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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.13 by root, Sat Apr 20 01:03:59 2019 UTC vs.
Revision 1.32 by root, Sat Apr 20 16:12:53 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" ],
…		…
42	# let's decode it a bit with some helper functions	42	# let's decode it a bit with some helper functions
43		43
44	my $msg = ber_is_seq $ber	44	my $msg = ber_is_seq $ber
45	or die "SNMP message does not start with a sequence";	45	or die "SNMP message does not start with a sequence";
46		46
47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0	47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0
48	or die "SNMP message does not start with snmp version\n";	48	or die "SNMP message does not start with snmp version\n";
49		49
50	# message is SNMP v1 or v2c?	50	# message is SNMP v1 or v2c?
51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {	51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {
52		52
…		…
55	my $trap = $msg->[2][BER_DATA];	55	my $trap = $msg->[2][BER_DATA];
56		56
57	# check whether trap is a cisco mac notification mac changed message	57	# check whether trap is a cisco mac notification mac changed message
58	if (	58	if (
59	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects	59	(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects
60	and (ber_is_i32 $trap->[2], 6)	60	and (ber_is_int $trap->[2], 6)
61	and (ber_is_i32 $trap->[3], 1) # mac changed msg	61	and (ber_is_int $trap->[3], 1) # mac changed msg
62	) {	62	) {
63	... and so on	63	... and so on
64		64
65	# finally, let's encode it again and hope it results in the same bit pattern	65	# finally, let's encode it again and hope it results in the same bit pattern
66		66
67	my $buf = ber_encode $ber;	67	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
68		68
69	=head1 DESCRIPTION	69	=head1 DESCRIPTION
70		70
71	WARNING: Before release 1.0, the API is not considered stable in any way.	71	WARNING: Before release 1.0, the API is not considered stable in any way.
72		72
73	This module implements a I<very> low level BER/DER en-/decoder.	73	This module implements a I<very> low level BER/DER en-/decoder.
74		74
75	If is tuned for low memory and high speed, while still maintaining some	75	It is tuned for low memory and high speed, while still maintaining some
76	level of user-friendlyness.	76	level of user-friendlyness.
77		77
78	Currently, not much is documented, as this is an initial release to	78	=head2 EXPORT TAGS AND CONSTANTS
79	reserve CPAN namespace, stay tuned for a few days.	79
		80	By default this module doesn't export any symbols, but if you don't want
		81	to break your keyboard, editor or eyesight with extremely long names, I
		82	recommend importing the C<:all> tag. Still, you can selectively import
		83	things.
		84
		85	=over
		86
		87	=item C<:all>
		88
		89	All of the below. Really. Recommended for at least first steps, or if you
		90	don't care about a few kilobytes of wasted memory (and namespace).
		91
		92	=item C<:const>
		93
		94	All of the strictly ASN.1-related constants defined by this module, the
		95	same as C<:const_asn :const_index>. Notably, this does not contain
		96	C<:const_ber_type> and C<:const_snmp>.
		97
		98	A good set to get everything you need to decode and match BER data would be
		99	C<:decode :const>.
		100
		101	=item C<:const_index>
		102
		103	The BER tuple array index constants:
		104
		105	BER_CLASS BER_TAG BER_FLAGS BER_DATA
		106
		107	=item C<:const_asn>
		108
		109	ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively -
		110	exactly thw two topmost bits from the identifier octet shifted 6 bits to
		111	the right):
		112
		113	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		114
		115	ASN tag values (some of which are aliases, such as C<ASN_OID>). Their
		116	numerical value corresponds exactly to the numbers used in BER/X.690.
