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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.6 by root, Fri Apr 19 20:38:38 2019 UTC vs.
Revision 1.25 by root, Sat Apr 20 15:23:26 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 (class, tag,	12	# The above results in a data structure consisting of
		13	# (class, tag, # constructed, data)
13	# constructed, data) tuples. Below is such a message, SNMPv1 trap	14	# tuples. Below is such a message, SNMPv1 trap
14	# with a Cisco mac change notification.	15	# with a Cisco mac change notification.
15	# Did you know that Cisco is in the news almost every week because	16	# Did you know that Cisco is in the news almost
		17	# every week because of some backdoor password
16	# of some backdoor password or other extremely stupid security bug?	18	# or other extremely stupid security bug?
17		19
18	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,	20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,
19	[	21	[
20	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1	22	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 0 ], # snmp version 1
21	[ ASN_UNIVERSAL, 4, 0, "public" ], # community	23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community
22	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU	24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU
23	[	25	[
24	[ 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
25	[ 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
26	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap	28	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 6 ], # generic trap
27	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap	29	[ ASN_UNIVERSAL, ASN_INTEGER, 0, 1 ], # specific trap
28	[ ASN_APPLICATION, ASN_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks	30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks
29	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist	31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist
30	[	32	[
31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair	33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair
32	[	34	[
33	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ], # the oid	35	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ],
34	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value	36	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value
35	]	37	]
36	]	38	]
37	],	39	],
38	...	40	...
…		…
40	# let's decode it a bit with some helper functions	42	# let's decode it a bit with some helper functions
41		43
42	my $msg = ber_is_seq $ber	44	my $msg = ber_is_seq $ber
43	or die "SNMP message does not start with a sequence";	45	or die "SNMP message does not start with a sequence";
44		46
45	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0	47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0
46	or die "SNMP message does not start with snmp version\n";	48	or die "SNMP message does not start with snmp version\n";
47		49
48	# message is SNMP v1 or v2c?	50	# message is SNMP v1 or v2c?
49	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {	51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {
50		52
…		…
53	my $trap = $msg->[2][BER_DATA];	55	my $trap = $msg->[2][BER_DATA];
54		56
55	# check whether trap is a cisco mac notification mac changed message	57	# check whether trap is a cisco mac notification mac changed message
56	if (	58	if (
57	(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
58	and (ber_is_i32 $trap->[2], 6)	60	and (ber_is_int $trap->[2], 6)
59	and (ber_is_i32 $trap->[3], 1) # mac changed msg	61	and (ber_is_int $trap->[3], 1) # mac changed msg
60	) {	62	) {
61	... and so on	63	... and so on
62		64
63	# 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
64		66
65	my $buf = ber_encode $ber;	67	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
66		68
67	=head1 DESCRIPTION	69	=head1 DESCRIPTION
68		70
		71	WARNING: Before release 1.0, the API is not considered stable in any way.
		72
69	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.
70		74
71	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
72	level of user-friendlyness.	76	level of user-friendlyness.
73		77
74	Currently, not much is documented, as this is an initial release to	78	=head2 EXPORT TAGS AND CONSTANTS
75	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_CONSTRUCTED 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
76		154
77	=head2 ASN.1/BER/DER/... BASICS	155	=head2 ASN.1/BER/DER/... BASICS
78		156
79	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
80	data structures. It supports various mappings to JSON, XML, but most	158	data structures. It supports various mappings to JSON, XML, but most
81	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
82	of this module, and is used in SNMP or LDAP for example.	160	of this module, and is used in SNMP or LDAP for example.
83		161
84	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,
85	the BER encoding is actually somehat self-describing: you might not know	163	the BER encoding is actually somewhat self-describing: you might not know
86	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,
87	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
88	with just a binary blob for the actual value.	166	with just a binary blob for the actual value.
89		167
90	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,
91	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
92	"constructed") or not (is "primitive").	170	"constructed") or not (is "primitive").
93		171
94	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
95	those - for example, you have 32 bit signed integers and 16(!) different	173	of those - for example, you have one integers and 16(!) different
96	string types, but there is no unsigned32 type for example. Different	174	string types, but there is no Unsigned32 type for example. Different
97	applications work around this in different ways, for example, SNMP defines	175	applications work around this in different ways, for example, SNMP defines
98	application-specific Gauge32, Counter32 and Unsigned32, which are mapped	176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
99	to two different tags: you can distinguish between Counter32 and the	177	to two different tags: you can distinguish between Counter32 and the
100	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.
