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

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.64 by root, Fri Nov 25 23:37:27 2016 UTC vs.
Revision 1.79 by root, Fri Dec 11 06:03:40 2020 UTC

…		…
38	with the added ability of supporting serialisation of Perl objects. (JSON	38	with the added ability of supporting serialisation of Perl objects. (JSON
39	often compresses better than CBOR though, so if you plan to compress the	39	often compresses better than CBOR though, so if you plan to compress the
40	data later and speed is less important you might want to compare both	40	data later and speed is less important you might want to compare both
41	formats first).	41	formats first).
42		42
		43	The primary goal of this module is to be I<correct> and the secondary goal
		44	is to be I<fast>. To reach the latter goal it was written in C.
		45
43	To give you a general idea about speed, with texts in the megabyte range,	46	To give you a general idea about speed, with texts in the megabyte range,
44	C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or	47	C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or
45	L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the	48	L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the
46	data, the worse L<Storable> performs in comparison.	49	data, the worse L<Storable> performs in comparison.
47		50
…		…
52	In addition to the core CBOR data format, this module implements a	55	In addition to the core CBOR data format, this module implements a
53	number of extensions, to support cyclic and shared data structures	56	number of extensions, to support cyclic and shared data structures
54	(see C<allow_sharing> and C<allow_cycles>), string deduplication (see	57	(see C<allow_sharing> and C<allow_cycles>), string deduplication (see
55	C<pack_strings>) and scalar references (always enabled).	58	C<pack_strings>) and scalar references (always enabled).
56		59
57	The primary goal of this module is to be I<correct> and the secondary goal
58	is to be I<fast>. To reach the latter goal it was written in C.
59
60	See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and	60	See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and
61	vice versa.	61	vice versa.
62		62
63	=cut	63	=cut
64		64
65	package CBOR::XS;	65	package CBOR::XS;
66		66
67	use common::sense;	67	use common::sense;
68		68
69	our $VERSION = 1.51;	69	our $VERSION = 1.83;
70	our @ISA = qw(Exporter);	70	our @ISA = qw(Exporter);
71		71
72	our @EXPORT = qw(encode_cbor decode_cbor);	72	our @EXPORT = qw(encode_cbor decode_cbor);
73		73
74	use Exporter;	74	use Exporter;
…		…
112		112
113	The mutators for flags all return the CBOR object again and thus calls can	113	The mutators for flags all return the CBOR object again and thus calls can
114	be chained:	114	be chained:
115		115
116	my $cbor = CBOR::XS->new->encode ({a => [1,2]});	116	my $cbor = CBOR::XS->new->encode ({a => [1,2]});
		117
		118	=item $cbor = new_safe CBOR::XS
		119
		120	Create a new, safe/secure CBOR::XS object. This is similar to C<new>,
		121	but configures the coder object to be safe to use with untrusted
		122	data. Currently, this is equivalent to:
		123
		124	my $cbor = CBOR::XS
		125	->new
		126	->forbid_objects
		127	->filter (\&CBOR::XS::safe_filter)
		128	->max_size (1e8);
		129
		130	But is more future proof (it is better to crash because of a change than
		131	to be exploited in other ways).
		132
		133	=cut
		134
		135	sub new_safe {
		136	CBOR::XS
		137	->new
		138	->forbid_objects
		139	->filter (\&CBOR::XS::safe_filter)
		140	->max_size (1e8)
		141	}
117		142
118	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])	143	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])
119		144
120	=item $max_depth = $cbor->get_max_depth	145	=item $max_depth = $cbor->get_max_depth
121		146
…		…
137		162
138	Note that nesting is implemented by recursion in C. The default value has	163	Note that nesting is implemented by recursion in C. The default value has
139	been chosen to be as large as typical operating systems allow without	164	been chosen to be as large as typical operating systems allow without
140	crashing.	165	crashing.
141		166
142	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	167	See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
143		168
144	=item $cbor = $cbor->max_size ([$maximum_string_size])	169	=item $cbor = $cbor->max_size ([$maximum_string_size])
145		170
146	=item $max_size = $cbor->get_max_size	171	=item $max_size = $cbor->get_max_size
147		172
…		…
152	effect on C<encode> (yet).	177	effect on C<encode> (yet).
