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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC vs.
Revision 1.60 by root, Thu Feb 6 11:51:40 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
…		…
100		103
101	=item C<:const_index>	104	=item C<:const_index>
102		105
103	The BER tuple array index constants:	106	The BER tuple array index constants:
104		107
105	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	108	BER_CLASS BER_TAG BER_FLAGS BER_DATA
106		109
107	=item C<:const_asn>	110	=item C<:const_asn>
108		111
109	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -	112	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	113	exactly the two topmost bits from the identifier octet shifted 6 bits to
111	the right):	114	the right):
112		115
113	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE	116	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
114		117
115	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their	118	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.	119	numerical value corresponds exactly to the numbers used in BER/X.690.
117		120
118	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	121	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	122	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	123	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	124	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	125	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	126	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
124		127
…		…
134		137
135	Constants only relevant to SNMP. These are the tag values used by SNMP in	138	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	139	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
137	BER/RFC 2578.	140	BER/RFC 2578.
138		141
139	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	142	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_GAUGE32
		143	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
140		144
141	=item C<:decode>	145	=item C<:decode>
142		146
143	C<ber_decode> and the match helper functions:	147	C<ber_decode> and the match helper functions:
144		148
		149	ber_decode ber-decode_prefix
145	ber_decode ber_is ber_is_seq ber_is_i32 ber_is_oid	150	ber_is ber_is_seq ber_is_int ber_is_oid
		151	ber_dump
146		152
147	=item C<:encode>	153	=item C<:encode>
148		154
149	C<ber_encode> and the construction helper functions:	155	C<ber_encode> and the construction helper functions:
150		156
151	ber_encode ber_i32	157	ber_encode
		158	ber_int
152		159
153	=back	160	=back
154		161
155	=head2 ASN.1/BER/DER/... BASICS	162	=head2 ASN.1/BER/DER/... BASICS
156		163
157	ASN.1 is a strange language that can be used to describe protocols and	164	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	165	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	166	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.	167	of this module, and is used in SNMP, LDAP or X.509 for example.
161		168
162	While ASN.1 defines a schema that is useful to interpret encoded data,	169	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	170	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,	171	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	172	but you can nevertheless decode the overall structure, even if you end up
…		…
167		174
168	This works because BER values are tagged with a type and a namespace,	175	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	176	and also have a flag that says whether a value consists of subvalues (is
170	"constructed") or not (is "primitive").	177	"constructed") or not (is "primitive").
171		178
172	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of	179	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	180	of those - for example, you have one integers and 16(!) different
174	string types, but there is no Unsigned32 type for example. Different	181	string types, but there is no Unsigned32 type for example. Different
175	applications work around this in different ways, for example, SNMP defines	182	applications work around this in different ways, for example, SNMP defines
176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	183	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
177	to two different tags: you can distinguish between Counter32 and the	184	to two different tags: you can distinguish between Counter32 and the
178	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.	185	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
…		…
182	=head2 DECODED BER REPRESENTATION	189	=head2 DECODED BER REPRESENTATION
183		190
184	This module represents every BER value as a 4-element tuple (actually an	191	This module represents every BER value as a 4-element tuple (actually an
185	array-reference):	192	array-reference):
186		193
187	[CLASS, TAG, CONSTRUCTED, DATA]	194	[CLASS, TAG, FLAGS, DATA]
188		195
189	For example:	196	For example:
190		197
191	[ASN_UNIVERSAL, ASN_INTEGER32, 0, 177] # the integer 177	198	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
192	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"	199	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
193	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID	200	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
194	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequencE	201	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
195		202
196	To avoid non-descriptive hardcoded array index numbers, this module	203	To avoid non-descriptive hardcoded array index numbers, this module
197	defines symbolic constants to access these members: C<BER_CLASS>,	204	defines symbolic constants to access these members: C<BER_CLASS>,
198	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	205	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
199		206
200	Also, the first three members are integers with a little caveat: for	207	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	208	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	209	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.:	210	I<DATA> member, and you may re-assign the array itself, e.g.:
204		211
205	$ber = ber_decode $binbuf;	212	$ber = ber_decode $binbuf;
206		213
207	# the following is NOT legal:	214	# the following is NOT legal:
208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)	215	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
209		216
210	# but all of the following are fine:	217	# but all of the following are fine:
211	$ber->[BER_DATA] = "string";	218	$ber->[BER_DATA] = "string";
212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	219	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	220	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
214		221
215	I<CLASS> is something like a namespace for I<TAG>s - there is the	222	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	223	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
217	implementations, the C<ASN_APPLICATION> namespace which defines tags for	224	implementations, the C<ASN_APPLICATION> namespace which defines tags for
218	specific applications (for example, the SNMP C<Unsigned32> type is in this	225	specific applications (for example, the SNMP C<Unsigned32> type is in this
219	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.	226	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
220	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).	227	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
221		228
222	The meaning of the I<TAG> depends on the namespace, and defines a	229	The meaning of the I<TAG> depends on the namespace, and defines a
223	(partial) interpretation of the data value. For example, right now, SNMP	230	(partial) interpretation of the data value. For example, SNMP defines
224	application namespace knowledge ix hardcoded into this module, so it	231	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
225	knows that SNMP C<Unsigned32> values need to be decoded into actual perl	232	of these, you need to tell this module how to handle those via profiles.