101		179
…		…
106	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
107	array-reference):	185	array-reference):
108		186
109	[CLASS, TAG, CONSTRUCTED, DATA]	187	[CLASS, TAG, CONSTRUCTED, DATA]
110		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
		195
111	To avoid non-descriptive hardcoded array index numbers, this module	196	To avoid non-descriptive hardcoded array index numbers, this module
112	defines symbolic constants to access these members: C<BER_CLASS>,	197	defines symbolic constants to access these members: C<BER_CLASS>,
113	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.	198	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.
114		199
115	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
…		…
118	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.:
119		204
120	$ber = ber_decode $binbuf;	205	$ber = ber_decode $binbuf;
121		206
122	# the following is NOT legal:	207	# the following is NOT legal:
123	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, readonly(!)	208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)
124		209
125	# but all of the following are fine:	210	# but all of the following are fine:
126	$ber->[BER_DATA] = "string";	211	$ber->[BER_DATA] = "string";
127	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];	212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
128	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 1000);	213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
129		214
130	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
131	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
132	implementations, the C<ASN_APPLICATION> namespace which defines tags for	217	implementations, the C<ASN_APPLICATION> namespace which defines tags for
133	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
134	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.
135	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).	220	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
136		221
137	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
138	(partial) interpretation of the data value. For example, right now, SNMP	223	(partial) interpretation of the data value. For example, SNMP defines
139	application namespace knowledge ix hardcoded into this module, so it	224	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
140	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.
141	integers.
142		226
143	The most common tags in the C<ASN_UNIVERSAL> namespace are	227	The most common tags in the C<ASN_UNIVERSAL> namespace are
144	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>,
145	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and	229	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
146	C<ASN_IA5_STRING>.	230	C<ASN_IA5_STRING>.
147		231
148	The most common tags in SNMP's C<ASN_APPLICATION> namespace	232	The most common tags in SNMP's C<ASN_APPLICATION> namespace are
149	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,	233	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
150	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.	234	C<SNMP_COUNTER64>.
151		235
152	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the	236	The I<CONSTRUCTED> flag is really just a boolean - if it is false,
153	the value is "primitive" and contains no subvalues, kind of like a	237	the value is "primitive" and contains no subvalues, kind of like a
154	non-reference perl scalar. IF it is true, then the value is "constructed"	238	non-reference perl scalar. If it is true, then the value is "constructed"
155	which just means it contains a list of subvalues which this module will	239	which just means it contains a list of subvalues which this module will
156	en-/decode as BER tuples themselves.	240	en-/decode as BER tuples themselves.
157		241
158	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 (if
159	the value is I<CONSTRUCTED>), some decoded representation of the value,	243	the value is I<CONSTRUCTED>), some decoded representation of the value,
…		…
164	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
165	string in place of some nice decoded value.	249	string in place of some nice decoded value.
166		250
167	See the SYNOPSIS for an example of such an encoded tuple representation.	251	See the SYNOPSIS for an example of such an encoded tuple representation.
168		252
		253	=head2 DECODING AND ENCODING
		254
		255	=over
		256
		257	=item $tuple = ber_decoded $bindata[, $profile]
		258
		259	Decodes binary BER data in C<$bindata> and returns the resulting BER
		260	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
		261	valid.
		262
		263	How tags are interpreted is defined by the second argument, which must
		264	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		265	profile will be used (C<$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
		280	=item $bindata = ber_encode $tuple[, $profile]
		281
		282	Encodes the BER tuple into a BER/DER data structure. AS with
		283	Cyber_decode>, an optional profile can be given.
		284
		285	=back
		286
169	=head2 HELPER FUNCTIONS	287	=head2 HELPER FUNCTIONS
170		288
171	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>	289	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
172	annoying. To reduce this a bit, this module defines a number of helper	290	annoying. To reduce this a bit, this module defines a number of helper
173	functions, both to match BER tuples and to conmstruct BER tuples:	291	functions, both to match BER tuples and to construct BER tuples:
174		292
175	=head3 MATCH HELPERS	293	=head3 MATCH HELPERS
176		294
177	Thse functions accept a BER tuple as first argument and either paertially	295	These functions accept a BER tuple as first argument and either partially
178	or fully match it. They often come in two forms, one which exactly matches	296	or fully match it. They often come in two forms, one which exactly matches
179	a value, and one which only matches the type and returns the value.	297	a value, and one which only matches the type and returns the value.
