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Revision 1.31 by root, Sat Nov 30 18:13:53 2013 UTC vs.
Revision 1.88 by root, Thu Sep 7 23:52:24 2023 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
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 56number 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
55C<pack_strings>) and scalar references (always enabled). 58C<pack_strings>) and scalar references (always enabled).
56 59
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
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 = 1.86;
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 ->validate_utf8
127 ->forbid_objects
128 ->filter (\&CBOR::XS::safe_filter)
129 ->max_size (1e8);
130
131But is more future proof (it is better to crash because of a change than
132to be exploited in other ways).
133
134=cut
135
136sub new_safe {
137 CBOR::XS
138 ->new
139 ->validate_utf8
140 ->forbid_objects
141 ->filter (\&CBOR::XS::safe_filter)
142 ->max_size (1e8)
143}
117 144
118=item $cbor = $cbor->max_depth ([$maximum_nesting_depth]) 145=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])
119 146
120=item $max_depth = $cbor->get_max_depth 147=item $max_depth = $cbor->get_max_depth
121 148
137 164
138Note that nesting is implemented by recursion in C. The default value has 165Note that nesting is implemented by recursion in C. The default value has
139been chosen to be as large as typical operating systems allow without 166been chosen to be as large as typical operating systems allow without
140crashing. 167crashing.
141 168
142See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 169See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
143 170
144=item $cbor = $cbor->max_size ([$maximum_string_size]) 171=item $cbor = $cbor->max_size ([$maximum_string_size])
145 172
146=item $max_size = $cbor->get_max_size 173=item $max_size = $cbor->get_max_size
147 174
152effect on C<encode> (yet). 179effect on C<encode> (yet).
153 180
154If no argument is given, the limit check will be deactivated (same as when 181If no argument is given, the limit check will be deactivated (same as when
155C<0> is specified). 182C<0> is specified).
156 183
157See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 184See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
158 185
159=item $cbor = $cbor->allow_unknown ([$enable]) 186=item $cbor = $cbor->allow_unknown ([$enable])
160 187
161=item $enabled = $cbor->get_allow_unknown 188=item $enabled = $cbor->get_allow_unknown
162 189
180reference to the earlier value. 207reference to the earlier value.
181 208
182This means that such values will only be encoded once, and will not result 209This 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 210in a deep cloning of the value on decode, in decoders supporting the value
184sharing extension. This also makes it possible to encode cyclic data 211sharing extension. This also makes it possible to encode cyclic data
185structures (which need C<allow_cycles> to ne enabled to be decoded by this 212structures (which need C<allow_cycles> to be enabled to be decoded by this
186module). 213module).
187 214
188It is recommended to leave it off unless you know your 215It is recommended to leave it off unless you know your
189communication partner supports the value sharing extensions to CBOR 216communication partner supports the value sharing extensions to CBOR
190(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the 217(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the
191resulting data structure might be unusable. 218resulting data structure might be unusable.
192 219
193Detecting shared values incurs a runtime overhead when values are encoded 220Detecting shared values incurs a runtime overhead when values are encoded
194that have a reference counter large than one, and might unnecessarily 221that have a reference counter larger than one, and might unnecessarily
195increase the encoded size, as potentially shared values are encode as 222increase the encoded size, as potentially shared values are encoded as
196shareable whether or not they are actually shared. 223shareable whether or not they are actually shared.
197 224
198At the moment, only targets of references can be shared (e.g. scalars, 225At the moment, only targets of references can be shared (e.g. scalars,
199arrays or hashes pointed to by a reference). Weirder constructs, such as 226arrays or hashes pointed to by a reference). Weirder constructs, such as
200an array with multiple "copies" of the I<same> string, which are hard but 227an array with multiple "copies" of the I<same> string, which are hard but
218isn't prepared for this will not leak memory. 245isn't prepared for this will not leak memory.
219 246
220If C<$enable> is false (the default), then C<decode> will throw an error 247If C<$enable> is false (the default), then C<decode> will throw an error
221when it encounters a self-referential/cyclic data structure. 248when it encounters a self-referential/cyclic data structure.
222 249
250FUTURE DIRECTION: the motivation behind this option is to avoid I<real>
251cycles - future versions of this module might chose to decode cyclic data
252structures using weak references when this option is off, instead of
253throwing an error.
254
223This option does not affect C<encode> in any way - shared values and 255This option does not affect C<encode> in any way - shared values and
224references will always be decoded properly if present. 256references will always be encoded properly if present.
257
258=item $cbor = $cbor->forbid_objects ([$enable])
259
260=item $enabled = $cbor->get_forbid_objects
261
262Disables the use of the object serialiser protocol.
263
264If C<$enable> is true (or missing), then C<encode> will will throw an
265exception when it encounters perl objects that would be encoded using the
266perl-object tag (26). When C<decode> encounters such tags, it will fall
267back to the general filter/tagged logic as if this were an unknown tag (by
268default resulting in a C<CBOR::XC::Tagged> object).
269
270If C<$enable> is false (the default), then C<encode> will use the
271L<Types::Serialiser> object serialisation protocol to serialise objects
272into perl-object tags, and C<decode> will do the same to decode such tags.
273
274See L<SECURITY CONSIDERATIONS>, below, for more info on why forbidding this
275protocol can be useful.
225 276
226=item $cbor = $cbor->pack_strings ([$enable]) 277=item $cbor = $cbor->pack_strings ([$enable])
227 278
228=item $enabled = $cbor->get_pack_strings 279=item $enabled = $cbor->get_pack_strings
229 280
242the standard CBOR way. 293the standard CBOR way.
243 294
244This option does not affect C<decode> in any way - string references will 295This option does not affect C<decode> in any way - string references will
245always be decoded properly if present. 296always be decoded properly if present.
246 297
298=item $cbor = $cbor->text_keys ([$enable])
299
300=item $enabled = $cbor->get_text_keys
301
302If C<$enabled> is true (or missing), then C<encode> will encode all
303perl hash keys as CBOR text strings/UTF-8 string, upgrading them as needed.