153		178
154	If no argument is given, the limit check will be deactivated (same as when	179	If no argument is given, the limit check will be deactivated (same as when
155	C<0> is specified).	180	C<0> is specified).
156		181
157	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	182	See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
158		183
159	=item $cbor = $cbor->allow_unknown ([$enable])	184	=item $cbor = $cbor->allow_unknown ([$enable])
160		185
161	=item $enabled = $cbor->get_allow_unknown	186	=item $enabled = $cbor->get_allow_unknown
162		187
…		…
190	(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the	215	(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the
191	resulting data structure might be unusable.	216	resulting data structure might be unusable.
192		217
193	Detecting shared values incurs a runtime overhead when values are encoded	218	Detecting shared values incurs a runtime overhead when values are encoded
194	that have a reference counter large than one, and might unnecessarily	219	that have a reference counter large than one, and might unnecessarily
195	increase the encoded size, as potentially shared values are encode as	220	increase the encoded size, as potentially shared values are encoded as
196	shareable whether or not they are actually shared.	221	shareable whether or not they are actually shared.
197		222
198	At the moment, only targets of references can be shared (e.g. scalars,	223	At the moment, only targets of references can be shared (e.g. scalars,
199	arrays or hashes pointed to by a reference). Weirder constructs, such as	224	arrays or hashes pointed to by a reference). Weirder constructs, such as
200	an array with multiple "copies" of the I<same> string, which are hard but	225	an array with multiple "copies" of the I<same> string, which are hard but
…		…
226	throwing an error.	251	throwing an error.
227		252
228	This option does not affect C<encode> in any way - shared values and	253	This option does not affect C<encode> in any way - shared values and
229	references will always be encoded properly if present.	254	references will always be encoded properly if present.
230		255
		256	=item $cbor = $cbor->forbid_objects ([$enable])
		257
		258	=item $enabled = $cbor->get_forbid_objects
		259
		260	Disables the use of the object serialiser protocol.
		261
		262	If C<$enable> is true (or missing), then C<encode> will will throw an
		263	exception when it encounters perl objects that would be encoded using the
		264	perl-object tag (26). When C<decode> encounters such tags, it will fall
		265	back to the general filter/tagged logic as if this were an unknown tag (by
		266	default resulting in a C<CBOR::XC::Tagged> object).
		267
		268	If C<$enable> is false (the default), then C<encode> will use the
		269	L<Types::Serialiser> object serialisation protocol to serialise objects
		270	into perl-object tags, and C<decode> will do the same to decode such tags.
		271
		272	See L<SECURITY CONSIDERATIONS>, below, for more info on why forbidding this
		273	protocol can be useful.
		274
231	=item $cbor = $cbor->pack_strings ([$enable])	275	=item $cbor = $cbor->pack_strings ([$enable])
232		276
233	=item $enabled = $cbor->get_pack_strings	277	=item $enabled = $cbor->get_pack_strings
234		278
235	If C<$enable> is true (or missing), then C<encode> will try not to encode	279	If C<$enable> is true (or missing), then C<encode> will try not to encode
…		…
286	strings as CBOR byte strings.	330	strings as CBOR byte strings.
287		331
288	This option does not affect C<decode> in any way.	332	This option does not affect C<decode> in any way.
289		333
290	This option has similar advantages and disadvantages as C<text_keys>. In	334	This option has similar advantages and disadvantages as C<text_keys>. In
291	addition, this option effectively removes the ability to encode byte	335	addition, this option effectively removes the ability to automatically
292	strings, which might break some C<FREEZE> and C<TO_CBOR> methods that rely	336	encode byte strings, which might break some C<FREEZE> and C<TO_CBOR>
293	on this, such as bignum encoding, so this option is mainly useful for very	337	methods that rely on this.
