[ViewVC] Diff of: cvs/Convert-BER-XS/XS.pm

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.24 by root, Sat Apr 20 14:59:26 2019 UTC vs.
Revision 1.62 by root, Thu Feb 6 23:15:44 2020 UTC

…		…
8		8
9	my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE	9	my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE
10	or die "unable to decode SNMP message";	10	or die "unable to decode SNMP message";
11		11
12	# The above results in a data structure consisting of	12	# The above results in a data structure consisting of
13	# (class, tag, # constructed, data)	13	# (class, tag, flags, data)
14	# tuples. Below is such a message, SNMPv1 trap	14	# tuples. Below is such a message, SNMPv1 trap
15	# with a Cisco mac change notification.	15	# with a Cisco mac change notification.
16	# Did you know that Cisco is in the news almost	16	# Did you know that Cisco is in the news almost
17	# every week because of some backdoor password	17	# every week because of some backdoor password
18	# or other extremely stupid security bug?	18	# or other extremely stupid security bug?
19		19
20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,	20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,
21	[	21	[
22	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1	22	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 0 ], # snmp version 1
23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community	23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community
24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU	24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU
25	[	25	[
26	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid	26	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid
27	[ ASN_APPLICATION, SNMP_IPADDRESS, 0, "10.0.0.1" ], # SNMP IpAddress	27	[ ASN_APPLICATION, SNMP_IPADDRESS, 0, "10.0.0.1" ], # SNMP IpAddress
28	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap	28	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 6 ], # generic trap
29	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap	29	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 1 ], # specific trap
30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks	30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks
31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist	31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist
32	[	32	[
33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair	33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair
34	[	34	[
…		…
36	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value	36	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value
37	]	37	]
38	]	38	]
39	],	39	],
40	...	40	...
		41	# let's dump it, for debugging
		42
		43	ber_dump $ber, $Convert::BER::XS::SNMP_PROFILE;
41		44
42	# let's decode it a bit with some helper functions	45	# let's decode it a bit with some helper functions
43		46
44	my $msg = ber_is_seq $ber	47	my $msg = ber_is_seq $ber
45	or die "SNMP message does not start with a sequence";	48	or die "SNMP message does not start with a sequence";
46		49
47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0	50	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0
48	or die "SNMP message does not start with snmp version\n";	51	or die "SNMP message does not start with snmp version\n";
49		52
50	# message is SNMP v1 or v2c?	53	# message is SNMP v1 or v2c?
51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {	54	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {
52		55
…		…
55	my $trap = $msg->[2][BER_DATA];	58	my $trap = $msg->[2][BER_DATA];
56		59
57	# check whether trap is a cisco mac notification mac changed message	60	# check whether trap is a cisco mac notification mac changed message
58	if (	61	if (
59	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects	62	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects
60	and (ber_is_i32 $trap->[2], 6)	63	and (ber_is_int $trap->[2], 6)
61	and (ber_is_i32 $trap->[3], 1) # mac changed msg	64	and (ber_is_int $trap->[3], 1) # mac changed msg
62	) {	65	) {
63	... and so on	66	... and so on
64		67
65	# finally, let's encode it again and hope it results in the same bit pattern	68	# finally, let's encode it again and hope it results in the same bit pattern
66		69
67	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;	70	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
68		71
69	=head1 DESCRIPTION	72	=head1 DESCRIPTION
70
71	WARNING: Before release 1.0, the API is not considered stable in any way.
72		73
73	This module implements a I<very> low level BER/DER en-/decoder.	74	This module implements a I<very> low level BER/DER en-/decoder.
74		75
75	It is tuned for low memory and high speed, while still maintaining some	76	It is tuned for low memory and high speed, while still maintaining some
76	level of user-friendlyness.	77	level of user-friendlyness.