226	integers.
227		233
228	The most common tags in the C<ASN_UNIVERSAL> namespace are	234	The most common tags in the C<ASN_UNIVERSAL> namespace are
229	C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,	235	C<ASN_INTEGER>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,
230	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and	236	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
231	C<ASN_IA5_STRING>.	237	C<ASN_IA5_STRING>.
232		238
233	The most common tags in SNMP's C<ASN_APPLICATION> namespace	239	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
234	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,	240	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
235	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.	241	C<SNMP_COUNTER64>.
236		242
237	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the	243	The I<FLAGS> value is really just a boolean at this time (but might
238	the value is "primitive" and contains no subvalues, kind of like a	244	get extended) - if it is C<0>, the value is "primitive" and contains
239	non-reference perl scalar. IF it is true, then the value is "constructed"	245	no subvalues, kind of like a non-reference perl scalar. If it is C<1>,
240	which just means it contains a list of subvalues which this module will	246	then the value is "constructed" which just means it contains a list of
241	en-/decode as BER tuples themselves.	247	subvalues which this module will en-/decode as BER tuples themselves.
242		248
243	The I<DATA> value is either a reference to an array of further tuples (if	249	The I<DATA> value is either a reference to an array of further tuples
244	the value is I<CONSTRUCTED>), some decoded representation of the value,	250	(if the value is I<FLAGS>), some decoded representation of the value, if
245	if this module knows how to decode it (e.g. for the integer types above)	251	this module knows how to decode it (e.g. for the integer types above) or
246	or a binary string with the raw octets if this module doesn't know how to	252	a binary string with the raw octets if this module doesn't know how to
247	interpret the namespace/tag.	253	interpret the namespace/tag.
248		254
249	Thus, you can always decode a BER data structure and at worst you get a	255	Thus, you can always decode a BER data structure and at worst you get a
250	string in place of some nice decoded value.	256	string in place of some nice decoded value.
251		257
…		…
253		259
254	=head2 DECODING AND ENCODING	260	=head2 DECODING AND ENCODING
255		261
256	=over	262	=over
257		263
258	=item $tuple = ber_decoded $bindata	264	=item $tuple = ber_decode $bindata[, $profile]
259		265
260	Decodes binary BER data in C<$bindata> and returns the resulting BER	266	Decodes binary BER data in C<$bindata> and returns the resulting BER
261	tuple. Croaks on any decoding error, so the returned C<$tuple> is always	267	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
262	valid.	268	valid.
263		269
		270	How tags are interpreted is defined by the second argument, which must
		271	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		272	profile will be used (C<$Convert::BER::XS::DEFAULT_PROFILE>).
		273
		274	In addition to rolling your own, this module provides a
		275	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
		276	types.
		277
		278	Example: decode a BER blob using the default profile - SNMP values will be
		279	decided as raw strings.
		280
		281	$tuple = ber_decode $data;
		282
		283	Example: as above, but use the provided SNMP profile.
		284
		285	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		286
		287	=item ($tuple, $bytes) = ber_decode_prefix $bindata[, $profile]
		288
		289	Works like C<ber_decode>, except it doesn't croak when there is data after
		290	the BER data, but instead returns the decoded value and the number of
		291	bytes it decoded.
		292
		293	This is useful when you have BER data at the start of a buffer and other
		294	data after, and you need to find the length.
