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Revision 1.30 by root, Sat Nov 30 16:19:59 2013 UTC vs.
Revision 1.80 by root, Fri Dec 11 06:05:33 2020 UTC

38with the added ability of supporting serialisation of Perl objects. (JSON 38with the added ability of supporting serialisation of Perl objects. (JSON
39often compresses better than CBOR though, so if you plan to compress the 39often compresses better than CBOR though, so if you plan to compress the
40data later and speed is less important you might want to compare both 40data later and speed is less important you might want to compare both
41formats first). 41formats first).
42 42
43The primary goal of this module is to be I<correct> and the secondary goal
44is to be I<fast>. To reach the latter goal it was written in C.
45
43To give you a general idea about speed, with texts in the megabyte range, 46To give you a general idea about speed, with texts in the megabyte range,
44C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or 47C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or
45L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the 48L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the
46data, the worse L<Storable> performs in comparison. 49data, the worse L<Storable> performs in comparison.
47 50
48Regarding compactness, C<CBOR::XS>-encoded data structures are usually 51Regarding compactness, C<CBOR::XS>-encoded data structures are usually
49about 20% smaller than the same data encoded as (compact) JSON or 52about 20% smaller than the same data encoded as (compact) JSON or
50L<Storable>. 53L<Storable>.
51 54
52In addition to the core CBOR data format, this module implements a 55In addition to the core CBOR data format, this module implements a
53number of extensions, to support cyclic and shared data structures (see 56number of extensions, to support cyclic and shared data structures
54C<allow_sharing>), string deduplication (see C<pack_strings>) and scalar 57(see C<allow_sharing> and C<allow_cycles>), string deduplication (see
55references (always enabled). 58C<pack_strings>) and scalar references (always enabled).
56
57The primary goal of this module is to be I<correct> and the secondary goal
58is to be I<fast>. To reach the latter goal it was written in C.
59 59
60See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and 60See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and
61vice versa. 61vice versa.
62 62
63=cut 63=cut
64 64
65package CBOR::XS; 65package CBOR::XS;
66 66
67use common::sense; 67use common::sense;
68 68
69our $VERSION = '1.0'; 69our $VERSION = 1.83;
70our @ISA = qw(Exporter); 70our @ISA = qw(Exporter);
71 71
72our @EXPORT = qw(encode_cbor decode_cbor); 72our @EXPORT = qw(encode_cbor decode_cbor);
73 73
74use Exporter; 74use Exporter;
112 112
113The mutators for flags all return the CBOR object again and thus calls can 113The mutators for flags all return the CBOR object again and thus calls can
114be chained: 114be 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
120Create a new, safe/secure CBOR::XS object. This is similar to C<new>,
121but configures the coder object to be safe to use with untrusted
122data. 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
130But is more future proof (it is better to crash because of a change than
131to be exploited in other ways).
132
133=cut
134
135sub 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
138Note that nesting is implemented by recursion in C. The default value has 163Note that nesting is implemented by recursion in C. The default value has
139been chosen to be as large as typical operating systems allow without 164been chosen to be as large as typical operating systems allow without
140crashing. 165crashing.
141 166
142See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 167See 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
152effect on C<encode> (yet). 177effect on C<encode> (yet).
153 178
154If no argument is given, the limit check will be deactivated (same as when 179If no argument is given, the limit check will be deactivated (same as when
155C<0> is specified). 180C<0> is specified).
156 181
157See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 182See 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
180reference to the earlier value. 205reference to the earlier value.
181 206
182This means that such values will only be encoded once, and will not result 207This means that such values will only be encoded once, and will not result
183in a deep cloning of the value on decode, in decoders supporting the value 208in a deep cloning of the value on decode, in decoders supporting the value
184sharing extension. This also makes it possible to encode cyclic data 209sharing extension. This also makes it possible to encode cyclic data
185structures. 210structures (which need C<allow_cycles> to be enabled to be decoded by this
211module).
186 212
187It is recommended to leave it off unless you know your 213It is recommended to leave it off unless you know your
188communication partner supports the value sharing extensions to CBOR 214communication partner supports the value sharing extensions to CBOR
189(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
190resulting data structure might be unusable. 216resulting data structure might be unusable.
191 217
192Detecting shared values incurs a runtime overhead when values are encoded 218Detecting shared values incurs a runtime overhead when values are encoded
193that have a reference counter large than one, and might unnecessarily 219that have a reference counter large than one, and might unnecessarily
194increase the encoded size, as potentially shared values are encode as 220increase the encoded size, as potentially shared values are encoded as
195sharable whether or not they are actually shared. 221shareable whether or not they are actually shared.
196 222
197At the moment, only targets of references can be shared (e.g. scalars, 223At the moment, only targets of references can be shared (e.g. scalars,
198arrays or hashes pointed to by a reference). Weirder constructs, such as 224arrays or hashes pointed to by a reference). Weirder constructs, such as
199an array with multiple "copies" of the I<same> string, which are hard but 225an array with multiple "copies" of the I<same> string, which are hard but
200not impossible to create in Perl, are not supported (this is the same as 226not impossible to create in Perl, are not supported (this is the same as
205structures cannot be encoded in this mode. 231structures cannot be encoded in this mode.
206 232
207This option does not affect C<decode> in any way - shared values and 233This option does not affect C<decode> in any way - shared values and
208references will always be decoded properly if present. 234references will always be decoded properly if present.
209 235
236=item $cbor = $cbor->allow_cycles ([$enable])
237
238=item $enabled = $cbor->get_allow_cycles
239
240If C<$enable> is true (or missing), then C<decode> will happily decode
241self-referential (cyclic) data structures. By default these will not be
242decoded, as they need manual cleanup to avoid memory leaks, so code that
243isn't prepared for this will not leak memory.
244
245If C<$enable> is false (the default), then C<decode> will throw an error
246when it encounters a self-referential/cyclic data structure.
247
248FUTURE DIRECTION: the motivation behind this option is to avoid I<real>
249cycles - future versions of this module might chose to decode cyclic data
250structures using weak references when this option is off, instead of
251throwing an error.