…		…
100		101
101	=item C<:const_index>	102	=item C<:const_index>
102		103
103	The BER tuple array index constants:	104	The BER tuple array index constants:
104		105
105	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	106	BER_CLASS BER_TAG BER_FLAGS BER_DATA
106		107
107	=item C<:const_asn>	108	=item C<:const_asn>
108		109
109	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -	110	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -
110	exactly thw two topmost bits from the identifier octet shifted 6 bits to	111	exactly the two topmost bits from the identifier octet shifted 6 bits to
111	the right):	112	the right):
112		113
113	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE	114	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
114		115
115	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their	116	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their
116	numerical value corresponds exactly to the numbers used in BER/X.690.	117	numerical value corresponds exactly to the numbers used in BER/X.690.
117		118
118	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	119	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID
119	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED	120	ASN_OBJECT_IDENTIFIER ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
120	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING	121	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
121	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING	122	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
122	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING	123	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
123	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING	124	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
124		125
…		…
134		135
135	Constants only relevant to SNMP. These are the tag values used by SNMP in	136	Constants only relevant to SNMP. These are the tag values used by SNMP in
136	the C<ASN_APPLICATION> namespace and have the exact numerical value as in	137	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
137	BER/RFC 2578.	138	BER/RFC 2578.
138		139
139	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	140	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_GAUGE32
		141	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
140		142
141	=item C<:decode>	143	=item C<:decode>
142		144
143	C<ber_decode> and the match helper functions:	145	C<ber_decode> and the match helper functions:
144		146
		147	ber_decode ber-decode_prefix
145	ber_decode ber_is ber_is_seq ber_is_i32 ber_is_oid	148	ber_is ber_is_seq ber_is_int ber_is_oid
		149	ber_dump
146		150
147	=item C<:encode>	151	=item C<:encode>
148		152
149	C<ber_encode> and the construction helper functions:	153	C<ber_encode> and the construction helper functions:
150		154
151	ber_encode ber_i32	155	ber_encode
		156	ber_int
152		157
153	=back	158	=back
154		159
155	=head2 ASN.1/BER/DER/... BASICS	160	=head2 ASN.1/BER/DER/... BASICS
156		161
157	ASN.1 is a strange language that can be used to describe protocols and	162	ASN.1 is a strange language that can be used to describe protocols and
158	data structures. It supports various mappings to JSON, XML, but most	163	data structures. It supports various mappings to JSON, XML, but most
159	importantly, to a various binary encodings such as BER, that is the topic	164	importantly, to a various binary encodings such as BER, that is the topic
160	of this module, and is used in SNMP or LDAP for example.	165	of this module, and is used in SNMP, LDAP or X.509 for example.
161		166
162	While ASN.1 defines a schema that is useful to interpret encoded data,	167	While ASN.1 defines a schema that is useful to interpret encoded data,
163	the BER encoding is actually somewhat self-describing: you might not know	168	the BER encoding is actually somewhat self-describing: you might not know
164	whether something is a string or a number or a sequence or something else,	169	whether something is a string or a number or a sequence or something else,
165	but you can nevertheless decode the overall structure, even if you end up	170	but you can nevertheless decode the overall structure, even if you end up
…		…
167		172
168	This works because BER values are tagged with a type and a namespace,	173	This works because BER values are tagged with a type and a namespace,
169	and also have a flag that says whether a value consists of subvalues (is	174	and also have a flag that says whether a value consists of subvalues (is
170	"constructed") or not (is "primitive").	175	"constructed") or not (is "primitive").