		295
		296	Also, since BER is self-delimited, this can be used to decode multiple BER
		297	values joined together.
		298
264	=item $bindata = ber_encode $tuple	299	=item $bindata = ber_encode $tuple[, $profile]
265		300
266	Encodes the BER tuple into a BER/DER data structure.	301	Encodes the BER tuple into a BER/DER data structure. As with
		302	Cyber_decode>, an optional profile can be given.
		303
		304	The encoded data should be both BER and DER ("shortest form") compliant
		305	unless the input says otherwise (e.g. it uses constructed strings).
267		306
268	=back	307	=back
269		308
270	=head2 HELPER FUNCTIONS	309	=head2 HELPER FUNCTIONS
271		310
272	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>	311	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
273	annoying. To reduce this a bit, this module defines a number of helper	312	annoying. To reduce this a bit, this module defines a number of helper
274	functions, both to match BER tuples and to conmstruct BER tuples:	313	functions, both to match BER tuples and to construct BER tuples:
275		314
276	=head3 MATCH HELPERS	315	=head3 MATCH HELPERS
277		316
278	Thse functions accept a BER tuple as first argument and either paertially	317	These functions accept a BER tuple as first argument and either partially
279	or fully match it. They often come in two forms, one which exactly matches	318	or fully match it. They often come in two forms, one which exactly matches
280	a value, and one which only matches the type and returns the value.	319	a value, and one which only matches the type and returns the value.
281		320
282	They do check whether valid tuples are passed in and croak otherwise. As	321	They do check whether valid tuples are passed in and croak otherwise. As
283	a ease-of-use exception, they usually also accept C<undef> instead of a	322	a ease-of-use exception, they usually also accept C<undef> instead of a
284	tuple reference. in which case they silently fail to match.	323	tuple reference, in which case they silently fail to match.
285		324
286	=over	325	=over
287		326
288	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	327	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
289		328
290	This takes a BER C<$tuple> and matches its elements agains the privded	329	This takes a BER C<$tuple> and matches its elements against the provided
291	values, all of which are optional - values that are either missing or	330	values, all of which are optional - values that are either missing or
292	C<undef> will be ignored, the others will be matched exactly (e.g. as if	331	C<undef> will be ignored, the others will be matched exactly (e.g. as if
293	you used C<==> or C<eq> (for C<$data>)).	332	you used C<==> or C<eq> (for C<$data>)).
294		333
295	Some examples:	334	Some examples:
…		…
298	orf die "tuple is not an ASN SEQUENCE";	337	orf die "tuple is not an ASN SEQUENCE";
299		338
300	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	339	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
301	or die "tuple is not an ASN NULL value";	340	or die "tuple is not an ASN NULL value";
302		341
303	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	342	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
304	or die "BER integer must be 50";	343	or die "BER integer must be 50";
305		344
306	=item $seq = ber_is_seq $tuple	345	=item $seq = ber_is_seq $tuple
307		346
308	Returns the sequence members (the array of subvalues) if the C<$tuple> is	347	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
315	my $snmp = ber_is_seq $ber	354	my $snmp = ber_is_seq $ber
316	or die "SNMP packet invalid: does not start with SEQUENCE";	355	or die "SNMP packet invalid: does not start with SEQUENCE";
317		356
318	# now we know $snmp is a sequence, so decode the SNMP version	357	# now we know $snmp is a sequence, so decode the SNMP version
319		358
320	my $version = ber_is_i32 $snmp->[0]	359	my $version = ber_is_int $snmp->[0]
321	or die "SNMP packet invalid: does not start with version number";	360	or die "SNMP packet invalid: does not start with version number";
322		361
323	=item $bool = ber_is_i32 $tuple, $i32	362	=item $bool = ber_is_int $tuple, $int
324		363
325	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	364	Returns a true value if the C<$tuple> represents an ASN INTEGER with
326	the value C<$i32>.	365	the value C<$int>.
327		366
328	=item $i32 = ber_is_i32 $tuple	367	=item $int = ber_is_int $tuple
329		368
330	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	369	Returns true (and extracts the integer value) if the C<$tuple> is an
331	INTEGER32. For C<0>, this function returns a special value that is 0 but	370	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
332	true.	371	but true.