		117
		118	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
		119	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		120	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		121	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		122	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		123	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		124
		125	=item C<:const_ber_type>
		126
		127	The BER type constants, explained in the PROFILES section.
		128
		129	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		130	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		131	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		132
		133	=item C<:const_snmp>
		134
		135	Constants only relevant to SNMP. These are the tag values used by SNMP in
		136	the C<ASN_APPLICATION> namespace and have the exact numerical value as in
		137	BER/RFC 2578.
		138
		139	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		140
		141	=item C<:decode>
		142
		143	C<ber_decode> and the match helper functions:
		144
		145	ber_decode ber_is ber_is_seq ber_is_int ber_is_oid
		146
		147	=item C<:encode>
		148
		149	C<ber_encode> and the construction helper functions:
		150
		151	ber_encode ber_int
		152
		153	=back
80		154
81	=head2 ASN.1/BER/DER/... BASICS	155	=head2 ASN.1/BER/DER/... BASICS
82		156
83	ASN.1 is a strange language that can be sed to describe protocols and	157	ASN.1 is a strange language that can be used to describe protocols and
84	data structures. It supports various mappings to JSON, XML, but most	158	data structures. It supports various mappings to JSON, XML, but most
85	importantly, to a various binary encodings such as BER, that is the topic	159	importantly, to a various binary encodings such as BER, that is the topic
86	of this module, and is used in SNMP or LDAP for example.	160	of this module, and is used in SNMP, LDAP or X.509 for example.
87		161
88	While ASN.1 defines a schema that is useful to interpret encoded data,	162	While ASN.1 defines a schema that is useful to interpret encoded data,
89	the BER encoding is actually somewhat self-describing: you might not know	163	the BER encoding is actually somewhat self-describing: you might not know
90	whether something is a string or a number or a sequence or something else,	164	whether something is a string or a number or a sequence or something else,
91	but you can nevertheless decode the overall structure, even if you end up	165	but you can nevertheless decode the overall structure, even if you end up
92	with just a binary blob for the actual value.	166	with just a binary blob for the actual value.
93		167
94	This works because BER values are tagged with a type and a namespace,	168	This works because BER values are tagged with a type and a namespace,
95	and also have a flag that says whther a value consists of subvalues (is	169	and also have a flag that says whether a value consists of subvalues (is
96	"constructed") or not (is "primitive").	170	"constructed") or not (is "primitive").
97		171
98	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of	172	Tags are simple integers, and ASN.1 defines a somewhat weird assortment
99	those - for example, you have 32 bit signed integers and 16(!) different	173	of those - for example, you have one integers and 16(!) different
100	string types, but there is no unsigned32 type for example. Different	174	string types, but there is no Unsigned32 type for example. Different
101	applications work around this in different ways, for example, SNMP defines	175	applications work around this in different ways, for example, SNMP defines
102	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
103	to two different tags: you can distinguish between Counter32 and the	177	to two different tags: you can distinguish between Counter32 and the
104	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.	178	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
105		179
…		…
108	=head2 DECODED BER REPRESENTATION	182	=head2 DECODED BER REPRESENTATION
109		183
110	This module represents every BER value as a 4-element tuple (actually an	184	This module represents every BER value as a 4-element tuple (actually an
111	array-reference):	185	array-reference):
112		186
113	[CLASS, TAG, CONSTRUCTED, DATA]	187	[CLASS, TAG, FLAGS, DATA]
		188
		189	For example:
		190
		191	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
		192	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
		193	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
		194	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
114		195
115	To avoid non-descriptive hardcoded array index numbers, this module	196	To avoid non-descriptive hardcoded array index numbers, this module
116	defines symbolic constants to access these members: C<BER_CLASS>,	197	defines symbolic constants to access these members: C<BER_CLASS>,
117	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	198	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
118		199
119	Also, the first three members are integers with a little caveat: for	200	Also, the first three members are integers with a little caveat: for
120	performance reasons, these are readonly and shared, so you must not modify	201	performance reasons, these are readonly and shared, so you must not modify
121	them (increment, assign to them etc.) in any way. You may modify the	202	them (increment, assign to them etc.) in any way. You may modify the
