[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 1.63 by root, Wed Mar 3 05:30:23 2021 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use Convert::BER::XS ':all';	7	use Convert::BER::XS ':all';
8		8
		9	# decode a binary BER data structure using the SNMP profile
9	my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE	10	my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE
10	or die "unable to decode SNMP message";	11	or die "unable to decode SNMP message";
11		12
12	# The above results in a data structure consisting of	13	# The above results in a data structure consisting of
13	# (class, tag, # constructed, data)	14	# (class, tag, flags, data)
14	# tuples. Below is such a message, SNMPv1 trap	15	# tuples. Below is such a message, an SNMPv1 trap
15	# with a Cisco mac change notification.	16	# with a Cisco mac change notification.
16	# Did you know that Cisco is in the news almost	17	# (Did you know that Cisco is in the news almost
17	# every week because of some backdoor password	18	# every week because of some backdoor password
18	# or other extremely stupid security bug?	19	# or other extremely stupid security bug?)
19		20
20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,	21	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,
21	[	22	[
22	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1	23	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 0 ], # snmp version 1
23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community	24	[ ASN_UNIVERSAL, 4, 0, "public" ], # community
24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU	25	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU
25	[	26	[
26	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid	27	[ 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	28	[ ASN_APPLICATION, SNMP_IPADDRESS, 0, "10.0.0.1" ], # SNMP IpAddress
28	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap	29	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 6 ], # generic trap
29	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap	30	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 1 ], # specific trap
30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks	31	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks
31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist	32	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist
32	[	33	[
33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair	34	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair
34	[	35	[
…		…
37	]	38	]
38	]	39	]
39	],	40	],
40	...	41	...
41		42
		43	# let's dump the above structure, for debugging
		44	ber_dump $ber, $Convert::BER::XS::SNMP_PROFILE;
		45
42	# let's decode it a bit with some helper functions	46	# let's decode it a bit with some helper functions.
43		47	# first check whether it starts with a sequence
44	my $msg = ber_is_seq $ber	48	my $msg = ber_is_seq $ber
45	or die "SNMP message does not start with a sequence";	49	or die "SNMP message does not start with a sequence";
46		50
		51	# then check if its some kind of integer
47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0	52	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0
48	or die "SNMP message does not start with snmp version\n";	53	or die "SNMP message does not start with snmp version";
49		54
50	# message is SNMP v1 or v2c?	55	# message is SNMP v1 or v2c?
51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {	56	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {
52		57
53	# message is v1 trap?	58	# message is v1 trap?
…		…
55	my $trap = $msg->[2][BER_DATA];	60	my $trap = $msg->[2][BER_DATA];
56		61
57	# check whether trap is a cisco mac notification mac changed message	62	# check whether trap is a cisco mac notification mac changed message
58	if (	63	if (
59	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects	64	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects
60	and (ber_is_i32 $trap->[2], 6)	65	and (ber_is_int $trap->[2], 6)
61	and (ber_is_i32 $trap->[3], 1) # mac changed msg	66	and (ber_is_int $trap->[3], 1) # mac changed msg
62	) {	67	) {
63	... and so on	68	... and so on
64		69
65	# finally, let's encode it again and hope it results in the same bit pattern	70	# finally, let's encode it again and hope it results in the same bit pattern
66
67	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;	71	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
68		72
69	=head1 DESCRIPTION	73	=head1 DESCRIPTION
70
71	WARNING: Before release 1.0, the API is not considered stable in any way.
72		74
73	This module implements a I<very> low level BER/DER en-/decoder.	75	This module implements a I<very> low level BER/DER en-/decoder.
74		76
75	It is tuned for low memory and high speed, while still maintaining some	77	It is tuned for low memory and high speed, while still maintaining some
76	level of user-friendlyness.	78	level of user-friendlyness.
…		…
100		102
101	=item C<:const_index>	103	=item C<:const_index>
102		104
103	The BER tuple array index constants:	105	The BER tuple array index constants:
104		106
105	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	107	BER_CLASS BER_TAG BER_FLAGS BER_DATA
106		108
107	=item C<:const_asn>	109	=item C<:const_asn>
108		110
109	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -	111	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	112	exactly the two topmost bits from the identifier octet shifted 6 bits to
111	the right):	113	the right):
112		114
113	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE	115	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
114		116
115	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their	117	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.	118	numerical value corresponds exactly to the numbers used in BER/X.690.
