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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.17 by root, Sat Apr 20 13:46:14 2019 UTC vs.
Revision 1.62 by root, Thu Feb 6 23:15:44 2020 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.
72
73	This module implements a I<very> low level BER/DER en-/decoder.	74	This module implements a I<very> low level BER/DER en-/decoder.
74		75
75	If is tuned for low memory and high speed, while still maintaining some	76	It is tuned for low memory and high speed, while still maintaining some
76	level of user-friendlyness.	77	level of user-friendlyness.
		78
		79	=head2 EXPORT TAGS AND CONSTANTS
		80
		81	By default this module doesn't export any symbols, but if you don't want
		82	to break your keyboard, editor or eyesight with extremely long names, I
		83	recommend importing the C<:all> tag. Still, you can selectively import
		84	things.
		85
		86	=over
		87
		88	=item C<:all>
		89
		90	All of the below. Really. Recommended for at least first steps, or if you
		91	don't care about a few kilobytes of wasted memory (and namespace).
		92
		93	=item C<:const>
		94
		95	All of the strictly ASN.1-related constants defined by this module, the
		96	same as C<:const_asn :const_index>. Notably, this does not contain
		97	C<:const_ber_type> and C<:const_snmp>.
		98
		99	A good set to get everything you need to decode and match BER data would be
		100	C<:decode :const>.
		101
		102	=item C<:const_index>
		103
		104	The BER tuple array index constants:
		105
		106	BER_CLASS BER_TAG BER_FLAGS BER_DATA
		107
		108	=item C<:const_asn>
		109
		110	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -
		111	exactly the two topmost bits from the identifier octet shifted 6 bits to
		112	the right):
		113
		114	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		115
		116	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their
		117	numerical value corresponds exactly to the numbers used in BER/X.690.
		118
		119	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID
		120	ASN_OBJECT_IDENTIFIER ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		121	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		122	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		123	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		124	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		125
		126	=item C<:const_ber_type>
		127
		128	The BER type constants, explained in the PROFILES section.
		129
		130	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		131	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		132	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		133
		134	=item C<:const_snmp>
		135
		136	Constants only relevant to SNMP. These are the tag values used by SNMP in
		137	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
		138	BER/RFC 2578.
		139
		140	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_GAUGE32
		141	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		142
		143	=item C<:decode>
		144
		145	C<ber_decode> and the match helper functions:
		146
		147	ber_decode ber-decode_prefix
		148	ber_is ber_is_seq ber_is_int ber_is_oid
		149	ber_dump
		150
		151	=item C<:encode>
		152
		153	C<ber_encode> and the construction helper functions:
		154
		155	ber_encode
		156	ber_int
		157
		158	=back
77		159
78	=head2 ASN.1/BER/DER/... BASICS	160	=head2 ASN.1/BER/DER/... BASICS
79		161
80	ASN.1 is a strange language that can be used to describe protocols and	162	ASN.1 is a strange language that can be used to describe protocols and
81	data structures. It supports various mappings to JSON, XML, but most	163	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	164	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.	165	of this module, and is used in SNMP, LDAP or X.509 for example.
84		166
85	While ASN.1 defines a schema that is useful to interpret encoded data,	167	While ASN.1 defines a schema that is useful to interpret encoded data,
86	the BER encoding is actually somewhat self-describing: you might not know	168	the BER encoding is actually somewhat self-describing: you might not know
87	whether something is a string or a number or a sequence or something else,	169	whether something is a string or a number or a sequence or something else,
88	but you can nevertheless decode the overall structure, even if you end up	170	but you can nevertheless decode the overall structure, even if you end up
…		…
90		172
91	This works because BER values are tagged with a type and a namespace,	173	This works because BER values are tagged with a type and a namespace,
92	and also have a flag that says whether a value consists of subvalues (is	174	and also have a flag that says whether a value consists of subvalues (is
93	"constructed") or not (is "primitive").	175	"constructed") or not (is "primitive").
