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

Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.2 by root, Fri Apr 19 16:23:00 2019 UTC vs.
Revision 1.22 by root, Sat Apr 20 14:50:08 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
		12	# The above results in a data structure consisting of
		13	# (class, tag, # constructed, data)
		14	# tuples. Below is such a message, SNMPv1 trap
		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?
		19
		20	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1,
		21	[
		22	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1
		23	[ ASN_UNIVERSAL, 4, 0, "public" ], # community
		24	[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU
		25	[
		26	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid
		27	[ ASN_APPLICATION, SNMP_IPADDRESS, 0, "10.0.0.1" ], # SNMP IpAddress
		28	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap
		29	[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap
		30	[ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks
		31	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist
		32	[
		33	[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair
		34	[
		35	[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ],
		36	[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value
		37	]
		38	]
		39	],
		40	...
		41
		42	# let's decode it a bit with some helper functions
11		43
12	my $msg = ber_is_seq $ber	44	my $msg = ber_is_seq $ber
13	or die "SNMP message does not start with a sequence";	45	or die "SNMP message does not start with a sequence";
14		46
15	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0	47	ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0
16	or die "SNMP message does not start with snmp version\n";	48	or die "SNMP message does not start with snmp version\n";
17		49
		50	# message is SNMP v1 or v2c?
18	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {	51	if ($msg->[0][BER_DATA] == 0 \|\| $msg->[0][BER_DATA] == 1) {
		52
19	# message is SNMP v1 or v2c	53	# message is v1 trap?
20
21	if (ber_is $msg->[2], ASN_CONTEXT, 4, 1) {	54	if (ber_is $msg->[2], ASN_CONTEXT, 4, 1) {
22	# message is v1 trap
23	my $trap = $msg->[2][BER_DATA];	55	my $trap = $msg->[2][BER_DATA];
24		56
25	# check whether trap is a cisco mac notification mac changed message	57	# check whether trap is a cisco mac notification mac changed message
26	if (	58	if (
27	(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
28	and (ber_is_i32 $trap->[2], 6)	60	and (ber_is_i32 $trap->[2], 6)
29	and (ber_is_i32 $trap->[3], 1) # mac changed msg	61	and (ber_is_i32 $trap->[3], 1) # mac changed msg
30	) {	62	) {
31	... and so on	63	... and so on
32		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
33	=head1 DESCRIPTION	69	=head1 DESCRIPTION
34		70
		71	WARNING: Before release 1.0, the API is not considered stable in any way.
		72
35	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.
36	future, probably also an encoder (tell me if you want an encoder, this
37	might speed up the process of getting one).
38		74
39	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
40	level of user-friendlyness.	76	level of user-friendlyness.
41		77
42	Currently, not much is documented, as this is an initial release to	78	=head2 EXPORT TAGS AND CONSTANTS
43	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 eyesigh with extreemly 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. Rcommended 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 stricly 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>, reespectively -
		110	exactly thw two topmost bits from the identifdier 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	To avoid non-descriptive hardcoded array index numbers, this module
		190	defines symbolic constants to access these members: C<BER_CLASS>,
		191	C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>.
		192
		193	Also, the first three members are integers with a little caveat: for
		194	performance reasons, these are readonly and shared, so you must not modify
		195	them (increment, assign to them etc.) in any way. You may modify the
		196	I<DATA> member, and you may re-assign the array itself, e.g.:
		197
		198	$ber = ber_decode $binbuf;
		199
		200	# the following is NOT legal:
		201	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!)
		202
		203	# but all of the following are fine:
		204	$ber->[BER_DATA] = "string";
		205	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123];
		206	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
		207
		208	I<CLASS> is something like a namespace for I<TAG>s - there is the
		209	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
		210	implementations, the C<ASN_APPLICATION> namespace which defines tags for
		211	specific applications (for example, the SNMP C<Unsigned32> type is in this
		212	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
		213	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
		214
		215	The meaning of the I<TAG> depends on the namespace, and defines a
		216	(partial) interpretation of the data value. For example, right now, SNMP
		217	application namespace knowledge ix hardcoded into this module, so it
		218	knows that SNMP C<Unsigned32> values need to be decoded into actual perl
		219	integers.
		220
		221	The most common tags in the C<ASN_UNIVERSAL> namespace are
		222	C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>,
		223	C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and
		224	C<ASN_IA5_STRING>.
		225
		226	The most common tags in SNMP's C<ASN_APPLICATION> namespace
		227	are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>,
		228	C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>.
		229
		230	The I<CONSTRUCTED> flag is really just a boolean - if it is false, the
		231	the value is "primitive" and contains no subvalues, kind of like a
		232	non-reference perl scalar. IF it is true, then the value is "constructed"
		233	which just means it contains a list of subvalues which this module will
		234	en-/decode as BER tuples themselves.