117		119
118	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	120	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	121	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	122	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	123	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	124	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	125	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
124		126
…		…
134		136
135	Constants only relevant to SNMP. These are the tag values used by SNMP in	137	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	138	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
137	BER/RFC 2578.	139	BER/RFC 2578.
138		140
139	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	141	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_GAUGE32
		142	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
140		143
141	=item C<:decode>	144	=item C<:decode>
142		145
143	C<ber_decode> and the match helper functions:	146	C<ber_decode> and the match helper functions:
144		147
		148	ber_decode ber-decode_prefix
145	ber_decode ber_is ber_is_seq ber_is_i32 ber_is_oid	149	ber_is ber_is_seq ber_is_int ber_is_oid
		150	ber_dump
146		151
147	=item C<:encode>	152	=item C<:encode>
148		153
149	C<ber_encode> and the construction helper functions:	154	C<ber_encode> and the construction helper functions:
150		155
151	ber_encode ber_i32	156	ber_encode
		157	ber_int
152		158
153	=back	159	=back
154		160
155	=head2 ASN.1/BER/DER/... BASICS	161	=head2 ASN.1/BER/DER/... BASICS
156		162
157	ASN.1 is a strange language that can be used to describe protocols and	163	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	164	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	165	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.	166	of this module, and is used in SNMP, LDAP or X.509 for example.
161		167
162	While ASN.1 defines a schema that is useful to interpret encoded data,	168	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	169	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,	170	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	171	but you can nevertheless decode the overall structure, even if you end up
…		…
167		173
168	This works because BER values are tagged with a type and a namespace,	174	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	175	and also have a flag that says whether a value consists of subvalues (is
170	"constructed") or not (is "primitive").	176	"constructed") or not (is "primitive").
171		177
172	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of	178	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	179	of those - for example, you have one integer but 16(!) different
174	string types, but there is no Unsigned32 type for example. Different	180	string types, but there is no Unsigned32 type for example. Different
175	applications work around this in different ways, for example, SNMP defines	181	applications work around this in different ways, for example, SNMP defines
176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	182	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
177	to two different tags: you can distinguish between Counter32 and the	183	to two different tags: you can distinguish between Counter32 and the
178	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.	184	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
…		…
182	=head2 DECODED BER REPRESENTATION	188	=head2 DECODED BER REPRESENTATION
183		189
184	This module represents every BER value as a 4-element tuple (actually an	190	This module represents every BER value as a 4-element tuple (actually an
185	array-reference):	191	array-reference):
186		192
187	[CLASS, TAG, CONSTRUCTED, DATA]	193	[CLASS, TAG, FLAGS, DATA]
188		194
189	For example:	195	For example:
190		196
191	[ASN_UNIVERSAL, ASN_INTEGER32, 0, 177] # the integer 177	197	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
192	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"	198	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
193	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID	199	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
194	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence	200	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
195		201
196	To avoid non-descriptive hardcoded array index numbers, this module	202	To avoid non-descriptive hardcoded array index numbers, this module
197	defines symbolic constants to access these members: C<BER_CLASS>,	203	defines symbolic constants to access these members: C<BER_CLASS>,
198	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	204	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
199		205
200	Also, the first three members are integers with a little caveat: for	206	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	207	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	208	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.:	209	I<DATA> member, and you may re-assign the array itself, e.g.:
204		210
205	$ber = ber_decode $binbuf;	211	$ber = ber_decode $binbuf;
206		212
207	# the following is NOT legal:	213	# the following is NOT legal:
208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)	214	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
209		215
210	# but all of the following are fine:	216	# but all of the following are fine:
211	$ber->[BER_DATA] = "string";	217	$ber->[BER_DATA] = "string";
212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	218	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	219	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
214		220
215	I<CLASS> is something like a namespace for I<TAG>s - there is the	221	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	222	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
217	implementations, the C<ASN_APPLICATION> namespace which defines tags for	223	implementations, the C<ASN_APPLICATION> namespace which defines tags for
…		…
223	(partial) interpretation of the data value. For example, SNMP defines	229	(partial) interpretation of the data value. For example, SNMP defines
224	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage	230	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.	231	of these, you need to tell this module how to handle those via profiles.