171		176
172	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of	177	Tags are simple integers, and ASN.1 defines a somewhat weird assortment
173	those - for example, you have 32 bit signed integers and 16(!) different	178	of those - for example, you have one integers and 16(!) different
174	string types, but there is no Unsigned32 type for example. Different	179	string types, but there is no Unsigned32 type for example. Different
175	applications work around this in different ways, for example, SNMP defines	180	applications work around this in different ways, for example, SNMP defines
176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	181	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
177	to two different tags: you can distinguish between Counter32 and the	182	to two different tags: you can distinguish between Counter32 and the
178	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.	183	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
…		…
182	=head2 DECODED BER REPRESENTATION	187	=head2 DECODED BER REPRESENTATION
183		188
184	This module represents every BER value as a 4-element tuple (actually an	189	This module represents every BER value as a 4-element tuple (actually an
185	array-reference):	190	array-reference):
186		191
187	[CLASS, TAG, CONSTRUCTED, DATA]	192	[CLASS, TAG, FLAGS, DATA]
188		193
189	For example:	194	For example:
190		195
191	[ASN_UNIVERSAL, ASN_INTEGER32, 0, 177] # the integer 177	196	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
192	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"	197	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
193	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID	198	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
194	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence	199	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
195		200
196	To avoid non-descriptive hardcoded array index numbers, this module	201	To avoid non-descriptive hardcoded array index numbers, this module
197	defines symbolic constants to access these members: C<BER_CLASS>,	202	defines symbolic constants to access these members: C<BER_CLASS>,
198	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	203	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
199		204
200	Also, the first three members are integers with a little caveat: for	205	Also, the first three members are integers with a little caveat: for
201	performance reasons, these are readonly and shared, so you must not modify	206	performance reasons, these are readonly and shared, so you must not modify
202	them (increment, assign to them etc.) in any way. You may modify the	207	them (increment, assign to them etc.) in any way. You may modify the
203	I<DATA> member, and you may re-assign the array itself, e.g.:	208	I<DATA> member, and you may re-assign the array itself, e.g.:
204		209
205	$ber = ber_decode $binbuf;	210	$ber = ber_decode $binbuf;
206		211
207	# the following is NOT legal:	212	# the following is NOT legal:
208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)	213	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
209		214
210	# but all of the following are fine:	215	# but all of the following are fine:
211	$ber->[BER_DATA] = "string";	216	$ber->[BER_DATA] = "string";
212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	217	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	218	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
214		219
215	I<CLASS> is something like a namespace for I<TAG>s - there is the	220	I<CLASS> is something like a namespace for I<TAG>s - there is the
216	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1	221	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
217	implementations, the C<ASN_APPLICATION> namespace which defines tags for	222	implementations, the C<ASN_APPLICATION> namespace which defines tags for
…		…
223	(partial) interpretation of the data value. For example, SNMP defines	228	(partial) interpretation of the data value. For example, SNMP defines
224	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage	229	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
225	of these, you need to tell this module how to handle those via profiles.	230	of these, you need to tell this module how to handle those via profiles.
226		231
227	The most common tags in the C<ASN_UNIVERSAL> namespace are	232	The most common tags in the C<ASN_UNIVERSAL> namespace are
228	C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,	233	C<ASN_INTEGER>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,
229	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and	234	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
230	C<ASN_IA5_STRING>.	235	C<ASN_IA5_STRING>.
231		236
232	The most common tags in SNMP's C<ASN_APPLICATION> namespace are	237	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
233	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and	238	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
234	C<SNMP_COUNTER64>.	239	C<SNMP_COUNTER64>.
235		240
236	The I<CONSTRUCTED> flag is really just a boolean - if it is false,	241	The I<FLAGS> value is really just a boolean at this time (but might
237	the value is "primitive" and contains no subvalues, kind of like a	242	get extended) - if it is C<0>, the value is "primitive" and contains
238	non-reference perl scalar. If it is true, then the value is "constructed"	243	no subvalues, kind of like a non-reference perl scalar. If it is C<1>,
239	which just means it contains a list of subvalues which this module will	244	then the value is "constructed" which just means it contains a list of
240	en-/decode as BER tuples themselves.	245	subvalues which this module will en-/decode as BER tuples themselves.
