[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 1.33 by root, Sat Apr 20 17:23:21 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, flags, 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_INTEGER, 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_INTEGER, 0, 6 ], # generic trap
		29	[ ASN_UNIVERSAL, ASN_INTEGER, 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 $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0
16	or die "SNMP message does not start with snmp version\n";	48	or die "SNMP message does not start with snmp version\n";
17		49
		50	# message is SNMP v1 or v2c?
18	if ($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_int $trap->[2], 6)
29	and (ber_is_i32 $trap->[3], 1) # mac changed msg	61	and (ber_is_int $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 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_GAUGE32
		140	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		141
		142	=item C<:decode>
		143
		144	C<ber_decode> and the match helper functions:
		145
		146	ber_decode ber_is ber_is_seq ber_is_int ber_is_oid
		147
		148	=item C<:encode>
		149
		150	C<ber_encode> and the construction helper functions:
		151
		152	ber_encode ber_int
		153
		154	=back
		155
		156	=head2 ASN.1/BER/DER/... BASICS
		157
		158	ASN.1 is a strange language that can be used to describe protocols and
		159	data structures. It supports various mappings to JSON, XML, but most
		160	importantly, to a various binary encodings such as BER, that is the topic
		161	of this module, and is used in SNMP, LDAP or X.509 for example.
		162
		163	While ASN.1 defines a schema that is useful to interpret encoded data,
		164	the BER encoding is actually somewhat self-describing: you might not know
		165	whether something is a string or a number or a sequence or something else,
		166	but you can nevertheless decode the overall structure, even if you end up
		167	with just a binary blob for the actual value.
		168
		169	This works because BER values are tagged with a type and a namespace,
		170	and also have a flag that says whether a value consists of subvalues (is
		171	"constructed") or not (is "primitive").
		172
		173	Tags are simple integers, and ASN.1 defines a somewhat weird assortment
		174	of those - for example, you have one integers and 16(!) different
		175	string types, but there is no Unsigned32 type for example. Different
		176	applications work around this in different ways, for example, SNMP defines
		177	application-specific Gauge32, Counter32 and Unsigned32, which are mapped
		178	to two different tags: you can distinguish between Counter32 and the
		179	others, but not between Gause32 and Unsigned32, without the ASN.1 schema.
		180
		181	Ugh.
		182
		183	=head2 DECODED BER REPRESENTATION
		184
		185	This module represents every BER value as a 4-element tuple (actually an
		186	array-reference):
		187
		188	[CLASS, TAG, FLAGS, DATA]
		189
		190	For example:
		191
		192	[ASN_UNIVERSAL, ASN_INTEGER, 0, 177] # the integer 177
		193	[ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john"
		194	[ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID
		195	[ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence
		196
		197	To avoid non-descriptive hardcoded array index numbers, this module
		198	defines symbolic constants to access these members: C<BER_CLASS>,
		199	C<BER_TAG>, C<BER_FLAGS> and C<BER_DATA>.
		200
		201	Also, the first three members are integers with a little caveat: for
		202	performance reasons, these are readonly and shared, so you must not modify
		203	them (increment, assign to them etc.) in any way. You may modify the
		204	I<DATA> member, and you may re-assign the array itself, e.g.:
		205
		206	$ber = ber_decode $binbuf;
		207
		208	# the following is NOT legal:
		209	$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/FLAGS are READ ONLY(!)
		210
		211	# but all of the following are fine:
		212	$ber->[BER_DATA] = "string";
		213	$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER, 0, 123];
		214	@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000);
		215
		216	I<CLASS> is something like a namespace for I<TAG>s - there is the
		217	C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1
		218	implementations, the C<ASN_APPLICATION> namespace which defines tags for
		219	specific applications (for example, the SNMP C<Unsigned32> type is in this
		220	namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g.
		221	for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>).