122	I<DATA> member, and you may re-assign the array itself, e.g.:	203	I<DATA> member, and you may re-assign the array itself, e.g.:
123		204
124	$ber = ber_decode $binbuf;	205	$ber = ber_decode $binbuf;
125		206
126	# the following is NOT legal:	207	# the following is NOT legal:
127	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)	208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
128		209
129	# but all of the following are fine:	210	# but all of the following are fine:
130	$ber->[BER_DATA] = "string";	211	$ber->[BER_DATA] = "string";
131	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
132	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);	213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
133		214
134	I<CLASS> is something like a namespace for I<TAG>s - there is the	215	I<CLASS> is something like a namespace for I<TAG>s - there is the
135	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1	216	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
136	implementations, the C<ASN_APPLICATION> namespace which defines tags for	217	implementations, the C<ASN_APPLICATION> namespace which defines tags for
137	specific applications (for example, the SNMP C<Unsigned32> type is in this	218	specific applications (for example, the SNMP C<Unsigned32> type is in this
138	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.	219	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
139	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).	220	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
140		221
141	The meaning of the I<TAG> depends on the namespace, and defines a	222	The meaning of the I<TAG> depends on the namespace, and defines a
142	(partial) interpretation of the data value. For example, right now, SNMP	223	(partial) interpretation of the data value. For example, SNMP defines
143	application namespace knowledge ix hardcoded into this module, so it	224	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
144	knows that SNMP C<Unsigned32> values need to be decoded into actual perl	225	of these, you need to tell this module how to handle those via profiles.
145	integers.
146		226
147	The most common tags in the C<ASN_UNIVERSAL> namespace are	227	The most common tags in the C<ASN_UNIVERSAL> namespace are
148	C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,	228	C<ASN_INTEGER>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,
149	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and	229	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
150	C<ASN_IA5_STRING>.	230	C<ASN_IA5_STRING>.
151		231
152	The most common tags in SNMP's C<ASN_APPLICATION> namespace	232	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
153	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,	233	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
154	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.	234	C<SNMP_COUNTER64>.
155		235
156	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the	236	The I<FLAGS> value is really just a boolean at this time (but might
157	the value is "primitive" and contains no subvalues, kind of like a	237	get extended) - if it is C<0>, the value is "primitive" and contains
158	non-reference perl scalar. IF it is true, then the value is "constructed"	238	no subvalues, kind of like a non-reference perl scalar. If it is C<1>,
159	which just means it contains a list of subvalues which this module will	239	then the value is "constructed" which just means it contains a list of
160	en-/decode as BER tuples themselves.	240	subvalues which this module will en-/decode as BER tuples themselves.
161		241
162	The I<DATA> value is either a reference to an array of further tuples (if	242	The I<DATA> value is either a reference to an array of further tuples
163	the value is I<CONSTRUCTED>), some decoded representation of the value,	243	(if the value is I<FLAGS>), some decoded representation of the value, if
164	if this module knows how to decode it (e.g. for the integer types above)	244	this module knows how to decode it (e.g. for the integer types above) or
165	or a binary string with the raw octets if this module doesn't know how to	245	a binary string with the raw octets if this module doesn't know how to
166	interpret the namespace/tag.	246	interpret the namespace/tag.
167		247
168	Thus, you can always decode a BER data structure and at worst you get a	248	Thus, you can always decode a BER data structure and at worst you get a
169	string in place of some nice decoded value.	249	string in place of some nice decoded value.
170		250
…		…
172		252
173	=head2 DECODING AND ENCODING	253	=head2 DECODING AND ENCODING
174		254
175	=over	255	=over
176		256
177	=item $tuple = ber_decoded $bindata	257	=item $tuple = ber_decoded $bindata[, $profile]
178		258
179	Decodes binary BER data in C<$bindata> and returns the resulting BER	259	Decodes binary BER data in C<$bindata> and returns the resulting BER
180	tuple. Croaks on any decoding error, so the returned C<$tuple> is always	260	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
181	valid.	261	valid.
182		262
		263	How tags are interpreted is defined by the second argument, which must
		264	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		265	profile will be used (C<$Convert::BER::XS::DEFAULT_PROFILE>).