241		246
242	The I<DATA> value is either a reference to an array of further tuples (if	247	The I<DATA> value is either a reference to an array of further tuples
243	the value is I<CONSTRUCTED>), some decoded representation of the value,	248	(if the value is I<FLAGS>), some decoded representation of the value, if
244	if this module knows how to decode it (e.g. for the integer types above)	249	this module knows how to decode it (e.g. for the integer types above) or
245	or a binary string with the raw octets if this module doesn't know how to	250	a binary string with the raw octets if this module doesn't know how to
246	interpret the namespace/tag.	251	interpret the namespace/tag.
247		252
248	Thus, you can always decode a BER data structure and at worst you get a	253	Thus, you can always decode a BER data structure and at worst you get a
249	string in place of some nice decoded value.	254	string in place of some nice decoded value.
250		255
…		…
252		257
253	=head2 DECODING AND ENCODING	258	=head2 DECODING AND ENCODING
254		259
255	=over	260	=over
256		261
257	=item $tuple = ber_decoded $bindata[, $profile]	262	=item $tuple = ber_decode $bindata[, $profile]
258		263
259	Decodes binary BER data in C<$bindata> and returns the resulting BER	264	Decodes binary BER data in C<$bindata> and returns the resulting BER
260	tuple. Croaks on any decoding error, so the returned C<$tuple> is always	265	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
261	valid.	266	valid.
262		267
…		…
266		271
267	In addition to rolling your own, this module provides a	272	In addition to rolling your own, this module provides a
268	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP	273	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
269	types.	274	types.
270		275
		276	Example: decode a BER blob using the default profile - SNMP values will be
		277	decided as raw strings.
		278
		279	$tuple = ber_decode $data;
		280
		281	Example: as above, but use the provided SNMP profile.
		282
		283	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		284
		285	=item ($tuple, $bytes) = ber_decode_prefix $bindata[, $profile]
		286
		287	Works like C<ber_decode>, except it doesn't croak when there is data after
		288	the BER data, but instead returns the decoded value and the number of
		289	bytes it decoded.
		290
		291	This is useful when you have BER data at the start of a buffer and other
		292	data after, and you need to find the length.
		293
		294	Also, since BER is self-delimited, this can be used to decode multiple BER
		295	values joined together.
		296
271	=item $bindata = ber_encode $tuple[, $profile]	297	=item $bindata = ber_encode $tuple[, $profile]
272		298
273	Encodes the BER tuple into a BER/DER data structure. AS with	299	Encodes the BER tuple into a BER/DER data structure. As with
274	Cyber_decode>, an optional profile can be given.	300	Cyber_decode>, an optional profile can be given.
		301
		302	The encoded data should be both BER and DER ("shortest form") compliant
		303	unless the input says otherwise (e.g. it uses constructed strings).
275		304
276	=back	305	=back
277		306
278	=head2 HELPER FUNCTIONS	307	=head2 HELPER FUNCTIONS
279		308
…		…
291	a ease-of-use exception, they usually also accept C<undef> instead of a	320	a ease-of-use exception, they usually also accept C<undef> instead of a
292	tuple reference, in which case they silently fail to match.	321	tuple reference, in which case they silently fail to match.
293		322
294	=over	323	=over
295		324
296	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	325	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
297		326
298	This takes a BER C<$tuple> and matches its elements against the provided	327	This takes a BER C<$tuple> and matches its elements against the provided
299	values, all of which are optional - values that are either missing or	328	values, all of which are optional - values that are either missing or
300	C<undef> will be ignored, the others will be matched exactly (e.g. as if	329	C<undef> will be ignored, the others will be matched exactly (e.g. as if
301	you used C<==> or C<eq> (for C<$data>)).	330	you used C<==> or C<eq> (for C<$data>)).