180		298
181	They do check whether valid tuples are passed in and croak otherwise. As	299	They do check whether valid tuples are passed in and croak otherwise. As
182	a ease-of-use exception, they usually also accept C<undef> instead of a	300	a ease-of-use exception, they usually also accept C<undef> instead of a
183	tuple reference. in which case they silently fail to match.	301	tuple reference, in which case they silently fail to match.
184		302
185	=over	303	=over
186		304
187	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data	305	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data
188		306
189	This takes a BER C<$tuple> and matches its elements agains the privded	307	This takes a BER C<$tuple> and matches its elements against the provided
190	values, all of which are optional - values that are either missing or	308	values, all of which are optional - values that are either missing or
191	C<undef> will be ignored, the others will be matched exactly (e.g. as if	309	C<undef> will be ignored, the others will be matched exactly (e.g. as if
192	you used C<==> or C<eq> (for C<$data>)).	310	you used C<==> or C<eq> (for C<$data>)).
193		311
194	Some examples:	312	Some examples:
…		…
197	orf die "tuple is not an ASN SEQUENCE";	315	orf die "tuple is not an ASN SEQUENCE";
198		316
199	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL	317	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
200	or die "tuple is not an ASN NULL value";	318	or die "tuple is not an ASN NULL value";
201		319
202	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50	320	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
203	or die "BER integer must be 50";	321	or die "BER integer must be 50";
204		322
205	=item $seq = ber_is_seq $tuple	323	=item $seq = ber_is_seq $tuple
206		324
207	Returns the sequence members (the array of subvalues) if the C<$tuple> is	325	Returns the sequence members (the array of subvalues) if the C<$tuple> is
…		…
214	my $snmp = ber_is_seq $ber	332	my $snmp = ber_is_seq $ber
215	or die "SNMP packet invalid: does not start with SEQUENCE";	333	or die "SNMP packet invalid: does not start with SEQUENCE";
216		334
217	# now we know $snmp is a sequence, so decode the SNMP version	335	# now we know $snmp is a sequence, so decode the SNMP version
218		336
219	my $version = ber_is_i32 $snmp->[0]	337	my $version = ber_is_int $snmp->[0]
220	or die "SNMP packet invalid: does not start with version number";	338	or die "SNMP packet invalid: does not start with version number";
221		339
222	=item $bool = ber_is_i32 $tuple, $i32	340	=item $bool = ber_is_int $tuple, $int
223		341
224	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with	342	Returns a true value if the C<$tuple> represents an ASN INTEGER with
225	the value C<$i32>.	343	the value C<$int>.
226		344
227	=item $i32 = ber_is_i32 $tuple	345	=item $int = ber_is_int $tuple
228		346
229	Returns true (and extracts the integer value) if the C<$tuple> is an ASN	347	Returns true (and extracts the integer value) if the C<$tuple> is an
230	INTEGER32. For C<0>, this function returns a special value that is 0 but	348	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
231	true.	349	but true.
232		350
233	=item $bool = ber_is_oid $tuple, $oid_string	351	=item $bool = ber_is_oid $tuple, $oid_string
234		352
235	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER	353	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
236	that exactly matches C$oid_string>. Exmaple:	354	that exactly matches C<$oid_string>. Example:
237		355
238	ber_is_oid $tuple, "1.3.6.1.4"	356	ber_is_oid $tuple, "1.3.6.1.4"
239	or die "oid must be 1.3.6.1.4";	357	or die "oid must be 1.3.6.1.4";