294	simple data.	338
		339	A workaround is to use explicit type casts, which are unaffected by this option.
295		340
296	=item $cbor = $cbor->validate_utf8 ([$enable])	341	=item $cbor = $cbor->validate_utf8 ([$enable])
297		342
298	=item $enabled = $cbor->get_validate_utf8	343	=item $enabled = $cbor->get_validate_utf8
299		344
…		…
337	replace the tagged value in the decoded data structure, or no values,	382	replace the tagged value in the decoded data structure, or no values,
338	which will result in default handling, which currently means the decoder	383	which will result in default handling, which currently means the decoder
339	creates a C<CBOR::XS::Tagged> object to hold the tag and the value.	384	creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
340		385
341	When the filter is cleared (the default state), the default filter	386	When the filter is cleared (the default state), the default filter
342	function, C<CBOR::XS::default_filter>, is used. This function simply looks	387	function, C<CBOR::XS::default_filter>, is used. This function simply
343	up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be	388	looks up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists
344	a code reference that is called with tag and value, and is responsible for	389	it must be a code reference that is called with tag and value, and is
345	decoding the value. If no entry exists, it returns no values.	390	responsible for decoding the value. If no entry exists, it returns no
		391	values. C<CBOR::XS> provides a number of default filter functions already,
		392	the the C<%CBOR::XS::FILTER> hash can be freely extended with more.
		393
		394	C<CBOR::XS> additionally provides an alternative filter function that is
		395	supposed to be safe to use with untrusted data (which the default filter
		396	might not), called C<CBOR::XS::safe_filter>, which works the same as
		397	the C<default_filter> but uses the C<%CBOR::XS::SAFE_FILTER> variable
		398	instead. It is prepopulated with the tag decoding functions that are
		399	deemed safe (basically the same as C<%CBOR::XS::FILTER> without all
		400	the bignum tags), and can be extended by user code as wlel, although,
		401	obviously, one should be very careful about adding decoding functions
		402	here, since the expectation is that they are safe to use on untrusted
		403	data, after all.
346		404
347	Example: decode all tags not handled internally into C<CBOR::XS::Tagged>	405	Example: decode all tags not handled internally into C<CBOR::XS::Tagged>
348	objects, with no other special handling (useful when working with	406	objects, with no other special handling (useful when working with
349	potentially "unsafe" CBOR data).	407	potentially "unsafe" CBOR data).
350		408
…		…
357	my ($tag, $value);	415	my ($tag, $value);
358		416
359	"tag 1347375694 value $value"	417	"tag 1347375694 value $value"
360	};	418	};
361		419
		420	Example: provide your own filter function that looks up tags in your own
		421	hash:
		422
		423	my %my_filter = (
		424	998347484 => sub {
		425	my ($tag, $value);
		426
		427	"tag 998347484 value $value"
		428	};
		429	);
		430
		431	my $coder = CBOR::XS->new->filter (sub {
		432	&{ $my_filter{$_[0]} or return }
		433	});
		434
		435
		436	Example: use the safe filter function (see L<SECURITY CONSIDERATIONS> for
		437	more considerations on security).
		438
		439	CBOR::XS->new->filter (\&CBOR::XS::safe_filter)->decode ($cbor_data);
		440
362	=item $cbor_data = $cbor->encode ($perl_scalar)	441	=item $cbor_data = $cbor->encode ($perl_scalar)
363		442
364	Converts the given Perl data structure (a scalar value) to its CBOR	443	Converts the given Perl data structure (a scalar value) to its CBOR
365	representation.	444	representation.
366		445
…		…
375	when there is trailing garbage after the CBOR string, it will silently	454	when there is trailing garbage after the CBOR string, it will silently
376	stop parsing there and return the number of characters consumed so far.	455	stop parsing there and return the number of characters consumed so far.
377		456
378	This is useful if your CBOR texts are not delimited by an outer protocol	457	This is useful if your CBOR texts are not delimited by an outer protocol
379	and you need to know where the first CBOR string ends amd the next one	458	and you need to know where the first CBOR string ends amd the next one
380	starts.	459	starts - CBOR strings are self-delimited, so it is possible to concatenate
		460	CBOR strings without any delimiters or size fields and recover their data.
381		461
382	CBOR::XS->new->decode_prefix ("......")	462	CBOR::XS->new->decode_prefix ("......")
383	=> ("...", 3)	463	=> ("...", 3)
384		464
385	=back	465	=back
…		…
589	"$x"; # stringified	669	"$x"; # stringified
590	$x .= ""; # another, more awkward way to stringify	670	$x .= ""; # another, more awkward way to stringify
591	print $x; # perl does it for you, too, quite often	671	print $x; # perl does it for you, too, quite often
592		672
593	You can force whether a string is encoded as byte or text string by using	673	You can force whether a string is encoded as byte or text string by using
594	C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled):	674	C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled).
