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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.3 by root, Fri Apr 19 16:49:02 2019 UTC vs.
Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	Convert::BER::XS - I<very> low level BER decoding	3	Convert::BER::XS - I<very> low level BER en-/decoding
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 v1/v2c 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. here is such a message, SNMPv1 trap	14	# tuples. Below is such a message, SNMPv1 trap
14	# with a cisoc mac change notification	15	# with a Cisco mac change notification.
		16	# Did you know that Cisco is in the news almost
		17	# every week because of some backdoor password
		18	# or other extremely stupid security bug?
15		19
16	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,	20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,
17	[	21	[
18	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1	22	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1
19	[ ASN_UNIVERSAL, 4, 0, "public" ], # community	23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community
20	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed	24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU
21	[	25	[
22	[ 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
23	[ 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
24	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap	28	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap
25	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap	29	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap
26	[ ASN_APPLICATION, ASN_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks	30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks
27	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist	31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist
28	[	32	[
29	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair	33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair
30	[	34	[
31	[ 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" ],
32	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value	36	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value
33	]	37	]
34	]	38	]
35	],	39	],
36	...	40	...
56	and (ber_is_i32 $trap->[2], 6)	60	and (ber_is_i32 $trap->[2], 6)
57	and (ber_is_i32 $trap->[3], 1) # mac changed msg	61	and (ber_is_i32 $trap->[3], 1) # mac changed msg
58	) {	62	) {
59	... and so on	63	... and so on
60		64
		65	# finally, let's encode it again and hope it results in the same bit pattern
		66
		67	my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE;
		68
61	=head1 DESCRIPTION	69	=head1 DESCRIPTION
62		70
		71	WARNING: Before release 1.0, the API is not considered stable in any way.
		72
63	This module implements a I<very> low level BER/DER decoder, and in the	73	This module implements a I<very> low level BER/DER en-/decoder.
64	future, probably also an encoder (tell me if you want an encoder, this
65	might speed up the process of getting one).
66		74
67	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
68	level of user-friendlyness.	76	level of user-friendlyness.
69		77
70	Currently, not much is documented, as this is an initial release to	78	=head2 EXPORT TAGS AND CONSTANTS
71	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_INTEGER32 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_i32 ber_is_oid
		146
		147	=item C<:encode>
		148
		149	C<ber_encode> and the construction helper functions:
		150
		151	ber_encode ber_i32
		152
		153	=back
		154
		155	=head2 ASN.1/BER/DER/... BASICS
		156
		157	ASN.1 is a strange language that can be used to describe protocols and
		158	data structures. It supports various mappings to JSON, XML, but most
		159	importantly, to a various binary encodings such as BER, that is the topic
		160	of this module, and is used in SNMP or LDAP for example.
		161
		162	While ASN.1 defines a schema that is useful to interpret encoded data,
		163	the BER encoding is actually somewhat self-describing: you might not know
		164	whether something is a string or a number or a sequence or something else,
		165	but you can nevertheless decode the overall structure, even if you end up
		166	with just a binary blob for the actual value.
		167
		168	This works because BER values are tagged with a type and a namespace,
		169	and also have a flag that says whether a value consists of subvalues (is
		170	"constructed") or not (is "primitive").
		171
		172	Tags are simple integers, and ASN.1 defines a somewhat weird assortment of
		173	those - for example, you have 32 bit signed integers and 16(!) different
		174	string types, but there is no Unsigned32 type for example. Different
		175	applications work around this in different ways, for example, SNMP defines
		176	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
		177	to two different tags: you can distinguish between Counter32 and the
		178	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
		179
		180	Ugh.
		181
		182	=head2 DECODED BER REPRESENTATION
		183
		184	This module represents every BER value as a 4-element tuple (actually an
		185	array-reference):
		186
		187	[CLASS, TAG, CONSTRUCTED, DATA]
		188
		189	For example:
		190
		191	[ASN_UNIVERSAL, ASN_INTEGER32, 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
		196	To avoid non-descriptive hardcoded array index numbers, this module
		197	defines symbolic constants to access these members: C<BER_CLASS>,
		198	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.
		199
		200	Also, the first three members are integers with a little caveat: for
		201	performance reasons, these are readonly and shared, so you must not modify
		202	them (increment, assign to them etc.) in any way. You may modify the
		203	I<DATA> member, and you may re-assign the array itself, e.g.:
		204
		205	$ber = ber_decode $binbuf;
		206
		207	# the following is NOT legal:
		208	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)
		209
		210	# but all of the following are fine:
		211	$ber->[BER_DATA] = "string";
		212	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];
		213	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
		214
		215	I<CLASS> is something like a namespace for I<TAG>s - there is the
		216	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
		217	implementations, the C<ASN_APPLICATION> namespace which defines tags for
		218	specific applications (for example, the SNMP C<Unsigned32> type is in this
		219	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
		220	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
		221
		222	The meaning of the I<TAG> depends on the namespace, and defines a
		223	(partial) interpretation of the data value. For example, right now, SNMP
		224	application namespace knowledge ix hardcoded into this module, so it
		225	knows that SNMP C<Unsigned32> values need to be decoded into actual perl
		226	integers.
