X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=pyderasn.py;h=2972db70407fe7ce715f8e1cd47ddf687c360d6b;hb=418137a7bd197ebebad6414665963eabfe006ff4;hp=e8e200c69196820912b314f0fa7e84844eeb47d0;hpb=597f028b5d602b4af53830ac682078aa5fb59e38;p=pyderasn.git

diff --git a/pyderasn.py b/pyderasn.py
index e8e200c..2972db7 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # coding: utf-8
 # PyDERASN -- Python ASN.1 DER/BER codec with abstract structures
-# Copyright (C) 2017-2019 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
@@ -517,6 +517,11 @@ lengths will be invalid in that case.
    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
 ---------------
 
@@ -626,10 +631,10 @@ Various
 .. 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
@@ -650,6 +655,7 @@ 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
@@ -673,6 +679,7 @@ except ImportError:  # pragma: no cover
     def colored(what, *args, **kwargs):
         return what
 
+__version__ = "5.6"
 
 __all__ = (
     "Any",
@@ -684,6 +691,7 @@ __all__ = (
     "DecodeError",
     "DecodePathDefBy",
     "Enumerated",
+    "ExceedingData",
     "GeneralizedTime",
     "GeneralString",
     "GraphicString",
@@ -794,6 +802,18 @@ 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
 
@@ -1019,9 +1039,9 @@ 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)
@@ -1095,10 +1115,14 @@ class Obj(object):
 
     @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
@@ -1123,6 +1147,10 @@ class Obj(object):
         raise NotImplementedError()
 
     def encode(self):
+        """Encode the structure
+
+        :returns: DER representation
+        """
         raw = self._encode()
         if self._expl is None:
             return raw
@@ -1150,6 +1178,8 @@ class Obj(object):
                          determine if tag satisfies the scheme)
         :param _ctx_immutable: do we need to copy ``ctx`` before using it
         :returns: (Obj, remaining data)
+
+        .. seealso:: :ref:`decoding`
         """
         if ctx is None:
             ctx = {}
@@ -1165,7 +1195,7 @@ class Obj(object):
                 tag_only=tag_only,
             )
             if tag_only:
-                return
+                return None
             obj, tail = result
         else:
             try:
@@ -1203,7 +1233,7 @@ class Obj(object):
                     tag_only=tag_only,
                 )
                 if tag_only:  # pragma: no cover
-                    return
+                    return None
                 obj, tail = result
                 eoc_expected, tail = tail[:EOC_LEN], tail[EOC_LEN:]
                 if eoc_expected.tobytes() != EOC:
@@ -1238,7 +1268,7 @@ class Obj(object):
                     tag_only=tag_only,
                 )
                 if tag_only:  # pragma: no cover
-                    return
+                    return None
                 obj, tail = result
                 if obj.tlvlen < l and not ctx.get("allow_expl_oob", False):
                     raise DecodeError(
@@ -1249,42 +1279,80 @@ class Obj(object):
                     )
         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
+
     @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):
@@ -1747,7 +1815,7 @@ class Boolean(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         try:
             l, _, v = len_decode(lv)
         except DecodeError as err:
@@ -1977,6 +2045,7 @@ class Integer(Obj):
         for name, value in iteritems(self.specs):
             if value == self._value:
                 return name
+        return None
 
     def __call__(
             self,
@@ -2056,7 +2125,7 @@ class Integer(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -2276,7 +2345,7 @@ class BitString(Obj):
                     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,
@@ -2284,8 +2353,7 @@ class BitString(Obj):
                     )
             if isinstance(value, binary_type):
                 return (len(value) * 8, value)
-            else:
-                raise InvalidValueType((self.__class__, string_types, binary_type))
+            raise InvalidValueType((self.__class__, string_types, binary_type))
         if isinstance(value, tuple):
             if (
                     len(value) == 2 and
@@ -2404,7 +2472,7 @@ class BitString(Obj):
             octets,
         ))
 