		235
		236	The I<DATA> value is either a reference to an array of further tuples (if
		237	the value is I<CONSTRUCTED>), some decoded representation of the value,
		238	if this module knows how to decode it (e.g. for the integer types above)
		239	or a binary string with the raw octets if this module doesn't know how to
		240	interpret the namespace/tag.
		241
		242	Thus, you can always decode a BER data structure and at worst you get a
		243	string in place of some nice decoded value.
		244
		245	See the SYNOPSIS for an example of such an encoded tuple representation.
		246
		247	=head2 DECODING AND ENCODING
		248
		249	=over
		250
		251	=item $tuple = ber_decoded $bindata
		252
		253	Decodes binary BER data in C<$bindata> and returns the resulting BER
		254	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
		255	valid.
		256
		257	=item $bindata = ber_encode $tuple
		258
		259	Encodes the BER tuple into a BER/DER data structure.
		260
		261	=back
		262
		263	=head2 HELPER FUNCTIONS
		264
		265	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
		266	annoying. To reduce this a bit, this module defines a number of helper
		267	functions, both to match BER tuples and to conmstruct BER tuples:
		268
		269	=head3 MATCH HELPERS
		270
		271	Thse functions accept a BER tuple as first argument and either paertially
		272	or fully match it. They often come in two forms, one which exactly matches
		273	a value, and one which only matches the type and returns the value.
		274
		275	They do check whether valid tuples are passed in and croak otherwise. As
		276	a ease-of-use exception, they usually also accept C<undef> instead of a
		277	tuple reference. in which case they silently fail to match.
		278
		279	=over
		280
		281	=item $bool = ber_is $tuple, $class, $tag, $constructed, $data
		282
		283	This takes a BER C<$tuple> and matches its elements agains the privded
		284	values, all of which are optional - values that are either missing or
		285	C<undef> will be ignored, the others will be matched exactly (e.g. as if
		286	you used C<==> or C<eq> (for C<$data>)).
		287
		288	Some examples:
		289
		290	ber_is $tuple, ASN_UNIVERSAL, ASN_SEQUENCE, 1
		291	orf die "tuple is not an ASN SEQUENCE";
		292
		293	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
		294	or die "tuple is not an ASN NULL value";
		295
		296	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50
		297	or die "BER integer must be 50";
		298
		299	=item $seq = ber_is_seq $tuple
		300
		301	Returns the sequence members (the array of subvalues) if the C<$tuple> is
		302	an ASN SEQUENCE, i.e. the C<BER_DATA> member. If the C<$tuple> is not a
		303	sequence it returns C<undef>. For example, SNMP version 1/2c/3 packets all
		304	consist of an outer SEQUENCE value:
		305
		306	my $ber = ber_decode $snmp_data;
		307
		308	my $snmp = ber_is_seq $ber
		309	or die "SNMP packet invalid: does not start with SEQUENCE";
		310
		311	# now we know $snmp is a sequence, so decode the SNMP version
		312
		313	my $version = ber_is_i32 $snmp->[0]
		314	or die "SNMP packet invalid: does not start with version number";
		315
		316	=item $bool = ber_is_i32 $tuple, $i32
		317
		318	Returns a true value if the C<$tuple> represents an ASN INTEGER32 with
		319	the value C<$i32>.
		320
		321	=item $i32 = ber_is_i32 $tuple
		322
		323	Returns true (and extracts the integer value) if the C<$tuple> is an ASN
		324	INTEGER32. For C<0>, this function returns a special value that is 0 but
		325	true.
		326
		327	=item $bool = ber_is_oid $tuple, $oid_string
		328
		329	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
		330	that exactly matches C<$oid_string>. Example:
		331
		332	ber_is_oid $tuple, "1.3.6.1.4"
		333	or die "oid must be 1.3.6.1.4";
		334
		335	=item $oid = ber_is_oid $tuple
		336
		337	Returns true (and extracts the OID string) if the C<$tuple> is an ASN
		338	OBJECT IDENTIFIER. Otherwise, it returns C<undef>.
		339
		340	=back
		341
		342	=head3 CONSTRUCTION HELPERS
		343
		344	=over
		345
		346	=item $tuple = ber_i32 $value
		347
		348	Constructs a new C<ASN_INTEGER32> tuple.
		349
		350	=back
44		351
45	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	352	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
46		353
47	This module is I<not> the XS version of L<Convert::BER>, but a different	354	This module is I<not> the XS version of L<Convert::BER>, but a different
48	take at doing the same thing. I imagine this module would be a good base	355	take at doing the same thing. I imagine this module would be a good base
49	for speeding up either fo these, or write a similar module, or write your	356	for speeding up either of these, or write a similar module, or write your
50	own LDAP or SNMP module for example.	357	own LDAP or SNMP module for example.