304
305If C<$enable> is false (the default), then C<encode> will encode hash keys
306normally - upgraded perl strings (strings internally encoded as UTF-8) as
307CBOR text strings, and downgraded perl strings as CBOR byte strings.
308
309This option does not affect C<decode> in any way.
310
311This option is useful for interoperability with CBOR decoders that don't
312treat byte strings as a form of text. It is especially useful as Perl
313gives very little control over hash keys.
314
315Enabling this option can be slow, as all downgraded hash keys that are
316encoded need to be scanned and converted to UTF-8.
317
318=item $cbor = $cbor->text_strings ([$enable])
319
320=item $enabled = $cbor->get_text_strings
321
322This option works similar to C<text_keys>, above, but works on all strings
323(including hash keys), so C<text_keys> has no further effect after
324enabling C<text_strings>.
325
326If C<$enabled> is true (or missing), then C<encode> will encode all perl
327strings as CBOR text strings/UTF-8 strings, upgrading them as needed.
328
329If C<$enable> is false (the default), then C<encode> will encode strings
330normally (but see C<text_keys>) - upgraded perl strings (strings
331internally encoded as UTF-8) as CBOR text strings, and downgraded perl
332strings as CBOR byte strings.
333
334This option does not affect C<decode> in any way.
335
336This option has similar advantages and disadvantages as C<text_keys>. In
337addition, this option effectively removes the ability to automatically
338encode byte strings, which might break some C<FREEZE> and C<TO_CBOR>
339methods that rely on this.
340
341A workaround is to use explicit type casts, which are unaffected by this option.
342
343=item $cbor = $cbor->validate_utf8 ([$enable])
344
345=item $enabled = $cbor->get_validate_utf8
346
347If C<$enable> is true (or missing), then C<decode> will validate that
348elements (text strings) containing UTF-8 data in fact contain valid UTF-8
349data (instead of blindly accepting it). This validation obviously takes
350extra time during decoding.
351
352The concept of "valid UTF-8" used is perl's concept, which is a superset
353of the official UTF-8.
354
355If C<$enable> is false (the default), then C<decode> will blindly accept
356UTF-8 data, marking them as valid UTF-8 in the resulting data structure
357regardless of whether that's true or not.
358
359Perl isn't too happy about corrupted UTF-8 in strings, but should
360generally not crash or do similarly evil things. Extensions might be not
361so forgiving, so it's recommended to turn on this setting if you receive
362untrusted CBOR.
363
364This option does not affect C<encode> in any way - strings that are
365supposedly valid UTF-8 will simply be dumped into the resulting CBOR
366string without checking whether that is, in fact, true or not.
367
247=item $cbor = $cbor->filter ([$cb->($tag, $value)]) 368=item $cbor = $cbor->filter ([$cb->($tag, $value)])
248 369
249=item $cb_or_undef = $cbor->get_filter 370=item $cb_or_undef = $cbor->get_filter
250 371
251Sets or replaces the tagged value decoding filter (when C<$cb> is 372Sets or replaces the tagged value decoding filter (when C<$cb> is
263replace the tagged value in the decoded data structure, or no values, 384replace the tagged value in the decoded data structure, or no values,
264which will result in default handling, which currently means the decoder 385which will result in default handling, which currently means the decoder
265creates a C<CBOR::XS::Tagged> object to hold the tag and the value. 386creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
266 387
267When the filter is cleared (the default state), the default filter 388When the filter is cleared (the default state), the default filter
268function, C<CBOR::XS::default_filter>, is used. This function simply looks 389function, C<CBOR::XS::default_filter>, is used. This function simply
269up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be 390looks up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists
270a code reference that is called with tag and value, and is responsible for 391it must be a code reference that is called with tag and value, and is
271decoding the value. If no entry exists, it returns no values. 392responsible for decoding the value. If no entry exists, it returns no
393values. C<CBOR::XS> provides a number of default filter functions already,
394the the C<%CBOR::XS::FILTER> hash can be freely extended with more.
395
396C<CBOR::XS> additionally provides an alternative filter function that is
397supposed to be safe to use with untrusted data (which the default filter
398might not), called C<CBOR::XS::safe_filter>, which works the same as
399the C<default_filter> but uses the C<%CBOR::XS::SAFE_FILTER> variable
400instead. It is prepopulated with the tag decoding functions that are
401deemed safe (basically the same as C<%CBOR::XS::FILTER> without all
402the bignum tags), and can be extended by user code as wlel, although,
403obviously, one should be very careful about adding decoding functions
404here, since the expectation is that they are safe to use on untrusted
405data, after all.
272 406
273Example: decode all tags not handled internally into C<CBOR::XS::Tagged> 407Example: decode all tags not handled internally into C<CBOR::XS::Tagged>
274objects, with no other special handling (useful when working with 408objects, with no other special handling (useful when working with
275potentially "unsafe" CBOR data). 409potentially "unsafe" CBOR data).
276 410
283 my ($tag, $value); 417 my ($tag, $value);
284 418
285 "tag 1347375694 value $value" 419 "tag 1347375694 value $value"
286 }; 420 };
287 421
422Example: provide your own filter function that looks up tags in your own
423hash:
424
425 my %my_filter = (
426 998347484 => sub {
427 my ($tag, $value);
428
429 "tag 998347484 value $value"
430 };
431 );
432
433 my $coder = CBOR::XS->new->filter (sub {
434 &{ $my_filter{$_[0]} or return }
435 });
436
437
438Example: use the safe filter function (see L<SECURITY CONSIDERATIONS> for
439more considerations on security).
440
441 CBOR::XS->new->filter (\&CBOR::XS::safe_filter)->decode ($cbor_data);
442
288=item $cbor_data = $cbor->encode ($perl_scalar) 443=item $cbor_data = $cbor->encode ($perl_scalar)
289 444
290Converts the given Perl data structure (a scalar value) to its CBOR 445Converts the given Perl data structure (a scalar value) to its CBOR
291representation. 446representation.