94		176
95	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of	177	Tags are simple integers, and ASN.1 defines a somewhat weird assortment
96	those - for example, you have 32 bit signed integers and 16(!) different	178	of those - for example, you have one integers and 16(!) different
97	string types, but there is no unsigned32 type for example. Different	179	string types, but there is no Unsigned32 type for example. Different
98	applications work around this in different ways, for example, SNMP defines	180	applications work around this in different ways, for example, SNMP defines
99	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	181	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
100	to two different tags: you can distinguish between Counter32 and the	182	to two different tags: you can distinguish between Counter32 and the
101	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.	183	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
102		184
…		…
105	=head2 DECODED BER REPRESENTATION	187	=head2 DECODED BER REPRESENTATION
106		188
107	This module represents every BER value as a 4-element tuple (actually an	189	This module represents every BER value as a 4-element tuple (actually an
108	array-reference):	190	array-reference):
109		191
110	[CLASS, TAG, CONSTRUCTED, DATA]	192	[CLASS, TAG, FLAGS, DATA]
		193
		194	For example:
		195
		196	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
		197	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
		198	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
		199	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
111		200
112	To avoid non-descriptive hardcoded array index numbers, this module	201	To avoid non-descriptive hardcoded array index numbers, this module
113	defines symbolic constants to access these members: C<BER_CLASS>,	202	defines symbolic constants to access these members: C<BER_CLASS>,
114	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	203	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
115		204
116	Also, the first three members are integers with a little caveat: for	205	Also, the first three members are integers with a little caveat: for
117	performance reasons, these are readonly and shared, so you must not modify	206	performance reasons, these are readonly and shared, so you must not modify
118	them (increment, assign to them etc.) in any way. You may modify the	207	them (increment, assign to them etc.) in any way. You may modify the
119	I<DATA> member, and you may re-assign the array itself, e.g.:	208	I<DATA> member, and you may re-assign the array itself, e.g.:
120		209
121	$ber = ber_decode $binbuf;	210	$ber = ber_decode $binbuf;
122		211
123	# the following is NOT legal:	212	# the following is NOT legal:
124	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)	213	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
125		214
126	# but all of the following are fine:	215	# but all of the following are fine:
127	$ber->[BER_DATA] = "string";	216	$ber->[BER_DATA] = "string";
128	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	217	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
129	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	218	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
130		219
131	I<CLASS> is something like a namespace for I<TAG>s - there is the	220	I<CLASS> is something like a namespace for I<TAG>s - there is the
132	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1	221	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
133	implementations, the C<ASN_APPLICATION> namespace which defines tags for	222	implementations, the C<ASN_APPLICATION> namespace which defines tags for
134	specific applications (for example, the SNMP C<Unsigned32> type is in this	223	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.	224	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
136	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).	225	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
137		226
138	The meaning of the I<TAG> depends on the namespace, and defines a	227	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	228	(partial) interpretation of the data value. For example, SNMP defines
140	application namespace knowledge ix hardcoded into this module, so it	229	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	230	of these, you need to tell this module how to handle those via profiles.
142	integers.
143		231
144	The most common tags in the C<ASN_UNIVERSAL> namespace are	232	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>,	233	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	234	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
147	C<ASN_IA5_STRING>.	235	C<ASN_IA5_STRING>.
148		236
149	The most common tags in SNMP's C<ASN_APPLICATION> namespace	237	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
150	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,	238	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
151	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.	239	C<SNMP_COUNTER64>.
152		240
153	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the	241	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	242	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"	243	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	244	then the value is "constructed" which just means it contains a list of
157	en-/decode as BER tuples themselves.	245	subvalues which this module will en-/decode as BER tuples themselves.
158		246
159	The I<DATA> value is either a reference to an array of further tuples (if	247	The I<DATA> value is either a reference to an array of further tuples
160	the value is I<CONSTRUCTED>), some decoded representation of the value,	248	(if the value is I<FLAGS>), some decoded representation of the value, if
161	if this module knows how to decode it (e.g. for the integer types above)	249	this module knows how to decode it (e.g. for the integer types above) or
162	or a binary string with the raw octets if this module doesn't know how to	250	a binary string with the raw octets if this module doesn't know how to
163	interpret the namespace/tag.	251	interpret the namespace/tag.
164		252
165	Thus, you can always decode a BER data structure and at worst you get a	253	Thus, you can always decode a BER data structure and at worst you get a
166	string in place of some nice decoded value.	254	string in place of some nice decoded value.
