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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
|
## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license
"""
ASN.1 (Abstract Syntax Notation One)
"""
import random
from scapy.config import conf
from scapy.error import Scapy_Exception,warning
from scapy.volatile import RandField
from scapy.utils import Enum_metaclass, EnumElement
class RandASN1Object(RandField):
def __init__(self, objlist=None):
if objlist is None:
objlist = map(lambda x:x._asn1_obj,
filter(lambda x:hasattr(x,"_asn1_obj"), ASN1_Class_UNIVERSAL.__rdict__.values()))
self.objlist = objlist
self.chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
def _fix(self, n=0):
o = random.choice(self.objlist)
if issubclass(o, ASN1_INTEGER):
return o(int(random.gauss(0,1000)))
elif issubclass(o, ASN1_IPADDRESS):
z = RandIP()._fix()
return o(z)
elif issubclass(o, ASN1_STRING):
z = int(random.expovariate(0.05)+1)
return o("".join([random.choice(self.chars) for i in range(z)]))
elif issubclass(o, ASN1_SEQUENCE) and (n < 10):
z = int(random.expovariate(0.08)+1)
return o(map(lambda x:x._fix(n+1), [self.__class__(objlist=self.objlist)]*z))
return ASN1_INTEGER(int(random.gauss(0,1000)))
##############
#### ASN1 ####
##############
class ASN1_Error(Scapy_Exception):
pass
class ASN1_Encoding_Error(ASN1_Error):
pass
class ASN1_Decoding_Error(ASN1_Error):
pass
class ASN1_BadTag_Decoding_Error(ASN1_Decoding_Error):
pass
class ASN1Codec(EnumElement):
def register_stem(cls, stem):
cls._stem = stem
def dec(cls, s, context=None):
return cls._stem.dec(s, context=context)
def safedec(cls, s, context=None):
return cls._stem.safedec(s, context=context)
def get_stem(cls):
return cls.stem
class ASN1_Codecs_metaclass(Enum_metaclass):
element_class = ASN1Codec
class ASN1_Codecs:
__metaclass__ = ASN1_Codecs_metaclass
BER = 1
DER = 2
PER = 3
CER = 4
LWER = 5
BACnet = 6
OER = 7
SER = 8
XER = 9
class ASN1Tag(EnumElement):
def __init__(self, key, value, context=None, codec=None):
EnumElement.__init__(self, key, value)
self._context = context
if codec == None:
codec = {}
self._codec = codec
def clone(self): # /!\ not a real deep copy. self.codec is shared
return self.__class__(self._key, self._value, self._context, self._codec)
def register_asn1_object(self, asn1obj):
self._asn1_obj = asn1obj
def asn1_object(self, val):
if hasattr(self,"_asn1_obj"):
return self._asn1_obj(val)
raise ASN1_Error("%r does not have any assigned ASN1 object" % self)
def register(self, codecnum, codec):
self._codec[codecnum] = codec
def get_codec(self, codec):
try:
c = self._codec[codec]
except KeyError,msg:
raise ASN1_Error("Codec %r not found for tag %r" % (codec, self))
return c
class ASN1_Class_metaclass(Enum_metaclass):
element_class = ASN1Tag
def __new__(cls, name, bases, dct): # XXX factorise a bit with Enum_metaclass.__new__()
for b in bases:
for k,v in b.__dict__.iteritems():
if k not in dct and isinstance(v,ASN1Tag):
dct[k] = v.clone()
rdict = {}
for k,v in dct.iteritems():
if type(v) is int:
v = ASN1Tag(k,v)
dct[k] = v
rdict[v] = v
elif isinstance(v, ASN1Tag):
rdict[v] = v
dct["__rdict__"] = rdict
cls = type.__new__(cls, name, bases, dct)
for v in cls.__dict__.values():
if isinstance(v, ASN1Tag):
v.context = cls # overwrite ASN1Tag contexts, even cloned ones
return cls
class ASN1_Class:
__metaclass__ = ASN1_Class_metaclass
class ASN1_Class_UNIVERSAL(ASN1_Class):
name = "UNIVERSAL"
ERROR = -3
RAW = -2
NONE = -1
ANY = 0
BOOLEAN = 1
INTEGER = 2
BIT_STRING = 3
STRING = 4
NULL = 5
OID = 6
OBJECT_DESCRIPTOR = 7
EXTERNAL = 8
REAL = 9
ENUMERATED = 10
EMBEDDED_PDF = 11
UTF8_STRING = 12
RELATIVE_OID = 13
SEQUENCE = 0x30#XXX 16 ??