		266
		267	In addition to rolling your own, this module provides a
		268	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
		269	types.
		270
		271	Example: decode a BER blob using the default profile - SNMP values will be
		272	decided as raw strings.
		273
		274	$tuple = ber_decode $data;
		275
		276	Example: as above, but use the provided SNMP profile.
		277
		278	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		279
183	=item $bindata = ber_encode $tuple	280	=item $bindata = ber_encode $tuple[, $profile]
184		281
185	Encodes the BER tuple into a BER/DER data structure.	282	Encodes the BER tuple into a BER/DER data structure. AS with
		283	Cyber_decode>, an optional profile can be given.
		284
		285	The encoded data should be both BER and DER ("shortest form") compliant
		286	unless the input says otherwise (e.g. it uses constructed strings).
186		287
187	=back	288	=back
188		289
189	=head2 HELPER FUNCTIONS	290	=head2 HELPER FUNCTIONS
190		291
191	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>	292	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
192	annoying. To reduce this a bit, this module defines a number of helper	293	annoying. To reduce this a bit, this module defines a number of helper
193	functions, both to match BER tuples and to conmstruct BER tuples:	294	functions, both to match BER tuples and to construct BER tuples:
194		295
195	=head3 MATCH HELPERS	296	=head3 MATCH HELPERS
196		297
197	Thse functions accept a BER tuple as first argument and either paertially	298	These functions accept a BER tuple as first argument and either partially
198	or fully match it. They often come in two forms, one which exactly matches	299	or fully match it. They often come in two forms, one which exactly matches
199	a value, and one which only matches the type and returns the value.	300	a value, and one which only matches the type and returns the value.
200		301
201	They do check whether valid tuples are passed in and croak otherwise. As	302	They do check whether valid tuples are passed in and croak otherwise. As
202	a ease-of-use exception, they usually also accept C<undef> instead of a	303	a ease-of-use exception, they usually also accept C<undef> instead of a
203	tuple reference. in which case they silently fail to match.	304	tuple reference, in which case they silently fail to match.
204		305
205	=over	306	=over
206		307
207	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	308	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
208		309
209	This takes a BER C<$tuple> and matches its elements agains the privded	310	This takes a BER C<$tuple> and matches its elements against the provided
210	values, all of which are optional - values that are either missing or	311	values, all of which are optional - values that are either missing or
211	C<undef> will be ignored, the others will be matched exactly (e.g. as if	312	C<undef> will be ignored, the others will be matched exactly (e.g. as if
212	you used C<==> or C<eq> (for C<$data>)).	313	you used C<==> or C<eq> (for C<$data>)).
213		314
214	Some examples:	315	Some examples:
…		…
217	orf die "tuple is not an ASN SEQUENCE";	318	orf die "tuple is not an ASN SEQUENCE";
218		319
219	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	320	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
220	or die "tuple is not an ASN NULL value";	321	or die "tuple is not an ASN NULL value";
221		322
222	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	323	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
223	or die "BER integer must be 50";	324	or die "BER integer must be 50";
224		325
225	=item $seq = ber_is_seq $tuple	326	=item $seq = ber_is_seq $tuple
226		327
227	Returns the sequence members (the array of subvalues) if the C<$tuple> is	328	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
234	my $snmp = ber_is_seq $ber	335	my $snmp = ber_is_seq $ber
235	or die "SNMP packet invalid: does not start with SEQUENCE";	336	or die "SNMP packet invalid: does not start with SEQUENCE";
236		337
237	# now we know $snmp is a sequence, so decode the SNMP version	338	# now we know $snmp is a sequence, so decode the SNMP version
238		339
239	my $version = ber_is_i32 $snmp->[0]	340	my $version = ber_is_int $snmp->[0]
240	or die "SNMP packet invalid: does not start with version number";	341	or die "SNMP packet invalid: does not start with version number";
241		342
242	=item $bool = ber_is_i32 $tuple, $i32	343	=item $bool = ber_is_int $tuple, $int
243		344
244	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	345	Returns a true value if the C<$tuple> represents an ASN INTEGER with
245	the value C<$i32>.	346	the value C<$int>.