		222
		223	The meaning of the I<TAG> depends on the namespace, and defines a
		224	(partial) interpretation of the data value. For example, SNMP defines
		225	extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage
		226	of these, you need to tell this module how to handle those via profiles.
		227
		228	The most common tags in the C<ASN_UNIVERSAL> namespace are
		229	C<ASN_INTEGER>, 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 are
		234	C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and
		235	C<SNMP_COUNTER64>.
		236
		237	The I<FLAGS> value is really just a boolean at this time (but might
		238	get extended) - if it is C<0>, the value is "primitive" and contains
		239	no subvalues, kind of like a non-reference perl scalar. If it is C<1>,
		240	then the value is "constructed" which just means it contains a list of
		241	subvalues which this module will en-/decode as BER tuples themselves.
		242
		243	The I<DATA> value is either a reference to an array of further tuples
		244	(if the value is I<FLAGS>), some decoded representation of the value, if
		245	this module knows how to decode it (e.g. for the integer types above) or
		246	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[, $profile]
		259
		260	Decodes binary BER data in C<$bindata> and returns the resulting BER
		261	tuple. Croaks on any decoding error, so the returned C<$tuple> is always
		262	valid.
		263
		264	How tags are interpreted is defined by the second argument, which must
		265	be a C<Convert::BER::XS::Profile> object. If it is missing, the default
		266	profile will be used (C<$Convert::BER::XS::DEFAULT_PROFILE>).
		267
		268	In addition to rolling your own, this module provides a
		269	C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP
		270	types.
		271
		272	Example: decode a BER blob using the default profile - SNMP values will be
		273	decided as raw strings.
		274
		275	$tuple = ber_decode $data;
		276
		277	Example: as above, but use the provided SNMP profile.
		278
		279	$tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE;
		280
		281	=item $bindata = ber_encode $tuple[, $profile]
		282
		283	Encodes the BER tuple into a BER/DER data structure. AS with
		284	Cyber_decode>, an optional profile can be given.
		285
		286	The encoded data should be both BER and DER ("shortest form") compliant
		287	unless the input says otherwise (e.g. it uses constructed strings).
		288
		289	=back
		290
		291	=head2 HELPER FUNCTIONS
		292
		293	Working with a 4-tuple for every value can be annoying. Or, rather, I<is>
		294	annoying. To reduce this a bit, this module defines a number of helper
		295	functions, both to match BER tuples and to construct BER tuples:
		296
		297	=head3 MATCH HELPERS
		298
		299	These functions accept a BER tuple as first argument and either partially
		300	or fully match it. They often come in two forms, one which exactly matches
		301	a value, and one which only matches the type and returns the value.
		302
		303	They do check whether valid tuples are passed in and croak otherwise. As
		304	a ease-of-use exception, they usually also accept C<undef> instead of a
		305	tuple reference, in which case they silently fail to match.
		306
		307	=over
		308
		309	=item $bool = ber_is $tuple, $class, $tag, $flags, $data
		310
		311	This takes a BER C<$tuple> and matches its elements against the provided
		312	values, all of which are optional - values that are either missing or
		313	C<undef> will be ignored, the others will be matched exactly (e.g. as if
		314	you used C<==> or C<eq> (for C<$data>)).
		315
		316	Some examples:
		317
		318	ber_is $tuple, ASN_UNIVERSAL, ASN_SEQUENCE, 1
		319	orf die "tuple is not an ASN SEQUENCE";
		320
		321	ber_is $tuple, ASN_UNIVERSAL, ASN_NULL
		322	or die "tuple is not an ASN NULL value";
		323
		324	ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER, 0, 50
		325	or die "BER integer must be 50";
		326
		327	=item $seq = ber_is_seq $tuple
		328
		329	Returns the sequence members (the array of subvalues) if the C<$tuple> is
		330	an ASN SEQUENCE, i.e. the C<BER_DATA> member. If the C<$tuple> is not a
		331	sequence it returns C<undef>. For example, SNMP version 1/2c/3 packets all
		332	consist of an outer SEQUENCE value:
		333
		334	my $ber = ber_decode $snmp_data;
		335
		336	my $snmp = ber_is_seq $ber
		337	or die "SNMP packet invalid: does not start with SEQUENCE";
		338
		339	# now we know $snmp is a sequence, so decode the SNMP version
		340
		341	my $version = ber_is_int $snmp->[0]
		342	or die "SNMP packet invalid: does not start with version number";
		343
		344	=item $bool = ber_is_int $tuple, $int
		345
		346	Returns a true value if the C<$tuple> represents an ASN INTEGER with
		347	the value C<$int>.