292 447
301when there is trailing garbage after the CBOR string, it will silently 456when there is trailing garbage after the CBOR string, it will silently
302stop parsing there and return the number of characters consumed so far. 457stop parsing there and return the number of characters consumed so far.
303 458
304This is useful if your CBOR texts are not delimited by an outer protocol 459This is useful if your CBOR texts are not delimited by an outer protocol
305and you need to know where the first CBOR string ends amd the next one 460and you need to know where the first CBOR string ends amd the next one
306starts. 461starts - CBOR strings are self-delimited, so it is possible to concatenate
462CBOR strings without any delimiters or size fields and recover their data.
307 463
308 CBOR::XS->new->decode_prefix ("......") 464 CBOR::XS->new->decode_prefix ("......")
309 => ("...", 3) 465 => ("...", 3)
466
467=back
468
469=head2 INCREMENTAL PARSING
470
471In some cases, there is the need for incremental parsing of JSON
472texts. While this module always has to keep both CBOR text and resulting
473Perl data structure in memory at one time, it does allow you to parse a
474CBOR stream incrementally, using a similar to using "decode_prefix" to see
475if a full CBOR object is available, but is much more efficient.
476
477It basically works by parsing as much of a CBOR string as possible - if
478the CBOR data is not complete yet, the parser will remember where it was,
479to be able to restart when more data has been accumulated. Once enough
480data is available to either decode a complete CBOR value or raise an
481error, a real decode will be attempted.
482
483A typical use case would be a network protocol that consists of sending
484and receiving CBOR-encoded messages. The solution that works with CBOR and
485about anything else is by prepending a length to every CBOR value, so the
486receiver knows how many octets to read. More compact (and slightly slower)
487would be to just send CBOR values back-to-back, as C<CBOR::XS> knows where
488a CBOR value ends, and doesn't need an explicit length.
489
490The following methods help with this:
491
492=over 4
493
494=item @decoded = $cbor->incr_parse ($buffer)
495
496This method attempts to decode exactly one CBOR value from the beginning
497of the given C<$buffer>. The value is removed from the C<$buffer> on
498success. When C<$buffer> doesn't contain a complete value yet, it returns
499nothing. Finally, when the C<$buffer> doesn't start with something
500that could ever be a valid CBOR value, it raises an exception, just as
501C<decode> would. In the latter case the decoder state is undefined and
502must be reset before being able to parse further.
503
504This method modifies the C<$buffer> in place. When no CBOR value can be
505decoded, the decoder stores the current string offset. On the next call,
506continues decoding at the place where it stopped before. For this to make
507sense, the C<$buffer> must begin with the same octets as on previous
508unsuccessful calls.
509
510You can call this method in scalar context, in which case it either
511returns a decoded value or C<undef>. This makes it impossible to
512distinguish between CBOR null values (which decode to C<undef>) and an
513unsuccessful decode, which is often acceptable.
514
515=item @decoded = $cbor->incr_parse_multiple ($buffer)
516
517Same as C<incr_parse>, but attempts to decode as many CBOR values as
518possible in one go, instead of at most one. Calls to C<incr_parse> and
519C<incr_parse_multiple> can be interleaved.
520
521=item $cbor->incr_reset
522
523Resets the incremental decoder. This throws away any saved state, so that
524subsequent calls to C<incr_parse> or C<incr_parse_multiple> start to parse
525a new CBOR value from the beginning of the C<$buffer> again.
526
527This method can be called at any time, but it I<must> be called if you want
528to change your C<$buffer> or there was a decoding error and you want to
529reuse the C<$cbor> object for future incremental parsings.
310 530
311=back 531=back
312 532
313 533
314=head1 MAPPING 534=head1 MAPPING
387 607
388=item hash references 608=item hash references
389 609
390Perl hash references become CBOR maps. As there is no inherent ordering in 610Perl hash references become CBOR maps. As there is no inherent ordering in
391hash keys (or CBOR maps), they will usually be encoded in a pseudo-random 611hash keys (or CBOR maps), they will usually be encoded in a pseudo-random
392order. This order can be different each time a hahs is encoded. 612order. This order can be different each time a hash is encoded.
393 613
394Currently, tied hashes will use the indefinite-length format, while normal 614Currently, tied hashes will use the indefinite-length format, while normal
395hashes will use the fixed-length format. 615hashes will use the fixed-length format.
396 616
397=item array references 617=item array references
415create such objects. 635create such objects.
416 636
417=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error 637=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error
418 638
419These special values become CBOR true, CBOR false and CBOR undefined 639These special values become CBOR true, CBOR false and CBOR undefined
420values, respectively. You can also use C<\1>, C<\0> and C<\undef> directly 640values, respectively.
421if you want.
422 641
423=item other blessed objects 642=item other blessed objects
424 643
425Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See 644Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See
426L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this 645L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this
450 my $x = 3.1; # some variable containing a number 669 my $x = 3.1; # some variable containing a number
451 "$x"; # stringified 670 "$x"; # stringified
452 $x .= ""; # another, more awkward way to stringify 671 $x .= ""; # another, more awkward way to stringify
453 print $x; # perl does it for you, too, quite often 672 print $x; # perl does it for you, too, quite often
454 673
455You can force whether a string ie encoded as byte or text string by using 674You can force whether a string is encoded as byte or text string by using
456C<utf8::upgrade> and C<utf8::downgrade>): 675C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled).
457 676
458 utf8::upgrade $x; # encode $x as text string 677 utf8::upgrade $x; # encode $x as text string
459 utf8::downgrade $x; # encode $x as byte string 678 utf8::downgrade $x; # encode $x as byte string
460 679
680More options are available, see L<TYPE CASTS>, below, and the C<text_keys>
681and C<text_strings> options.