167		255
…		…
169		257
170	=head2 DECODING AND ENCODING	258	=head2 DECODING AND ENCODING
171		259
172	=over	260	=over
173		261
174	=item $tuple = ber_decoded $bindata	262	=item $tuple = ber_decode $bindata[, $profile]
175		263
176	Decodes binary BER data in C<$bindata> and returns the resulting BER	264	Decodes binary BER data in C<$bindata> and returns the resulting BER
177	tuple. Croaks on any decoding error, so the returned C<$tuple> is always	265	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
178	valid.	266	valid.
179		267
		268	How tags are interpreted is defined by the second argument, which must
		269	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		270	profile will be used (C<$Convert::BER::XS::DEFAULT_PROFILE>).
		271
		272	In addition to rolling your own, this module provides a
		273	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
		274	types.
		275
		276	Example: decode a BER blob using the default profile - SNMP values will be
		277	decided as raw strings.
		278
		279	$tuple = ber_decode $data;
		280
		281	Example: as above, but use the provided SNMP profile.
		282
		283	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		284
		285	=item ($tuple, $bytes) = ber_decode_prefix $bindata[, $profile]
		286
		287	Works like C<ber_decode>, except it doesn't croak when there is data after
		288	the BER data, but instead returns the decoded value and the number of
		289	bytes it decoded.
		290
		291	This is useful when you have BER data at the start of a buffer and other
		292	data after, and you need to find the length.
		293
		294	Also, since BER is self-delimited, this can be used to decode multiple BER
		295	values joined together.
		296
180	=item $bindata = ber_encode $tuple	297	=item $bindata = ber_encode $tuple[, $profile]
181		298
182	Encodes the BER tuple into a BER/DER data structure.	299	Encodes the BER tuple into a BER/DER data structure. As with
		300	Cyber_decode>, an optional profile can be given.
		301
		302	The encoded data should be both BER and DER ("shortest form") compliant
		303	unless the input says otherwise (e.g. it uses constructed strings).
183		304
184	=back	305	=back
185		306
186	=head2 HELPER FUNCTIONS	307	=head2 HELPER FUNCTIONS
187		308
188	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>	309	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	310	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:	311	functions, both to match BER tuples and to construct BER tuples:
191		312
192	=head3 MATCH HELPERS	313	=head3 MATCH HELPERS
193		314
194	Thse functions accept a BER tuple as first argument and either paertially	315	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	316	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.	317	a value, and one which only matches the type and returns the value.
197		318
198	They do check whether valid tuples are passed in and croak otherwise. As	319	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	320	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.	321	tuple reference, in which case they silently fail to match.
201		322
202	=over	323	=over
203		324
204	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	325	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
205		326
206	This takes a BER C<$tuple> and matches its elements agains the privded	327	This takes a BER C<$tuple> and matches its elements against the provided
207	values, all of which are optional - values that are either missing or	328	values, all of which are optional - values that are either missing or
208	C<undef> will be ignored, the others will be matched exactly (e.g. as if	329	C<undef> will be ignored, the others will be matched exactly (e.g. as if
209	you used C<==> or C<eq> (for C<$data>)).	330	you used C<==> or C<eq> (for C<$data>)).
210		331
211	Some examples:	332	Some examples:
…		…
214	orf die "tuple is not an ASN SEQUENCE";	335	orf die "tuple is not an ASN SEQUENCE";
215		336
216	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	337	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
217	or die "tuple is not an ASN NULL value";	338	or die "tuple is not an ASN NULL value";
218		339
219	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	340	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
220	or die "BER integer must be 50";	341	or die "BER integer must be 50";
221		342
222	=item $seq = ber_is_seq $tuple	343	=item $seq = ber_is_seq $tuple
223		344
224	Returns the sequence members (the array of subvalues) if the C<$tuple> is	345	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
231	my $snmp = ber_is_seq $ber	352	my $snmp = ber_is_seq $ber
232	or die "SNMP packet invalid: does not start with SEQUENCE";	353	or die "SNMP packet invalid: does not start with SEQUENCE";
233		354
234	# now we know $snmp is a sequence, so decode the SNMP version	355	# now we know $snmp is a sequence, so decode the SNMP version
235		356
236	my $version = ber_is_i32 $snmp->[0]	357	my $version = ber_is_int $snmp->[0]
237	or die "SNMP packet invalid: does not start with version number";	358	or die "SNMP packet invalid: does not start with version number";
238		359
239	=item $bool = ber_is_i32 $tuple, $i32	360	=item $bool = ber_is_int $tuple, $int
240		361
241	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	362	Returns a true value if the C<$tuple> represents an ASN INTEGER with
242	the value C<$i32>.	363	the value C<$int>.