…		…
306	orf die "tuple is not an ASN SEQUENCE";	335	orf die "tuple is not an ASN SEQUENCE";
307		336
308	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	337	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
309	or die "tuple is not an ASN NULL value";	338	or die "tuple is not an ASN NULL value";
310		339
311	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	340	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
312	or die "BER integer must be 50";	341	or die "BER integer must be 50";
313		342
314	=item $seq = ber_is_seq $tuple	343	=item $seq = ber_is_seq $tuple
315		344
316	Returns the sequence members (the array of subvalues) if the C<$tuple> is	345	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
323	my $snmp = ber_is_seq $ber	352	my $snmp = ber_is_seq $ber
324	or die "SNMP packet invalid: does not start with SEQUENCE";	353	or die "SNMP packet invalid: does not start with SEQUENCE";
325		354
326	# now we know $snmp is a sequence, so decode the SNMP version	355	# now we know $snmp is a sequence, so decode the SNMP version
327		356
328	my $version = ber_is_i32 $snmp->[0]	357	my $version = ber_is_int $snmp->[0]
329	or die "SNMP packet invalid: does not start with version number";	358	or die "SNMP packet invalid: does not start with version number";
330		359
331	=item $bool = ber_is_i32 $tuple, $i32	360	=item $bool = ber_is_int $tuple, $int
332		361
333	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	362	Returns a true value if the C<$tuple> represents an ASN INTEGER with
334	the value C<$i32>.	363	the value C<$int>.
335		364
336	=item $i32 = ber_is_i32 $tuple	365	=item $int = ber_is_int $tuple
337		366
338	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	367	Returns true (and extracts the integer value) if the C<$tuple> is an
339	INTEGER32. For C<0>, this function returns a special value that is 0 but	368	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
340	true.	369	but true.
341		370
342	=item $bool = ber_is_oid $tuple, $oid_string	371	=item $bool = ber_is_oid $tuple, $oid_string
343		372
344	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	373	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
345	that exactly matches C<$oid_string>. Example:	374	that exactly matches C<$oid_string>. Example:
…		…
356		385
357	=head3 CONSTRUCTION HELPERS	386	=head3 CONSTRUCTION HELPERS
358		387
359	=over	388	=over
360		389
361	=item $tuple = ber_i32 $value	390	=item $tuple = ber_int $value
362		391
363	Constructs a new C<ASN_INTEGER32> tuple.	392	Constructs a new C<ASN_INTEGER> tuple.
364		393
365	=back	394	=back
366		395
367	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	396	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
368		397
…		…
378	use common::sense;	407	use common::sense;
379		408
380	use XSLoader ();	409	use XSLoader ();
381	use Exporter qw(import);	410	use Exporter qw(import);
382		411
		412	use Carp ();
		413
383	our $VERSION;	414	our $VERSION;
384		415
385	BEGIN {	416	BEGIN {
386	$VERSION = 0.8;	417	$VERSION = 1.21;
387	XSLoader::load __PACKAGE__, $VERSION;	418	XSLoader::load __PACKAGE__, $VERSION;
388	}	419	}
389		420
390	our %EXPORT_TAGS = (	421	our %EXPORT_TAGS = (
391	const_index => [qw(	422	const_index => [qw(
392	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	423	BER_CLASS BER_TAG BER_FLAGS BER_DATA
393	)],	424	)],
		425	const_asn_class => [qw(
		426	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		427	)],
394	const_asn => [qw(	428	const_asn_tag => [qw(
395	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	429	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID ASN_OBJECT_IDENTIFIER
396	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED	430	ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
397	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING	431	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
398	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING	432	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
399	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING	433	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
400	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING	434	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
401
402	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
403	)],	435	)],
404	const_ber_type => [qw(	436	const_ber_type => [qw(
405	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT	437	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
406	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL	438	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
407	BER_TYPE_IPADDRESS BER_TYPE_CROAK	439	BER_TYPE_IPADDRESS BER_TYPE_CROAK
408	)],	440	)],
409	const_snmp => [qw(	441	const_snmp => [qw(
410	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	442	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32
		443	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
411	)],	444	)],
412	decode => [qw(	445	decode => [qw(
413	ber_decode	446	ber_decode ber_decode_prefix
414	ber_is ber_is_seq ber_is_i32 ber_is_oid	447	ber_is ber_is_seq ber_is_int ber_is_oid
		448	ber_dump
415	)],	449	)],
416	encode => [qw(	450	encode => [qw(
417	ber_encode	451	ber_encode
418	ber_i32	452	ber_int
419	)],	453	)],
420	);	454	);
421		455
422	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	456	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
423		457
424	$EXPORT_TAGS{all} = \@EXPORT_OK;	458	$EXPORT_TAGS{all} = \@EXPORT_OK;
		459	$EXPORT_TAGS{const_asn} = [map @{ $EXPORT_TAGS{$_} }, qw(const_asn_class const_asn_tag)];
425	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];	460	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
426	use Data::Dump; ddx \%EXPORT_TAGS;	461
		462	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		463
		464	$DEFAULT_PROFILE->_set_default;
		465
		466	# additional SNMP application types
		467	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		468
		469	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		470	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		471	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		472	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		473
		474	# decodes REAL values according to ECMA-63
		475	# this is pretty strict, except it doesn't catch -0.