-    def _decode_chunk(self, lv, offset, decode_path, ctx):
+    def _decode_chunk(self, lv, offset, decode_path):
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -2474,8 +2542,8 @@ class BitString(Obj):
             )
         if t == self.tag:
             if tag_only:  # pragma: no cover
-                return
-            return self._decode_chunk(lv, offset, decode_path, ctx)
+                return None
+            return self._decode_chunk(lv, offset, decode_path)
         if t == self.tag_constructed:
             if not ctx.get("bered", False):
                 raise DecodeError(
@@ -2485,7 +2553,7 @@ class BitString(Obj):
                     offset=offset,
                 )
             if tag_only:  # pragma: no cover
-                return
+                return None
             lenindef = False
             try:
                 l, llen, v = len_decode(lv)
@@ -2683,13 +2751,7 @@ 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,
@@ -2794,7 +2856,7 @@ class OctetString(Obj):
             self._value,
         ))
 
-    def _decode_chunk(self, lv, offset, decode_path, ctx):
+    def _decode_chunk(self, lv, offset, decode_path):
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -2850,8 +2912,8 @@ class OctetString(Obj):
             )
         if t == self.tag:
             if tag_only:
-                return
-            return self._decode_chunk(lv, offset, decode_path, ctx)
+                return None
+            return self._decode_chunk(lv, offset, decode_path)
         if t == self.tag_constructed:
             if not ctx.get("bered", False):
                 raise DecodeError(
@@ -2861,7 +2923,7 @@ class OctetString(Obj):
                     offset=offset,
                 )
             if tag_only:
-                return
+                return None
             lenindef = False
             try:
                 l, llen, v = len_decode(lv)
@@ -3077,7 +3139,7 @@ class Null(Obj):
                 offset=offset,
             )
         if tag_only:  # pragma: no cover
-            return
+            return None
         try:
             l, _, v = len_decode(lv)
         except DecodeError as err:
@@ -3179,13 +3241,7 @@ 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)
@@ -3332,7 +3388,7 @@ class ObjectIdentifier(Obj):
                 offset=offset,
             )
         if tag_only:  # pragma: no cover
-            return
+            return None
         try:
             l, llen, v = len_decode(lv)
         except DecodeError as err:
@@ -3456,13 +3512,7 @@ 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")
@@ -3523,6 +3573,12 @@ class Enumerated(Integer):
         )
 
 
+def escape_control_unicode(c):
+    if unicat(c).startswith("C"):
+        c = repr(c).lstrip("u").strip("'")
+    return c
+
+
 class CommonString(OctetString):
     """Common class for all strings
 
@@ -3641,7 +3697,10 @@ 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,
@@ -3801,11 +3860,7 @@ 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, default, optional, _decoded,
         )
         self._value = value
         if value is not None:
@@ -4250,7 +4305,7 @@ class Choice(Obj):
                 offset=offset,
             )
         if tag_only:  # pragma: no cover
-            return
+            return None
         value, tail = spec.decode(
             tlv,
             offset=offset,
@@ -4719,9 +4774,8 @@ class Sequence(Obj):
                 if spec.optional:
                     continue
                 return False
-            else:
-                if not value.ready:
-                    return False
+            if not value.ready:
+                return False
         return True
 
     @property
@@ -4833,7 +4887,7 @@ class Sequence(Obj):
                 offset=offset,
             )
         if tag_only:  # pragma: no cover
-            return
+            return None
         lenindef = False
         ctx_bered = ctx.get("bered", False)
         try:
@@ -5083,7 +5137,7 @@ class Set(Sequence):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         lenindef = False
         ctx_bered = ctx.get("bered", False)
         try:
@@ -5255,13 +5309,7 @@ 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:
@@ -5416,7 +5464,7 @@ class SequenceOf(Obj):
                 offset=offset,
             )
         if tag_only:
-            return
+            return None
         lenindef = False
         ctx_bered = ctx.get("bered", False)
         try:
@@ -5720,7 +5768,7 @@ def main():  # pragma: no cover
     print(pprinter(
         obj,
         oid_maps=oid_maps,
-        with_colours=True if environ.get("NO_COLOR") is None else False,
+        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