226		232
227	The most common tags in the C<ASN_UNIVERSAL> namespace are	233	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>,	234	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	235	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
230	C<ASN_IA5_STRING>.	236	C<ASN_IA5_STRING>.
231		237
232	The most common tags in SNMP's C<ASN_APPLICATION> namespace are	238	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
233	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and	239	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
234	C<SNMP_COUNTER64>.	240	C<SNMP_COUNTER64>.
235		241
236	The I<CONSTRUCTED> flag is really just a boolean - if it is false,	242	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	243	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"	244	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	245	then the value is "constructed" which just means it contains a list of
240	en-/decode as BER tuples themselves.	246	subvalues which this module will en-/decode as BER tuples themselves.
241		247
242	The I<DATA> value is either a reference to an array of further tuples (if	248	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,	249	(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)	250	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	251	a binary string with the raw octets if this module doesn't know how to
246	interpret the namespace/tag.	252	interpret the namespace/tag.
247		253
248	Thus, you can always decode a BER data structure and at worst you get a	254	Thus, you can always decode a BER data structure and at worst you get a
249	string in place of some nice decoded value.	255	string in place of some nice decoded value.
250		256
…		…
252		258
253	=head2 DECODING AND ENCODING	259	=head2 DECODING AND ENCODING
254		260
255	=over	261	=over
256		262
257	=item $tuple = ber_decoded $bindata[, $profile]	263	=item $tuple = ber_decode $bindata[, $profile]
258		264
259	Decodes binary BER data in C<$bindata> and returns the resulting BER	265	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	266	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
261	valid.	267	valid.
262		268
…		…
266		272
267	In addition to rolling your own, this module provides a	273	In addition to rolling your own, this module provides a
268	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP	274	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
269	types.	275	types.
270		276
		277	Example: decode a BER blob using the default profile - SNMP values will be
		278	decided as raw strings.
		279
		280	$tuple = ber_decode $data;
		281
		282	Example: as above, but use the provided SNMP profile.
		283
		284	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		285
		286	=item ($tuple, $bytes) = ber_decode_prefix $bindata[, $profile]
		287
		288	Works like C<ber_decode>, except it doesn't croak when there is data after
		289	the BER data, but instead returns the decoded value and the number of
		290	bytes it decoded.
		291
		292	This is useful when you have BER data at the start of a buffer and other
		293	data after, and you need to find the length.
		294
		295	Also, since BER is self-delimited, this can be used to decode multiple BER
		296	values joined together.
		297
271	=item $bindata = ber_encode $tuple[, $profile]	298	=item $bindata = ber_encode $tuple[, $profile]
272		299
273	Encodes the BER tuple into a BER/DER data structure. AS with	300	Encodes the BER tuple into a BER/DER data structure. As with
274	Cyber_decode>, an optional profile can be given.	301	Cyber_decode>, an optional profile can be given.
		302
		303	The encoded data should be both BER and DER ("shortest form") compliant
		304	unless the input says otherwise (e.g. it uses constructed strings).
275		305
276	=back	306	=back
277		307
278	=head2 HELPER FUNCTIONS	308	=head2 HELPER FUNCTIONS
279		309
…		…
291	a ease-of-use exception, they usually also accept C<undef> instead of a	321	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.	322	tuple reference, in which case they silently fail to match.
293		323
294	=over	324	=over
295		325
296	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	326	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
297		327
298	This takes a BER C<$tuple> and matches its elements against the provided	328	This takes a BER C<$tuple> and matches its elements against the provided
299	values, all of which are optional - values that are either missing or	329	values, all of which are optional - values that are either missing or
300	C<undef> will be ignored, the others will be matched exactly (e.g. as if	330	C<undef> will be ignored, the others will be matched exactly (e.g. as if
301	you used C<==> or C<eq> (for C<$data>)).	331	you used C<==> or C<eq> (for C<$data>)).