682
461Perl doesn't define what operations up- and downgrade strings, so if the 683Perl doesn't define what operations up- and downgrade strings, so if the
462difference between byte and text is important, you should up- or downgrade 684difference between byte and text is important, you should up- or downgrade
463your string as late as possible before encoding. 685your string as late as possible before encoding. You can also force the
686use of CBOR text strings by using C<text_keys> or C<text_strings>.
464 687
465You can force the type to be a CBOR number by numifying it: 688You can force the type to be a CBOR number by numifying it:
466 689
467 my $x = "3"; # some variable containing a string 690 my $x = "3"; # some variable containing a string
468 $x += 0; # numify it, ensuring it will be dumped as a number 691 $x += 0; # numify it, ensuring it will be dumped as a number
479represent numerical values are supported, but might suffer loss of 702represent numerical values are supported, but might suffer loss of
480precision. 703precision.
481 704
482=back 705=back
483 706
707=head2 TYPE CASTS
708
709B<EXPERIMENTAL>: As an experimental extension, C<CBOR::XS> allows you to
710force specific CBOR types to be used when encoding. That allows you to
711encode types not normally accessible (e.g. half floats) as well as force
712string types even when C<text_strings> is in effect.
713
714Type forcing is done by calling a special "cast" function which keeps a
715copy of the value and returns a new value that can be handed over to any
716CBOR encoder function.
717
718The following casts are currently available (all of which are unary
719operators, that is, have a prototype of C<$>):
720
721=over
722
723=item CBOR::XS::as_int $value
724
725Forces the value to be encoded as some form of (basic, not bignum) integer
726type.
727
728=item CBOR::XS::as_text $value
729
730Forces the value to be encoded as (UTF-8) text values.
731
732=item CBOR::XS::as_bytes $value
733
734Forces the value to be encoded as a (binary) string value.
735
736Example: encode a perl string as binary even though C<text_strings> is in
737effect.
738
739 CBOR::XS->new->text_strings->encode ([4, "text", CBOR::XS::bytes "bytevalue"]);
740
741=item CBOR::XS::as_bool $value
742
743Converts a Perl boolean (which can be any kind of scalar) into a CBOR
744boolean. Strictly the same, but shorter to write, than:
745
746 $value ? Types::Serialiser::true : Types::Serialiser::false
747
748=item CBOR::XS::as_float16 $value
749
750Forces half-float (IEEE 754 binary16) encoding of the given value.
751
752=item CBOR::XS::as_float32 $value
753
754Forces single-float (IEEE 754 binary32) encoding of the given value.
755
756=item CBOR::XS::as_float64 $value
757
758Forces double-float (IEEE 754 binary64) encoding of the given value.
759
760=item CBOR::XS::as_cbor $cbor_text
761
762Not a type cast per-se, this type cast forces the argument to be encoded
763as-is. This can be used to embed pre-encoded CBOR data.
764
765Note that no checking on the validity of the C<$cbor_text> is done - it's
766the callers responsibility to correctly encode values.
767
768=item CBOR::XS::as_map [key => value...]
769
770Treat the array reference as key value pairs and output a CBOR map. This
771allows you to generate CBOR maps with arbitrary key types (or, if you
772don't care about semantics, duplicate keys or pairs in a custom order),
773which is otherwise hard to do with Perl.
774
775The single argument must be an array reference with an even number of
776elements.
777
778Note that only the reference to the array is copied, the array itself is
779not. Modifications done to the array before calling an encoding function
780will be reflected in the encoded output.
781
782Example: encode a CBOR map with a string and an integer as keys.
783
784 encode_cbor CBOR::XS::as_map [string => "value", 5 => "value"]
785
786=back
787
788=cut
789
790sub CBOR::XS::as_cbor ($) { bless [$_[0], 0, undef], CBOR::XS::Tagged:: }
791sub CBOR::XS::as_int ($) { bless [$_[0], 1, undef], CBOR::XS::Tagged:: }
792sub CBOR::XS::as_bytes ($) { bless [$_[0], 2, undef], CBOR::XS::Tagged:: }
793sub CBOR::XS::as_text ($) { bless [$_[0], 3, undef], CBOR::XS::Tagged:: }
794sub CBOR::XS::as_float16 ($) { bless [$_[0], 4, undef], CBOR::XS::Tagged:: }
795sub CBOR::XS::as_float32 ($) { bless [$_[0], 5, undef], CBOR::XS::Tagged:: }
796sub CBOR::XS::as_float64 ($) { bless [$_[0], 6, undef], CBOR::XS::Tagged:: }
797
798sub CBOR::XS::as_bool ($) { $_[0] ? $Types::Serialiser::true : $Types::Serialiser::false }
799
800sub CBOR::XS::as_map ($) {
801 ARRAY:: eq ref $_[0]
802 and $#{ $_[0] } & 1
803 or do { require Carp; Carp::croak ("CBOR::XS::as_map only acepts array references with an even number of elements, caught") };
804
805 bless [$_[0], 7, undef], CBOR::XS::Tagged::
806}
807
484=head2 OBJECT SERIALISATION 808=head2 OBJECT SERIALISATION
485 809
486This module implements both a CBOR-specific and the generic 810This module implements both a CBOR-specific and the generic
487L<Types::Serialier> object serialisation protocol. The following 811L<Types::Serialier> object serialisation protocol. The following
488subsections explain both methods. 812subsections explain both methods.
569 "$self" # encode url string 893 "$self" # encode url string
570 } 894 }
571 895
572 sub URI::THAW { 896 sub URI::THAW {
573 my ($class, $serialiser, $uri) = @_; 897 my ($class, $serialiser, $uri) = @_;
574
575 $class->new ($uri) 898 $class->new ($uri)
576 } 899 }
577 900
578Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For 901Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For
579example, a C<FREEZE> method that returns "type", "id" and "variant" values 902example, a C<FREEZE> method that returns "type", "id" and "variant" values
710additional tags (such as base64url). 1033additional tags (such as base64url).