595		675
596	utf8::upgrade $x; # encode $x as text string	676	utf8::upgrade $x; # encode $x as text string
597	utf8::downgrade $x; # encode $x as byte string	677	utf8::downgrade $x; # encode $x as byte string
		678
		679	More options are available, see L<TYPE CASTS>, below, and the C<text_keys>
		680	and C<text_strings> options.
598		681
599	Perl doesn't define what operations up- and downgrade strings, so if the	682	Perl doesn't define what operations up- and downgrade strings, so if the
600	difference between byte and text is important, you should up- or downgrade	683	difference between byte and text is important, you should up- or downgrade
601	your string as late as possible before encoding. You can also force the	684	your string as late as possible before encoding. You can also force the
602	use of CBOR text strings by using C<text_keys> or C<text_strings>.	685	use of CBOR text strings by using C<text_keys> or C<text_strings>.
…		…
617	format will be used. Perls that use formats other than IEEE double to	700	format will be used. Perls that use formats other than IEEE double to
618	represent numerical values are supported, but might suffer loss of	701	represent numerical values are supported, but might suffer loss of
619	precision.	702	precision.
620		703
621	=back	704	=back
		705
		706	=head2 TYPE CASTS
		707
		708	B<EXPERIMENTAL>: As an experimental extension, C<CBOR::XS> allows you to
		709	force specific cbor types to be used when encoding. That allows you to
		710	encode types not normally accessible (e.g. half floats) as well as force
		711	string types even when C<text_strings> is in effect.
		712
		713	Type forcing is done by calling a special "cast" function which keeps a
		714	copy of the value and returns a new value that can be handed over to any
		715	CBOR encoder function.
		716
		717	The following casts are currently available (all of which are unary
		718	operators, that is, have a prototype of C<$>):
		719
		720	=over
		721
		722	=item CBOR::XS::as_int $value
		723
		724	Forces the value to be encoded as some form of (basic, not bignum) integer
		725	type.
		726
		727	=item CBOR::XS::as_text $value
		728
		729	Forces the value to be encoded as (UTF-8) text values.
		730
		731	=item CBOR::XS::as_bytes $value
		732
		733	Forces the value to be encoded as a (binary) string value.
		734
		735	Example: encode a perl string as binary even though C<text_strings> is in
		736	effect.
		737
		738	CBOR::XS->new->text_strings->encode ([4, "text", CBOR::XS::bytes "bytevalue"]);
		739
		740	=item CBOR::XS::as_bool $value
		741
		742	Converts a Perl boolean (which can be any kind of scalar) into a CBOR
		743	boolean. Strictly the same, but shorter to write, than:
		744
		745	$value ? Types::Serialiser::true : Types::Serialiser::false
		746
		747	=item CBOR::XS::as_float16 $value
		748
		749	Forces half-float (IEEE 754 binary16) encoding of the given value.
		750
		751	=item CBOR::XS::as_float32 $value
		752
		753	Forces single-float (IEEE 754 binary32) encoding of the given value.
		754
		755	=item CBOR::XS::as_float64 $value
		756
		757	Forces double-float (IEEE 754 binary64) encoding of the given value.
		758
		759	=item CBOR::XS::as_cbor $cbor_text
		760
		761	Not a type cast per-se, this type cast forces the argument to eb encoded
		762	as-is. This can be used to embed pre-encoded CBOR data.
		763
		764	Note that no checking on the validity of the C<$cbor_text> is done - it's
		765	the callers responsibility to correctly encode values.
		766
		767	=item CBOR::XS::as_map [key => value...]
		768
		769	Treat the array reference as key value pairs and output a CBOR map. This
		770	allows you to generate CBOR maps with arbitrary key types (or, if you
		771	don't care about semantics, duplicate keys or prairs in a custom order),
		772	which is otherwise hard to do with Perl.
		773
		774	The single argument must be an array reference with an even number of
		775	elements.