246		347
247	=item $i32 = ber_is_i32 $tuple	348	=item $int = ber_is_int $tuple
248		349
249	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	350	Returns true (and extracts the integer value) if the C<$tuple> is an
250	INTEGER32. For C<0>, this function returns a special value that is 0 but	351	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
251	true.	352	but true.
252		353
253	=item $bool = ber_is_oid $tuple, $oid_string	354	=item $bool = ber_is_oid $tuple, $oid_string
254		355
255	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	356	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
256	that exactly matches C<$oid_string>. Example:	357	that exactly matches C<$oid_string>. Example:
…		…
267		368
268	=head3 CONSTRUCTION HELPERS	369	=head3 CONSTRUCTION HELPERS
269		370
270	=over	371	=over
271		372
272	=item $tuple = ber_i32 $value	373	=item $tuple = ber_int $value
273		374
274	Constructs a new C<ASN_INTEGER32> tuple.	375	Constructs a new C<ASN_INTEGER> tuple.
275		376
276	=back	377	=back
277		378
278	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	379	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
279		380
…		…
292	use Exporter qw(import);	393	use Exporter qw(import);
293		394
294	our $VERSION;	395	our $VERSION;
295		396
296	BEGIN {	397	BEGIN {
297	$VERSION = 0.7;	398	$VERSION = 0.9;
298	XSLoader::load __PACKAGE__, $VERSION;	399	XSLoader::load __PACKAGE__, $VERSION;
299	}	400	}
300		401
301	our %EXPORT_TAGS = (	402	our %EXPORT_TAGS = (
		403	const_index => [qw(
		404	BER_CLASS BER_TAG BER_FLAGS BER_DATA
		405	)],
302	const => [qw(	406	const_asn => [qw(
303	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA
304
305	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER	407	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
306	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED	408	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
307	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING	409	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
308	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING	410	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
309	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING	411	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
310	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING	412	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
311		413
312	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE	414	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
313		415	)],
		416	const_ber_type => [qw(
314	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT	417	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
315	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL	418	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
316	BER_TYPE_IPADDRESS BER_TYPE_CROAK	419	BER_TYPE_IPADDRESS BER_TYPE_CROAK
317	)],	420	)],
318	const_snmp => [qw(	421	const_snmp => [qw(
319	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	422	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
320	)],	423	)],
		424	decode => [qw(
		425	ber_decode
		426	ber_is ber_is_seq ber_is_int ber_is_oid
		427	)],
321	encode => [qw(	428	encode => [qw(
322	ber_decode
323	ber_is ber_is_seq ber_is_i32 ber_is_oid
324	)],
325	decode => [qw(
326	ber_encode	429	ber_encode
327	ber_i32	430	ber_int
328	)],	431	)],
329	);	432	);
330		433
331	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	434	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
332		435
333	$EXPORT_TAGS{all} = \@EXPORT_OK;	436	$EXPORT_TAGS{all} = \@EXPORT_OK;
		437	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
334		438
335	=head1 PROFILES	439	=head1 PROFILES
336		440
337	While any BER data can be correctly encoded and decoded out of the box, it	441	While any BER data can be correctly encoded and decoded out of the box, it
338	can be inconvenient to have to manually decode some values into a "better"	442	can be inconvenient to have to manually decode some values into a "better"
…		…
347		451
348	The default profile supports the standard ASN.1 types, but no	452	The default profile supports the standard ASN.1 types, but no
349	application-specific ones. This means that class/tag combinations not in	453	application-specific ones. This means that class/tag combinations not in
350	the base set of ASN.1 are decoded into their raw octet strings.	454	the base set of ASN.1 are decoded into their raw octet strings.