711 1034
712=head2 ENFORCED TAGS 1035=head2 ENFORCED TAGS
713 1036
714These tags are always handled when decoding, and their handling cannot be 1037These tags are always handled when decoding, and their handling cannot be
715overriden by the user. 1038overridden by the user.
716 1039
717=over 4 1040=over 4
718 1041
719=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>) 1042=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>)
720 1043
721These tags are automatically created (and decoded) for serialisable 1044These tags are automatically created (and decoded) for serialisable
722objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object 1045objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
723serialisation protocol). See L<OBJECT SERIALISATION> for details. 1046serialisation protocol). See L<OBJECT SERIALISATION> for details.
724 1047
725=item 28, 29 (shareable, sharedref, L <http://cbor.schmorp.de/value-sharing>) 1048=item 28, 29 (shareable, sharedref, L<http://cbor.schmorp.de/value-sharing>)
726 1049
727These tags are automatically decoded when encountered (and they do not 1050These tags are automatically decoded when encountered (and they do not
728result in a cyclic data structure, see C<allow_cycles>), resulting in 1051result in a cyclic data structure, see C<allow_cycles>), resulting in
729shared values in the decoded object. They are only encoded, however, when 1052shared values in the decoded object. They are only encoded, however, when
730C<allow_sharing> is enabled. 1053C<allow_sharing> is enabled.
740will be shared, others will not. While non-reference shared values can be 1063will be shared, others will not. While non-reference shared values can be
741generated in Perl with some effort, they were considered too unimportant 1064generated in Perl with some effort, they were considered too unimportant
742to be supported in the encoder. The decoder, however, will decode these 1065to be supported in the encoder. The decoder, however, will decode these
743values as shared values. 1066values as shared values.
744 1067
745=item 256, 25 (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>) 1068=item 256, 25 (stringref-namespace, stringref, L<http://cbor.schmorp.de/stringref>)
746 1069
747These tags are automatically decoded when encountered. They are only 1070These tags are automatically decoded when encountered. They are only
748encoded, however, when C<pack_strings> is enabled. 1071encoded, however, when C<pack_strings> is enabled.
749 1072
750=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) 1073=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
751 1074
752This tag is automatically generated when a reference are encountered (with 1075This tag is automatically generated when a reference are encountered (with
753the exception of hash and array refernces). It is converted to a reference 1076the exception of hash and array references). It is converted to a reference
754when decoding. 1077when decoding.
755 1078
756=item 55799 (self-describe CBOR, RFC 7049) 1079=item 55799 (self-describe CBOR, RFC 7049)
757 1080
758This value is not generated on encoding (unless explicitly requested by 1081This value is not generated on encoding (unless explicitly requested by
761=back 1084=back
762 1085
763=head2 NON-ENFORCED TAGS 1086=head2 NON-ENFORCED TAGS
764 1087
765These tags have default filters provided when decoding. Their handling can 1088These tags have default filters provided when decoding. Their handling can
766be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by 1089be overridden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
767providing a custom C<filter> callback when decoding. 1090providing a custom C<filter> callback when decoding.
768 1091
769When they result in decoding into a specific Perl class, the module 1092When they result in decoding into a specific Perl class, the module
770usually provides a corresponding C<TO_CBOR> method as well. 1093usually provides a corresponding C<TO_CBOR> method as well.
771 1094
774provide these modules. The decoding usually fails with an exception if the 1097provide these modules. The decoding usually fails with an exception if the
775required module cannot be loaded. 1098required module cannot be loaded.
776 1099
777=over 4 1100=over 4
778 1101
1102=item 0, 1 (date/time string, seconds since the epoch)
1103
1104These tags are decoded into L<Time::Piece> objects. The corresponding
1105C<Time::Piece::TO_CBOR> method always encodes into tag 1 values currently.
1106
1107The L<Time::Piece> API is generally surprisingly bad, and fractional
1108seconds are only accidentally kept intact, so watch out. On the plus side,
1109the module comes with perl since 5.10, which has to count for something.
1110
779=item 2, 3 (positive/negative bignum) 1111=item 2, 3 (positive/negative bignum)
780 1112
781These tags are decoded into L<Math::BigInt> objects. The corresponding 1113These tags are decoded into L<Math::BigInt> objects. The corresponding
782C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR 1114C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
783integers, and others into positive/negative CBOR bignums. 1115integers, and others into positive/negative CBOR bignums.
784 1116
785=item 4, 5 (decimal fraction/bigfloat) 1117=item 4, 5, 264, 265 (decimal fraction/bigfloat)
786 1118
787Both decimal fractions and bigfloats are decoded into L<Math::BigFloat> 1119Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
788objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always> 1120objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
789encodes into a decimal fraction. 1121encodes into a decimal fraction (either tag 4 or 264).
790 1122
791CBOR cannot represent bigfloats with I<very> large exponents - conversion 1123NaN and infinities are not encoded properly, as they cannot be represented
792of such big float objects is undefined. 1124in CBOR.
793 1125
794Also, NaN and infinities are not encoded properly. 1126See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
1127
1128=item 30 (rational numbers)
1129
1130These tags are decoded into L<Math::BigRat> objects. The corresponding
1131C<Math::BigRat::TO_CBOR> method encodes rational numbers with denominator
1132C<1> via their numerator only, i.e., they become normal integers or
1133C<bignums>.
1134
1135See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
795 1136
796=item 21, 22, 23 (expected later JSON conversion) 1137=item 21, 22, 23 (expected later JSON conversion)
797 1138
798CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these 1139CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
799tags. 1140tags.
804C<URI::TO_CBOR> method again results in a CBOR URI value. 1145C<URI::TO_CBOR> method again results in a CBOR URI value.
