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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.16 by root, Sat Apr 20 02:07:45 2019 UTC vs.
Revision 1.47 by root, Sun Apr 21 10:40:30 2019 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	my $ber = ber_decode $buf	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, 0, 0, "\x0a\x00\x00\x01" ], # SNMP IpAddress, 10.0.0.1	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, ASN_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	[
35	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ],	35	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ],
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;	70	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
68		71
69	=head1 DESCRIPTION	72	=head1 DESCRIPTION
70		73
71	WARNING: Before release 1.0, the API is not considered stable in any way.	74	WARNING: Before release 1.0, the API is not considered stable in any way.
72		75
73	This module implements a I<very> low level BER/DER en-/decoder.	76	This module implements a I<very> low level BER/DER en-/decoder.
74		77
75	If is tuned for low memory and high speed, while still maintaining some	78	It is tuned for low memory and high speed, while still maintaining some
76	level of user-friendlyness.	79	level of user-friendlyness.
		80
		81	=head2 EXPORT TAGS AND CONSTANTS
		82
		83	By default this module doesn't export any symbols, but if you don't want
		84	to break your keyboard, editor or eyesight with extremely long names, I
		85	recommend importing the C<:all> tag. Still, you can selectively import
		86	things.
		87
		88	=over
		89
		90	=item C<:all>
		91
		92	All of the below. Really. Recommended for at least first steps, or if you
		93	don't care about a few kilobytes of wasted memory (and namespace).
		94
		95	=item C<:const>
		96
		97	All of the strictly ASN.1-related constants defined by this module, the
		98	same as C<:const_asn :const_index>. Notably, this does not contain
		99	C<:const_ber_type> and C<:const_snmp>.
		100
		101	A good set to get everything you need to decode and match BER data would be
		102	C<:decode :const>.
		103
		104	=item C<:const_index>
		105
		106	The BER tuple array index constants:
		107
		108	BER_CLASS BER_TAG BER_FLAGS BER_DATA
		109
		110	=item C<:const_asn>
		111
		112	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -
		113	exactly thw two topmost bits from the identifier octet shifted 6 bits to
		114	the right):
		115
		116	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		117
		118	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their
		119	numerical value corresponds exactly to the numbers used in BER/X.690.
		120
		121	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID
		122	ASN_OBJECT_IDENTIFIER ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		123	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		124	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		125	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		126	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		127
		128	=item C<:const_ber_type>
		129
		130	The BER type constants, explained in the PROFILES section.
		131
		132	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		133	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		134	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		135
		136	=item C<:const_snmp>
		137
		138	Constants only relevant to SNMP. These are the tag values used by SNMP in
		139	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
		140	BER/RFC 2578.
		141
		142	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_GAUGE32
		143	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		144
		145	=item C<:decode>
		146
		147	C<ber_decode> and the match helper functions:
		148
		149	ber_decode ber-decode_prefix
		150	ber_is ber_is_seq ber_is_int ber_is_oid
		151	ber_dump
		152
		153	=item C<:encode>
		154
		155	C<ber_encode> and the construction helper functions:
		156
		157	ber_encode
		158	ber_int
		159
		160	=back
77		161
78	=head2 ASN.1/BER/DER/... BASICS	162	=head2 ASN.1/BER/DER/... BASICS
79		163
80	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
81	data structures. It supports various mappings to JSON, XML, but most	165	data structures. It supports various mappings to JSON, XML, but most
82	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
83	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.
84		168
85	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,
86	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
87	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,
88	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
…		…
90		174
91	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,
92	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
93	"constructed") or not (is "primitive").	177	"constructed") or not (is "primitive").
94		178
95	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
96	those - for example, you have 32 bit signed integers and 16(!) different	180	of those - for example, you have one integers and 16(!) different
97	string types, but there is no unsigned32 type for example. Different	181	string types, but there is no Unsigned32 type for example. Different
98	applications work around this in different ways, for example, SNMP defines	182	applications work around this in different ways, for example, SNMP defines
99	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	183	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
100	to two different tags: you can distinguish between Counter32 and the	184	to two different tags: you can distinguish between Counter32 and the
101	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.