		348
		349	=item $int = ber_is_int $tuple
		350
		351	Returns true (and extracts the integer value) if the C<$tuple> is an
		352	C<ASN_INTEGER>. For C<0>, this function returns a special value that is 0
		353	but true.
		354
		355	=item $bool = ber_is_oid $tuple, $oid_string
		356
		357	Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER
		358	that exactly matches C<$oid_string>. Example:
		359
		360	ber_is_oid $tuple, "1.3.6.1.4"
		361	or die "oid must be 1.3.6.1.4";
		362
		363	=item $oid = ber_is_oid $tuple
		364
		365	Returns true (and extracts the OID string) if the C<$tuple> is an ASN
		366	OBJECT IDENTIFIER. Otherwise, it returns C<undef>.
		367
		368	=back
		369
		370	=head3 CONSTRUCTION HELPERS
		371
		372	=over
		373
		374	=item $tuple = ber_int $value
		375
		376	Constructs a new C<ASN_INTEGER> tuple.
		377
		378	=back
44		379
45	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>	380	=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1>
46		381
47	This module is I<not> the XS version of L<Convert::BER>, but a different	382	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	383	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	384	for speeding up either of these, or write a similar module, or write your
50	own LDAP or SNMP module for example.	385	own LDAP or SNMP module for example.
51		386
52	=cut	387	=cut
53		388
54	package Convert::BER::XS;	389	package Convert::BER::XS;
56	use common::sense;	391	use common::sense;
57		392
58	use XSLoader ();	393	use XSLoader ();
59	use Exporter qw(import);	394	use Exporter qw(import);
60		395
		396	our $VERSION;
		397
		398	BEGIN {
61	our $VERSION = '0.0';	399	$VERSION = 0.9;
62
63	XSLoader::load __PACKAGE__, $VERSION;	400	XSLoader::load __PACKAGE__, $VERSION;
		401	}
64		402
65	our %EXPORT_TAGS = (	403	our %EXPORT_TAGS = (
66	all => [qw(	404	const_index => [qw(
		405	BER_CLASS BER_TAG BER_FLAGS BER_DATA
		406	)],
		407	const_asn => [qw(
		408	ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER
		409	ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED
		410	ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING
		411	ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING
		412	ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING
		413	ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING
		414
		415	ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE
		416	)],
		417	const_ber_type => [qw(
		418	BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT
		419	BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL
		420	BER_TYPE_IPADDRESS BER_TYPE_CROAK
		421	)],
		422	const_snmp => [qw(
		423	SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32
		424	SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64
		425	)],
		426	decode => [qw(
67	ber_decode	427	ber_decode
68	ber_is ber_is_seq ber_is_i32 ber_is_oid	428	ber_is ber_is_seq ber_is_int ber_is_oid
69	BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA	429	)],
70	ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER ASN_TAG_BER ASN_TAG_MASK	430	encode => [qw(
71	ASN_CONSTRUCTED ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE ASN_CLASS_MASK ASN_CLASS_SHIFT	431	ber_encode
72	ASN_SEQUENCE ASN_IPADDRESS ASN_COUNTER32 ASN_UNSIGNED32 ASN_TIMETICKS ASN_OPAQUE ASN_COUNTER64	432	ber_int
73	)],	433	)],
74	);	434	);
75		435
76	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;	436	our @EXPORT_OK = map @$_, values %EXPORT_TAGS;
77		437
		438	$EXPORT_TAGS{all} = \@EXPORT_OK;
		439	$EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)];
		440
		441	=head1 PROFILES
		442
		443	While any BER data can be correctly encoded and decoded out of the box, it
		444	can be inconvenient to have to manually decode some values into a "better"
		445	format: for instance, SNMP TimeTicks values are decoded into the raw octet
		446	strings of their BER representation, which is quite hard to decode. With
		447	profiles, you can change which class/tag combinations map to which decoder
		448	function inside C<ber_decode> (and of course also which encoder functions
		449	are used in C<ber_encode>).