51		358
52	=cut	359	=cut
53		360
54	package Convert::BER::XS;	361	package Convert::BER::XS;
56	use common::sense;	363	use common::sense;
57		364
58	use XSLoader ();	365	use XSLoader ();
59	use Exporter qw(import);	366	use Exporter qw(import);
60		367
		368	our $VERSION;
		369
		370	BEGIN {
61	our $VERSION = '0.0';	371	$VERSION = 0.8;
62
63	XSLoader::load __PACKAGE__, $VERSION;	372	XSLoader::load __PACKAGE__, $VERSION;
		373	}
64		374
65	our %EXPORT_TAGS = (	375	our %EXPORT_TAGS = (
66	all => [qw(	376	const_index => [qw(
		377	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA
		378	)],
		379	const_asn => [qw(
		380	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
		381	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		382	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		383	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		384	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		385	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		386
		387	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		388	)],
		389	const_ber_type => [qw(
		390	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		391	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		392	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		393	)],
		394	const_snmp => [qw(
		395	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		396	)],
		397	decode => [qw(
67	ber_decode	398	ber_decode
68	ber_is ber_is_seq ber_is_i32 ber_is_oid	399	ber_is ber_is_seq ber_is_i32 ber_is_oid
69	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	400	)],
70	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER ASN_TAG_BER ASN_TAG_MASK	401	encode => [qw(
71	ASN_CONSTRUCTED ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE ASN_CLASS_MASK ASN_CLASS_SHIFT	402	ber_encode
72	ASN_SEQUENCE ASN_IPADDRESS ASN_COUNTER32 ASN_UNSIGNED32 ASN_TIMETICKS ASN_OPAQUE ASN_COUNTER64	403	ber_i32
73	)],	404	)],
74	);	405	);
75		406
76	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	407	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
77		408
		409	$EXPORT_TAGS{all} = \@EXPORT_OK;
		410	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
		411	use Data::Dump; ddx \%EXPORT_TAGS;
		412
		413	=head1 PROFILES
		414
		415	While any BER data can be correctly encoded and decoded out of the box, it
		416	can be inconvenient to have to manually decode some values into a "better"
		417	format: for instance, SNMP TimeTicks values are decoded into the raw octet
		418	strings of their BER representation, which is quite hard to decode. With
		419	profiles, you can change which class/tag combinations map to which decoder
		420	function inside C<ber_decode> (and of course also which encoder functions
		421	are used in C<ber_encode>).
		422
		423	This works by mapping specific class/tag combinations to an internal "ber
		424	type".
		425
		426	The default profile supports the standard ASN.1 types, but no
		427	application-specific ones. This means that class/tag combinations not in
		428	the base set of ASN.1 are decoded into their raw octet strings.
		429
		430	C<Convert::BER::XS> defines two profile variables you can use out of the box:
		431
		432	=over
		433
		434	=item C<$Convert::BER::XS::DEFAULT_PROFILE>
		435
		436	This is the default profile, i.e. the profile that is used when no
		437	profile is specified for de-/encoding.
		438
		439	You can modify it, but remember that this modifies the defaults for all
		440	callers that rely on the default profile.
		441
		442	=item C<$Convert::BER::XS::SNMP_PROFILE>
		443
		444	A profile with mappings for SNMP-specific application tags added. This is
		445	useful when de-/encoding SNMP data.
		446
		447	Example:
		448
		449	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
		450
		451	=back
		452
		453	=head2 The Convert::BER::XS::Profile class
		454
		455	=over
		456
		457	=item $profile = new Convert::BER::XS::Profile
		458
		459	Create a new profile. The profile will be identical to the default
		460	profile.
		461
		462	=item $profile->set ($class, $tag, $type)
		463
		464	Sets the mapping for the given C<$class>/C<$tag> combination to C<$type>,
		465	which must be one of the C<BER_TYPE_*> constants.
		466
		467	Note that currently, the mapping is stored in a flat array, so large
		468	values of C<$tag> will consume large amounts of memory.
		469
		470	Example:
		471
		472	$profile = new Convert::BER::XS::Profile;
		473	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);
		474	$ber = ber_decode $data, $profile;
		475
		476	=item $type = $profile->get ($class, $tag)
		477
		478	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
		479
		480	=back
		481
		482	=head2 BER TYPES
		483
		484	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>
		485	combination to any C<BER_TYPE_*>.