805 1146
806=back 1147=back
807 1148
808=cut 1149=cut
809
810our %FILTER = (
811 # 0 # rfc4287 datetime, utf-8
812 # 1 # unix timestamp, any
813
814 2 => sub { # pos bigint
815 require Math::BigInt;
816 Math::BigInt->new ("0x" . unpack "H*", pop)
817 },
818
819 3 => sub { # neg bigint
820 require Math::BigInt;
821 -Math::BigInt->new ("0x" . unpack "H*", pop)
822 },
823
824 4 => sub { # decimal fraction, array
825 require Math::BigFloat;
826 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
827 },
828
829 5 => sub { # bigfloat, array
830 require Math::BigFloat;
831 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
832 },
833
834 21 => sub { pop }, # expected conversion to base64url encoding
835 22 => sub { pop }, # expected conversion to base64 encoding
836 23 => sub { pop }, # expected conversion to base16 encoding
837
838 # 24 # embedded cbor, byte string
839
840 32 => sub {
841 require URI;
842 URI->new (pop)
843 },
844
845 # 33 # base64url rfc4648, utf-8
846 # 34 # base64 rfc46484, utf-8
847 # 35 # regex pcre/ecma262, utf-8
848 # 36 # mime message rfc2045, utf-8
849);
850
851 1150
852=head1 CBOR and JSON 1151=head1 CBOR and JSON
853 1152
854CBOR is supposed to implement a superset of the JSON data model, and is, 1153CBOR is supposed to implement a superset of the JSON data model, and is,
855with some coercion, able to represent all JSON texts (something that other 1154with some coercion, able to represent all JSON texts (something that other
864CBOR intact. 1163CBOR intact.
865 1164
866 1165
867=head1 SECURITY CONSIDERATIONS 1166=head1 SECURITY CONSIDERATIONS
868 1167
869When you are using CBOR in a protocol, talking to untrusted potentially 1168Tl;dr... if you want to decode or encode CBOR from untrusted sources, you
870hostile creatures requires relatively few measures. 1169should start with a coder object created via C<new_safe> (which implements
1170the mitigations explained below):
871 1171
1172 my $coder = CBOR::XS->new_safe;
1173
1174 my $data = $coder->decode ($cbor_text);
1175 my $cbor = $coder->encode ($data);
1176
1177Longer version: When you are using CBOR in a protocol, talking to
1178untrusted potentially hostile creatures requires some thought:
1179
1180=over 4
1181
1182=item Security of the CBOR decoder itself
1183
872First of all, your CBOR decoder should be secure, that is, should not have 1184First and foremost, your CBOR decoder should be secure, that is, should
1185not have any buffer overflows or similar bugs that could potentially be
873any buffer overflows. Obviously, this module should ensure that and I am 1186exploited. Obviously, this module should ensure that and I am trying hard
874trying hard on making that true, but you never know. 1187on making that true, but you never know.
875 1188
1189=item CBOR::XS can invoke almost arbitrary callbacks during decoding
1190
1191CBOR::XS supports object serialisation - decoding CBOR can cause calls
1192to I<any> C<THAW> method in I<any> package that exists in your process
1193(that is, CBOR::XS will not try to load modules, but any existing C<THAW>
1194method or function can be called, so they all have to be secure).
1195
1196Less obviously, it will also invoke C<TO_CBOR> and C<FREEZE> methods -
1197even if all your C<THAW> methods are secure, encoding data structures from
1198untrusted sources can invoke those and trigger bugs in those.
1199
1200So, if you are not sure about the security of all the modules you
1201have loaded (you shouldn't), you should disable this part using
1202C<forbid_objects> or using C<new_safe>.
1203
1204=item CBOR can be extended with tags that call library code
1205
1206CBOR can be extended with tags, and C<CBOR::XS> has a registry of
1207conversion functions for many existing tags that can be extended via
1208third-party modules (see the C<filter> method).
1209
1210If you don't trust these, you should configure the "safe" filter function,
1211C<CBOR::XS::safe_filter> (C<new_safe> does this), which by default only
1212includes conversion functions that are considered "safe" by the author
1213(but again, they can be extended by third party modules).
1214
1215Depending on your level of paranoia, you can use the "safe" filter:
1216
1217 $cbor->filter (\&CBOR::XS::safe_filter);
1218
1219... your own filter...
1220
1221 $cbor->filter (sub { ... do your stuffs here ... });
1222
1223... or even no filter at all, disabling all tag decoding:
1224
1225 $cbor->filter (sub { });
1226
1227This is never a problem for encoding, as the tag mechanism only exists in
1228CBOR texts.
1229
1230=item Resource-starving attacks: object memory usage
1231
876Second, you need to avoid resource-starving attacks. That means you should 1232You need to avoid resource-starving attacks. That means you should limit
877limit the size of CBOR data you accept, or make sure then when your 1233the size of CBOR data you accept, or make sure then when your resources
878resources run out, that's just fine (e.g. by using a separate process that 1234run out, that's just fine (e.g. by using a separate process that can
879can crash safely). The size of a CBOR string in octets is usually a good 1235crash safely). The size of a CBOR string in octets is usually a good
880indication of the size of the resources required to decode it into a Perl 1236indication of the size of the resources required to decode it into a Perl
881structure. While CBOR::XS can check the size of the CBOR text, it might be 1237structure. While CBOR::XS can check the size of the CBOR text (using
882too late when you already have it in memory, so you might want to check 1238C<max_size> - done by C<new_safe>), it might be too late when you already
883the size before you accept the string. 1239have it in memory, so you might want to check the size before you accept
1240the string.
884 1241
1242As for encoding, it is possible to construct data structures that are
1243relatively small but result in large CBOR texts (for example by having an
1244array full of references to the same big data structure, which will all be
1245deep-cloned during encoding by default). This is rarely an actual issue
1246(and the worst case is still just running out of memory), but you can
1247reduce this risk by using C<allow_sharing>.