333		372
334	=item $bool = ber_is_oid $tuple, $oid_string	373	=item $bool = ber_is_oid $tuple, $oid_string
335		374
336	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	375	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
337	that exactly matches C<$oid_string>. Example:	376	that exactly matches C<$oid_string>. Example:
…		…
348		387
349	=head3 CONSTRUCTION HELPERS	388	=head3 CONSTRUCTION HELPERS
350		389
351	=over	390	=over
352		391
353	=item $tuple = ber_i32 $value	392	=item $tuple = ber_int $value
354		393
355	Constructs a new C<ASN_INTEGER32> tuple.	394	Constructs a new C<ASN_INTEGER> tuple.
356		395
357	=back	396	=back
358		397
359	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	398	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
360		399
…		…
370	use common::sense;	409	use common::sense;
371		410
372	use XSLoader ();	411	use XSLoader ();
373	use Exporter qw(import);	412	use Exporter qw(import);
374		413
		414	use Carp ();
		415
375	our $VERSION;	416	our $VERSION;
376		417
377	BEGIN {	418	BEGIN {
378	$VERSION = 0.8;	419	$VERSION = 1.21;
379	XSLoader::load __PACKAGE__, $VERSION;	420	XSLoader::load __PACKAGE__, $VERSION;
380	}	421	}
381		422
382	our %EXPORT_TAGS = (	423	our %EXPORT_TAGS = (
383	const_index => [qw(	424	const_index => [qw(
384	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	425	BER_CLASS BER_TAG BER_FLAGS BER_DATA
385	)],	426	)],
		427	const_asn_class => [qw(
		428	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		429	)],
386	const_asn => [qw(	430	const_asn_tag => [qw(
387	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	431	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID ASN_OBJECT_IDENTIFIER
388	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED	432	ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
389	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING	433	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
390	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING	434	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
391	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING	435	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
392	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING	436	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
393
394	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
395	)],	437	)],
396	const_ber_type => [qw(	438	const_ber_type => [qw(
397	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT	439	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
398	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL	440	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
399	BER_TYPE_IPADDRESS BER_TYPE_CROAK	441	BER_TYPE_IPADDRESS BER_TYPE_CROAK
400	)],	442	)],
401	const_snmp => [qw(	443	const_snmp => [qw(
402	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	444	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32
		445	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
403	)],	446	)],
404	decode => [qw(	447	decode => [qw(
405	ber_decode	448	ber_decode ber_decode_prefix
406	ber_is ber_is_seq ber_is_i32 ber_is_oid	449	ber_is ber_is_seq ber_is_int ber_is_oid
		450	ber_dump
407	)],	451	)],
408	encode => [qw(	452	encode => [qw(
409	ber_encode	453	ber_encode
410	ber_i32	454	ber_int
411	)],	455	)],
412	);	456	);
413		457
414	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	458	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
415		459
416	$EXPORT_TAGS{all} = \@EXPORT_OK;	460	$EXPORT_TAGS{all} = \@EXPORT_OK;
		461	$EXPORT_TAGS{const_asn} = [map @{ $EXPORT_TAGS{$_} }, qw(const_asn_class const_asn_tag)];
417	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];	462	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
418	use Data::Dump; ddx \%EXPORT_TAGS;	463
		464	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		465
		466	$DEFAULT_PROFILE->_set_default;
		467
		468	# additional SNMP application types
		469	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		470
		471	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		472	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		473	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		474	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		475
		476	# decodes REAL values according to ECMA-63
		477	# this is pretty strict, except it doesn't catch -0.
		478	# I don't have access to ISO 6093 (or BS 6727, or ANSI X.3-42)), so this is all guesswork.
