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Revision 1.29 by root, Sat Nov 30 15:23:59 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
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 = 1.86;
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. 212structures (which need C<allow_cycles> to be enabled to be decoded by this
213module).
186 214
187It is recommended to leave it off unless you know your 215It is recommended to leave it off unless you know your
188communication partner supports the value sharing extensions to CBOR 216communication partner supports the value sharing extensions to CBOR
189(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
190resulting data structure might be unusable. 218resulting data structure might be unusable.
191 219
192Detecting shared values incurs a runtime overhead when values are encoded 220Detecting shared values incurs a runtime overhead when values are encoded
193that have a reference counter large than one, and might unnecessarily 221that have a reference counter larger than one, and might unnecessarily
194increase the encoded size, as potentially shared values are encode as 222increase the encoded size, as potentially shared values are encoded as
195sharable whether or not they are actually shared. 223shareable whether or not they are actually shared.
196 224
197At 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,
198arrays or hashes pointed to by a reference). Weirder constructs, such as 226arrays 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 227an 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 228not impossible to create in Perl, are not supported (this is the same as
205structures cannot be encoded in this mode. 233structures cannot be encoded in this mode.
206 234
207This option does not affect C<decode> in any way - shared values and 235This option does not affect C<decode> in any way - shared values and
208references will always be decoded properly if present. 236references will always be decoded properly if present.
209 237
238=item $cbor = $cbor->allow_cycles ([$enable])
239
240=item $enabled = $cbor->get_allow_cycles
241
242If C<$enable> is true (or missing), then C<decode> will happily decode
243self-referential (cyclic) data structures. By default these will not be
244decoded, as they need manual cleanup to avoid memory leaks, so code that
245isn't prepared for this will not leak memory.
246
247If C<$enable> is false (the default), then C<decode> will throw an error
248when it encounters a self-referential/cyclic data structure.
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
255This option does not affect C<encode> in any way - shared values and
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.
276
210=item $cbor = $cbor->pack_strings ([$enable]) 277=item $cbor = $cbor->pack_strings ([$enable])
211 278
212=item $enabled = $cbor->get_pack_strings 279=item $enabled = $cbor->get_pack_strings
213 280
214If C<$enable> is true (or missing), then C<encode> will try not to encode 281If C<$enable> is true (or missing), then C<encode> will try not to encode
226the standard CBOR way. 293the standard CBOR way.
227 294
228This 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
229always be decoded properly if present. 296always be decoded properly if present.
230 297
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
231=item $cbor = $cbor->filter ([$cb->($tag, $value)]) 368=item $cbor = $cbor->filter ([$cb->($tag, $value)])
232 369
233=item $cb_or_undef = $cbor->get_filter 370=item $cb_or_undef = $cbor->get_filter
234 371
235Sets or replaces the tagged value decoding filter (when C<$cb> is 372Sets or replaces the tagged value decoding filter (when C<$cb> is
247replace the tagged value in the decoded data structure, or no values, 384replace the tagged value in the decoded data structure, or no values,
248which will result in default handling, which currently means the decoder 385which will result in default handling, which currently means the decoder
249creates 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.
250 387
251When the filter is cleared (the default state), the default filter 388When the filter is cleared (the default state), the default filter
252function, C<CBOR::XS::default_filter>, is used. This function simply looks 389function, 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 390looks 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 391it 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. 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.
256 406
257Example: decode all tags not handled internally into C<CBOR::XS::Tagged> 407Example: decode all tags not handled internally into C<CBOR::XS::Tagged>
258objects, with no other special handling (useful when working with 408objects, with no other special handling (useful when working with
259potentially "unsafe" CBOR data). 409potentially "unsafe" CBOR data).
260 410
267 my ($tag, $value); 417 my ($tag, $value);
268 418
269 "tag 1347375694 value $value" 419 "tag 1347375694 value $value"
270 }; 420 };
271 421
422Example: provide your own filter function that looks up tags in your own
423hash:
424
425 my %my_filter = (
426 998347484 => sub {
427 my ($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
272=item $cbor_data = $cbor->encode ($perl_scalar) 443=item $cbor_data = $cbor->encode ($perl_scalar)
273 444
274Converts the given Perl data structure (a scalar value) to its CBOR 445Converts the given Perl data structure (a scalar value) to its CBOR
275representation. 446representation.
276 447
285when there is trailing garbage after the CBOR string, it will silently 456when there is trailing garbage after the CBOR string, it will silently
286stop parsing there and return the number of characters consumed so far. 457stop parsing there and return the number of characters consumed so far.
287 458
288This 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
289and 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
290starts. 461starts - CBOR strings are self-delimited, so it is possible to concatenate
462CBOR strings without any delimiters or size fields and recover their data.
291 463
292 CBOR::XS->new->decode_prefix ("......") 464 CBOR::XS->new->decode_prefix ("......")
293 => ("...", 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.
