1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
#
# This file is part of pyasn1 software.
#
# Copyright (c) 2005-2019, Ilya Etingof <etingof@gmail.com>
# License: http://snmplabs.com/pyasn1/license.html
#
from pyasn1 import debug
from pyasn1 import error
from pyasn1.type import base
from pyasn1.type import char
from pyasn1.type import tag
from pyasn1.type import univ
from pyasn1.type import useful
__all__ = ['decode']
LOG = debug.registerLoggee(__name__, flags=debug.DEBUG_DECODER)
class AbstractScalarPayloadDecoder(object):
def __call__(self, pyObject, asn1Spec, decodeFun=None, **options):
return asn1Spec.clone(pyObject)
class BitStringPayloadDecoder(AbstractScalarPayloadDecoder):
def __call__(self, pyObject, asn1Spec, decodeFun=None, **options):
return asn1Spec.clone(univ.BitString.fromBinaryString(pyObject))
class SequenceOrSetPayloadDecoder(object):
def __call__(self, pyObject, asn1Spec, decodeFun=None, **options):
asn1Value = asn1Spec.clone()
componentsTypes = asn1Spec.componentType
for field in asn1Value:
if field in pyObject:
asn1Value[field] = decodeFun(pyObject[field], componentsTypes[field].asn1Object, **options)
return asn1Value
class SequenceOfOrSetOfPayloadDecoder(object):
def __call__(self, pyObject, asn1Spec, decodeFun=None, **options):
asn1Value = asn1Spec.clone()
for pyValue in pyObject:
asn1Value.append(decodeFun(pyValue, asn1Spec.componentType), **options)
return asn1Value
class ChoicePayloadDecoder(object):
def __call__(self, pyObject, asn1Spec, decodeFun=None, **options):
asn1Value = asn1Spec.clone()
componentsTypes = asn1Spec.componentType
for field in pyObject:
if field in componentsTypes:
asn1Value[field] = decodeFun(pyObject[field], componentsTypes[field].asn1Object, **options)
break
return asn1Value
TAG_MAP = {
univ.Integer.tagSet: AbstractScalarPayloadDecoder(),
univ.Boolean.tagSet: AbstractScalarPayloadDecoder(),
univ.BitString.tagSet: BitStringPayloadDecoder(),
univ.OctetString.tagSet: AbstractScalarPayloadDecoder(),
univ.Null.tagSet: AbstractScalarPayloadDecoder(),
univ.ObjectIdentifier.tagSet: AbstractScalarPayloadDecoder(),
univ.Enumerated.tagSet: AbstractScalarPayloadDecoder(),
univ.Real.tagSet: AbstractScalarPayloadDecoder(),
univ.Sequence.tagSet: SequenceOrSetPayloadDecoder(), # conflicts with SequenceOf
univ.Set.tagSet: SequenceOrSetPayloadDecoder(), # conflicts with SetOf
univ.Choice.tagSet: ChoicePayloadDecoder(), # conflicts with Any
# character string types
char.UTF8String.tagSet: AbstractScalarPayloadDecoder(),
char.NumericString.tagSet: AbstractScalarPayloadDecoder(),
char.PrintableString.tagSet: AbstractScalarPayloadDecoder(),
char.TeletexString.tagSet: AbstractScalarPayloadDecoder(),
char.VideotexString.tagSet: AbstractScalarPayloadDecoder(),
char.IA5String.tagSet: AbstractScalarPayloadDecoder(),
char.GraphicString.tagSet: AbstractScalarPayloadDecoder(),
char.VisibleString.tagSet: AbstractScalarPayloadDecoder(),
char.GeneralString.tagSet: AbstractScalarPayloadDecoder(),
char.UniversalString.tagSet: AbstractScalarPayloadDecoder(),
char.BMPString.tagSet: AbstractScalarPayloadDecoder(),
# useful types
useful.ObjectDescriptor.tagSet: AbstractScalarPayloadDecoder(),
useful.GeneralizedTime.tagSet: AbstractScalarPayloadDecoder(),
useful.UTCTime.tagSet: AbstractScalarPayloadDecoder()
}
# Put in ambiguous & non-ambiguous types for faster codec lookup
TYPE_MAP = {
univ.Integer.typeId: AbstractScalarPayloadDecoder(),
univ.Boolean.typeId: AbstractScalarPayloadDecoder(),
univ.BitString.typeId: BitStringPayloadDecoder(),
univ.OctetString.typeId: AbstractScalarPayloadDecoder(),
univ.Null.typeId: AbstractScalarPayloadDecoder(),
univ.ObjectIdentifier.typeId: AbstractScalarPayloadDecoder(),
univ.Enumerated.typeId: AbstractScalarPayloadDecoder(),
univ.Real.typeId: AbstractScalarPayloadDecoder(),
# ambiguous base types
univ.Set.typeId: SequenceOrSetPayloadDecoder(),