1248
1249=item Resource-starving attacks: stack overflows
1250
885Third, CBOR::XS recurses using the C stack when decoding objects and 1251CBOR::XS recurses using the C stack when decoding objects and arrays. The
886arrays. The C stack is a limited resource: for instance, on my amd64 1252C stack is a limited resource: for instance, on my amd64 machine with 8MB
887machine with 8MB of stack size I can decode around 180k nested arrays but 1253of stack size I can decode around 180k nested arrays but only 14k nested
888only 14k nested CBOR objects (due to perl itself recursing deeply on croak 1254CBOR objects (due to perl itself recursing deeply on croak to free the
889to free the temporary). If that is exceeded, the program crashes. To be 1255temporary). If that is exceeded, the program crashes. To be conservative,
890conservative, the default nesting limit is set to 512. If your process 1256the default nesting limit is set to 512. If your process has a smaller
891has a smaller stack, you should adjust this setting accordingly with the 1257stack, you should adjust this setting accordingly with the C<max_depth>
892C<max_depth> method. 1258method.
1259
1260=item Resource-starving attacks: CPU en-/decoding complexity
1261
1262CBOR::XS will use the L<Math::BigInt>, L<Math::BigFloat> and
1263L<Math::BigRat> libraries to represent encode/decode bignums. These can be
1264very slow (as in, centuries of CPU time) and can even crash your program
1265(and are generally not very trustworthy). See the next section on bignum
1266security for details.
1267
1268=item Data breaches: leaking information in error messages
1269
1270CBOR::XS might leak contents of your Perl data structures in its error
1271messages, so when you serialise sensitive information you might want to
1272make sure that exceptions thrown by CBOR::XS will not end up in front of
1273untrusted eyes.
1274
1275=item Something else...
893 1276
894Something else could bomb you, too, that I forgot to think of. In that 1277Something else could bomb you, too, that I forgot to think of. In that
895case, you get to keep the pieces. I am always open for hints, though... 1278case, you get to keep the pieces. I am always open for hints, though...
896 1279
897Also keep in mind that CBOR::XS might leak contents of your Perl data 1280=back
898structures in its error messages, so when you serialise sensitive 1281
899information you might want to make sure that exceptions thrown by CBOR::XS 1282
900will not end up in front of untrusted eyes. 1283=head1 BIGNUM SECURITY CONSIDERATIONS
1284
1285CBOR::XS provides a C<TO_CBOR> method for both L<Math::BigInt> and
1286L<Math::BigFloat> that tries to encode the number in the simplest possible
1287way, that is, either a CBOR integer, a CBOR bigint/decimal fraction (tag
12884) or an arbitrary-exponent decimal fraction (tag 264). Rational numbers
1289(L<Math::BigRat>, tag 30) can also contain bignums as members.
1290
1291CBOR::XS will also understand base-2 bigfloat or arbitrary-exponent
1292bigfloats (tags 5 and 265), but it will never generate these on its own.
1293
1294Using the built-in L<Math::BigInt::Calc> support, encoding and decoding
1295decimal fractions is generally fast. Decoding bigints can be slow for very
1296big numbers (tens of thousands of digits, something that could potentially
1297be caught by limiting the size of CBOR texts), and decoding bigfloats or
1298arbitrary-exponent bigfloats can be I<extremely> slow (minutes, decades)
1299for large exponents (roughly 40 bit and longer).
1300
1301Additionally, L<Math::BigInt> can take advantage of other bignum
1302libraries, such as L<Math::GMP>, which cannot handle big floats with large
1303exponents, and might simply abort or crash your program, due to their code
1304quality.
1305
1306This can be a concern if you want to parse untrusted CBOR. If it is, you
1307might want to disable decoding of tag 2 (bigint) and 3 (negative bigint)
1308types. You should also disable types 5 and 265, as these can be slow even
1309without bigints.
1310
1311Disabling bigints will also partially or fully disable types that rely on
1312them, e.g. rational numbers that use bignums.
1313
901 1314
902=head1 CBOR IMPLEMENTATION NOTES 1315=head1 CBOR IMPLEMENTATION NOTES
903 1316
904This section contains some random implementation notes. They do not 1317This section contains some random implementation notes. They do not
905describe guaranteed behaviour, but merely behaviour as-is implemented 1318describe guaranteed behaviour, but merely behaviour as-is implemented
919 1332
920 1333
921=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT 1334=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT
922 1335
923On perls that were built without 64 bit integer support (these are rare 1336On perls that were built without 64 bit integer support (these are rare
924nowadays, even on 32 bit architectures), support for any kind of 64 bit 1337nowadays, even on 32 bit architectures, as all major Perl distributions
1338are built with 64 bit integer support), support for any kind of 64 bit
925integer in CBOR is very limited - most likely, these 64 bit values will 1339value in CBOR is very limited - most likely, these 64 bit values will
926be truncated, corrupted, or otherwise not decoded correctly. This also 1340be truncated, corrupted, or otherwise not decoded correctly. This also
927includes string, array and map sizes that are stored as 64 bit integers. 1341includes string, float, array and map sizes that are stored as 64 bit
1342integers.
928 1343
929 1344
930=head1 THREADS 1345=head1 THREADS
931 1346
932This module is I<not> guaranteed to be thread safe and there are no 1347This module is I<not> guaranteed to be thread safe and there are no
946Please refrain from using rt.cpan.org or any other bug reporting 1361Please refrain from using rt.cpan.org or any other bug reporting
947service. I put the contact address into my modules for a reason. 1362service. I put the contact address into my modules for a reason.
948 1363
949=cut 1364=cut
950 1365
1366# clumsy and slow hv_store-in-hash helper function
1367sub _hv_store {
1368 $_[0]{$_[1]} = $_[2];
1369}
1370
951our %FILTER = ( 1371our %FILTER = (
952 # 0 # rfc4287 datetime, utf-8 1372 0 => sub { # rfc4287 datetime, utf-8
953 # 1 # unix timestamp, any 1373 require Time::Piece;
1374 # Time::Piece::Strptime uses the "incredibly flexible date parsing routine"
1375 # from FreeBSD, which can't parse ISO 8601, RFC3339, RFC4287 or much of anything
1376 # else either. Whats incredibe over standard strptime totally escapes me.