252
253This option does not affect C<encode> in any way - shared values and
254references will always be encoded properly if present.
255
256=item $cbor = $cbor->forbid_objects ([$enable])
257
258=item $enabled = $cbor->get_forbid_objects
259
260Disables the use of the object serialiser protocol.
261
262If C<$enable> is true (or missing), then C<encode> will will throw an
263exception when it encounters perl objects that would be encoded using the
264perl-object tag (26). When C<decode> encounters such tags, it will fall
265back to the general filter/tagged logic as if this were an unknown tag (by
266default resulting in a C<CBOR::XC::Tagged> object).
267
268If C<$enable> is false (the default), then C<encode> will use the
269L<Types::Serialiser> object serialisation protocol to serialise objects
270into perl-object tags, and C<decode> will do the same to decode such tags.
271
272See L<SECURITY CONSIDERATIONS>, below, for more info on why forbidding this
273protocol can be useful.
274
210=item $cbor = $cbor->pack_strings ([$enable]) 275=item $cbor = $cbor->pack_strings ([$enable])
211 276
212=item $enabled = $cbor->get_pack_strings 277=item $enabled = $cbor->get_pack_strings
213 278
214If C<$enable> is true (or missing), then C<encode> will try not to encode 279If C<$enable> is true (or missing), then C<encode> will try not to encode
226the standard CBOR way. 291the standard CBOR way.
227 292
228This option does not affect C<decode> in any way - string references will 293This option does not affect C<decode> in any way - string references will
229always be decoded properly if present. 294always be decoded properly if present.
230 295
296=item $cbor = $cbor->text_keys ([$enable])
297
298=item $enabled = $cbor->get_text_keys
299
300If C<$enabled> is true (or missing), then C<encode> will encode all
301perl hash keys as CBOR text strings/UTF-8 string, upgrading them as needed.
302
303If C<$enable> is false (the default), then C<encode> will encode hash keys
304normally - upgraded perl strings (strings internally encoded as UTF-8) as
305CBOR text strings, and downgraded perl strings as CBOR byte strings.
306
307This option does not affect C<decode> in any way.
308
309This option is useful for interoperability with CBOR decoders that don't
310treat byte strings as a form of text. It is especially useful as Perl
311gives very little control over hash keys.
312
313Enabling this option can be slow, as all downgraded hash keys that are
314encoded need to be scanned and converted to UTF-8.
315
316=item $cbor = $cbor->text_strings ([$enable])
317
318=item $enabled = $cbor->get_text_strings
319
320This option works similar to C<text_keys>, above, but works on all strings
321(including hash keys), so C<text_keys> has no further effect after
322enabling C<text_strings>.
323
324If C<$enabled> is true (or missing), then C<encode> will encode all perl
325strings as CBOR text strings/UTF-8 strings, upgrading them as needed.
326
327If C<$enable> is false (the default), then C<encode> will encode strings
328normally (but see C<text_keys>) - upgraded perl strings (strings
329internally encoded as UTF-8) as CBOR text strings, and downgraded perl
330strings as CBOR byte strings.
331
332This option does not affect C<decode> in any way.
333
334This option has similar advantages and disadvantages as C<text_keys>. In
335addition, this option effectively removes the ability to automatically
336encode byte strings, which might break some C<FREEZE> and C<TO_CBOR>
337methods that rely on this.
338
339A workaround is to use explicit type casts, which are unaffected by this option.
340
341=item $cbor = $cbor->validate_utf8 ([$enable])
342
343=item $enabled = $cbor->get_validate_utf8
344
345If C<$enable> is true (or missing), then C<decode> will validate that
346elements (text strings) containing UTF-8 data in fact contain valid UTF-8
347data (instead of blindly accepting it). This validation obviously takes
348extra time during decoding.
349
350The concept of "valid UTF-8" used is perl's concept, which is a superset
351of the official UTF-8.
352
353If C<$enable> is false (the default), then C<decode> will blindly accept
354UTF-8 data, marking them as valid UTF-8 in the resulting data structure
355regardless of whether that's true or not.
356
357Perl isn't too happy about corrupted UTF-8 in strings, but should
358generally not crash or do similarly evil things. Extensions might be not
359so forgiving, so it's recommended to turn on this setting if you receive
360untrusted CBOR.
361
362This option does not affect C<encode> in any way - strings that are
363supposedly valid UTF-8 will simply be dumped into the resulting CBOR
364string without checking whether that is, in fact, true or not.
365
231=item $cbor = $cbor->filter ([$cb->($tag, $value)]) 366=item $cbor = $cbor->filter ([$cb->($tag, $value)])
232 367
233=item $cb_or_undef = $cbor->get_filter 368=item $cb_or_undef = $cbor->get_filter
234 369
235Sets or replaces the tagged value decoding filter (when C<$cb> is 370Sets or replaces the tagged value decoding filter (when C<$cb> is
247replace the tagged value in the decoded data structure, or no values, 382replace the tagged value in the decoded data structure, or no values,
248which will result in default handling, which currently means the decoder 383which will result in default handling, which currently means the decoder
249creates a C<CBOR::XS::Tagged> object to hold the tag and the value. 384creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
250 385
251When the filter is cleared (the default state), the default filter 386When the filter is cleared (the default state), the default filter
252function, C<CBOR::XS::default_filter>, is used. This function simply looks 387function, C<CBOR::XS::default_filter>, is used. This function simply
253up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be 388looks up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists
254a code reference that is called with tag and value, and is responsible for 389it must be a code reference that is called with tag and value, and is
255decoding the value. If no entry exists, it returns no values. 390responsible for decoding the value. If no entry exists, it returns no
391values. C<CBOR::XS> provides a number of default filter functions already,
392the the C<%CBOR::XS::FILTER> hash can be freely extended with more.