SET = 0x31 #XXX 17 ??
NUMERIC_STRING = 18
PRINTABLE_STRING = 19
T61_STRING = 20
VIDEOTEX_STRING = 21
IA5_STRING = 22
UTC_TIME = 23
GENERALIZED_TIME = 24
GRAPHIC_STRING = 25
ISO646_STRING = 26
GENERAL_STRING = 27
UNIVERSAL_STRING = 28
CHAR_STRING = 29
BMP_STRING = 30
IPADDRESS = 0x40
COUNTER32 = 0x41
GAUGE32 = 0x42
TIME_TICKS = 0x43
SEP = 0x80
class ASN1_Object_metaclass(type):
def __new__(cls, name, bases, dct):
c = super(ASN1_Object_metaclass, cls).__new__(cls, name, bases, dct)
try:
c.tag.register_asn1_object(c)
except:
warning("Error registering %r for %r" % (c.tag, c.codec))
return c
class ASN1_Object:
__metaclass__ = ASN1_Object_metaclass
tag = ASN1_Class_UNIVERSAL.ANY
def __init__(self, val):
self.val = val
def enc(self, codec):
return self.tag.get_codec(codec).enc(self.val)
def __repr__(self):
return "<%s[%r]>" % (self.__dict__.get("name", self.__class__.__name__), self.val)
def __str__(self):
return self.enc(conf.ASN1_default_codec)
def strshow(self, lvl=0):
return (" "*lvl)+repr(self)+"\n"
def show(self, lvl=0):
print self.strshow(lvl)
def __eq__(self, other):
return self.val == other
def __cmp__(self, other):
return cmp(self.val, other)
class ASN1_DECODING_ERROR(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.ERROR
def __init__(self, val, exc=None):
ASN1_Object.__init__(self, val)
self.exc = exc
def __repr__(self):
return "<%s[%r]{{%s}}>" % (self.__dict__.get("name", self.__class__.__name__),
self.val, self.exc.args[0])
def enc(self, codec):
if isinstance(self.val, ASN1_Object):
return self.val.enc(codec)
return self.val
class ASN1_force(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.RAW
def enc(self, codec):
if isinstance(self.val, ASN1_Object):
return self.val.enc(codec)
return self.val
class ASN1_BADTAG(ASN1_force):
pass
class ASN1_INTEGER(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.INTEGER
class ASN1_STRING(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.STRING
class ASN1_BIT_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.BIT_STRING
class ASN1_PRINTABLE_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.PRINTABLE_STRING
class ASN1_T61_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.T61_STRING
class ASN1_IA5_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.IA5_STRING
class ASN1_NUMERIC_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.NUMERIC_STRING
class ASN1_VIDEOTEX_STRING(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.VIDEOTEX_STRING
class ASN1_IPADDRESS(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.IPADDRESS
class ASN1_UTC_TIME(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.UTC_TIME
class ASN1_GENERALIZED_TIME(ASN1_STRING):
tag = ASN1_Class_UNIVERSAL.GENERALIZED_TIME
class ASN1_TIME_TICKS(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.TIME_TICKS
class ASN1_BOOLEAN(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.BOOLEAN
class ASN1_ENUMERATED(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.ENUMERATED
class ASN1_NULL(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.NULL
class ASN1_SEP(ASN1_NULL):
tag = ASN1_Class_UNIVERSAL.SEP
class ASN1_GAUGE32(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.GAUGE32
class ASN1_COUNTER32(ASN1_INTEGER):
tag = ASN1_Class_UNIVERSAL.COUNTER32
class ASN1_SEQUENCE(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.SEQUENCE
def strshow(self, lvl=0):
s = (" "*lvl)+("# %s:" % self.__class__.__name__)+"\n"
for o in self.val:
s += o.strshow(lvl=lvl+1)
return s
class ASN1_SET(ASN1_SEQUENCE):
tag = ASN1_Class_UNIVERSAL.SET
class ASN1_OID(ASN1_Object):
tag = ASN1_Class_UNIVERSAL.OID
def __init__(self, val):
val = conf.mib._oid(val)
ASN1_Object.__init__(self, val)
def __repr__(self):
return "<%s[%r]>" % (self.__dict__.get("name", self.__class__.__name__), conf.mib._oidname(self.val))
def __oidname__(self):
return '%s'%conf.mib._oidname(self.val)
conf.ASN1_default_codec = ASN1_Codecs.BER
|