243		364
244	=item $i32 = ber_is_i32 $tuple	365	=item $int = ber_is_int $tuple
245		366
246	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	367	Returns true (and extracts the integer value) if the C<$tuple> is an
247	INTEGER32. For C<0>, this function returns a special value that is 0 but	368	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
248	true.	369	but true.
249		370
250	=item $bool = ber_is_oid $tuple, $oid_string	371	=item $bool = ber_is_oid $tuple, $oid_string
251		372
252	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	373	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
253	that exactly matches C<$oid_string>. Example:	374	that exactly matches C<$oid_string>. Example:
…		…
264		385
265	=head3 CONSTRUCTION HELPERS	386	=head3 CONSTRUCTION HELPERS
266		387
267	=over	388	=over
268		389
269	=item $tuple = ber_i32 $value	390	=item $tuple = ber_int $value
270		391
271	Constructs a new C<ASN_INTEGER32> tuple.	392	Constructs a new C<ASN_INTEGER> tuple.
272		393
273	=back	394	=back
274		395
275	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	396	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
276		397
…		…
286	use common::sense;	407	use common::sense;
287		408
288	use XSLoader ();	409	use XSLoader ();
289	use Exporter qw(import);	410	use Exporter qw(import);
290		411
		412	use Carp ();
		413
291	our $VERSION;	414	our $VERSION;
292		415
293	BEGIN {	416	BEGIN {
294	$VERSION = 0.7;	417	$VERSION = 1.21;
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	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		473
		474	# decodes REAL values according to ECMA-63
		475	# this is pretty strict, except it doesn't catch -0.
		476	# I don't have access to ISO 6093 (or BS 6727, or ANSI X.3-42)), so this is all guesswork.
		477	sub _decode_real_decimal {
		478	my ($format, $val) = @_;
		479
		480	$val =~ y/,/./; # probably not in ISO-6093
		481
		482	if ($format == 1) {
		483	$val =~ /^ \ * [+-]? [0-9]+ \z/x
		484	or Carp::croak "BER_TYPE_REAL NR1 value not in NR1 format ($val) (X.690 8.5.8)";
		485	} elsif ($format == 2) {
		486	$val =~ /^ \ * [+-]? (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) \z/x
		487	or Carp::croak "BER_TYPE_REAL NR2 value not in NR2 format ($val) (X.690 8.5.8)";
		488	} elsif ($format == 3) {
		489	$val =~ /^ \ * [+-] (?: [0-9]+\.[0-9]* \| [0-9]*\.[0-9]+ ) [eE] [+-]? [0-9]+ \z/x
		490	or Carp::croak "BER_TYPE_REAL NR3 value not in NR3 format ($val) (X.690 8.5.8)";
		491	} else {
		492	Carp::croak "BER_TYPE_REAL invalid decimal numerical representation format $format";
		493	}
		494
		495	$val
		496	}
		497
		498	# this is a mess, but perl's support for floating point formatting is nearly nonexistant
		499	sub _encode_real_decimal {
		500	my ($val, $nvdig) = @_;
		501
		502	$val = sprintf "%.*G", $nvdig + 1, $val;
		503
		504	if ($val =~ /E/) {
		505	$val =~ s/E(?=[^+-])/E+/;
		506	$val =~ s/E/.E/ if $val !~ /\./;
		507	$val =~ s/^/+/ unless $val =~ /^-/;
		508
		509	return "\x03$val" # NR3
		510	}
		511
		512	$val =~ /\./
		513	? "\x02$val" # NR2
		514	: "\x01$val" # NR1
		515	}
		516
		517	=head2 DEBUGGING
		518
		519	To aid debugging, you can call the C<ber_dump> function to print a "nice"
		520	representation to STDOUT.