393
394C<CBOR::XS> additionally provides an alternative filter function that is
395supposed to be safe to use with untrusted data (which the default filter
396might not), called C<CBOR::XS::safe_filter>, which works the same as
397the C<default_filter> but uses the C<%CBOR::XS::SAFE_FILTER> variable
398instead. It is prepopulated with the tag decoding functions that are
399deemed safe (basically the same as C<%CBOR::XS::FILTER> without all
400the bignum tags), and can be extended by user code as wlel, although,
401obviously, one should be very careful about adding decoding functions
402here, since the expectation is that they are safe to use on untrusted
403data, after all.
256 404
257Example: decode all tags not handled internally into C<CBOR::XS::Tagged> 405Example: decode all tags not handled internally into C<CBOR::XS::Tagged>
258objects, with no other special handling (useful when working with 406objects, with no other special handling (useful when working with
259potentially "unsafe" CBOR data). 407potentially "unsafe" CBOR data).
260 408
267 my ($tag, $value); 415 my ($tag, $value);
268 416
269 "tag 1347375694 value $value" 417 "tag 1347375694 value $value"
270 }; 418 };
271 419
420Example: provide your own filter function that looks up tags in your own
421hash:
422
423 my %my_filter = (
424 998347484 => sub {
425 my ($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
436Example: use the safe filter function (see L<SECURITY CONSIDERATIONS> for
437more considerations on security).
438
439 CBOR::XS->new->filter (\&CBOR::XS::safe_filter)->decode ($cbor_data);
440
272=item $cbor_data = $cbor->encode ($perl_scalar) 441=item $cbor_data = $cbor->encode ($perl_scalar)
273 442
274Converts the given Perl data structure (a scalar value) to its CBOR 443Converts the given Perl data structure (a scalar value) to its CBOR
275representation. 444representation.
276 445
285when there is trailing garbage after the CBOR string, it will silently 454when there is trailing garbage after the CBOR string, it will silently
286stop parsing there and return the number of characters consumed so far. 455stop parsing there and return the number of characters consumed so far.
287 456
288This is useful if your CBOR texts are not delimited by an outer protocol 457This is useful if your CBOR texts are not delimited by an outer protocol
289and you need to know where the first CBOR string ends amd the next one 458and you need to know where the first CBOR string ends amd the next one
290starts. 459starts - CBOR strings are self-delimited, so it is possible to concatenate
460CBOR strings without any delimiters or size fields and recover their data.
291 461
292 CBOR::XS->new->decode_prefix ("......") 462 CBOR::XS->new->decode_prefix ("......")
293 => ("...", 3) 463 => ("...", 3)
464
465=back
466
467=head2 INCREMENTAL PARSING
468
469In some cases, there is the need for incremental parsing of JSON
470texts. While this module always has to keep both CBOR text and resulting
471Perl data structure in memory at one time, it does allow you to parse a
472CBOR stream incrementally, using a similar to using "decode_prefix" to see
473if a full CBOR object is available, but is much more efficient.
474
475It basically works by parsing as much of a CBOR string as possible - if
476the CBOR data is not complete yet, the pasrer will remember where it was,
477to be able to restart when more data has been accumulated. Once enough
478data is available to either decode a complete CBOR value or raise an
479error, a real decode will be attempted.
480
481A typical use case would be a network protocol that consists of sending
482and receiving CBOR-encoded messages. The solution that works with CBOR and
483about anything else is by prepending a length to every CBOR value, so the
484receiver knows how many octets to read. More compact (and slightly slower)
485would be to just send CBOR values back-to-back, as C<CBOR::XS> knows where
486a CBOR value ends, and doesn't need an explicit length.
487
488The following methods help with this:
489
490=over 4
491
492=item @decoded = $cbor->incr_parse ($buffer)
493
494This method attempts to decode exactly one CBOR value from the beginning
495of the given C<$buffer>. The value is removed from the C<$buffer> on
496success. When C<$buffer> doesn't contain a complete value yet, it returns
497nothing. Finally, when the C<$buffer> doesn't start with something
498that could ever be a valid CBOR value, it raises an exception, just as
499C<decode> would. In the latter case the decoder state is undefined and
500must be reset before being able to parse further.
501
502This method modifies the C<$buffer> in place. When no CBOR value can be
503decoded, the decoder stores the current string offset. On the next call,
504continues decoding at the place where it stopped before. For this to make
505sense, the C<$buffer> must begin with the same octets as on previous
506unsuccessful calls.
507
508You can call this method in scalar context, in which case it either
509returns a decoded value or C<undef>. This makes it impossible to
510distinguish between CBOR null values (which decode to C<undef>) and an
511unsuccessful decode, which is often acceptable.
512
513=item @decoded = $cbor->incr_parse_multiple ($buffer)
514
515Same as C<incr_parse>, but attempts to decode as many CBOR values as
516possible in one go, instead of at most one. Calls to C<incr_parse> and
517C<incr_parse_multiple> can be interleaved.
518
519=item $cbor->incr_reset
520
521Resets the incremental decoder. This throws away any saved state, so that
522subsequent calls to C<incr_parse> or C<incr_parse_multiple> start to parse
523a new CBOR value from the beginning of the C<$buffer> again.
524
525This method can be called at any time, but it I<must> be called if you want
526to change your C<$buffer> or there was a decoding error and you want to
527reuse the C<$cbor> object for future incremental parsings.
294 528
295=back 529=back
296 530
297 531
298=head1 MAPPING 532=head1 MAPPING
371 605
372=item hash references 606=item hash references
373 607
374Perl hash references become CBOR maps. As there is no inherent ordering in 608Perl hash references become CBOR maps. As there is no inherent ordering in
375hash keys (or CBOR maps), they will usually be encoded in a pseudo-random 609hash keys (or CBOR maps), they will usually be encoded in a pseudo-random
376order. This order can be different each time a hahs is encoded. 610order. This order can be different each time a hash is encoded.
377 611
378Currently, tied hashes will use the indefinite-length format, while normal 612Currently, tied hashes will use the indefinite-length format, while normal
379hashes will use the fixed-length format. 613hashes will use the fixed-length format.