…		…
306	orf die "tuple is not an ASN SEQUENCE";	336	orf die "tuple is not an ASN SEQUENCE";
307		337
308	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	338	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
309	or die "tuple is not an ASN NULL value";	339	or die "tuple is not an ASN NULL value";
310		340
311	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	341	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
312	or die "BER integer must be 50";	342	or die "BER integer must be 50";
313		343
314	=item $seq = ber_is_seq $tuple	344	=item $seq = ber_is_seq $tuple
315		345
316	Returns the sequence members (the array of subvalues) if the C<$tuple> is	346	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
323	my $snmp = ber_is_seq $ber	353	my $snmp = ber_is_seq $ber
324	or die "SNMP packet invalid: does not start with SEQUENCE";	354	or die "SNMP packet invalid: does not start with SEQUENCE";
325		355
326	# now we know $snmp is a sequence, so decode the SNMP version	356	# now we know $snmp is a sequence, so decode the SNMP version
327		357
328	my $version = ber_is_i32 $snmp->[0]	358	my $version = ber_is_int $snmp->[0]
329	or die "SNMP packet invalid: does not start with version number";	359	or die "SNMP packet invalid: does not start with version number";
330		360
331	=item $bool = ber_is_i32 $tuple, $i32	361	=item $bool = ber_is_int $tuple, $int
332		362
333	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	363	Returns a true value if the C<$tuple> represents an ASN INTEGER with
334	the value C<$i32>.	364	the value C<$int>.
335		365
336	=item $i32 = ber_is_i32 $tuple	366	=item $int = ber_is_int $tuple
337		367
338	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	368	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	369	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
340	true.	370	but true.
341		371
342	=item $bool = ber_is_oid $tuple, $oid_string	372	=item $bool = ber_is_oid $tuple, $oid_string
343		373
344	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	374	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
345	that exactly matches C<$oid_string>. Example:	375	that exactly matches C<$oid_string>. Example:
…		…
356		386
357	=head3 CONSTRUCTION HELPERS	387	=head3 CONSTRUCTION HELPERS
358		388
359	=over	389	=over
360		390
361	=item $tuple = ber_i32 $value	391	=item $tuple = ber_int $value
362		392
363	Constructs a new C<ASN_INTEGER32> tuple.	393	Constructs a new C<ASN_INTEGER> tuple.
364		394
365	=back	395	=back
366		396
367	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	397	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
368		398
…		…
378	use common::sense;	408	use common::sense;
379		409
380	use XSLoader ();	410	use XSLoader ();
381	use Exporter qw(import);	411	use Exporter qw(import);
382		412
		413	use Carp ();
		414
383	our $VERSION;	415	our $VERSION;
384		416
385	BEGIN {	417	BEGIN {
386	$VERSION = 0.8;	418	$VERSION = 1.21;
387	XSLoader::load __PACKAGE__, $VERSION;	419	XSLoader::load __PACKAGE__, $VERSION;
388	}	420	}
389		421
390	our %EXPORT_TAGS = (	422	our %EXPORT_TAGS = (
391	const_index => [qw(	423	const_index => [qw(
392	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	424	BER_CLASS BER_TAG BER_FLAGS BER_DATA
393	)],	425	)],
		426	const_asn_class => [qw(
		427	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		428	)],
394	const_asn => [qw(	429	const_asn_tag => [qw(
395	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	430	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	431	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	432	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	433	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	434	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	435	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	)],	436	)],
404	const_ber_type => [qw(	437	const_ber_type => [qw(
405	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT	438	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	439	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
407	BER_TYPE_IPADDRESS BER_TYPE_CROAK	440	BER_TYPE_IPADDRESS BER_TYPE_CROAK
408	)],	441	)],
409	const_snmp => [qw(	442	const_snmp => [qw(
410	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	443	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32
		444	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
411	)],	445	)],
412	decode => [qw(	446	decode => [qw(
413	ber_decode	447	ber_decode ber_decode_prefix
414	ber_is ber_is_seq ber_is_i32 ber_is_oid	448	ber_is ber_is_seq ber_is_int ber_is_oid
		449	ber_dump
415	)],	450	)],
416	encode => [qw(	451	encode => [qw(
417	ber_encode	452	ber_encode
418	ber_i32	453	ber_int
419	)],	454	)],
420	);	455	);
421		456
422	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	457	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
423		458
424	$EXPORT_TAGS{all} = \@EXPORT_OK;	459	$EXPORT_TAGS{all} = \@EXPORT_OK;
		460	$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)];	461	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
426	use Data::Dump; ddx \%EXPORT_TAGS;	462
		463	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		464
		465	$DEFAULT_PROFILE->_set_default;
		466
		467	# additional SNMP application types
		468	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		469
		470	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		471	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		472	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , 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	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, $_[2];
		617	}
427		618
428	=head1 PROFILES	619	=head1 PROFILES
429		620
430	While any BER data can be correctly encoded and decoded out of the box, it	621	While any BER data can be correctly encoded and decoded out of the box, it
431	can be inconvenient to have to manually decode some values into a "better"	622	can be inconvenient to have to manually decode some values into a "better"
…		…
457	=item C<$Convert::BER::XS::SNMP_PROFILE>	648	=item C<$Convert::BER::XS::SNMP_PROFILE>
458		649
459	A profile with mappings for SNMP-specific application tags added. This is	650	A profile with mappings for SNMP-specific application tags added. This is
460	useful when de-/encoding SNMP data.	651	useful when de-/encoding SNMP data.