351		455
352	C<Convert::BER::XS> defines two profile variables you cna use out of the box:	456	C<Convert::BER::XS> defines two profile variables you can use out of the box:
353		457
354	=over	458	=over
355		459
356	=item C<$Convert::BER::XS::DEFAULT_PROFILE>	460	=item C<$Convert::BER::XS::DEFAULT_PROFILE>
357		461
358	This is the default profile, i.e. the profile that is used when no	462	This is the default profile, i.e. the profile that is used when no
359	profile is specified for de-/encoding.	463	profile is specified for de-/encoding.
360		464
361	You cna modify it, but remember that this modifies the defaults for all	465	You can modify it, but remember that this modifies the defaults for all
362	callers that rely on the defauit profile.	466	callers that rely on the default profile.
363		467
364	=item C<$Convert::BER::XS::SNMP_PROFILE>	468	=item C<$Convert::BER::XS::SNMP_PROFILE>
365		469
366	A profile with mappings for SNMP-specific application tags added. This is	470	A profile with mappings for SNMP-specific application tags added. This is
367	useful when de-/encoding SNMP data.	471	useful when de-/encoding SNMP data.
368		472
369	Example:	473	Example:
		474
370	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;	475	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
371		476
372	=back	477	=back
373		478
374	=head2 The Convert::BER::XS::Profile class	479	=head2 The Convert::BER::XS::Profile class
…		…
387		492
388	Note that currently, the mapping is stored in a flat array, so large	493	Note that currently, the mapping is stored in a flat array, so large
389	values of C<$tag> will consume large amounts of memory.	494	values of C<$tag> will consume large amounts of memory.
390		495
391	Example:	496	Example:
		497
392	$profile = new Convert::BER::XS::Profile;	498	$profile = new Convert::BER::XS::Profile;
393	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);	499	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);
394	$ber = ber_decode $data, $profile;	500	$ber = ber_decode $data, $profile;
395		501
396	=item $type = $profile->get ($class, $tag)	502	=item $type = $profile->get ($class, $tag)
…		…
419	string.	525	string.
420		526
421	=item C<BER_TYPE_UCS2>	527	=item C<BER_TYPE_UCS2>
422		528
423	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded	529	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded
424	string. NOT IMPLEMENTED.	530	string.
425		531
426	=item C<BER_TYPE_UCS4>	532	=item C<BER_TYPE_UCS4>
427		533
428	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded	534	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded
429	string. NOT IMPLEMENTED.	535	string.
430		536
431	=item C<BER_TYPE_INT>	537	=item C<BER_TYPE_INT>
432		538
433	Encodes and decodes a BER integer value to a perl integer scalar. This	539	Encodes and decodes a BER integer value to a perl integer scalar. This
434	should correctly handle 64 bit signed and unsigned values.	540	should correctly handle 64 bit signed and unsigned values.
…		…
438	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading	544	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading
439	dot, e.g. C<1.3.6.1.213>.	545	dot, e.g. C<1.3.6.1.213>.
440		546
441	=item C<BER_TYPE_RELOID>	547	=item C<BER_TYPE_RELOID>
442		548
443	Same as C<BER_TYPE_OID> but uses relative OID encoding: ASN.1 has this	549	Same as C<BER_TYPE_OID> but uses relative object identifier
444	hack of encoding the first two OID components into a single integer in a	550	encoding: ASN.1 has this hack of encoding the first two OID components
445	weird attempt to save an insignificant amount of space in an otherwise	551	into a single integer in a weird attempt to save an insignificant amount
446	wasteful encoding, and relative OIDs are basically OIDs without this	552	of space in an otherwise wasteful encoding, and relative OIDs are
447	hack. The practical difference is that the second component of an OID	553	basically OIDs without this hack. The practical difference is that the
448	can only have the values 1..40, while relative OIDs do not have this	554	second component of an OID can only have the values 1..40, while relative
449	restriction.	555	OIDs do not have this restriction.