		776
		777	Example: encode a CBOR map with a string and an integer as keys.
		778
		779	encode_cbor CBOR::XS::as_map [string => "value", 5 => "value"]
		780
		781	=back
		782
		783	=cut
		784
		785	sub CBOR::XS::as_cbor ($) { bless [$_[0], 0, undef], CBOR::XS::Tagged:: }
		786	sub CBOR::XS::as_int ($) { bless [$_[0], 1, undef], CBOR::XS::Tagged:: }
		787	sub CBOR::XS::as_bytes ($) { bless [$_[0], 2, undef], CBOR::XS::Tagged:: }
		788	sub CBOR::XS::as_text ($) { bless [$_[0], 3, undef], CBOR::XS::Tagged:: }
		789	sub CBOR::XS::as_float16 ($) { bless [$_[0], 4, undef], CBOR::XS::Tagged:: }
		790	sub CBOR::XS::as_float32 ($) { bless [$_[0], 5, undef], CBOR::XS::Tagged:: }
		791	sub CBOR::XS::as_float64 ($) { bless [$_[0], 6, undef], CBOR::XS::Tagged:: }
		792
		793	sub CBOR::XS::as_bool ($) { $_[0] ? $Types::Serialiser::true : $Types::Serialiser::false }
		794
		795	sub CBOR::XS::as_map ($) {
		796	ARRAY:: eq ref $_[0]
		797	and $#{ $_[0] } & 1
		798	or do { require Carp; Carp::croak ("CBOR::XS::as_map only acepts array references with an even number of elements, caught") };
		799
		800	bless [$_[0], 7, undef], CBOR::XS::Tagged::
		801	}
622		802
623	=head2 OBJECT SERIALISATION	803	=head2 OBJECT SERIALISATION
624		804
625	This module implements both a CBOR-specific and the generic	805	This module implements both a CBOR-specific and the generic
626	L<Types::Serialier> object serialisation protocol. The following	806	L<Types::Serialier> object serialisation protocol. The following
…		…
978	CBOR intact.	1158	CBOR intact.
979		1159
980		1160
981	=head1 SECURITY CONSIDERATIONS	1161	=head1 SECURITY CONSIDERATIONS
982		1162
983	When you are using CBOR in a protocol, talking to untrusted potentially	1163	Tl;dr... if you want to decode or encode CBOR from untrusted sources, you
984	hostile creatures requires relatively few measures.	1164	should start with a coder object created via C<new_safe> (which implements
		1165	the mitigations explained below):
985		1166
		1167	my $coder = CBOR::XS->new_safe;
		1168
		1169	my $data = $coder->decode ($cbor_text);
		1170	my $cbor = $coder->encode ($data);
		1171
		1172	Longer version: When you are using CBOR in a protocol, talking to
		1173	untrusted potentially hostile creatures requires some thought:
		1174
		1175	=over 4
		1176
		1177	=item Security of the CBOR decoder itself
		1178
986	First of all, your CBOR decoder should be secure, that is, should not have	1179	First and foremost, your CBOR decoder should be secure, that is, should
		1180	not have any buffer overflows or similar bugs that could potentially be
987	any buffer overflows. Obviously, this module should ensure that and I am	1181	exploited. Obviously, this module should ensure that and I am trying hard
988	trying hard on making that true, but you never know.	1182	on making that true, but you never know.
989		1183
		1184	=item CBOR::XS can invoke almost arbitrary callbacks during decoding
		1185
990	Second, CBOR::XS supports object serialisation - decoding CBOR can cause	1186	CBOR::XS supports object serialisation - decoding CBOR can cause calls
991	calls to I<any> C<THAW> method in I<any> package that exists in your	1187	to I<any> C<THAW> method in I<any> package that exists in your process
992	process (that is, CBOR::XS will not try to load modules, but any existing	1188	(that is, CBOR::XS will not try to load modules, but any existing C<THAW>
993	C<THAW> method or function can be called, so they all have to be secure).	1189	method or function can be called, so they all have to be secure).
994		1190
		1191	Less obviously, it will also invoke C<TO_CBOR> and C<FREEZE> methods -
		1192	even if all your C<THAW> methods are secure, encoding data structures from
		1193	untrusted sources can invoke those and trigger bugs in those.
		1194
		1195	So, if you are not sure about the security of all the modules you
		1196	have loaded (you shouldn't), you should disable this part using
		1197	C<forbid_objects> or using C<new_safe>.
		1198
		1199	=item CBOR can be extended with tags that call library code
		1200
		1201	CBOR can be extended with tags, and C<CBOR::XS> has a registry of
		1202	conversion functions for many existing tags that can be extended via
		1203	third-party modules (see the C<filter> method).