		479	sub _decode_real_decimal {
		480	my ($format, $val) = @_;
		481
		482	$val =~ y/,/./; # probably not in ISO-6093
		483
		484	if ($format == 1) {
		485	$val =~ /^ \ * [+-]? [0-9]+ \z/x
		486	or Carp::croak "BER_TYPE_REAL NR1 value not in NR1 format ($val) (X.690 8.5.8)";
		487	} elsif ($format == 2) {
		488	$val =~ /^ \ * [+-]? (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) \z/x
		489	or Carp::croak "BER_TYPE_REAL NR2 value not in NR2 format ($val) (X.690 8.5.8)";
		490	} elsif ($format == 3) {
		491	$val =~ /^ \ * [+-] (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) [eE] [+-]? [0-9]+ \z/x
		492	or Carp::croak "BER_TYPE_REAL NR3 value not in NR3 format ($val) (X.690 8.5.8)";
		493	} else {
		494	Carp::croak "BER_TYPE_REAL invalid decimal numerical representation format $format";
		495	}
		496
		497	$val
		498	}
		499
		500	# this is a mess, but perl's support for floating point formatting is nearly nonexistant
		501	sub _encode_real_decimal {
		502	my ($val, $nvdig) = @_;
		503
		504	$val = sprintf "%.*G", $nvdig + 1, $val;
		505
		506	if ($val =~ /E/) {
		507	$val =~ s/E(?=[^+-])/E+/;
		508	$val =~ s/E/.E/ if $val !~ /\./;
		509	$val =~ s/^/+/ unless $val =~ /^-/;
		510
		511	return "\x03$val" # NR3
		512	}
		513
		514	$val =~ /\./
		515	? "\x02$val" # NR2
		516	: "\x01$val" # NR1
		517	}
		518
		519	=head2 DEBUGGING
		520
		521	To aid debugging, you can call the C<ber_dump> function to print a "nice"
		522	representation to STDOUT.
		523
		524	=over
		525
		526	=item ber_dump $tuple[, $profile[, $prefix]]
		527
		528	In addition to specifying the BER C<$tuple> to dump, you can also specify
		529	a C<$profile> and a C<$prefix> string that is printed in front of each line.
		530
		531	If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump>
		532	will try to improve its output for SNMP data.
		533
		534	The output usually contains three columns, the "human readable" tag, the
		535	BER type used to decode it, and the data value.
		536
		537	This function is somewhat slow and uses a number of heuristics and tricks,
		538	so it really is only suitable for debug prints.
		539
		540	Example output:
		541
		542	SEQUENCE
		543	\| OCTET_STRING bytes 800063784300454045045400000001
		544	\| OCTET_STRING bytes
		545	\| CONTEXT (7) CONSTRUCTED
		546	\| \| INTEGER int 1058588941
		547	\| \| INTEGER int 0
		548	\| \| INTEGER int 0
		549	\| \| SEQUENCE
		550	\| \| \| SEQUENCE
		551	\| \| \| \| OID oid 1.3.6.1.2.1.1.3.0
		552	\| \| \| \| TIMETICKS int 638085796
		553
		554	=back
		555
		556	=cut
		557
		558	# reverse enum, very slow and ugly hack
		559	sub _re {
		560	my ($export_tag, $value) = @_;
		561
		562	for my $symbol (@{ $EXPORT_TAGS{$export_tag} }) {
		563	$value == eval $symbol
		564	and return $symbol;
		565	}
		566
		567	"($value)"
		568	}
		569
		570	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		571
		572	sub _ber_dump {
		573	my ($ber, $profile, $indent) = @_;
		574
		575	if (my $seq = ber_is_seq $ber) {
		576	printf "%sSEQUENCE\n", $indent;
		577	&_ber_dump ($_, $profile, "$indent\| ")
		578	for @$seq;
		579	} else {
		580	my $asn = $ber->[BER_CLASS] == ASN_UNIVERSAL;
		581
		582	my $class = _re const_asn_class => $ber->[BER_CLASS];
		583	my $tag = $asn ? _re const_asn_tag => $ber->[BER_TAG] : $ber->[BER_TAG];
		584	my $type = _re const_ber_type => $profile->get ($ber->[BER_CLASS], $ber->[BER_TAG]);
		585	my $data = $ber->[BER_DATA];
		586
		587	if ($profile == $SNMP_PROFILE and $ber->[BER_CLASS] == ASN_APPLICATION) {
		588	$tag = _re const_snmp => $ber->[BER_TAG];
		589	} elsif (!$asn) {
		590	$tag = "$class ($tag)";
		591	}
		592
		593	$class =~ s/^ASN_//;
		594	$tag =~ s/^(ASN_\|SNMP_)//;
		595	$type =~ s/^BER_TYPE_//;
		596
		597	if ($ber->[BER_FLAGS]) {
		598	printf "$indent%-16.16s\n", $tag;
		599	&_ber_dump ($_, $profile, "$indent\| ")
		600	for @$data;
		601	} else {
		602	if ($data =~ y/\x20-\x7e//c / (length $data \|\| 1) > 0.2 or $data =~ /\x00./s) {
		603	# assume binary
		604	$data = unpack "H*", $data;
		605	} else {
		606	$data =~ s/[^\x20-\x7e]/./g;
		607	$data = "\"$data\"" if $tag =~ /string/i \|\| !length $data;
		608	}
		609
		610	substr $data, 40, 1e9, "..." if 40 < length $data;
		611
		612	printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data;
		613	}
		614	}
		615	}
		616
		617	sub ber_dump($;$$) {
		618	_ber_dump $_[0], $_[1] \|\| $DEFAULT_PROFILE, $_[2];
		619	}
419		620
420	=head1 PROFILES	621	=head1 PROFILES
421		622
422	While any BER data can be correctly encoded and decoded out of the box, it	623	While any BER data can be correctly encoded and decoded out of the box, it