		486
		487	=over
		488
		489	=item C<BER_TYPE_BYTES>
		490
		491	The raw octets of the value. This is the default type for unknown tags and
		492	de-/encodes the value as if it were an octet string, i.e. by copying the
		493	raw bytes.
		494
		495	=item C<BER_TYPE_UTF8>
		496
		497	Like C<BER_TYPE_BYTES>, but decodes the value as if it were a UTF-8 string
		498	(without validation!) and encodes a perl unicode string into a UTF-8 BER
		499	string.
		500
		501	=item C<BER_TYPE_UCS2>
		502
		503	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded
		504	string.
		505
		506	=item C<BER_TYPE_UCS4>
		507
		508	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded
		509	string.
		510
		511	=item C<BER_TYPE_INT>
		512
		513	Encodes and decodes a BER integer value to a perl integer scalar. This
		514	should correctly handle 64 bit signed and unsigned values.
		515
		516	=item C<BER_TYPE_OID>
		517
		518	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading
		519	dot, e.g. C<1.3.6.1.213>.
		520
		521	=item C<BER_TYPE_RELOID>
		522
		523	Same as C<BER_TYPE_OID> but uses relative object identifier
		524	encoding: ASN.1 has this hack of encoding the first two OID components
		525	into a single integer in a weird attempt to save an insignificant amount
		526	of space in an otherwise wasteful encoding, and relative OIDs are
		527	basically OIDs without this hack. The practical difference is that the
		528	second component of an OID can only have the values 1..40, while relative
		529	OIDs do not have this restriction.
		530
		531	=item C<BER_TYPE_NULL>
		532
		533	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a
		534	C<ASN_NULL> type, regardless of the perl value.
		535
		536	=item C<BER_TYPE_BOOL>
		537
		538	Decodes an C<ASN_BOOLEAN> value into C<0> or C<1>, and encodes a perl
		539	boolean value into an C<ASN_BOOLEAN>.
		540
		541	=item C<BER_TYPE_REAL>
		542
		543	Decodes/encodes a BER real value. NOT IMPLEMENTED.
		544
		545	=item C<BER_TYPE_IPADDRESS>
		546
		547	Decodes/encodes a four byte string into an IPv4 dotted-quad address string
		548	in Perl. Given the obsolete nature of this type, this is a low-effort
		549	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,
		550	so it won't handle all string forms supported by C<inet_aton> for example.
		551
		552	=item C<BER_TYPE_CROAK>
		553
		554	Always croaks when encountered during encoding or decoding - the
		555	default behaviour when encountering an unknown type is to treat it as
		556	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
		557	error for some types, then C<BER_TYPE_CROAK> is for you.
		558
		559	=back
		560
		561	=cut
		562
		563	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		564	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		565
		566	# additional SNMP application types
		567	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		568	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		569	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		570	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		571	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		572	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		573
		574	$DEFAULT_PROFILE->_set_default;
		575
78	1;	576	1;
		577
		578	=head2 LIMITATIONS/NOTES
		579
		580	This module can only en-/decode 64 bit signed and unsigned integers, and
		581	only when your perl supports those.
		582
		583	This module does not generally care about ranges, i.e. it will happily
		584	de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative
		585	number into an C<SNMP_COUNTER64>.
		586
		587	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
		588	much larger than e.g. the one imposed by SNMP or other protocols,a nd is
		589	about 4kB.
		590
		591	REAL values are not supported and will currently croak.
		592
		593	This module has undergone little to no testing so far.
		594
		595	=head2 ITHREADS SUPPORT
		596
		597	This module is unlikely to work when the (officially discouraged) ithreads
		598	are in use.
79		599
80	=head1 AUTHOR	600	=head1 AUTHOR
81		601
82	Marc Lehmann <schmorp@schmorp.de>	602	Marc Lehmann <schmorp@schmorp.de>
83	http://software.schmorp.de/pkg/Convert-BER-XS	603	http://software.schmorp.de/pkg/Convert-BER-XS

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Comparing Convert-BER-XS/XS.pm (file contents): Revision 1.2 by root, Fri Apr 19 16:23:00 2019 UTC vs. Revision 1.22 by root, Sat Apr 20 14:50:08 2019 UTC

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Comparing Convert-BER-XS/XS.pm (file contents):
Revision 1.2 by root, Fri Apr 19 16:23:00 2019 UTC vs.
Revision 1.22 by root, Sat Apr 20 14:50:08 2019 UTC