380 614
381=item array references 615=item array references
434 my $x = 3.1; # some variable containing a number 668 my $x = 3.1; # some variable containing a number
435 "$x"; # stringified 669 "$x"; # stringified
436 $x .= ""; # another, more awkward way to stringify 670 $x .= ""; # another, more awkward way to stringify
437 print $x; # perl does it for you, too, quite often 671 print $x; # perl does it for you, too, quite often
438 672
439You can force whether a string ie encoded as byte or text string by using 673You can force whether a string is encoded as byte or text string by using
440C<utf8::upgrade> and C<utf8::downgrade>): 674C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled).
441 675
442 utf8::upgrade $x; # encode $x as text string 676 utf8::upgrade $x; # encode $x as text string
443 utf8::downgrade $x; # encode $x as byte string 677 utf8::downgrade $x; # encode $x as byte string
444 678
679More options are available, see L<TYPE CASTS>, below, and the C<text_keys>
680and C<text_strings> options.
681
445Perl doesn't define what operations up- and downgrade strings, so if the 682Perl doesn't define what operations up- and downgrade strings, so if the
446difference between byte and text is important, you should up- or downgrade 683difference between byte and text is important, you should up- or downgrade
447your string as late as possible before encoding. 684your string as late as possible before encoding. You can also force the
685use of CBOR text strings by using C<text_keys> or C<text_strings>.
448 686
449You can force the type to be a CBOR number by numifying it: 687You can force the type to be a CBOR number by numifying it:
450 688
451 my $x = "3"; # some variable containing a string 689 my $x = "3"; # some variable containing a string
452 $x += 0; # numify it, ensuring it will be dumped as a number 690 $x += 0; # numify it, ensuring it will be dumped as a number
463represent numerical values are supported, but might suffer loss of 701represent numerical values are supported, but might suffer loss of
464precision. 702precision.
465 703
466=back 704=back
467 705
706=head2 TYPE CASTS
707
708B<EXPERIMENTAL>: As an experimental extension, C<CBOR::XS> allows you to
709force specific cbor types to be used when encoding. That allows you to
710encode types not normally accessible (e.g. half floats) as well as force
711string types even when C<text_strings> is in effect.
712
713Type forcing is done by calling a special "cast" function which keeps a
714copy of the value and returns a new value that can be handed over to any
715CBOR encoder function.
716
717The following casts are currently available (all of which are unary
718operators, that is, have a prototype of C<$>):
719
720=over
721
722=item CBOR::XS::as_int $value
723
724Forces the value to be encoded as some form of (basic, not bignum) integer
725type.
726
727=item CBOR::XS::as_text $value
728
729Forces the value to be encoded as (UTF-8) text values.
730
731=item CBOR::XS::as_bytes $value
732
733Forces the value to be encoded as a (binary) string value.
734
735Example: encode a perl string as binary even though C<text_strings> is in
736effect.
737
738 CBOR::XS->new->text_strings->encode ([4, "text", CBOR::XS::bytes "bytevalue"]);
739
740=item CBOR::XS::as_bool $value
741
742Converts a Perl boolean (which can be any kind of scalar) into a CBOR
743boolean. 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
749Forces half-float (IEEE 754 binary16) encoding of the given value.
750
751=item CBOR::XS::as_float32 $value
752
753Forces single-float (IEEE 754 binary32) encoding of the given value.
754
755=item CBOR::XS::as_float64 $value
756
757Forces double-float (IEEE 754 binary64) encoding of the given value.
758
759=item CBOR::XS::as_cbor $cbor_text
760
761Not a type cast per-se, this type cast forces the argument to eb encoded
762as-is. This can be used to embed pre-encoded CBOR data.
763
764Note that no checking on the validity of the C<$cbor_text> is done - it's
765the callers responsibility to correctly encode values.
766
767=item CBOR::XS::as_map [key => value...]
768
769Treat the array reference as key value pairs and output a CBOR map. This
770allows you to generate CBOR maps with arbitrary key types (or, if you
771don't care about semantics, duplicate keys or pairs in a custom order),
772which is otherwise hard to do with Perl.
773
774The single argument must be an array reference with an even number of
775elements.
776
777Note that only the reference to the array is copied, the array itself is
778not. Modifications done to the array before calling an encoding fuinction
779will be reflected in the encoded output.
780
781Example: encode a CBOR map with a string and an integer as keys.
782
783 encode_cbor CBOR::XS::as_map [string => "value", 5 => "value"]
784
785=back
786
787=cut
788
789sub CBOR::XS::as_cbor ($) { bless [$_[0], 0, undef], CBOR::XS::Tagged:: }
790sub CBOR::XS::as_int ($) { bless [$_[0], 1, undef], CBOR::XS::Tagged:: }
791sub CBOR::XS::as_bytes ($) { bless [$_[0], 2, undef], CBOR::XS::Tagged:: }
792sub CBOR::XS::as_text ($) { bless [$_[0], 3, undef], CBOR::XS::Tagged:: }
793sub CBOR::XS::as_float16 ($) { bless [$_[0], 4, undef], CBOR::XS::Tagged:: }
794sub CBOR::XS::as_float32 ($) { bless [$_[0], 5, undef], CBOR::XS::Tagged:: }
795sub CBOR::XS::as_float64 ($) { bless [$_[0], 6, undef], CBOR::XS::Tagged:: }
796
797sub CBOR::XS::as_bool ($) { $_[0] ? $Types::Serialiser::true : $Types::Serialiser::false }
798
799sub CBOR::XS::as_map ($) {
800 ARRAY:: eq ref $_[0]
801 and $#{ $_[0] } & 1
802 or do { require Carp; Carp::croak ("CBOR::XS::as_map only acepts array references with an even number of elements, caught") };
803
804 bless [$_[0], 7, undef], CBOR::XS::Tagged::
805}
806
468=head2 OBJECT SERIALISATION 807=head2 OBJECT SERIALISATION
469 808
470This module implements both a CBOR-specific and the generic 809This module implements both a CBOR-specific and the generic
471L<Types::Serialier> object serialisation protocol. The following 810L<Types::Serialier> object serialisation protocol. The following
472subsections explain both methods. 811subsections explain both methods.