461		652
		653	The L<Example Profile> section, below, shows how this profile is being
		654	constructed.
		655
462	Example:	656	Example:
463		657
464	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;	658	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
465		659
466	=back	660	=back
…		…
492		686
493	Returns the BER type mapped to the given C<$class>/C<$tag> combination.	687	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
494		688
495	=back	689	=back
496		690
497	=head2 BER TYPES	691	=head2 BER Types
498		692
499	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>	693	This lists the predefined BER types. BER types are formatters used
500	combination to any C<BER_TYPE_*>.	694	internally to format and encode BER values. You can assign any C<BER_TYPE>
		695	to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or
		696	encoded.
501		697
502	=over	698	=over
503		699
504	=item C<BER_TYPE_BYTES>	700	=item C<BER_TYPE_BYTES>
505		701
…		…
534	dot, e.g. C<1.3.6.1.213>.	730	dot, e.g. C<1.3.6.1.213>.
535		731
536	=item C<BER_TYPE_RELOID>	732	=item C<BER_TYPE_RELOID>
537		733
538	Same as C<BER_TYPE_OID> but uses relative object identifier	734	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	735	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	736	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	737	of space in an otherwise wasteful encoding, and relative OIDs are
542	basically OIDs without this hack. The practical difference is that the	738	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	739	second component of an OID can only have the values 1..40, while relative
544	OIDs do not have this restriction.	740	OIDs do not have this restriction.
…		…
571	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	767	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.	768	error for some types, then C<BER_TYPE_CROAK> is for you.
573		769
574	=back	770	=back
575		771
576	=cut	772	=head2 Example Profile
577		773
578	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	774	The following creates a profile suitable for SNMP - it's exactly identical
		775	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		776
579	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	777	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
580		778
581	# additional SNMP application types
582	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	779	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
583	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	780	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
584	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	781	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
585	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	782	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
586	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	783	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES);
587	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	784	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
588
589	$DEFAULT_PROFILE->_set_default;
590
591	1;
592		785
593	=head2 LIMITATIONS/NOTES	786	=head2 LIMITATIONS/NOTES
594		787
595	This module can only en-/decode 64 bit signed and unsigned integers, and	788	This module can only en-/decode 64 bit signed and unsigned
596	only when your perl supports those.	789	integers/tags/lengths, and only when your perl supports those. So no UUID
		790	OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something
		791	other than C<BER_TYPE_OID>).
597		792
598	This module does not generally care about ranges, i.e. it will happily	793	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	794	de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative
600	number into an C<SNMP_COUNTER64>.	795	number into an C<SNMP_COUNTER64>.
601		796
602	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is	797	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	798	much larger than e.g. the one imposed by SNMP or other protocols, and is
604	about 4kB.	799	about 4kB.
605		800
606	REAL values are not supported and will currently croak.	801	Constructed strings are decoded just fine, but there should be a way to
		802	join them for convenience.
607		803
608	This module has undergone little to no testing so far.	804	REAL values will always be encoded in decimal form and ssometimes is
		805	forced into a perl "NV" type, potentially losing precision.
609		806
610	=head2 ITHREADS SUPPORT	807	=head2 ITHREADS SUPPORT
611		808
612	This module is unlikely to work when the (officially discouraged) ithreads	809	This module is unlikely to work in any other than the loading thread when
613	are in use.	810	the (officially discouraged) ithreads are in use.
614		811
615	=head1 AUTHOR	812	=head1 AUTHOR
616		813
617	Marc Lehmann <schmorp@schmorp.de>	814	Marc Lehmann <schmorp@schmorp.de>
618	http://software.schmorp.de/pkg/Convert-BER-XS	815	http://software.schmorp.de/pkg/Convert-BER-XS
619		816
620	=cut	817	=cut
621		818
		819	1;
		820

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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 1.63 by root, Wed Mar 3 05:30:23 2021 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 1.63 by root, Wed Mar 3 05:30:23 2021 UTC