		227
		228	The most common tags in the C<ASN_UNIVERSAL> namespace are
		229	C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,
		230	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
		231	C<ASN_IA5_STRING>.
		232
		233	The most common tags in SNMP's C<ASN_APPLICATION> namespace
		234	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,
		235	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.
		236
		237	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the
		238	the value is "primitive" and contains no subvalues, kind of like a
		239	non-reference perl scalar. IF it is true, then the value is "constructed"
		240	which just means it contains a list of subvalues which this module will
		241	en-/decode as BER tuples themselves.
		242
		243	The I<DATA> value is either a reference to an array of further tuples (if
		244	the value is I<CONSTRUCTED>), some decoded representation of the value,
		245	if this module knows how to decode it (e.g. for the integer types above)
		246	or a binary string with the raw octets if this module doesn't know how to
		247	interpret the namespace/tag.
		248
		249	Thus, you can always decode a BER data structure and at worst you get a
		250	string in place of some nice decoded value.
		251
		252	See the SYNOPSIS for an example of such an encoded tuple representation.
		253
		254	=head2 DECODING AND ENCODING
		255
		256	=over
		257
		258	=item $tuple = ber_decoded $bindata
		259
		260	Decodes binary BER data in C<$bindata> and returns the resulting BER
		261	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
		262	valid.
		263
		264	=item $bindata = ber_encode $tuple
		265
		266	Encodes the BER tuple into a BER/DER data structure.
		267
		268	=back
		269
		270	=head2 HELPER FUNCTIONS
		271
		272	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
		273	annoying. To reduce this a bit, this module defines a number of helper
		274	functions, both to match BER tuples and to conmstruct BER tuples:
		275
		276	=head3 MATCH HELPERS
		277
		278	Thse functions accept a BER tuple as first argument and either paertially
		279	or fully match it. They often come in two forms, one which exactly matches
		280	a value, and one which only matches the type and returns the value.
		281
		282	They do check whether valid tuples are passed in and croak otherwise. As
		283	a ease-of-use exception, they usually also accept C<undef> instead of a
		284	tuple reference. in which case they silently fail to match.
		285
		286	=over
		287
		288	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data
		289
		290	This takes a BER C<$tuple> and matches its elements agains the privded
		291	values, all of which are optional - values that are either missing or
		292	C<undef> will be ignored, the others will be matched exactly (e.g. as if
		293	you used C<==> or C<eq> (for C<$data>)).
		294
		295	Some examples:
		296
		297	ber_is $tuple, ASN_UNIVERSAL, ASN_SEQUENCE, 1
		298	orf die "tuple is not an ASN SEQUENCE";
		299
		300	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
		301	or die "tuple is not an ASN NULL value";
		302
		303	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50
		304	or die "BER integer must be 50";
		305
		306	=item $seq = ber_is_seq $tuple
		307
		308	Returns the sequence members (the array of subvalues) if the C<$tuple> is
		309	an ASN SEQUENCE, i.e. the C<BER_DATA> member. If the C<$tuple> is not a
		310	sequence it returns C<undef>. For example, SNMP version 1/2c/3 packets all
		311	consist of an outer SEQUENCE value:
		312
		313	my $ber = ber_decode $snmp_data;
		314
		315	my $snmp = ber_is_seq $ber
		316	or die "SNMP packet invalid: does not start with SEQUENCE";
		317
		318	# now we know $snmp is a sequence, so decode the SNMP version
		319
		320	my $version = ber_is_i32 $snmp->[0]
		321	or die "SNMP packet invalid: does not start with version number";
		322
		323	=item $bool = ber_is_i32 $tuple, $i32
		324
		325	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with
		326	the value C<$i32>.
		327
		328	=item $i32 = ber_is_i32 $tuple
		329
		330	Returns true (and extracts the integer value) if the C<$tuple> is an ASN
		331	INTEGER32. For C<0>, this function returns a special value that is 0 but
		332	true.