		521
		522	=over
		523
		524	=item ber_dump $tuple[, $profile[, $prefix]]
		525
		526	In addition to specifying the BER C<$tuple> to dump, you can also specify
		527	a C<$profile> and a C<$prefix> string that is printed in front of each line.
		528
		529	If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump>
		530	will try to improve its output for SNMP data.
		531
		532	The output usually contains three columns, the "human readable" tag, the
		533	BER type used to decode it, and the data value.
		534
		535	This function is somewhat slow and uses a number of heuristics and tricks,
		536	so it really is only suitable for debug prints.
		537
		538	Example output:
		539
		540	SEQUENCE
		541	\| OCTET_STRING bytes 800063784300454045045400000001
		542	\| OCTET_STRING bytes
		543	\| CONTEXT (7) CONSTRUCTED
		544	\| \| INTEGER int 1058588941
		545	\| \| INTEGER int 0
		546	\| \| INTEGER int 0
		547	\| \| SEQUENCE
		548	\| \| \| SEQUENCE
		549	\| \| \| \| OID oid 1.3.6.1.2.1.1.3.0
		550	\| \| \| \| TIMETICKS int 638085796
		551
		552	=back
		553
		554	=cut
		555
		556	# reverse enum, very slow and ugly hack
		557	sub _re {
		558	my ($export_tag, $value) = @_;
		559
		560	for my $symbol (@{ $EXPORT_TAGS{$export_tag} }) {
		561	$value == eval $symbol
		562	and return $symbol;
		563	}
		564
		565	"($value)"
		566	}
		567
		568	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		569
		570	sub _ber_dump {
		571	my ($ber, $profile, $indent) = @_;
		572
		573	if (my $seq = ber_is_seq $ber) {
		574	printf "%sSEQUENCE\n", $indent;
		575	&_ber_dump ($_, $profile, "$indent\| ")
		576	for @$seq;
		577	} else {
		578	my $asn = $ber->[BER_CLASS] == ASN_UNIVERSAL;
		579
		580	my $class = _re const_asn_class => $ber->[BER_CLASS];
		581	my $tag = $asn ? _re const_asn_tag => $ber->[BER_TAG] : $ber->[BER_TAG];
		582	my $type = _re const_ber_type => $profile->get ($ber->[BER_CLASS], $ber->[BER_TAG]);
		583	my $data = $ber->[BER_DATA];
		584
		585	if ($profile == $SNMP_PROFILE and $ber->[BER_CLASS] == ASN_APPLICATION) {
		586	$tag = _re const_snmp => $ber->[BER_TAG];
		587	} elsif (!$asn) {
		588	$tag = "$class ($tag)";
		589	}
		590
		591	$class =~ s/^ASN_//;
		592	$tag =~ s/^(ASN_\|SNMP_)//;
		593	$type =~ s/^BER_TYPE_//;
		594
		595	if ($ber->[BER_FLAGS]) {
		596	printf "$indent%-16.16s\n", $tag;
		597	&_ber_dump ($_, $profile, "$indent\| ")
		598	for @$data;
		599	} else {
		600	if ($data =~ y/\x20-\x7e//c / (length $data \|\| 1) > 0.2 or $data =~ /\x00./s) {
		601	# assume binary
		602	$data = unpack "H*", $data;
		603	} else {
		604	$data =~ s/[^\x20-\x7e]/./g;
		605	$data = "\"$data\"" if $tag =~ /string/i \|\| !length $data;
		606	}
		607
		608	substr $data, 40, 1e9, "..." if 40 < length $data;
		609
		610	printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data;
		611	}
		612	}
		613	}
		614
		615	sub ber_dump($;$$) {
		616	_ber_dump $_[0], $_[1] \|\| $DEFAULT_PROFILE, $_[2];
		617	}
331		618
332	=head1 PROFILES	619	=head1 PROFILES
333		620
334	While any BER data can be correctly encoded and decoded out of the box, it	621	While any BER data can be correctly encoded and decoded out of the box, it
335	can be inconvenient to have to manually decode some values into a "better"	622	can be inconvenient to have to manually decode some values into a "better"
…		…
396		683
397	Returns the BER type mapped to the given C<$class>/C<$tag> combination.	684	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
398		685
399	=back	686	=back
400		687
401	=head2 BER TYPES	688	=head2 BER Types
402		689
403	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>	690	This lists the predefined BER types. BER types are formatters used
404	combination to any C<BER_TYPE_*>.	691	internally to format and encode BER values. You can assign any C<BER_TYPE>
		692	to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or
		693	encoded.