102		186
…		…
105	=head2 DECODED BER REPRESENTATION	189	=head2 DECODED BER REPRESENTATION
106		190
107	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
108	array-reference):	192	array-reference):
109		193
110	[CLASS, TAG, CONSTRUCTED, DATA]	194	[CLASS, TAG, FLAGS, DATA]
		195
		196	For example:
		197
		198	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
		199	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
		200	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
		201	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
111		202
112	To avoid non-descriptive hardcoded array index numbers, this module	203	To avoid non-descriptive hardcoded array index numbers, this module
113	defines symbolic constants to access these members: C<BER_CLASS>,	204	defines symbolic constants to access these members: C<BER_CLASS>,
114	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	205	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
115		206
116	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
117	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
118	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
119	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.:
120		211
121	$ber = ber_decode $binbuf;	212	$ber = ber_decode $binbuf;
122		213
123	# the following is NOT legal:	214	# the following is NOT legal:
124	$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(!)
125		216
126	# but all of the following are fine:	217	# but all of the following are fine:
127	$ber->[BER_DATA] = "string";	218	$ber->[BER_DATA] = "string";
128	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	219	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
129	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	220	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
130		221
131	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
132	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
133	implementations, the C<ASN_APPLICATION> namespace which defines tags for	224	implementations, the C<ASN_APPLICATION> namespace which defines tags for
134	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
135	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.
136	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).	227	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
137		228
138	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
139	(partial) interpretation of the data value. For example, right now, SNMP	230	(partial) interpretation of the data value. For example, SNMP defines
140	application namespace knowledge ix hardcoded into this module, so it	231	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
141	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.
142	integers.
143		233
144	The most common tags in the C<ASN_UNIVERSAL> namespace are	234	The most common tags in the C<ASN_UNIVERSAL> namespace are
145	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>,
146	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and	236	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
147	C<ASN_IA5_STRING>.	237	C<ASN_IA5_STRING>.
148		238
149	The most common tags in SNMP's C<ASN_APPLICATION> namespace	239	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
150	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,	240	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
151	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.	241	C<SNMP_COUNTER64>.
152		242
153	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
154	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
155	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>,
156	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
157	en-/decode as BER tuples themselves.	247	subvalues which this module will en-/decode as BER tuples themselves.
158		248
159	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
160	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
161	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
162	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
163	interpret the namespace/tag.	253	interpret the namespace/tag.
164		254
165	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
166	string in place of some nice decoded value.	256	string in place of some nice decoded value.
167		257
…		…
169		259
170	=head2 DECODING AND ENCODING	260	=head2 DECODING AND ENCODING
171		261
172	=over	262	=over
173		263
174	=item $tuple = ber_decoded $bindata	264	=item $tuple = ber_decode $bindata[, $profile]
175		265
176	Decodes binary BER data in C<$bindata> and returns the resulting BER	266	Decodes binary BER data in C<$bindata> and returns the resulting BER
177	tuple. Croaks on any decoding error, so the returned C<$tuple> is always	267	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
178	valid.	268	valid.
179		269
		270	How tags are interpreted is defined by the second argument, which must
		271	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		272	profile will be used (C<$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
180	=item $bindata = ber_encode $tuple	299	=item $bindata = ber_encode $tuple[, $profile]
181		300
182	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).
183		306
184	=back	307	=back
185		308
186	=head2 HELPER FUNCTIONS	309	=head2 HELPER FUNCTIONS
187		310
188	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>
189	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
190	functions, both to match BER tuples and to conmstruct BER tuples:	313	functions, both to match BER tuples and to construct BER tuples:
191		314
192	=head3 MATCH HELPERS	315	=head3 MATCH HELPERS
193		316
194	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
195	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
196	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.
197		320
198	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
199	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
200	tuple reference. in which case they silently fail to match.	323	tuple reference, in which case they silently fail to match.