		1204
		1205	If you don't trust these, you should configure the "safe" filter function,
		1206	C<CBOR::XS::safe_filter> (C<new_safe> does this), which by default only
		1207	includes conversion functions that are considered "safe" by the author
		1208	(but again, they can be extended by third party modules).
		1209
		1210	Depending on your level of paranoia, you can use the "safe" filter:
		1211
		1212	$cbor->filter (\&CBOR::XS::safe_filter);
		1213
		1214	... your own filter...
		1215
		1216	$cbor->filter (sub { ... do your stuffs here ... });
		1217
		1218	... or even no filter at all, disabling all tag decoding:
		1219
		1220	$cbor->filter (sub { });
		1221
		1222	This is never a problem for encoding, as the tag mechanism only exists in
		1223	CBOR texts.
		1224
		1225	=item Resource-starving attacks: object memory usage
		1226
995	Third, you need to avoid resource-starving attacks. That means you should	1227	You need to avoid resource-starving attacks. That means you should limit
996	limit the size of CBOR data you accept, or make sure then when your	1228	the size of CBOR data you accept, or make sure then when your resources
997	resources run out, that's just fine (e.g. by using a separate process that	1229	run out, that's just fine (e.g. by using a separate process that can
998	can crash safely). The size of a CBOR string in octets is usually a good	1230	crash safely). The size of a CBOR string in octets is usually a good
999	indication of the size of the resources required to decode it into a Perl	1231	indication of the size of the resources required to decode it into a Perl
1000	structure. While CBOR::XS can check the size of the CBOR text, it might be	1232	structure. While CBOR::XS can check the size of the CBOR text (using
1001	too late when you already have it in memory, so you might want to check	1233	C<max_size> - done by C<new_safe>), it might be too late when you already
1002	the size before you accept the string.	1234	have it in memory, so you might want to check the size before you accept
		1235	the string.
1003		1236
		1237	As for encoding, it is possible to construct data structures that are
		1238	relatively small but result in large CBOR texts (for example by having an
		1239	array full of references to the same big data structure, which will all be
		1240	deep-cloned during encoding by default). This is rarely an actual issue
		1241	(and the worst case is still just running out of memory), but you can
		1242	reduce this risk by using C<allow_sharing>.
		1243
		1244	=item Resource-starving attacks: stack overflows
		1245
1004	Fourth, CBOR::XS recurses using the C stack when decoding objects and	1246	CBOR::XS recurses using the C stack when decoding objects and arrays. The
1005	arrays. The C stack is a limited resource: for instance, on my amd64	1247	C stack is a limited resource: for instance, on my amd64 machine with 8MB
1006	machine with 8MB of stack size I can decode around 180k nested arrays but	1248	of stack size I can decode around 180k nested arrays but only 14k nested
1007	only 14k nested CBOR objects (due to perl itself recursing deeply on croak	1249	CBOR objects (due to perl itself recursing deeply on croak to free the
1008	to free the temporary). If that is exceeded, the program crashes. To be	1250	temporary). If that is exceeded, the program crashes. To be conservative,
1009	conservative, the default nesting limit is set to 512. If your process	1251	the default nesting limit is set to 512. If your process has a smaller
1010	has a smaller stack, you should adjust this setting accordingly with the	1252	stack, you should adjust this setting accordingly with the C<max_depth>
1011	C<max_depth> method.	1253	method.
		1254
		1255	=item Resource-starving attacks: CPU en-/decoding complexity
		1256
		1257	CBOR::XS will use the L<Math::BigInt>, L<Math::BigFloat> and
		1258	L<Math::BigRat> libraries to represent encode/decode bignums. These can be
		1259	very slow (as in, centuries of CPU time) and can even crash your program
		1260	(and are generally not very trustworthy). See the next section on bignum
		1261	security for details.
		1262
		1263	=item Data breaches: leaking information in error messages
		1264
		1265	CBOR::XS might leak contents of your Perl data structures in its error
		1266	messages, so when you serialise sensitive information you might want to
		1267	make sure that exceptions thrown by CBOR::XS will not end up in front of
		1268	untrusted eyes.
		1269
		1270	=item Something else...