553 "$self" # encode url string 892 "$self" # encode url string
554 } 893 }
555 894
556 sub URI::THAW { 895 sub URI::THAW {
557 my ($class, $serialiser, $uri) = @_; 896 my ($class, $serialiser, $uri) = @_;
558
559 $class->new ($uri) 897 $class->new ($uri)
560 } 898 }
561 899
562Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For 900Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For
563example, a C<FREEZE> method that returns "type", "id" and "variant" values 901example, a C<FREEZE> method that returns "type", "id" and "variant" values
694additional tags (such as base64url). 1032additional tags (such as base64url).
695 1033
696=head2 ENFORCED TAGS 1034=head2 ENFORCED TAGS
697 1035
698These tags are always handled when decoding, and their handling cannot be 1036These tags are always handled when decoding, and their handling cannot be
699overriden by the user. 1037overridden by the user.
700 1038
701=over 4 1039=over 4
702 1040
703=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>) 1041=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>)
704 1042
705These tags are automatically created (and decoded) for serialisable 1043These tags are automatically created (and decoded) for serialisable
706objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object 1044objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
707serialisation protocol). See L<OBJECT SERIALISATION> for details. 1045serialisation protocol). See L<OBJECT SERIALISATION> for details.
708 1046
709=item 28, 29 (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) 1047=item 28, 29 (shareable, sharedref, L<http://cbor.schmorp.de/value-sharing>)
710 1048
711These tags are automatically decoded when encountered, resulting in 1049These tags are automatically decoded when encountered (and they do not
1050result in a cyclic data structure, see C<allow_cycles>), resulting in
712shared values in the decoded object. They are only encoded, however, when 1051shared values in the decoded object. They are only encoded, however, when
713C<allow_sharable> is enabled. 1052C<allow_sharing> is enabled.
714 1053
1054Not all shared values can be successfully decoded: values that reference
1055themselves will I<currently> decode as C<undef> (this is not the same
1056as a reference pointing to itself, which will be represented as a value
1057that contains an indirect reference to itself - these will be decoded
1058properly).
1059
1060Note that considerably more shared value data structures can be decoded
1061than will be encoded - currently, only values pointed to by references
1062will be shared, others will not. While non-reference shared values can be
1063generated in Perl with some effort, they were considered too unimportant
1064to be supported in the encoder. The decoder, however, will decode these
1065values as shared values.
1066
715=item 256, 25 (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>) 1067=item 256, 25 (stringref-namespace, stringref, L<http://cbor.schmorp.de/stringref>)
716 1068
717These tags are automatically decoded when encountered. They are only 1069These tags are automatically decoded when encountered. They are only
718encoded, however, when C<pack_strings> is enabled. 1070encoded, however, when C<pack_strings> is enabled.
719 1071
720=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) 1072=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
721 1073
722This tag is automatically generated when a reference are encountered (with 1074This tag is automatically generated when a reference are encountered (with
723the exception of hash and array refernces). It is converted to a reference 1075the exception of hash and array references). It is converted to a reference
724when decoding. 1076when decoding.
725 1077
726=item 55799 (self-describe CBOR, RFC 7049) 1078=item 55799 (self-describe CBOR, RFC 7049)
727 1079
728This value is not generated on encoding (unless explicitly requested by 1080This value is not generated on encoding (unless explicitly requested by
731=back 1083=back
732 1084
733=head2 NON-ENFORCED TAGS 1085=head2 NON-ENFORCED TAGS
734 1086
735These tags have default filters provided when decoding. Their handling can 1087These tags have default filters provided when decoding. Their handling can
736be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by 1088be overridden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
737providing a custom C<filter> callback when decoding. 1089providing a custom C<filter> callback when decoding.
738 1090
739When they result in decoding into a specific Perl class, the module 1091When they result in decoding into a specific Perl class, the module
740usually provides a corresponding C<TO_CBOR> method as well. 1092usually provides a corresponding C<TO_CBOR> method as well.
741 1093
744provide these modules. The decoding usually fails with an exception if the 1096provide these modules. The decoding usually fails with an exception if the
745required module cannot be loaded. 1097required module cannot be loaded.
746 1098
747=over 4 1099=over 4
748 1100
1101=item 0, 1 (date/time string, seconds since the epoch)
1102
1103These tags are decoded into L<Time::Piece> objects. The corresponding
1104C<Time::Piece::TO_CBOR> method always encodes into tag 1 values currently.
1105
1106The L<Time::Piece> API is generally surprisingly bad, and fractional
1107seconds are only accidentally kept intact, so watch out. On the plus side,
1108the module comes with perl since 5.10, which has to count for something.
1109
749=item 2, 3 (positive/negative bignum) 1110=item 2, 3 (positive/negative bignum)
750 1111
751These tags are decoded into L<Math::BigInt> objects. The corresponding 1112These tags are decoded into L<Math::BigInt> objects. The corresponding
752C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR 1113C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
753integers, and others into positive/negative CBOR bignums. 1114integers, and others into positive/negative CBOR bignums.
754 1115
755=item 4, 5 (decimal fraction/bigfloat) 1116=item 4, 5, 264, 265 (decimal fraction/bigfloat)
756 1117
757Both decimal fractions and bigfloats are decoded into L<Math::BigFloat> 1118Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
758objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always> 1119objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
759encodes into a decimal fraction. 1120encodes into a decimal fraction (either tag 4 or 264).
760 1121
761CBOR cannot represent bigfloats with I<very> large exponents - conversion 1122NaN and infinities are not encoded properly, as they cannot be represented
762of such big float objects is undefined. 1123in CBOR.
763 1124
764Also, NaN and infinities are not encoded properly. 1125See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
1126
1127=item 30 (rational numbers)
1128
1129These tags are decoded into L<Math::BigRat> objects. The corresponding
1130C<Math::BigRat::TO_CBOR> method encodes rational numbers with denominator
1131C<1> via their numerator only, i.e., they become normal integers or
1132C<bignums>.