		450
		451	This works by mapping specific class/tag combinations to an internal "ber
		452	type".
		453
		454	The default profile supports the standard ASN.1 types, but no
		455	application-specific ones. This means that class/tag combinations not in
		456	the base set of ASN.1 are decoded into their raw octet strings.
		457
		458	C<Convert::BER::XS> defines two profile variables you can use out of the box:
		459
		460	=over
		461
		462	=item C<$Convert::BER::XS::DEFAULT_PROFILE>
		463
		464	This is the default profile, i.e. the profile that is used when no
		465	profile is specified for de-/encoding.
		466
		467	You can modify it, but remember that this modifies the defaults for all
		468	callers that rely on the default profile.
		469
		470	=item C<$Convert::BER::XS::SNMP_PROFILE>
		471
		472	A profile with mappings for SNMP-specific application tags added. This is
		473	useful when de-/encoding SNMP data.
		474
		475	Example:
		476
		477	$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE;
		478
		479	=back
		480
		481	=head2 The Convert::BER::XS::Profile class
		482
		483	=over
		484
		485	=item $profile = new Convert::BER::XS::Profile
		486
		487	Create a new profile. The profile will be identical to the default
		488	profile.
		489
		490	=item $profile->set ($class, $tag, $type)
		491
		492	Sets the mapping for the given C<$class>/C<$tag> combination to C<$type>,
		493	which must be one of the C<BER_TYPE_*> constants.
		494
		495	Note that currently, the mapping is stored in a flat array, so large
		496	values of C<$tag> will consume large amounts of memory.
		497
		498	Example:
		499
		500	$profile = new Convert::BER::XS::Profile;
		501	$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT);
		502	$ber = ber_decode $data, $profile;
		503
		504	=item $type = $profile->get ($class, $tag)
		505
		506	Returns the BER type mapped to the given C<$class>/C<$tag> combination.
		507
		508	=back
		509
		510	=head2 BER TYPES
		511
		512	This lists the predefined BER types - you can map any C<CLASS>/C<TAG>
		513	combination to any C<BER_TYPE_*>.
		514
		515	=over
		516
		517	=item C<BER_TYPE_BYTES>
		518
		519	The raw octets of the value. This is the default type for unknown tags and
		520	de-/encodes the value as if it were an octet string, i.e. by copying the
		521	raw bytes.
		522
		523	=item C<BER_TYPE_UTF8>
		524
		525	Like C<BER_TYPE_BYTES>, but decodes the value as if it were a UTF-8 string
		526	(without validation!) and encodes a perl unicode string into a UTF-8 BER
		527	string.
		528
		529	=item C<BER_TYPE_UCS2>
		530
		531	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded
		532	string.
		533
		534	=item C<BER_TYPE_UCS4>
		535
		536	Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded
		537	string.
		538
		539	=item C<BER_TYPE_INT>
		540
		541	Encodes and decodes a BER integer value to a perl integer scalar. This
		542	should correctly handle 64 bit signed and unsigned values.
		543
		544	=item C<BER_TYPE_OID>
		545
		546	Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading
		547	dot, e.g. C<1.3.6.1.213>.