		476	# I don't have access to ISO 6093 (or BS 6727, or ANSI X.3-42)), so this is all guesswork.
		477	sub _decode_real_decimal {
		478	my ($format, $val) = @_;
		479
		480	$val =~ y/,/./; # probably not in ISO-6093
		481
		482	if ($format == 1) {
		483	$val =~ /^ \ * [+-]? [0-9]+ \z/x
		484	or Carp::croak "BER_TYPE_REAL NR1 value not in NR1 format ($val) (X.690 8.5.8)";
		485	} elsif ($format == 2) {
		486	$val =~ /^ \ * [+-]? (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) \z/x
		487	or Carp::croak "BER_TYPE_REAL NR2 value not in NR2 format ($val) (X.690 8.5.8)";
		488	} elsif ($format == 3) {
		489	$val =~ /^ \ * [+-] (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) [eE] [+-]? [0-9]+ \z/x
		490	or Carp::croak "BER_TYPE_REAL NR3 value not in NR3 format ($val) (X.690 8.5.8)";
		491	} else {
		492	Carp::croak "BER_TYPE_REAL invalid decimal numerical representation format $format";
		493	}
		494
		495	$val
		496	}
		497
		498	# this is a mess, but perl's support for floating point formatting is nearly nonexistant
		499	sub _encode_real_decimal {
		500	my ($val, $nvdig) = @_;
		501
		502	$val = sprintf "%.*G", $nvdig + 1, $val;
		503
		504	if ($val =~ /E/) {
		505	$val =~ s/E(?=[^+-])/E+/;
		506	$val =~ s/E/.E/ if $val !~ /\./;
		507	$val =~ s/^/+/ unless $val =~ /^-/;
		508
		509	return "\x03$val" # NR3
		510	}
		511
		512	$val =~ /\./
		513	? "\x02$val" # NR2
		514	: "\x01$val" # NR1
		515	}
		516
		517	=head2 DEBUGGING
		518
		519	To aid debugging, you can call the C<ber_dump> function to print a "nice"
		520	representation to STDOUT.
		521
		522	=over
		523
		524	=item ber_dump $tuple[, $profile[, $prefix]]
		525
		526	In addition to specifying the BER C<$tuple> to dump, you can also specify
		527	a C<$profile> and a C<$prefix> string that is printed in front of each line.
		528
		529	If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump>
		530	will try to improve its output for SNMP data.
		531
		532	The output usually contains three columns, the "human readable" tag, the
		533	BER type used to decode it, and the data value.
		534
		535	This function is somewhat slow and uses a number of heuristics and tricks,
		536	so it really is only suitable for debug prints.