201		324
202	=over	325	=over
203		326
204	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	327	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
205		328
206	This takes a BER C<$tuple> and matches its elements agains the privded	329	This takes a BER C<$tuple> and matches its elements against the provided
207	values, all of which are optional - values that are either missing or	330	values, all of which are optional - values that are either missing or
208	C<undef> will be ignored, the others will be matched exactly (e.g. as if	331	C<undef> will be ignored, the others will be matched exactly (e.g. as if
209	you used C<==> or C<eq> (for C<$data>)).	332	you used C<==> or C<eq> (for C<$data>)).
210		333
211	Some examples:	334	Some examples:
…		…
214	orf die "tuple is not an ASN SEQUENCE";	337	orf die "tuple is not an ASN SEQUENCE";
215		338
216	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	339	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
217	or die "tuple is not an ASN NULL value";	340	or die "tuple is not an ASN NULL value";
218		341
219	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	342	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
220	or die "BER integer must be 50";	343	or die "BER integer must be 50";
221		344
222	=item $seq = ber_is_seq $tuple	345	=item $seq = ber_is_seq $tuple
223		346
224	Returns the sequence members (the array of subvalues) if the C<$tuple> is	347	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
231	my $snmp = ber_is_seq $ber	354	my $snmp = ber_is_seq $ber
232	or die "SNMP packet invalid: does not start with SEQUENCE";	355	or die "SNMP packet invalid: does not start with SEQUENCE";
233		356
234	# 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
235		358
236	my $version = ber_is_i32 $snmp->[0]	359	my $version = ber_is_int $snmp->[0]
237	or die "SNMP packet invalid: does not start with version number";	360	or die "SNMP packet invalid: does not start with version number";
238		361
239	=item $bool = ber_is_i32 $tuple, $i32	362	=item $bool = ber_is_int $tuple, $int
240		363
241	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	364	Returns a true value if the C<$tuple> represents an ASN INTEGER with
242	the value C<$i32>.	365	the value C<$int>.
243		366
244	=item $i32 = ber_is_i32 $tuple	367	=item $int = ber_is_int $tuple
245		368
246	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	369	Returns true (and extracts the integer value) if the C<$tuple> is an
247	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
248	true.	371	but true.
249		372
250	=item $bool = ber_is_oid $tuple, $oid_string	373	=item $bool = ber_is_oid $tuple, $oid_string
251		374
252	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	375	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
253	that exactly matches C<$oid_string>. Example:	376	that exactly matches C<$oid_string>. Example:
…		…
264		387
265	=head3 CONSTRUCTION HELPERS	388	=head3 CONSTRUCTION HELPERS
266		389
267	=over	390	=over
268		391
269	=item $tuple = ber_i32 $value	392	=item $tuple = ber_int $value
270		393
271	Constructs a new C<ASN_INTEGER32> tuple.	394	Constructs a new C<ASN_INTEGER> tuple.
272		395
273	=back	396	=back
274		397
275	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	398	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
276		399
…		…
289	use Exporter qw(import);	412	use Exporter qw(import);
290		413
291	our $VERSION;	414	our $VERSION;
292		415
293	BEGIN {	416	BEGIN {
294	$VERSION = 0.7;	417	$VERSION = '1.0';
295	XSLoader::load __PACKAGE__, $VERSION;	418	XSLoader::load __PACKAGE__, $VERSION;
296	}	419	}
297		420
298	our %EXPORT_TAGS = (	421	our %EXPORT_TAGS = (
299	const => [qw(	422	const_index => [qw(
300	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	423	BER_CLASS BER_TAG BER_FLAGS BER_DATA
301		424	)],
		425	const_asn_class => [qw(
		426	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		427	)],
		428	const_asn_tag => [qw(
302	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
303	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
304	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
305	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
306	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
307	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
308		435	)],
309	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE	436	const_ber_type => [qw(
310
311	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
312	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
313	BER_TYPE_IPADDRESS BER_TYPE_CROAK	439	BER_TYPE_IPADDRESS BER_TYPE_CROAK
314	)],	440	)],
315	const_snmp => [qw(	441	const_snmp => [qw(
316	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
		444	)],
		445	decode => [qw(
		446	ber_decode ber_decode_prefix
		447	ber_is ber_is_seq ber_is_int ber_is_oid
		448	ber_dump
317	)],	449	)],
318	encode => [qw(	450	encode => [qw(
319	ber_decode
320	ber_is ber_is_seq ber_is_i32 ber_is_oid
321	)],
322	decode => [qw(
323	ber_encode	451	ber_encode
324	ber_i32	452	ber_int
325	)],	453	)],
326	);	454	);
327		455
328	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	456	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
329		457
330	$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)];
		460	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
		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	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		474
		475	=head2 DEBUGGING
		476
		477	To aid debugging, you cna call the C<ber_dump> function to print a "nice"
		478	representation to STDOUT.