1133
1134See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
765 1135
766=item 21, 22, 23 (expected later JSON conversion) 1136=item 21, 22, 23 (expected later JSON conversion)
767 1137
768CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these 1138CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
769tags. 1139tags.
774C<URI::TO_CBOR> method again results in a CBOR URI value. 1144C<URI::TO_CBOR> method again results in a CBOR URI value.
775 1145
776=back 1146=back
777 1147
778=cut 1148=cut
779
780our %FILTER = (
781 # 0 # rfc4287 datetime, utf-8
782 # 1 # unix timestamp, any
783
784 2 => sub { # pos bigint
785 require Math::BigInt;
786 Math::BigInt->new ("0x" . unpack "H*", pop)
787 },
788
789 3 => sub { # neg bigint
790 require Math::BigInt;
791 -Math::BigInt->new ("0x" . unpack "H*", pop)
792 },
793
794 4 => sub { # decimal fraction, array
795 require Math::BigFloat;
796 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
797 },
798
799 5 => sub { # bigfloat, array
800 require Math::BigFloat;
801 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
802 },
803
804 21 => sub { pop }, # expected conversion to base64url encoding
805 22 => sub { pop }, # expected conversion to base64 encoding
806 23 => sub { pop }, # expected conversion to base16 encoding
807
808 # 24 # embedded cbor, byte string
809
810 32 => sub {
811 require URI;
812 URI->new (pop)
813 },
814
815 # 33 # base64url rfc4648, utf-8
816 # 34 # base64 rfc46484, utf-8
817 # 35 # regex pcre/ecma262, utf-8
818 # 36 # mime message rfc2045, utf-8
819);
820
821 1149
822=head1 CBOR and JSON 1150=head1 CBOR and JSON
823 1151
824CBOR is supposed to implement a superset of the JSON data model, and is, 1152CBOR is supposed to implement a superset of the JSON data model, and is,
825with some coercion, able to represent all JSON texts (something that other 1153with some coercion, able to represent all JSON texts (something that other
834CBOR intact. 1162CBOR intact.
835 1163
836 1164
837=head1 SECURITY CONSIDERATIONS 1165=head1 SECURITY CONSIDERATIONS
838 1166
839When you are using CBOR in a protocol, talking to untrusted potentially 1167Tl;dr... if you want to decode or encode CBOR from untrusted sources, you
840hostile creatures requires relatively few measures. 1168should start with a coder object created via C<new_safe> (which implements
1169the mitigations explained below):
841 1170
1171 my $coder = CBOR::XS->new_safe;
1172
1173 my $data = $coder->decode ($cbor_text);
1174 my $cbor = $coder->encode ($data);
1175
1176Longer version: When you are using CBOR in a protocol, talking to
1177untrusted potentially hostile creatures requires some thought:
1178
1179=over 4
1180
1181=item Security of the CBOR decoder itself
1182
842First of all, your CBOR decoder should be secure, that is, should not have 1183First and foremost, your CBOR decoder should be secure, that is, should
1184not have any buffer overflows or similar bugs that could potentially be
843any buffer overflows. Obviously, this module should ensure that and I am 1185exploited. Obviously, this module should ensure that and I am trying hard
844trying hard on making that true, but you never know. 1186on making that true, but you never know.
845 1187
1188=item CBOR::XS can invoke almost arbitrary callbacks during decoding
1189
1190CBOR::XS supports object serialisation - decoding CBOR can cause calls
1191to I<any> C<THAW> method in I<any> package that exists in your process
1192(that is, CBOR::XS will not try to load modules, but any existing C<THAW>
1193method or function can be called, so they all have to be secure).
1194
1195Less obviously, it will also invoke C<TO_CBOR> and C<FREEZE> methods -
1196even if all your C<THAW> methods are secure, encoding data structures from
1197untrusted sources can invoke those and trigger bugs in those.
1198
1199So, if you are not sure about the security of all the modules you
1200have loaded (you shouldn't), you should disable this part using
1201C<forbid_objects> or using C<new_safe>.
1202
1203=item CBOR can be extended with tags that call library code
1204
1205CBOR can be extended with tags, and C<CBOR::XS> has a registry of
1206conversion functions for many existing tags that can be extended via
1207third-party modules (see the C<filter> method).
1208
1209If you don't trust these, you should configure the "safe" filter function,
1210C<CBOR::XS::safe_filter> (C<new_safe> does this), which by default only
1211includes conversion functions that are considered "safe" by the author
1212(but again, they can be extended by third party modules).
1213
1214Depending on your level of paranoia, you can use the "safe" filter:
1215
1216 $cbor->filter (\&CBOR::XS::safe_filter);
1217
1218... your own filter...
1219
1220 $cbor->filter (sub { ... do your stuffs here ... });
1221
1222... or even no filter at all, disabling all tag decoding:
1223
1224 $cbor->filter (sub { });
1225
1226This is never a problem for encoding, as the tag mechanism only exists in
1227CBOR texts.
1228
1229=item Resource-starving attacks: object memory usage
1230
846Second, you need to avoid resource-starving attacks. That means you should 1231You need to avoid resource-starving attacks. That means you should limit
847limit the size of CBOR data you accept, or make sure then when your 1232the size of CBOR data you accept, or make sure then when your resources
848resources run out, that's just fine (e.g. by using a separate process that 1233run out, that's just fine (e.g. by using a separate process that can
849can crash safely). The size of a CBOR string in octets is usually a good 1234crash safely). The size of a CBOR string in octets is usually a good
850indication of the size of the resources required to decode it into a Perl 1235indication of the size of the resources required to decode it into a Perl
851structure. While CBOR::XS can check the size of the CBOR text, it might be 1236structure. While CBOR::XS can check the size of the CBOR text (using
852too late when you already have it in memory, so you might want to check 1237C<max_size> - done by C<new_safe>), it might be too late when you already
853the size before you accept the string. 1238have it in memory, so you might want to check the size before you accept
1239the string.
854 1240
1241As for encoding, it is possible to construct data structures that are
1242relatively small but result in large CBOR texts (for example by having an
1243array full of references to the same big data structure, which will all be
1244deep-cloned during encoding by default). This is rarely an actual issue
1245(and the worst case is still just running out of memory), but you can
1246reduce this risk by using C<allow_sharing>.