240		358
241	=item $oid = ber_is_oid $tuple	359	=item $oid = ber_is_oid $tuple
…		…
247		365
248	=head3 CONSTRUCTION HELPERS	366	=head3 CONSTRUCTION HELPERS
249		367
250	=over	368	=over
251		369
252	=item $tuple = ber_i32 $value	370	=item $tuple = ber_int $value
253		371
254	Constructs a new C<ASN_INTEGER32> tuple.	372	Constructs a new C<ASN_INTEGER> tuple.
255		373
256	=back	374	=back
257		375
258	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	376	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
259		377
…		…
269	use common::sense;	387	use common::sense;
270		388
271	use XSLoader ();	389	use XSLoader ();
272	use Exporter qw(import);	390	use Exporter qw(import);
273		391
274	our $VERSION = 0.1;	392	our $VERSION;
275		393
		394	BEGIN {
		395	$VERSION = 0.8;
276	XSLoader::load __PACKAGE__, $VERSION;	396	XSLoader::load __PACKAGE__, $VERSION;
		397	}
277		398
278	our %EXPORT_TAGS = (	399	our %EXPORT_TAGS = (
279	const => [qw(	400	const_index => [qw(
280	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	401	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA
281		402	)],
		403	const_asn => [qw(
282	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER ASN_TAG_BER ASN_TAG_MASK	404	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
283	ASN_CONSTRUCTED ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE ASN_CLASS_MASK ASN_CLASS_SHIFT	405	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
284	ASN_SEQUENCE	406	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
285		407	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		408	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		409	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		410
		411	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		412	)],
		413	const_ber_type => [qw(
		414	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		415	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		416	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		417	)],
		418	const_snmp => [qw(
286	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64	419	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
287	)],	420	)],
		421	decode => [qw(
		422	ber_decode
		423	ber_is ber_is_seq ber_is_int ber_is_oid
		424	)],
288	encode => [qw(	425	encode => [qw(
289	ber_decode
290	ber_is ber_is_seq ber_is_i32 ber_is_oid
291	)],
292	decode => [qw(
293	ber_encode	426	ber_encode
		427	ber_int
294	)],	428	)],
295	);	429	);
296		430
297	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	431	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
298		432
299	$EXPORT_TAGS{all} = \@EXPORT_OK;	433	$EXPORT_TAGS{all} = \@EXPORT_OK;
		434	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
		435	use Data::Dump; ddx \%EXPORT_TAGS;
		436
		437	=head1 PROFILES
		438
		439	While any BER data can be correctly encoded and decoded out of the box, it
		440	can be inconvenient to have to manually decode some values into a "better"
		441	format: for instance, SNMP TimeTicks values are decoded into the raw octet
		442	strings of their BER representation, which is quite hard to decode. With
		443	profiles, you can change which class/tag combinations map to which decoder
		444	function inside C<ber_decode> (and of course also which encoder functions
		445	are used in C<ber_encode>).
		446
		447	This works by mapping specific class/tag combinations to an internal "ber
		448	type".
		449
		450	The default profile supports the standard ASN.1 types, but no
		451	application-specific ones. This means that class/tag combinations not in
		452	the base set of ASN.1 are decoded into their raw octet strings.
		453
		454	C<Convert::BER::XS> defines two profile variables you can use out of the box:
		455
		456	=over
		457
		458	=item C<$Convert::BER::XS::DEFAULT_PROFILE>
		459
		460	This is the default profile, i.e. the profile that is used when no
		461	profile is specified for de-/encoding.
		462
		463	You can modify it, but remember that this modifies the defaults for all
		464	callers that rely on the default profile.
		465
		466	=item C<$Convert::BER::XS::SNMP_PROFILE>
		467
		468	A profile with mappings for SNMP-specific application tags added. This is
		469	useful when de-/encoding SNMP data.
		470
		471	Example:
		472
		473	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
		474
		475	=back
		476
		477	=head2 The Convert::BER::XS::Profile class
		478
		479	=over
		480
		481	=item $profile = new Convert::BER::XS::Profile
		482
		483	Create a new profile. The profile will be identical to the default
		484	profile.
		485
		486	=item $profile->set ($class, $tag, $type)
		487
		488	Sets the mapping for the given C<$class>/C<$tag> combination to C<$type>,
		489	which must be one of the C<BER_TYPE_*> constants.
		490
		491	Note that currently, the mapping is stored in a flat array, so large
		492	values of C<$tag> will consume large amounts of memory.
		493
		494	Example:
		495
		496	$profile = new Convert::BER::XS::Profile;
		497	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);
		498	$ber = ber_decode $data, $profile;
		499
		500	=item $type = $profile->get ($class, $tag)
		501
		502	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
		503
		504	=back
		505
		506	=head2 BER TYPES
		507
		508	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>
		509	combination to any C<BER_TYPE_*>.
		510
		511	=over
		512
		513	=item C<BER_TYPE_BYTES>
		514
		515	The raw octets of the value. This is the default type for unknown tags and
		516	de-/encodes the value as if it were an octet string, i.e. by copying the
		517	raw bytes.