		479
		480	=over
		481
		482	=item ber_dump $tuple[, $profile[, $prefix]]
		483
		484	In addition to specifying the BER C<$tuple> to dump, youc an also specify
		485	a C<$profile> and a C<$prefix> string that is printed in front of each line.
		486
		487	If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump>
		488	will try to improve its output for SNMP data.
		489
		490	The output usually contains three columns, the "human readable" tag, the
		491	BER type used to decode it, and the data value.
		492
		493	This function is somewhat slow and uses a number of heuristics and tricks,
		494	so it really is only suitable for debug prints.
		495
		496	Example output:
		497
		498	SEQUENCE
		499	\| OCTET_STRING bytes 800063784300454045045400000001
		500	\| OCTET_STRING bytes
		501	\| CONTEXT (7) bytes CONSTRUCTED
		502	\| \| INTEGER int 1058588941
		503	\| \| INTEGER int 0
		504	\| \| INTEGER int 0
		505	\| \| SEQUENCE
		506	\| \| \| SEQUENCE
		507	\| \| \| \| OID oid 1.3.6.1.2.1.1.3.0
		508	\| \| \| \| TIMETICKS int 638085796
		509
		510	=back
		511
		512	=cut
		513
		514	# reverse enum, very slow and ugly hack
		515	sub _re {
		516	my ($export_tag, $value) = @_;
		517
		518	for my $symbol (@{ $EXPORT_TAGS{$export_tag} }) {
		519	$value == eval $symbol
		520	and return $symbol;
		521	}
		522
		523	"($value)"
		524	}
		525
		526	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		527
		528	sub _ber_dump {
		529	my ($ber, $profile, $indent) = @_;
		530
		531	if (my $seq = ber_is_seq $ber) {
		532	printf "%sSEQUENCE\n", $indent;
		533	&_ber_dump ($_, $profile, "$indent\| ")
		534	for @$seq;
		535	} else {
		536	my $asn = $ber->[BER_CLASS] == ASN_UNIVERSAL;
		537
		538	my $class = _re const_asn_class => $ber->[BER_CLASS];
		539	my $tag = $asn ? _re const_asn_tag => $ber->[BER_TAG] : $ber->[BER_TAG];
		540	my $type = _re const_ber_type => $profile->get ($ber->[BER_CLASS], $ber->[BER_TAG]);
		541	my $data = $ber->[BER_DATA];
		542
		543	if ($profile == $SNMP_PROFILE and $ber->[BER_CLASS] == ASN_APPLICATION) {
		544	$tag = _re const_snmp => $ber->[BER_TAG];
		545	} elsif (!$asn) {
		546	$tag = "$class ($tag)";
		547	}
		548
		549	$class =~ s/^ASN_//;
		550	$tag =~ s/^(ASN_\|SNMP_)//;
		551	$type =~ s/^BER_TYPE_//;
		552
		553	if ($ber->[BER_FLAGS]) {
		554	printf "$indent%-16.16s %-6.6s CONSTRUCTED\n", $tag, lc $type;
		555	&_ber_dump ($_, $profile, "$indent\| ")
		556	for @$data;
		557	} else {
		558	if ($data =~ y/\x20-\x7e//c / (length $data \|\| 1) > 0.2 or $data =~ /\x00./s) {
		559	# assume binary
		560	$data = unpack "H*", $data;
		561	} else {
		562	$data =~ s/[^\x20-\x7e]/./g;
		563	$data = "\"$data\"" if $type =~ /string/i \|\| !length $data;
		564	}
		565
		566	substr $data, 40, 1e9, "..." if 40 < length $data;
		567
		568	printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data;
		569	}
		570	}
		571	}
		572
		573	sub ber_dump($;$$) {
		574	_ber_dump $_[0], $_[1] \|\| $DEFAULT_PROFILE, $_[2];
		575	}
331		576
332	=head1 PROFILES	577	=head1 PROFILES
333		578
334	While any BER data can be correctly encoded and decoded out of the box, it	579	While any BER data can be correctly encoded and decoded out of the box, it
335	can be inconvenient to have to manually decode some values into a "better"	580	can be inconvenient to have to manually decode some values into a "better"
…		…
396		641
397	Returns the BER type mapped to the given C<$class>/C<$tag> combination.	642	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
398		643
399	=back	644	=back
400		645
401	=head2 BER TYPES	646	=head2 BER Types
402		647
403	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>	648	This lists the predefined BER types. BER types are formatters used
404	combination to any C<BER_TYPE_*>.	649	internally to format and encode BER values. You can assign any C<BER_TYPE>
		650	to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or
		651	encoded.