423	can be inconvenient to have to manually decode some values into a "better"	624	can be inconvenient to have to manually decode some values into a "better"
…		…
484		685
485	Returns the BER type mapped to the given C<$class>/C<$tag> combination.	686	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
486		687
487	=back	688	=back
488		689
489	=head2 BER TYPES	690	=head2 BER Types
490		691
491	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>	692	This lists the predefined BER types. BER types are formatters used
492	combination to any C<BER_TYPE_*>.	693	internally to format and encode BER values. You can assign any C<BER_TYPE>
		694	to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or
		695	encoded.
493		696
494	=over	697	=over
495		698
496	=item C<BER_TYPE_BYTES>	699	=item C<BER_TYPE_BYTES>
497		700
…		…
563	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	766	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
564	error for some types, then C<BER_TYPE_CROAK> is for you.	767	error for some types, then C<BER_TYPE_CROAK> is for you.
565		768
566	=back	769	=back
567		770
568	=cut	771	=head2 Example Profile
569		772
570	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	773	The following creates a profile suitable for SNMP - it's exactly identical
		774	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		775
571	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	776	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
572		777
573	# additional SNMP application types
574	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	778	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
575	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	779	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
576	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	780	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
577	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	781	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
578	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	782	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES);
579	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	783	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
580
581	$DEFAULT_PROFILE->_set_default;
582
583	1;
584		784
585	=head2 LIMITATIONS/NOTES	785	=head2 LIMITATIONS/NOTES
586		786
587	This module can only en-/decode 64 bit signed and unsigned integers, and	787	This module can only en-/decode 64 bit signed and unsigned
588	only when your perl supports those.	788	integers/tags/lengths, and only when your perl supports those. So no UUID
		789	OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something
		790	other than C<BER_TYPE_OID>).
589		791
590	This module does not generally care about ranges, i.e. it will happily	792	This module does not generally care about ranges, i.e. it will happily
591	de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative	793	de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative
592	number into an C<SNMP_COUNTER64>.	794	number into an C<SNMP_COUNTER64>.
593		795
594	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is	796	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
595	much larger than e.g. the one imposed by SNMP or other protocols,a nd is	797	much larger than e.g. the one imposed by SNMP or other protocols, and is
596	about 4kB.	798	about 4kB.
597		799
598	REAL values are not supported and will currently croak.	800	Constructed strings are decoded just fine, but there should be a way to
		801	join them for convenience.
599		802
600	This module has undergone little to no testing so far.	803	REAL values will always be encoded in decimal form and ssometimes is
		804	forced into a perl "NV" type, potentially losing precision.
601		805
602	=head2 ITHREADS SUPPORT	806	=head2 ITHREADS SUPPORT
603		807
604	This module is unlikely to work when the (officially discouraged) ithreads	808	This module is unlikely to work in any other than the loading thread when
605	are in use.	809	the (officially discouraged) ithreads are in use.
606		810
607	=head1 AUTHOR	811	=head1 AUTHOR
608		812
609	Marc Lehmann <schmorp@schmorp.de>	813	Marc Lehmann <schmorp@schmorp.de>
610	http://software.schmorp.de/pkg/Convert-BER-XS	814	http://software.schmorp.de/pkg/Convert-BER-XS
611		815
612	=cut	816	=cut
613		817
		818	1;
		819

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC vs. Revision 1.60 by root, Thu Feb 6 11:51:40 2020 UTC

Diff Legend

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC vs.
Revision 1.60 by root, Thu Feb 6 11:51:40 2020 UTC