		537
		538	Example output:
		539
		540	SEQUENCE
		541	\| OCTET_STRING bytes 800063784300454045045400000001
		542	\| OCTET_STRING bytes
		543	\| CONTEXT (7) CONSTRUCTED
		544	\| \| INTEGER int 1058588941
		545	\| \| INTEGER int 0
		546	\| \| INTEGER int 0
		547	\| \| SEQUENCE
		548	\| \| \| SEQUENCE
		549	\| \| \| \| OID oid 1.3.6.1.2.1.1.3.0
		550	\| \| \| \| TIMETICKS int 638085796
		551
		552	=back
		553
		554	=cut
		555
		556	# reverse enum, very slow and ugly hack
		557	sub _re {
		558	my ($export_tag, $value) = @_;
		559
		560	for my $symbol (@{ $EXPORT_TAGS{$export_tag} }) {
		561	$value == eval $symbol
		562	and return $symbol;
		563	}
		564
		565	"($value)"
		566	}
		567
		568	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		569
		570	sub _ber_dump {
		571	my ($ber, $profile, $indent) = @_;
		572
		573	if (my $seq = ber_is_seq $ber) {
		574	printf "%sSEQUENCE\n", $indent;
		575	&_ber_dump ($_, $profile, "$indent\| ")
		576	for @$seq;
		577	} else {
		578	my $asn = $ber->[BER_CLASS] == ASN_UNIVERSAL;
		579
		580	my $class = _re const_asn_class => $ber->[BER_CLASS];
		581	my $tag = $asn ? _re const_asn_tag => $ber->[BER_TAG] : $ber->[BER_TAG];
		582	my $type = _re const_ber_type => $profile->get ($ber->[BER_CLASS], $ber->[BER_TAG]);
		583	my $data = $ber->[BER_DATA];
		584
		585	if ($profile == $SNMP_PROFILE and $ber->[BER_CLASS] == ASN_APPLICATION) {
		586	$tag = _re const_snmp => $ber->[BER_TAG];
		587	} elsif (!$asn) {
		588	$tag = "$class ($tag)";
		589	}
		590
		591	$class =~ s/^ASN_//;
		592	$tag =~ s/^(ASN_\|SNMP_)//;
		593	$type =~ s/^BER_TYPE_//;
		594
		595	if ($ber->[BER_FLAGS]) {
		596	printf "$indent%-16.16s\n", $tag;
		597	&_ber_dump ($_, $profile, "$indent\| ")
		598	for @$data;
		599	} else {
		600	if ($data =~ y/\x20-\x7e//c / (length $data \|\| 1) > 0.2 or $data =~ /\x00./s) {
		601	# assume binary
		602	$data = unpack "H*", $data;
		603	} else {
		604	$data =~ s/[^\x20-\x7e]/./g;
		605	$data = "\"$data\"" if $tag =~ /string/i \|\| !length $data;
		606	}
		607
		608	substr $data, 40, 1e9, "..." if 40 < length $data;
		609
		610	printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data;
		611	}
		612	}
		613	}
		614
		615	sub ber_dump($;$$) {
		616	_ber_dump $_[0], $_[1] \|\| $DEFAULT_PROFILE, $_[2];
		617	}
427		618
428	=head1 PROFILES	619	=head1 PROFILES
429		620
430	While any BER data can be correctly encoded and decoded out of the box, it	621	While any BER data can be correctly encoded and decoded out of the box, it
431	can be inconvenient to have to manually decode some values into a "better"	622	can be inconvenient to have to manually decode some values into a "better"
…		…
492		683
493	Returns the BER type mapped to the given C<$class>/C<$tag> combination.	684	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
494		685
495	=back	686	=back
496		687
497	=head2 BER TYPES	688	=head2 BER Types
498		689
499	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>	690	This lists the predefined BER types. BER types are formatters used
500	combination to any C<BER_TYPE_*>.	691	internally to format and encode BER values. You can assign any C<BER_TYPE>
		692	to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or
		693	encoded.
501		694
502	=over	695	=over
503		696
504	=item C<BER_TYPE_BYTES>	697	=item C<BER_TYPE_BYTES>
505		698
…		…
534	dot, e.g. C<1.3.6.1.213>.	727	dot, e.g. C<1.3.6.1.213>.