		333
		334	=item $bool = ber_is_oid $tuple, $oid_string
		335
		336	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
		337	that exactly matches C<$oid_string>. Example:
		338
		339	ber_is_oid $tuple, "1.3.6.1.4"
		340	or die "oid must be 1.3.6.1.4";
		341
		342	=item $oid = ber_is_oid $tuple
		343
		344	Returns true (and extracts the OID string) if the C<$tuple> is an ASN
		345	OBJECT IDENTIFIER. Otherwise, it returns C<undef>.
		346
		347	=back
		348
		349	=head3 CONSTRUCTION HELPERS
		350
		351	=over
		352
		353	=item $tuple = ber_i32 $value
		354
		355	Constructs a new C<ASN_INTEGER32> tuple.
		356
		357	=back
72		358
73	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	359	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
74		360
75	This module is I<not> the XS version of L<Convert::BER>, but a different	361	This module is I<not> the XS version of L<Convert::BER>, but a different
76	take at doing the same thing. I imagine this module would be a good base	362	take at doing the same thing. I imagine this module would be a good base
77	for speeding up either fo these, or write a similar module, or write your	363	for speeding up either of these, or write a similar module, or write your
78	own LDAP or SNMP module for example.	364	own LDAP or SNMP module for example.
79		365
80	=cut	366	=cut
81		367
82	package Convert::BER::XS;	368	package Convert::BER::XS;
…		…
84	use common::sense;	370	use common::sense;
85		371
86	use XSLoader ();	372	use XSLoader ();
87	use Exporter qw(import);	373	use Exporter qw(import);
88		374
		375	our $VERSION;
		376
		377	BEGIN {
89	our $VERSION = '0.0';	378	$VERSION = 0.8;
90
91	XSLoader::load __PACKAGE__, $VERSION;	379	XSLoader::load __PACKAGE__, $VERSION;
		380	}
92		381
93	our %EXPORT_TAGS = (	382	our %EXPORT_TAGS = (
94	all => [qw(	383	const_index => [qw(
		384	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA
		385	)],
		386	const_asn => [qw(
		387	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
		388	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		389	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		390	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		391	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		392	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		393
		394	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		395	)],
		396	const_ber_type => [qw(
		397	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		398	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		399	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		400	)],
		401	const_snmp => [qw(
		402	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		403	)],
		404	decode => [qw(
95	ber_decode	405	ber_decode
96	ber_is ber_is_seq ber_is_i32 ber_is_oid	406	ber_is ber_is_seq ber_is_i32 ber_is_oid
97	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	407	)],
98	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER ASN_TAG_BER ASN_TAG_MASK	408	encode => [qw(
99	ASN_CONSTRUCTED ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE ASN_CLASS_MASK ASN_CLASS_SHIFT	409	ber_encode
100	ASN_SEQUENCE ASN_IPADDRESS ASN_COUNTER32 ASN_UNSIGNED32 ASN_TIMETICKS ASN_OPAQUE ASN_COUNTER64	410	ber_i32
101	)],	411	)],
102	);	412	);
103		413
104	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	414	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
105		415
		416	$EXPORT_TAGS{all} = \@EXPORT_OK;
		417	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
		418	use Data::Dump; ddx \%EXPORT_TAGS;
		419
		420	=head1 PROFILES
		421
		422	While any BER data can be correctly encoded and decoded out of the box, it
		423	can be inconvenient to have to manually decode some values into a "better"
		424	format: for instance, SNMP TimeTicks values are decoded into the raw octet
		425	strings of their BER representation, which is quite hard to decode. With
		426	profiles, you can change which class/tag combinations map to which decoder
		427	function inside C<ber_decode> (and of course also which encoder functions
		428	are used in C<ber_encode>).
		429
		430	This works by mapping specific class/tag combinations to an internal "ber
		431	type".
		432
		433	The default profile supports the standard ASN.1 types, but no
		434	application-specific ones. This means that class/tag combinations not in
		435	the base set of ASN.1 are decoded into their raw octet strings.
		436
		437	C<Convert::BER::XS> defines two profile variables you can use out of the box:
		438
		439	=over
		440
		441	=item C<$Convert::BER::XS::DEFAULT_PROFILE>
		442
		443	This is the default profile, i.e. the profile that is used when no
		444	profile is specified for de-/encoding.
		445
		446	You can modify it, but remember that this modifies the defaults for all
		447	callers that rely on the default profile.
		448
		449	=item C<$Convert::BER::XS::SNMP_PROFILE>
		450
		451	A profile with mappings for SNMP-specific application tags added. This is
		452	useful when de-/encoding SNMP data.
		453
		454	Example:
		455
		456	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
		457
		458	=back
		459
		460	=head2 The Convert::BER::XS::Profile class
		461
		462	=over
		463
		464	=item $profile = new Convert::BER::XS::Profile
		465
		466	Create a new profile. The profile will be identical to the default
		467	profile.
		468
		469	=item $profile->set ($class, $tag, $type)
		470
		471	Sets the mapping for the given C<$class>/C<$tag> combination to C<$type>,
		472	which must be one of the C<BER_TYPE_*> constants.