1012		1271
1013	Something else could bomb you, too, that I forgot to think of. In that	1272	Something else could bomb you, too, that I forgot to think of. In that
1014	case, you get to keep the pieces. I am always open for hints, though...	1273	case, you get to keep the pieces. I am always open for hints, though...
1015		1274
1016	Also keep in mind that CBOR::XS might leak contents of your Perl data	1275	=back
1017	structures in its error messages, so when you serialise sensitive
1018	information you might want to make sure that exceptions thrown by CBOR::XS
1019	will not end up in front of untrusted eyes.
1020		1276
1021		1277
1022	=head1 BIGNUM SECURITY CONSIDERATIONS	1278	=head1 BIGNUM SECURITY CONSIDERATIONS
1023		1279
1024	CBOR::XS provides a C<TO_CBOR> method for both L<Math::BigInt> and	1280	CBOR::XS provides a C<TO_CBOR> method for both L<Math::BigInt> and
…		…
1073	=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT	1329	=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT
1074		1330
1075	On perls that were built without 64 bit integer support (these are rare	1331	On perls that were built without 64 bit integer support (these are rare
1076	nowadays, even on 32 bit architectures, as all major Perl distributions	1332	nowadays, even on 32 bit architectures, as all major Perl distributions
1077	are built with 64 bit integer support), support for any kind of 64 bit	1333	are built with 64 bit integer support), support for any kind of 64 bit
1078	integer in CBOR is very limited - most likely, these 64 bit values will	1334	value in CBOR is very limited - most likely, these 64 bit values will
1079	be truncated, corrupted, or otherwise not decoded correctly. This also	1335	be truncated, corrupted, or otherwise not decoded correctly. This also
1080	includes string, array and map sizes that are stored as 64 bit integers.	1336	includes string, float, array and map sizes that are stored as 64 bit
		1337	integers.
1081		1338
1082		1339
1083	=head1 THREADS	1340	=head1 THREADS
1084		1341
1085	This module is I<not> guaranteed to be thread safe and there are no	1342	This module is I<not> guaranteed to be thread safe and there are no
…		…
1099	Please refrain from using rt.cpan.org or any other bug reporting	1356	Please refrain from using rt.cpan.org or any other bug reporting
1100	service. I put the contact address into my modules for a reason.	1357	service. I put the contact address into my modules for a reason.
1101		1358
1102	=cut	1359	=cut
1103		1360
1104	# clumsy hv_store-in-perl	1361	# clumsy and slow hv_store-in-hash helper function
1105	sub _hv_store {	1362	sub _hv_store {
1106	$_[0]{$_[1]} = $_[2];	1363	$_[0]{$_[1]} = $_[2];
1107	}	1364	}
1108		1365
1109	our %FILTER = (	1366	our %FILTER = (
…		…
1185	# 34 # base64 rfc46484, utf-8	1442	# 34 # base64 rfc46484, utf-8
1186	# 35 # regex pcre/ecma262, utf-8	1443	# 35 # regex pcre/ecma262, utf-8
1187	# 36 # mime message rfc2045, utf-8	1444	# 36 # mime message rfc2045, utf-8
1188	);	1445	);
1189		1446
1190	sub CBOR::XS::default_filter {	1447	sub default_filter {
1191	&{ $FILTER{$_[0]} or return }	1448	&{ $FILTER{$_[0]} or return }
		1449	}
		1450
		1451	our %SAFE_FILTER = map { $_ => $FILTER{$_} } 0, 1, 21, 22, 23, 32;
		1452
		1453	sub safe_filter {
		1454	&{ $SAFE_FILTER{$_[0]} or return }
1192	}	1455	}
1193		1456
1194	sub URI::TO_CBOR {	1457	sub URI::TO_CBOR {
1195	my $uri = $_[0]->as_string;	1458	my $uri = $_[0]->as_string;
1196	utf8::upgrade $uri;	1459	utf8::upgrade $uri;

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Comparing CBOR-XS/XS.pm (file contents): Revision 1.64 by root, Fri Nov 25 23:37:27 2016 UTC vs. Revision 1.79 by root, Fri Dec 11 06:03:40 2020 UTC

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Comparing CBOR-XS/XS.pm (file contents):
Revision 1.64 by root, Fri Nov 25 23:37:27 2016 UTC vs.
Revision 1.79 by root, Fri Dec 11 06:03:40 2020 UTC