535		728
536	=item C<BER_TYPE_RELOID>	729	=item C<BER_TYPE_RELOID>
537		730
538	Same as C<BER_TYPE_OID> but uses relative object identifier	731	Same as C<BER_TYPE_OID> but uses relative object identifier
539	encoding: ASN.1 has this hack of encoding the first two OID components	732	encoding: ASN.1 uses some hack encoding of the first two OID components
540	into a single integer in a weird attempt to save an insignificant amount	733	into a single integer in a weird attempt to save an insignificant amount
541	of space in an otherwise wasteful encoding, and relative OIDs are	734	of space in an otherwise wasteful encoding, and relative OIDs are
542	basically OIDs without this hack. The practical difference is that the	735	basically OIDs without this hack. The practical difference is that the
543	second component of an OID can only have the values 1..40, while relative	736	second component of an OID can only have the values 1..40, while relative
544	OIDs do not have this restriction.	737	OIDs do not have this restriction.
…		…
571	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	764	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
572	error for some types, then C<BER_TYPE_CROAK> is for you.	765	error for some types, then C<BER_TYPE_CROAK> is for you.
573		766
574	=back	767	=back
575		768
576	=cut	769	=head2 Example Profile
577		770
578	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	771	The following creates a profile suitable for SNMP - it's exactly identical
		772	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		773
579	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	774	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
580		775
581	# additional SNMP application types
582	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	776	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
583	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	777	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
584	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	778	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
585	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	779	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
586	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	780	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES);
587	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	781	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
588
589	$DEFAULT_PROFILE->_set_default;
590
591	1;
592		782
593	=head2 LIMITATIONS/NOTES	783	=head2 LIMITATIONS/NOTES
594		784
595	This module can only en-/decode 64 bit signed and unsigned integers, and	785	This module can only en-/decode 64 bit signed and unsigned
596	only when your perl supports those.	786	integers/tags/lengths, and only when your perl supports those. So no UUID
		787	OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something
		788	other than C<BER_TYPE_OID>).
597		789
598	This module does not generally care about ranges, i.e. it will happily	790	This module does not generally care about ranges, i.e. it will happily
599	de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative	791	de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative
600	number into an C<SNMP_COUNTER64>.	792	number into an C<SNMP_COUNTER64>.
601		793
602	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is	794	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
603	much larger than e.g. the one imposed by SNMP or other protocols,a nd is	795	much larger than e.g. the one imposed by SNMP or other protocols, and is
604	about 4kB.	796	about 4kB.
605		797
606	REAL values are not supported and will currently croak.	798	Constructed strings are decoded just fine, but there should be a way to
		799	join them for convenience.
607		800
608	This module has undergone little to no testing so far.	801	REAL values will always be encoded in decimal form and ssometimes is
		802	forced into a perl "NV" type, potentially losing precision.
609		803
610	=head2 ITHREADS SUPPORT	804	=head2 ITHREADS SUPPORT
611		805
612	This module is unlikely to work when the (officially discouraged) ithreads	806	This module is unlikely to work in any other than the loading thread when
613	are in use.	807	the (officially discouraged) ithreads are in use.
614		808
615	=head1 AUTHOR	809	=head1 AUTHOR
616		810
617	Marc Lehmann <schmorp@schmorp.de>	811	Marc Lehmann <schmorp@schmorp.de>
618	http://software.schmorp.de/pkg/Convert-BER-XS	812	http://software.schmorp.de/pkg/Convert-BER-XS
619		813
620	=cut	814	=cut
621		815
		816	1;
		817

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.24 by root, Sat Apr 20 14:59:26 2019 UTC vs. Revision 1.62 by root, Thu Feb 6 23:15:44 2020 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.24 by root, Sat Apr 20 14:59:26 2019 UTC vs.
Revision 1.62 by root, Thu Feb 6 23:15:44 2020 UTC