		473
		474	Note that currently, the mapping is stored in a flat array, so large
		475	values of C<$tag> will consume large amounts of memory.
		476
		477	Example:
		478
		479	$profile = new Convert::BER::XS::Profile;
		480	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);
		481	$ber = ber_decode $data, $profile;
		482
		483	=item $type = $profile->get ($class, $tag)
		484
		485	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
		486
		487	=back
		488
		489	=head2 BER TYPES
		490
		491	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>
		492	combination to any C<BER_TYPE_*>.
		493
		494	=over
		495
		496	=item C<BER_TYPE_BYTES>
		497
		498	The raw octets of the value. This is the default type for unknown tags and
		499	de-/encodes the value as if it were an octet string, i.e. by copying the
		500	raw bytes.
		501
		502	=item C<BER_TYPE_UTF8>
		503
		504	Like C<BER_TYPE_BYTES>, but decodes the value as if it were a UTF-8 string
		505	(without validation!) and encodes a perl unicode string into a UTF-8 BER
		506	string.
		507
		508	=item C<BER_TYPE_UCS2>
		509
		510	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded
		511	string.
		512
		513	=item C<BER_TYPE_UCS4>
		514
		515	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded
		516	string.
		517
		518	=item C<BER_TYPE_INT>
		519
		520	Encodes and decodes a BER integer value to a perl integer scalar. This
		521	should correctly handle 64 bit signed and unsigned values.
		522
		523	=item C<BER_TYPE_OID>
		524
		525	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading
		526	dot, e.g. C<1.3.6.1.213>.
		527
		528	=item C<BER_TYPE_RELOID>
		529
		530	Same as C<BER_TYPE_OID> but uses relative object identifier
		531	encoding: ASN.1 has this hack of encoding the first two OID components
		532	into a single integer in a weird attempt to save an insignificant amount
		533	of space in an otherwise wasteful encoding, and relative OIDs are
		534	basically OIDs without this hack. The practical difference is that the
		535	second component of an OID can only have the values 1..40, while relative
		536	OIDs do not have this restriction.
		537
		538	=item C<BER_TYPE_NULL>
		539
		540	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a
		541	C<ASN_NULL> type, regardless of the perl value.
		542
		543	=item C<BER_TYPE_BOOL>
		544
		545	Decodes an C<ASN_BOOLEAN> value into C<0> or C<1>, and encodes a perl
		546	boolean value into an C<ASN_BOOLEAN>.
		547
		548	=item C<BER_TYPE_REAL>
		549
		550	Decodes/encodes a BER real value. NOT IMPLEMENTED.
		551
		552	=item C<BER_TYPE_IPADDRESS>
		553
		554	Decodes/encodes a four byte string into an IPv4 dotted-quad address string
		555	in Perl. Given the obsolete nature of this type, this is a low-effort
		556	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,
		557	so it won't handle all string forms supported by C<inet_aton> for example.
		558
		559	=item C<BER_TYPE_CROAK>
		560
		561	Always croaks when encountered during encoding or decoding - the
		562	default behaviour when encountering an unknown type is to treat it as
		563	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
		564	error for some types, then C<BER_TYPE_CROAK> is for you.
		565
		566	=back
		567
		568	=cut
		569
		570	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		571	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		572
		573	# additional SNMP application types
		574	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		575	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		576	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		577	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		578	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		579	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		580
		581	$DEFAULT_PROFILE->_set_default;
		582
106	1;	583	1;
		584
		585	=head2 LIMITATIONS/NOTES
		586
		587	This module can only en-/decode 64 bit signed and unsigned integers, and
		588	only when your perl supports those.
		589
		590	This module does not generally care about ranges, i.e. it will happily
		591	de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative
		592	number into an C<SNMP_COUNTER64>.
		593
		594	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
		595	much larger than e.g. the one imposed by SNMP or other protocols,a nd is
		596	about 4kB.
		597
		598	REAL values are not supported and will currently croak.
		599
		600	This module has undergone little to no testing so far.
		601
		602	=head2 ITHREADS SUPPORT
		603
		604	This module is unlikely to work when the (officially discouraged) ithreads
		605	are in use.
107		606
108	=head1 AUTHOR	607	=head1 AUTHOR
109		608
110	Marc Lehmann <schmorp@schmorp.de>	609	Marc Lehmann <schmorp@schmorp.de>
111	http://software.schmorp.de/pkg/Convert-BER-XS	610	http://software.schmorp.de/pkg/Convert-BER-XS

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.3 by root, Fri Apr 19 16:49:02 2019 UTC vs. Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.3 by root, Fri Apr 19 16:49:02 2019 UTC vs.
Revision 1.23 by root, Sat Apr 20 14:53:29 2019 UTC