		518
		519	=item C<BER_TYPE_UTF8>
		520
		521	Like C<BER_TYPE_BYTES>, but decodes the value as if it were a UTF-8 string
		522	(without validation!) and encodes a perl unicode string into a UTF-8 BER
		523	string.
		524
		525	=item C<BER_TYPE_UCS2>
		526
		527	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded
		528	string.
		529
		530	=item C<BER_TYPE_UCS4>
		531
		532	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded
		533	string.
		534
		535	=item C<BER_TYPE_INT>
		536
		537	Encodes and decodes a BER integer value to a perl integer scalar. This
		538	should correctly handle 64 bit signed and unsigned values.
		539
		540	=item C<BER_TYPE_OID>
		541
		542	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading
		543	dot, e.g. C<1.3.6.1.213>.
		544
		545	=item C<BER_TYPE_RELOID>
		546
		547	Same as C<BER_TYPE_OID> but uses relative object identifier
		548	encoding: ASN.1 has this hack of encoding the first two OID components
		549	into a single integer in a weird attempt to save an insignificant amount
		550	of space in an otherwise wasteful encoding, and relative OIDs are
		551	basically OIDs without this hack. The practical difference is that the
		552	second component of an OID can only have the values 1..40, while relative
		553	OIDs do not have this restriction.
		554
		555	=item C<BER_TYPE_NULL>
		556
		557	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a
		558	C<ASN_NULL> type, regardless of the perl value.
		559
		560	=item C<BER_TYPE_BOOL>
		561
		562	Decodes an C<ASN_BOOLEAN> value into C<0> or C<1>, and encodes a perl
		563	boolean value into an C<ASN_BOOLEAN>.
		564
		565	=item C<BER_TYPE_REAL>
		566
		567	Decodes/encodes a BER real value. NOT IMPLEMENTED.
		568
		569	=item C<BER_TYPE_IPADDRESS>
		570
		571	Decodes/encodes a four byte string into an IPv4 dotted-quad address string
		572	in Perl. Given the obsolete nature of this type, this is a low-effort
		573	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,
		574	so it won't handle all string forms supported by C<inet_aton> for example.
		575
		576	=item C<BER_TYPE_CROAK>
		577
		578	Always croaks when encountered during encoding or decoding - the
		579	default behaviour when encountering an unknown type is to treat it as
		580	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
		581	error for some types, then C<BER_TYPE_CROAK> is for you.
		582
		583	=back
		584
		585	=cut
		586
		587	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		588	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		589
		590	# additional SNMP application types
		591	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		592	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		593	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		594	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		595	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		596	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		597
		598	$DEFAULT_PROFILE->_set_default;
300		599
301	1;	600	1;
302		601
303	=head2 BUGS / SHORTCOMINGs	602	=head2 LIMITATIONS/NOTES
304		603
305	This module does have a number of SNMPisms hardcoded, such as the SNMP	604	This module can only en-/decode 64 bit signed and unsigned integers, and
306	tags for Unsigned32 and so on. More configurability is needed, and, if	605	only when your perl supports those.
307	ever implemented, will come in a form similar to how L<JSON::XS> and	606
308	L<CBOR::XS> respresent things, namely with an object-oriented interface.	607	This module does not generally care about ranges, i.e. it will happily
		608	de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative
		609	number into an C<SNMP_COUNTER64>.
		610
		611	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
		612	much larger than e.g. the one imposed by SNMP or other protocols,a nd is
		613	about 4kB.
		614
		615	REAL values are not supported and will currently croak.
		616
		617	This module has undergone little to no testing so far.
		618
		619	=head2 ITHREADS SUPPORT
		620
		621	This module is unlikely to work when the (officially discouraged) ithreads
		622	are in use.
309		623
310	=head1 AUTHOR	624	=head1 AUTHOR
311		625
312	Marc Lehmann <schmorp@schmorp.de>	626	Marc Lehmann <schmorp@schmorp.de>
313	http://software.schmorp.de/pkg/Convert-BER-XS	627	http://software.schmorp.de/pkg/Convert-BER-XS

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.6 by root, Fri Apr 19 20:38:38 2019 UTC vs. Revision 1.25 by root, Sat Apr 20 15:23:26 2019 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.6 by root, Fri Apr 19 20:38:38 2019 UTC vs.
Revision 1.25 by root, Sat Apr 20 15:23:26 2019 UTC