405		694
406	=over	695	=over
407		696
408	=item C<BER_TYPE_BYTES>	697	=item C<BER_TYPE_BYTES>
409		698
…		…
438	dot, e.g. C<1.3.6.1.213>.	727	dot, e.g. C<1.3.6.1.213>.
439		728
440	=item C<BER_TYPE_RELOID>	729	=item C<BER_TYPE_RELOID>
441		730
442	Same as C<BER_TYPE_OID> but uses relative object identifier	731	Same as C<BER_TYPE_OID> but uses relative object identifier
443	encoding: ASN.1 has this hack of encoding the first two OID components	732	encoding: ASN.1 uses some hack encoding of the first two OID components
444	into a single integer in a weird attempt to save an insignificant amount	733	into a single integer in a weird attempt to save an insignificant amount
445	of space in an otherwise wasteful encoding, and relative OIDs are	734	of space in an otherwise wasteful encoding, and relative OIDs are
446	basically OIDs without this hack. The practical difference is that the	735	basically OIDs without this hack. The practical difference is that the
447	second component of an OID can only have the values 1..40, while relative	736	second component of an OID can only have the values 1..40, while relative
448	OIDs do not have this restriction.	737	OIDs do not have this restriction.
…		…
475	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	764	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
476	error for some types, then C<BER_TYPE_CROAK> is for you.	765	error for some types, then C<BER_TYPE_CROAK> is for you.
477		766
478	=back	767	=back
479		768
480	=cut	769	=head2 Example Profile
481		770
482	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	771	The following creates a profile suitable for SNMP - it's exactly identical
		772	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		773
483	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	774	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
484		775
485	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	776	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
486	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	777	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
487	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	778	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
488	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	779	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
489	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	780	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES);
490	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	781	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
491		782
492	$DEFAULT_PROFILE->_set_default;
493
494	1;
495
496	=head2 LIMITATIONS	783	=head2 LIMITATIONS/NOTES
497		784
498	This module can only en-/decode 64 bit signed and unsigned integers, and	785	This module can only en-/decode 64 bit signed and unsigned
499	only when your perl supports those.	786	integers/tags/lengths, and only when your perl supports those. So no UUID
		787	OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something
		788	other than C<BER_TYPE_OID>).
		789
		790	This module does not generally care about ranges, i.e. it will happily
		791	de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative
		792	number into an C<SNMP_COUNTER64>.
500		793
501	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is	794	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
502	much larger than e.g. the one imposed by SNMP or other protocols.	795	much larger than e.g. the one imposed by SNMP or other protocols, and is
		796	about 4kB.
503		797
504	REAL values are not supported and will croak.	798	Constructed strings are decoded just fine, but there should be a way to
		799	join them for convenience.
505		800
506	This module has undergone little to no testing so far.	801	REAL values will always be encoded in decimal form and ssometimes is
		802	forced into a perl "NV" type, potentially losing precision.
507		803
508	=head2 ITHREADS SUPPORT	804	=head2 ITHREADS SUPPORT
509		805
510	This module is unlikely to work when the (officially discouraged) ithreads	806	This module is unlikely to work in any other than the loading thread when
511	are in use.	807	the (officially discouraged) ithreads are in use.
512		808
513	=head1 AUTHOR	809	=head1 AUTHOR
514		810
515	Marc Lehmann <schmorp@schmorp.de>	811	Marc Lehmann <schmorp@schmorp.de>
516	http://software.schmorp.de/pkg/Convert-BER-XS	812	http://software.schmorp.de/pkg/Convert-BER-XS
517		813
518	=cut	814	=cut
519		815
		816	1;
		817

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.17 by root, Sat Apr 20 13:46:14 2019 UTC vs. Revision 1.62 by root, Thu Feb 6 23:15:44 2020 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.17 by root, Sat Apr 20 13:46:14 2019 UTC vs.
Revision 1.62 by root, Thu Feb 6 23:15:44 2020 UTC