405		652
406	=over	653	=over
407		654
408	=item C<BER_TYPE_BYTES>	655	=item C<BER_TYPE_BYTES>
409		656
…		…
475	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	722	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
476	error for some types, then C<BER_TYPE_CROAK> is for you.	723	error for some types, then C<BER_TYPE_CROAK> is for you.
477		724
478	=back	725	=back
479		726
480	=cut	727	=head2 Example Profile
481		728
482	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	729	The following creates a profile suitable for SNMP - it's exactly identical
		730	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		731
483	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	732	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
484		733
485	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	734	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
486	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	735	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
487	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	736	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
488	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	737	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
489	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	738	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
490	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	739	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
491		740
492	$DEFAULT_PROFILE->_set_default;
493
494	1;
495
496	=head2 LIMITATIONS	741	=head2 LIMITATIONS/NOTES
497		742
498	This module can only en-/decode 64 bit signed and unsigned integers, and	743	This module can only en-/decode 64 bit signed and unsigned integers, and
499	only when your perl supports those.	744	only when your perl supports those. So no UUID OIDs for now (unless you
		745	map the C<OBJECT IDENTIFIER> tag to something other than C<BER_TYPE_OID>).
		746
		747	This module does not generally care about ranges, i.e. it will happily
		748	de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative
		749	number into an C<SNMP_COUNTER64>.
500		750
501	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is	751	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
502	much larger than e.g. the one imposed by SNMP or other protocols.	752	much larger than e.g. the one imposed by SNMP or other protocols, and is
		753	about 4kB.
503		754
		755	Indefinite length encoding is not supported.
		756
		757	Constructed strings are decoded just fine, but there should be a way to
		758	join them for convenience.
		759
504	REAL values are not supported and will croak.	760	REAL values are not supported and will currently croak.
		761
		762	The encoder and decoder tend to accept more formats than should be
		763	strictly supported - security sensitive applications are strongly advised
		764	to review the code first.
505		765
506	This module has undergone little to no testing so far.	766	This module has undergone little to no testing so far.
		767
		768	=head2 ITHREADS SUPPORT
		769
		770	This module is unlikely to work when the (officially discouraged) ithreads
		771	are in use.
507		772
508	=head1 AUTHOR	773	=head1 AUTHOR
509		774
510	Marc Lehmann <schmorp@schmorp.de>	775	Marc Lehmann <schmorp@schmorp.de>
511	http://software.schmorp.de/pkg/Convert-BER-XS	776	http://software.schmorp.de/pkg/Convert-BER-XS
512		777
513	=cut	778	=cut
514		779
		780	1;
		781

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.16 by root, Sat Apr 20 02:07:45 2019 UTC vs. Revision 1.47 by root, Sun Apr 21 10:40:30 2019 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.16 by root, Sat Apr 20 02:07:45 2019 UTC vs.
Revision 1.47 by root, Sun Apr 21 10:40:30 2019 UTC