1247
1248=item Resource-starving attacks: stack overflows
1249
855Third, CBOR::XS recurses using the C stack when decoding objects and 1250CBOR::XS recurses using the C stack when decoding objects and arrays. The
856arrays. The C stack is a limited resource: for instance, on my amd64 1251C stack is a limited resource: for instance, on my amd64 machine with 8MB
857machine with 8MB of stack size I can decode around 180k nested arrays but 1252of stack size I can decode around 180k nested arrays but only 14k nested
858only 14k nested CBOR objects (due to perl itself recursing deeply on croak 1253CBOR objects (due to perl itself recursing deeply on croak to free the
859to free the temporary). If that is exceeded, the program crashes. To be 1254temporary). If that is exceeded, the program crashes. To be conservative,
860conservative, the default nesting limit is set to 512. If your process 1255the default nesting limit is set to 512. If your process has a smaller
861has a smaller stack, you should adjust this setting accordingly with the 1256stack, you should adjust this setting accordingly with the C<max_depth>
862C<max_depth> method. 1257method.
1258
1259=item Resource-starving attacks: CPU en-/decoding complexity
1260
1261CBOR::XS will use the L<Math::BigInt>, L<Math::BigFloat> and
1262L<Math::BigRat> libraries to represent encode/decode bignums. These can be
1263very slow (as in, centuries of CPU time) and can even crash your program
1264(and are generally not very trustworthy). See the next section on bignum
1265security for details.
1266
1267=item Data breaches: leaking information in error messages
1268
1269CBOR::XS might leak contents of your Perl data structures in its error
1270messages, so when you serialise sensitive information you might want to
1271make sure that exceptions thrown by CBOR::XS will not end up in front of
1272untrusted eyes.
1273
1274=item Something else...
863 1275
864Something else could bomb you, too, that I forgot to think of. In that 1276Something else could bomb you, too, that I forgot to think of. In that
865case, you get to keep the pieces. I am always open for hints, though... 1277case, you get to keep the pieces. I am always open for hints, though...
866 1278
867Also keep in mind that CBOR::XS might leak contents of your Perl data 1279=back
868structures in its error messages, so when you serialise sensitive 1280
869information you might want to make sure that exceptions thrown by CBOR::XS 1281
870will not end up in front of untrusted eyes. 1282=head1 BIGNUM SECURITY CONSIDERATIONS
1283
1284CBOR::XS provides a C<TO_CBOR> method for both L<Math::BigInt> and
1285L<Math::BigFloat> that tries to encode the number in the simplest possible
1286way, that is, either a CBOR integer, a CBOR bigint/decimal fraction (tag
12874) or an arbitrary-exponent decimal fraction (tag 264). Rational numbers
1288(L<Math::BigRat>, tag 30) can also contain bignums as members.
1289
1290CBOR::XS will also understand base-2 bigfloat or arbitrary-exponent
1291bigfloats (tags 5 and 265), but it will never generate these on its own.
1292
1293Using the built-in L<Math::BigInt::Calc> support, encoding and decoding
1294decimal fractions is generally fast. Decoding bigints can be slow for very
1295big numbers (tens of thousands of digits, something that could potentially
1296be caught by limiting the size of CBOR texts), and decoding bigfloats or
1297arbitrary-exponent bigfloats can be I<extremely> slow (minutes, decades)
1298for large exponents (roughly 40 bit and longer).
1299
1300Additionally, L<Math::BigInt> can take advantage of other bignum
1301libraries, such as L<Math::GMP>, which cannot handle big floats with large
1302exponents, and might simply abort or crash your program, due to their code
1303quality.
1304
1305This can be a concern if you want to parse untrusted CBOR. If it is, you
1306might want to disable decoding of tag 2 (bigint) and 3 (negative bigint)
1307types. You should also disable types 5 and 265, as these can be slow even
1308without bigints.
1309
1310Disabling bigints will also partially or fully disable types that rely on
1311them, e.g. rational numbers that use bignums.
1312
871 1313
872=head1 CBOR IMPLEMENTATION NOTES 1314=head1 CBOR IMPLEMENTATION NOTES
873 1315
874This section contains some random implementation notes. They do not 1316This section contains some random implementation notes. They do not
875describe guaranteed behaviour, but merely behaviour as-is implemented 1317describe guaranteed behaviour, but merely behaviour as-is implemented
889 1331
890 1332
891=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT 1333=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT
892 1334
893On perls that were built without 64 bit integer support (these are rare 1335On perls that were built without 64 bit integer support (these are rare
894nowadays, even on 32 bit architectures), support for any kind of 64 bit 1336nowadays, even on 32 bit architectures, as all major Perl distributions
1337are built with 64 bit integer support), support for any kind of 64 bit
895integer in CBOR is very limited - most likely, these 64 bit values will 1338value in CBOR is very limited - most likely, these 64 bit values will
896be truncated, corrupted, or otherwise not decoded correctly. This also 1339be truncated, corrupted, or otherwise not decoded correctly. This also
897includes string, array and map sizes that are stored as 64 bit integers. 1340includes string, float, array and map sizes that are stored as 64 bit
1341integers.
898 1342
899 1343
900=head1 THREADS 1344=head1 THREADS
901 1345
902This module is I<not> guaranteed to be thread safe and there are no 1346This module is I<not> guaranteed to be thread safe and there are no
916Please refrain from using rt.cpan.org or any other bug reporting 1360Please refrain from using rt.cpan.org or any other bug reporting
917service. I put the contact address into my modules for a reason. 1361service. I put the contact address into my modules for a reason.
918 1362
919=cut 1363=cut
920 1364
1365# clumsy and slow hv_store-in-hash helper function
1366sub _hv_store {
1367 $_[0]{$_[1]} = $_[2];
1368}
1369
921our %FILTER = ( 1370our %FILTER = (
922 # 0 # rfc4287 datetime, utf-8 1371 0 => sub { # rfc4287 datetime, utf-8
923 # 1 # unix timestamp, any 1372 require Time::Piece;
1373 # Time::Piece::Strptime uses the "incredibly flexible date parsing routine"
1374 # from FreeBSD, which can't parse ISO 8601, RFC3339, RFC4287 or much of anything
1375 # else either. Whats incredibe over standard strptime totally escapes me.