450		556
451	=item C<BER_TYPE_NULL>	557	=item C<BER_TYPE_NULL>
452		558
453	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a	559	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a
454	C<ASN_NULL> type, regardless of the perl value.	560	C<ASN_NULL> type, regardless of the perl value.
…		…
462		568
463	Decodes/encodes a BER real value. NOT IMPLEMENTED.	569	Decodes/encodes a BER real value. NOT IMPLEMENTED.
464		570
465	=item C<BER_TYPE_IPADDRESS>	571	=item C<BER_TYPE_IPADDRESS>
466		572
467	Decodes/encodes a four byte string into an IOv4 dotted-quad address string	573	Decodes/encodes a four byte string into an IPv4 dotted-quad address string
468	in perl. Given ther obsolete nature of this type, this is a low-effort	574	in Perl. Given the obsolete nature of this type, this is a low-effort
469	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,	575	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,
470	so it won't handle all string forms supported by C<inet_aton>.	576	so it won't handle all string forms supported by C<inet_aton> for example.
471		577
472	=item C<BER_TYPE_CROAK>	578	=item C<BER_TYPE_CROAK>
473		579
474	Always croaks when encountered during encoding or decoding - the	580	Always croaks when encountered during encoding or decoding - the
475	default behaviour when encountering an unknown type is to treat it as	581	default behaviour when encountering an unknown type is to treat it as
476	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard	582	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
477	error for some types, then CyBER_TYPE_CROAK> is for you.	583	error for some types, then C<BER_TYPE_CROAK> is for you.
478		584
479	=back	585	=back
480		586
		587	=head2 Example Profile
		588
		589	The following creates a profile suitable for SNMP - it's exactly identical
		590	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		591
		592	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		593
		594	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		595	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		596	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		597	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		598	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		599	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		600
481	=cut	601	=cut
482		602
483	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;	603	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		604
		605	$DEFAULT_PROFILE->_set_default;
		606
		607	# additional SNMP application types
484	our $SNMP_PROFILE = new Convert::BER::XS::Profile;	608	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
485		609
486	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);	610	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
487	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);	611	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
488	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);	612	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
489	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);	613	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
490	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);	614	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
491	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);	615	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
492		616
493	$DEFAULT_PROFILE->_set_default;
494
495	1;	617	1;
496		618
497	=head2 LIMITATIONS	619	=head2 LIMITATIONS/NOTES
498		620
499	This module can only en-/decode 64 bit signed and unsigned integers, and	621	This module can only en-/decode 64 bit signed and unsigned integers, and
500	only when your perl supports those.	622	only when your perl supports those.
501		623
		624	This module does not generally care about ranges, i.e. it will happily
		625	de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative
		626	number into an C<SNMP_COUNTER64>.
		627
502	OBJECT IDENTIFIEERS cannot have unlimited length, although the limit is	628	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
503	much larger than e.g. the one imposed by SNMP or other protocols.	629	much larger than e.g. the one imposed by SNMP or other protocols,a nd is
		630	about 4kB.
		631
		632	Indefinite length encoding is not supported.
		633
		634	Constructed strings are decoded just fine, but there should be a way to
		635	join them for convenience.
		636
		637	REAL values are not supported and will currently croak.
		638
		639	The encoder and decoder tend to accept more formats than should be
		640	strictly supported.
		641
		642	This module has undergone little to no testing so far.
		643
		644	=head2 ITHREADS SUPPORT
		645
		646	This module is unlikely to work when the (officially discouraged) ithreads
		647	are in use.
504		648
505	=head1 AUTHOR	649	=head1 AUTHOR
506		650
507	Marc Lehmann <schmorp@schmorp.de>	651	Marc Lehmann <schmorp@schmorp.de>
508	http://software.schmorp.de/pkg/Convert-BER-XS	652	http://software.schmorp.de/pkg/Convert-BER-XS

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.13 by root, Sat Apr 20 01:03:59 2019 UTC vs. Revision 1.32 by root, Sat Apr 20 16:12:53 2019 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.13 by root, Sat Apr 20 01:03:59 2019 UTC vs.
Revision 1.32 by root, Sat Apr 20 16:12:53 2019 UTC