univ.SetOf.typeId: SequenceOfOrSetOfPayloadDecoder(),
univ.Sequence.typeId: SequenceOrSetPayloadDecoder(),
univ.SequenceOf.typeId: SequenceOfOrSetOfPayloadDecoder(),
univ.Choice.typeId: ChoicePayloadDecoder(),
univ.Any.typeId: AbstractScalarPayloadDecoder(),
# character string types
char.UTF8String.typeId: AbstractScalarPayloadDecoder(),
char.NumericString.typeId: AbstractScalarPayloadDecoder(),
char.PrintableString.typeId: AbstractScalarPayloadDecoder(),
char.TeletexString.typeId: AbstractScalarPayloadDecoder(),
char.VideotexString.typeId: AbstractScalarPayloadDecoder(),
char.IA5String.typeId: AbstractScalarPayloadDecoder(),
char.GraphicString.typeId: AbstractScalarPayloadDecoder(),
char.VisibleString.typeId: AbstractScalarPayloadDecoder(),
char.GeneralString.typeId: AbstractScalarPayloadDecoder(),
char.UniversalString.typeId: AbstractScalarPayloadDecoder(),
char.BMPString.typeId: AbstractScalarPayloadDecoder(),
# useful types
useful.ObjectDescriptor.typeId: AbstractScalarPayloadDecoder(),
useful.GeneralizedTime.typeId: AbstractScalarPayloadDecoder(),
useful.UTCTime.typeId: AbstractScalarPayloadDecoder()
}
class SingleItemDecoder(object):
TAG_MAP = TAG_MAP
TYPE_MAP = TYPE_MAP
def __init__(self, tagMap=None, typeMap=None):
self.__tagMap = tagMap or self.TAG_MAP
self.__typeMap = typeMap or self.TYPE_MAP
def __call__(self, pyObject, asn1Spec, **options):
if LOG:
debug.scope.push(type(pyObject).__name__)
LOG('decoder called at scope %s, working with '
'type %s' % (debug.scope, type(pyObject).__name__))
if asn1Spec is None or not isinstance(asn1Spec, base.Asn1Item):
raise error.PyAsn1Error(
'asn1Spec is not valid (should be an instance of an ASN.1 '
'Item, not %s)' % asn1Spec.__class__.__name__)
try:
valueDecoder = self.__typeMap[asn1Spec.typeId]
except KeyError:
# use base type for codec lookup to recover untagged types
baseTagSet = tag.TagSet(asn1Spec.tagSet.baseTag, asn1Spec.tagSet.baseTag)
try:
valueDecoder = self.__tagMap[baseTagSet]
except KeyError:
raise error.PyAsn1Error('Unknown ASN.1 tag %s' % asn1Spec.tagSet)
if LOG:
LOG('calling decoder %s on Python type %s '
'<%s>' % (type(valueDecoder).__name__,
type(pyObject).__name__, repr(pyObject)))
value = valueDecoder(pyObject, asn1Spec, self, **options)
if LOG:
LOG('decoder %s produced ASN.1 type %s '
'<%s>' % (type(valueDecoder).__name__,
type(value).__name__, repr(value)))
debug.scope.pop()
return value
class Decoder(object):
SINGLE_ITEM_DECODER = SingleItemDecoder
@classmethod
def __call__(cls, pyObject, asn1Spec=None, **kwargs):
singleItemDecoder = cls.SINGLE_ITEM_DECODER()
return singleItemDecoder(pyObject, asn1Spec=asn1Spec, **kwargs)
#: Turns Python objects of built-in types into ASN.1 objects.
#:
#: Takes Python objects of built-in types and turns them into a tree of
#: ASN.1 objects (e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative) which
#: may be a scalar or an arbitrary nested structure.
#:
#: Parameters
#: ----------
#: pyObject: :py:class:`object`
#: A scalar or nested Python objects
#:
#: Keyword Args
#: ------------
#: asn1Spec: any pyasn1 type object e.g. :py:class:`~pyasn1.type.base.PyAsn1Item` derivative
#: A pyasn1 type object to act as a template guiding the decoder. It is required
#: for successful interpretation of Python objects mapping into their ASN.1
#: representations.
#:
#: Returns
#: -------
#: : :py:class:`~pyasn1.type.base.PyAsn1Item` derivative
#: A scalar or constructed pyasn1 object
#:
#: Raises
#: ------
#: ~pyasn1.error.PyAsn1Error
#: On decoding errors
#:
#: Examples
#: --------
#: Decode native Python object into ASN.1 objects with ASN.1 schema
#:
#: .. code-block:: pycon
#:
#: >>> seq = SequenceOf(componentType=Integer())
#: >>> s, _ = decode([1, 2, 3], asn1Spec=seq)
#: >>> str(s)
#: SequenceOf:
#: 1 2 3
#:
decode = Decoder()
|