294 530
295=back 531=back
296 532
297 533
298=head1 MAPPING 534=head1 MAPPING
371 607
372=item hash references 608=item hash references
373 609
374Perl 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
375hash 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
376order. This order can be different each time a hahs is encoded. 612order. This order can be different each time a hash is encoded.
377 613
378Currently, tied hashes will use the indefinite-length format, while normal 614Currently, tied hashes will use the indefinite-length format, while normal
379hashes will use the fixed-length format. 615hashes will use the fixed-length format.
380 616
381=item array references 617=item array references
399create such objects. 635create such objects.
400 636
401=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error 637=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error
402 638
403These special values become CBOR true, CBOR false and CBOR undefined 639These special values become CBOR true, CBOR false and CBOR undefined
404values, respectively. You can also use C<\1>, C<\0> and C<\undef> directly 640values, respectively.
405if you want.
406 641
407=item other blessed objects 642=item other blessed objects
408 643
409Other 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
410L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this 645L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this
434 my $x = 3.1; # some variable containing a number 669 my $x = 3.1; # some variable containing a number
435 "$x"; # stringified 670 "$x"; # stringified
436 $x .= ""; # another, more awkward way to stringify 671 $x .= ""; # another, more awkward way to stringify
437 print $x; # perl does it for you, too, quite often 672 print $x; # perl does it for you, too, quite often
438 673
439You 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
440C<utf8::upgrade> and C<utf8::downgrade>): 675C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled).
441 676
442 utf8::upgrade $x; # encode $x as text string 677 utf8::upgrade $x; # encode $x as text string
443 utf8::downgrade $x; # encode $x as byte string 678 utf8::downgrade $x; # encode $x as byte string
444 679
680More options are available, see L<TYPE CASTS>, below, and the C<text_keys>
681and C<text_strings> options.
682
445Perl 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
446difference between byte and text is important, you should up- or downgrade 684difference between byte and text is important, you should up- or downgrade
447your 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>.
448 687
449You 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:
450 689
451 my $x = "3"; # some variable containing a string 690 my $x = "3"; # some variable containing a string
452 $x += 0; # numify it, ensuring it will be dumped as a number 691 $x += 0; # numify it, ensuring it will be dumped as a number
463represent numerical values are supported, but might suffer loss of 702represent numerical values are supported, but might suffer loss of
464precision. 703precision.
465 704
466=back 705=back
467 706
707=head2 TYPE CASTS
708
709B<EXPERIMENTAL>: As an experimental extension, C<CBOR::XS> allows you to
710force specific CBOR types to be used when encoding. That allows you to
711encode types not normally accessible (e.g. half floats) as well as force
712string types even when C<text_strings> is in effect.
713
714Type forcing is done by calling a special "cast" function which keeps a
715copy of the value and returns a new value that can be handed over to any
716CBOR encoder function.
717
718The following casts are currently available (all of which are unary
719operators, that is, have a prototype of C<$>):
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
468=head2 OBJECT SERIALISATION 808=head2 OBJECT SERIALISATION
469 809
470This module implements both a CBOR-specific and the generic 810This module implements both a CBOR-specific and the generic
471L<Types::Serialier> object serialisation protocol. The following 811L<Types::Serialier> object serialisation protocol. The following
472subsections explain both methods. 812subsections explain both methods.
553 "$self" # encode url string 893 "$self" # encode url string
554 } 894 }
555 895
556 sub URI::THAW { 896 sub URI::THAW {
557 my ($class, $serialiser, $uri) = @_; 897 my ($class, $serialiser, $uri) = @_;
558
559 $class->new ($uri) 898 $class->new ($uri)
560 } 899 }
561 900
562Unlike 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
563example, a C<FREEZE> method that returns "type", "id" and "variant" values 902example, a C<FREEZE> method that returns "type", "id" and "variant" values
694additional tags (such as base64url). 1033additional tags (such as base64url).
695 1034
696=head2 ENFORCED TAGS 1035=head2 ENFORCED TAGS
697 1036
698These tags are always handled when decoding, and their handling cannot be 1037These tags are always handled when decoding, and their handling cannot be
699overriden by the user. 1038overridden by the user.
700 1039
701=over 4 1040=over 4
702 1041
703=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>) 1042=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>)
704 1043
705These tags are automatically created (and decoded) for serialisable 1044These tags are automatically created (and decoded) for serialisable
706objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object 1045objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
707serialisation protocol). See L<OBJECT SERIALISATION> for details. 1046serialisation protocol). See L<OBJECT SERIALISATION> for details.
708 1047
709=item 28, 29 (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) 1048=item 28, 29 (shareable, sharedref, L<http://cbor.schmorp.de/value-sharing>)
710 1049
711These tags are automatically decoded when encountered, resulting in 1050These tags are automatically decoded when encountered (and they do not
1051result in a cyclic data structure, see C<allow_cycles>), resulting in
712shared values in the decoded object. They are only encoded, however, when 1052shared values in the decoded object. They are only encoded, however, when
713C<allow_sharable> is enabled. 1053C<allow_sharing> is enabled.