1376 # doesn't do fractional times, either. sigh.
1377 # In fact, it's all a lie, it uses whatever strptime it wants, and of course,
1378 # they are all incompatible. The openbsd one simply ignores %z (but according to the
1379 # docs, it would be much more incredibly flexible indeed. If it worked, that is.).
1380 scalar eval {
1381 my $s = $_[1];
1382
1383 $s =~ s/Z$/+00:00/;
1384 $s =~ s/(\.[0-9]+)?([+-][0-9][0-9]):([0-9][0-9])$//
1385 or die;
1386
1387 my $b = $1 - ($2 * 60 + $3) * 60; # fractional part + offset. hopefully
1388 my $d = Time::Piece->strptime ($s, "%Y-%m-%dT%H:%M:%S");
1389
1390 Time::Piece::gmtime ($d->epoch + $b)
1391 } || die "corrupted CBOR date/time string ($_[0])";
1392 },
1393
1394 1 => sub { # seconds since the epoch, possibly fractional
1395 require Time::Piece;
1396 scalar Time::Piece::gmtime (pop)
1397 },
924 1398
925 2 => sub { # pos bigint 1399 2 => sub { # pos bigint
926 require Math::BigInt; 1400 require Math::BigInt;
927 Math::BigInt->new ("0x" . unpack "H*", pop) 1401 Math::BigInt->new ("0x" . unpack "H*", pop)
928 }, 1402 },
935 4 => sub { # decimal fraction, array 1409 4 => sub { # decimal fraction, array
936 require Math::BigFloat; 1410 require Math::BigFloat;
937 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0]) 1411 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
938 }, 1412 },
939 1413
1414 264 => sub { # decimal fraction with arbitrary exponent
1415 require Math::BigFloat;
1416 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
1417 },
1418
940 5 => sub { # bigfloat, array 1419 5 => sub { # bigfloat, array
941 require Math::BigFloat; 1420 require Math::BigFloat;
942 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2) 1421 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1422 },
1423
1424 265 => sub { # bigfloat with arbitrary exponent
1425 require Math::BigFloat;
1426 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1427 },
1428
1429 30 => sub { # rational number
1430 require Math::BigRat;
1431 Math::BigRat->new ("$_[1][0]/$_[1][1]") # separate parameters only work in recent versons
943 }, 1432 },
944 1433
945 21 => sub { pop }, # expected conversion to base64url encoding 1434 21 => sub { pop }, # expected conversion to base64url encoding
946 22 => sub { pop }, # expected conversion to base64 encoding 1435 22 => sub { pop }, # expected conversion to base64 encoding
947 23 => sub { pop }, # expected conversion to base16 encoding 1436 23 => sub { pop }, # expected conversion to base16 encoding
957 # 34 # base64 rfc46484, utf-8 1446 # 34 # base64 rfc46484, utf-8
958 # 35 # regex pcre/ecma262, utf-8 1447 # 35 # regex pcre/ecma262, utf-8
959 # 36 # mime message rfc2045, utf-8 1448 # 36 # mime message rfc2045, utf-8
960); 1449);
961 1450
962sub CBOR::XS::default_filter { 1451sub default_filter {
963 &{ $FILTER{$_[0]} or return } 1452 &{ $FILTER{$_[0]} or return }
1453}
1454
1455our %SAFE_FILTER = map { $_ => $FILTER{$_} } 0, 1, 21, 22, 23, 32;
1456
1457sub safe_filter {
1458 &{ $SAFE_FILTER{$_[0]} or return }
964} 1459}
965 1460
966sub URI::TO_CBOR { 1461sub URI::TO_CBOR {
967 my $uri = $_[0]->as_string; 1462 my $uri = $_[0]->as_string;
968 utf8::upgrade $uri; 1463 utf8::upgrade $uri;
969 CBOR::XS::tag 32, $uri 1464 tag 32, $uri
970} 1465}
971 1466
972sub Math::BigInt::TO_CBOR { 1467sub Math::BigInt::TO_CBOR {
973 if ($_[0] >= -2147483648 && $_[0] <= 2147483647) { 1468 if (-2147483648 <= $_[0] && $_[0] <= 2147483647) {
974 $_[0]->numify 1469 $_[0]->numify
975 } else { 1470 } else {
976 my $hex = substr $_[0]->as_hex, 2; 1471 my $hex = substr $_[0]->as_hex, 2;
977 $hex = "0$hex" if 1 & length $hex; # sigh 1472 $hex = "0$hex" if 1 & length $hex; # sigh
978 CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex 1473 tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
979 } 1474 }
980} 1475}
981 1476
982sub Math::BigFloat::TO_CBOR { 1477sub Math::BigFloat::TO_CBOR {
983 my ($m, $e) = $_[0]->parts; 1478 my ($m, $e) = $_[0]->parts;
1479
1480 -9223372036854775808 <= $e && $e <= 18446744073709551615
984 CBOR::XS::tag 4, [$e->numify, $m] 1481 ? tag 4, [$e->numify, $m]
1482 : tag 264, [$e, $m]
1483}
1484
1485sub Math::BigRat::TO_CBOR {
1486 my ($n, $d) = $_[0]->parts;
1487
1488 # older versions of BigRat need *1, as they not always return numbers
1489
1490 $d*1 == 1
1491 ? $n*1
1492 : tag 30, [$n*1, $d*1]
1493}
1494
1495sub Time::Piece::TO_CBOR {
1496 tag 1, 0 + $_[0]->epoch
985} 1497}
986 1498
987XSLoader::load "CBOR::XS", $VERSION; 1499XSLoader::load "CBOR::XS", $VERSION;
988 1500
989=head1 SEE ALSO 1501=head1 SEE ALSO

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