1377 # doesn't do fractional times, either. sigh.
1378 # In fact, it's all a lie, it uses whatever strptime it wants, and of course,
1379 # they are all incompatible. The openbsd one simply ignores %z (but according to the
1380 # docs, it would be much more incredibly flexible indeed. If it worked, that is.).
1381 scalar eval {
1382 my $s = $_[1];
1383
1384 $s =~ s/Z$/+00:00/;
1385 $s =~ s/(\.[0-9]+)?([+-][0-9][0-9]):([0-9][0-9])$//
1386 or die;
1387
1388 my $b = $1 - ($2 * 60 + $3) * 60; # fractional part + offset. hopefully
1389 my $d = Time::Piece->strptime ($s, "%Y-%m-%dT%H:%M:%S");
1390
1391 Time::Piece::gmtime ($d->epoch + $b)
1392 } || die "corrupted CBOR date/time string ($_[0])";
1393 },
1394
1395 1 => sub { # seconds since the epoch, possibly fractional
1396 require Time::Piece;
1397 scalar Time::Piece::gmtime (pop)
1398 },
954 1399
955 2 => sub { # pos bigint 1400 2 => sub { # pos bigint
956 require Math::BigInt; 1401 require Math::BigInt;
957 Math::BigInt->new ("0x" . unpack "H*", pop) 1402 Math::BigInt->new ("0x" . unpack "H*", pop)
958 }, 1403 },
965 4 => sub { # decimal fraction, array 1410 4 => sub { # decimal fraction, array
966 require Math::BigFloat; 1411 require Math::BigFloat;
967 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0]) 1412 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
968 }, 1413 },
969 1414
1415 264 => sub { # decimal fraction with arbitrary exponent
1416 require Math::BigFloat;
1417 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
1418 },
1419
970 5 => sub { # bigfloat, array 1420 5 => sub { # bigfloat, array
971 require Math::BigFloat; 1421 require Math::BigFloat;
972 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2) 1422 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1423 },
1424
1425 265 => sub { # bigfloat with arbitrary exponent
1426 require Math::BigFloat;
1427 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1428 },
1429
1430 30 => sub { # rational number
1431 require Math::BigRat;
1432 Math::BigRat->new ("$_[1][0]/$_[1][1]") # separate parameters only work in recent versons
973 }, 1433 },
974 1434
975 21 => sub { pop }, # expected conversion to base64url encoding 1435 21 => sub { pop }, # expected conversion to base64url encoding
976 22 => sub { pop }, # expected conversion to base64 encoding 1436 22 => sub { pop }, # expected conversion to base64 encoding
977 23 => sub { pop }, # expected conversion to base16 encoding 1437 23 => sub { pop }, # expected conversion to base16 encoding
987 # 34 # base64 rfc46484, utf-8 1447 # 34 # base64 rfc46484, utf-8
988 # 35 # regex pcre/ecma262, utf-8 1448 # 35 # regex pcre/ecma262, utf-8
989 # 36 # mime message rfc2045, utf-8 1449 # 36 # mime message rfc2045, utf-8
990); 1450);
991 1451
992sub CBOR::XS::default_filter { 1452sub default_filter {
993 &{ $FILTER{$_[0]} or return } 1453 &{ $FILTER{$_[0]} or return }
1454}
1455
1456our %SAFE_FILTER = map { $_ => $FILTER{$_} } 0, 1, 21, 22, 23, 32;
1457
1458sub safe_filter {
1459 &{ $SAFE_FILTER{$_[0]} or return }
994} 1460}
995 1461
996sub URI::TO_CBOR { 1462sub URI::TO_CBOR {
997 my $uri = $_[0]->as_string; 1463 my $uri = $_[0]->as_string;
998 utf8::upgrade $uri; 1464 utf8::upgrade $uri;
999 CBOR::XS::tag 32, $uri 1465 tag 32, $uri
1000} 1466}
1001 1467
1002sub Math::BigInt::TO_CBOR { 1468sub Math::BigInt::TO_CBOR {
1003 if ($_[0] >= -2147483648 && $_[0] <= 2147483647) { 1469 if (-2147483648 <= $_[0] && $_[0] <= 2147483647) {
1004 $_[0]->numify 1470 $_[0]->numify
1005 } else { 1471 } else {
1006 my $hex = substr $_[0]->as_hex, 2; 1472 my $hex = substr $_[0]->as_hex, 2;
1007 $hex = "0$hex" if 1 & length $hex; # sigh 1473 $hex = "0$hex" if 1 & length $hex; # sigh
1008 CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex 1474 tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
1009 } 1475 }
1010} 1476}
1011 1477
1012sub Math::BigFloat::TO_CBOR { 1478sub Math::BigFloat::TO_CBOR {
1013 my ($m, $e) = $_[0]->parts; 1479 my ($m, $e) = $_[0]->parts;
1480
1481 -9223372036854775808 <= $e && $e <= 18446744073709551615
1014 CBOR::XS::tag 4, [$e->numify, $m] 1482 ? tag 4, [$e->numify, $m]
1483 : tag 264, [$e, $m]
1484}
1485
1486sub Math::BigRat::TO_CBOR {
1487 my ($n, $d) = $_[0]->parts;
1488
1489 # older versions of BigRat need *1, as they not always return numbers
1490
1491 $d*1 == 1
1492 ? $n*1
1493 : tag 30, [$n*1, $d*1]
1494}
1495
1496sub Time::Piece::TO_CBOR {
1497 tag 1, 0 + $_[0]->epoch
1015} 1498}
1016 1499
1017XSLoader::load "CBOR::XS", $VERSION; 1500XSLoader::load "CBOR::XS", $VERSION;
1018 1501
1019=head1 SEE ALSO 1502=head1 SEE ALSO

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