error.SubstrateUnderrunError(
                         'Short octet stream on tag decoding'
                         )
+                if not isOctetsType(substrate) and \
+                   not isinstance(substrate, univ.OctetString):
+                    raise error.PyAsn1Error('Bad octet stream type')
                 
                 firstOctet = substrate[0]
                 substrate = substrate[1:]
diff --git a/pyasn1/compat/octets.py b/pyasn1/compat/octets.py
index d0303ea..f7f2a29 100644
--- a/pyasn1/compat/octets.py
+++ b/pyasn1/compat/octets.py
@@ -8,6 +8,7 @@ if version_info[0] <= 2:
     octs2ints = lambda s: [ oct2int(x) for x in s ]
     str2octs = lambda x: x
     octs2str = lambda x: x
+    isOctetsType = lambda s: isinstance(s, str)
 else:
     ints2octs = bytes
     int2oct = lambda x: ints2octs((x,))
@@ -16,3 +17,4 @@ else:
     octs2ints = lambda s: [ x for x in s ]
     str2octs = lambda x: x.encode()
     octs2str = lambda x: x.decode()
+    isOctetsType = lambda s: isinstance(s, bytes)
diff --git a/setup.py b/setup.py
index 74c8b0a..0c522e6 100644
--- a/setup.py
+++ b/setup.py
@@ -25,7 +25,7 @@ except ImportError:
 
 params.update( {
     'name': 'pyasn1',
-    'version': '0.1.4',
+    'version': '0.1.4rc0',
     'description': 'ASN.1 types and codecs',
     'author': 'Ilya Etingof',
     'author_email': 'ilya@glas.net',