		548
		549	=item C<BER_TYPE_RELOID>
		550
		551	Same as C<BER_TYPE_OID> but uses relative object identifier
		552	encoding: ASN.1 has this hack of encoding the first two OID components
		553	into a single integer in a weird attempt to save an insignificant amount
		554	of space in an otherwise wasteful encoding, and relative OIDs are
		555	basically OIDs without this hack. The practical difference is that the
		556	second component of an OID can only have the values 1..40, while relative
		557	OIDs do not have this restriction.
		558
		559	=item C<BER_TYPE_NULL>
		560
		561	Decodes an C<ASN_NULL> value into C<undef>, and always encodes a
		562	C<ASN_NULL> type, regardless of the perl value.
		563
		564	=item C<BER_TYPE_BOOL>
		565
		566	Decodes an C<ASN_BOOLEAN> value into C<0> or C<1>, and encodes a perl
		567	boolean value into an C<ASN_BOOLEAN>.
		568
		569	=item C<BER_TYPE_REAL>
		570
		571	Decodes/encodes a BER real value. NOT IMPLEMENTED.
		572
		573	=item C<BER_TYPE_IPADDRESS>
		574
		575	Decodes/encodes a four byte string into an IPv4 dotted-quad address string
		576	in Perl. Given the obsolete nature of this type, this is a low-effort
		577	implementation that simply uses C<sprintf> and C<sscanf>-style conversion,
		578	so it won't handle all string forms supported by C<inet_aton> for example.
		579
		580	=item C<BER_TYPE_CROAK>
		581
		582	Always croaks when encountered during encoding or decoding - the
		583	default behaviour when encountering an unknown type is to treat it as
		584	C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard
		585	error for some types, then C<BER_TYPE_CROAK> is for you.
		586
		587	=back
		588
		589	=head2 Example Profile
		590
		591	The following creates a profile suitable for SNMP - it's exactly identical
		592	to the C<$Convert::BER::XS::SNMP_PROFILE> profile.
		593
		594	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		595
		596	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		597	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		598	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		599	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		600	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		601	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		602
		603	=cut
		604
		605	our $DEFAULT_PROFILE = new Convert::BER::XS::Profile;
		606
		607	$DEFAULT_PROFILE->_set_default;
		608
		609	# additional SNMP application types
		610	our $SNMP_PROFILE = new Convert::BER::XS::Profile;
		611
		612	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS);
		613	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT);
		614	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT);
		615	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT);
		616	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS);
		617	$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT);
		618
78	1;	619	1;
		620
		621	=head2 LIMITATIONS/NOTES
		622
		623	This module can only en-/decode 64 bit signed and unsigned integers, and
		624	only when your perl supports those.
		625
		626	This module does not generally care about ranges, i.e. it will happily
		627	de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative
		628	number into an C<SNMP_COUNTER64>.
		629
		630	OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is
		631	much larger than e.g. the one imposed by SNMP or other protocols,a nd is
		632	about 4kB.
		633
		634	Indefinite length encoding is not supported.
		635
		636	Constructed strings are decoded just fine, but there should be a way to
		637	join them for convenience.
		638
		639	REAL values are not supported and will currently croak.
		640
		641	The encoder and decoder tend to accept more formats than should be
		642	strictly supported.
		643
		644	This module has undergone little to no testing so far.
		645
		646	=head2 ITHREADS SUPPORT
		647
		648	This module is unlikely to work when the (officially discouraged) ithreads
		649	are in use.
79		650
80	=head1 AUTHOR	651	=head1 AUTHOR
81		652
82	Marc Lehmann <schmorp@schmorp.de>	653	Marc Lehmann <schmorp@schmorp.de>
83	http://software.schmorp.de/pkg/Convert-BER-XS	654	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 1.33 by root, Sat Apr 20 17:23:21 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 1.33 by root, Sat Apr 20 17:23:21 2019 UTC