714 1054
1055Not all shared values can be successfully decoded: values that reference
1056themselves will I<currently> decode as C<undef> (this is not the same
1057as a reference pointing to itself, which will be represented as a value
1058that contains an indirect reference to itself - these will be decoded
1059properly).
1060
1061Note that considerably more shared value data structures can be decoded
1062than will be encoded - currently, only values pointed to by references
1063will be shared, others will not. While non-reference shared values can be
1064generated in Perl with some effort, they were considered too unimportant
1065to be supported in the encoder. The decoder, however, will decode these
1066values as shared values.
1067
715=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>)
716 1069
717These tags are automatically decoded when encountered. They are only 1070These tags are automatically decoded when encountered. They are only
718encoded, however, when C<pack_strings> is enabled. 1071encoded, however, when C<pack_strings> is enabled.
719 1072
720=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) 1073=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
721 1074
722This tag is automatically generated when a reference are encountered (with 1075This tag is automatically generated when a reference are encountered (with
723the 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
724when decoding. 1077when decoding.
725 1078
726=item 55799 (self-describe CBOR, RFC 7049) 1079=item 55799 (self-describe CBOR, RFC 7049)
727 1080
728This value is not generated on encoding (unless explicitly requested by 1081This value is not generated on encoding (unless explicitly requested by
731=back 1084=back
732 1085
733=head2 NON-ENFORCED TAGS 1086=head2 NON-ENFORCED TAGS
734 1087
735These tags have default filters provided when decoding. Their handling can 1088These 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 1089be overridden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
737providing a custom C<filter> callback when decoding. 1090providing a custom C<filter> callback when decoding.
738 1091
739When they result in decoding into a specific Perl class, the module 1092When they result in decoding into a specific Perl class, the module
740usually provides a corresponding C<TO_CBOR> method as well. 1093usually provides a corresponding C<TO_CBOR> method as well.
741 1094
744provide these modules. The decoding usually fails with an exception if the 1097provide these modules. The decoding usually fails with an exception if the
745required module cannot be loaded. 1098required module cannot be loaded.
746 1099
747=over 4 1100=over 4
748 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
749=item 2, 3 (positive/negative bignum) 1111=item 2, 3 (positive/negative bignum)
750 1112
751These tags are decoded into L<Math::BigInt> objects. The corresponding 1113These tags are decoded into L<Math::BigInt> objects. The corresponding
752C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR 1114C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
753integers, and others into positive/negative CBOR bignums. 1115integers, and others into positive/negative CBOR bignums.
754 1116
755=item 4, 5 (decimal fraction/bigfloat) 1117=item 4, 5, 264, 265 (decimal fraction/bigfloat)
756 1118
757Both decimal fractions and bigfloats are decoded into L<Math::BigFloat> 1119Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
758objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always> 1120objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
759encodes into a decimal fraction. 1121encodes into a decimal fraction (either tag 4 or 264).
760 1122
761CBOR cannot represent bigfloats with I<very> large exponents - conversion 1123NaN and infinities are not encoded properly, as they cannot be represented
762of such big float objects is undefined. 1124in CBOR.
763 1125
764Also, 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.
765 1136
766=item 21, 22, 23 (expected later JSON conversion) 1137=item 21, 22, 23 (expected later JSON conversion)
767 1138
768CBOR::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
769tags. 1140tags.
774C<URI::TO_CBOR> method again results in a CBOR URI value. 1145C<URI::TO_CBOR> method again results in a CBOR URI value.
775 1146
776=back 1147=back
777 1148
778=cut 1149=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 1150
822=head1 CBOR and JSON 1151=head1 CBOR and JSON
823 1152
824CBOR 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,
825with some coercion, able to represent all JSON texts (something that other 1154with some coercion, able to represent all JSON texts (something that other
834CBOR intact. 1163CBOR intact.
835 1164
836 1165
837=head1 SECURITY CONSIDERATIONS 1166=head1 SECURITY CONSIDERATIONS
838 1167
839When 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
840hostile creatures requires relatively few measures. 1169should start with a coder object created via C<new_safe> (which implements
1170the mitigations explained below):
841 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
842First 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
843any buffer overflows. Obviously, this module should ensure that and I am 1186exploited. Obviously, this module should ensure that and I am trying hard
844trying hard on making that true, but you never know. 1187on making that true, but you never know.
845 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
846Second, you need to avoid resource-starving attacks. That means you should 1232You 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 1233the 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 1234run 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 1235crash 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 1236indication 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 1237structure. 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 1238C<max_size> - done by C<new_safe>), it might be too late when you already
853the size before you accept the string. 1239have it in memory, so you might want to check the size before you accept
1240the string.
854 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
855Third, CBOR::XS recurses using the C stack when decoding objects and 1251CBOR::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 1252C 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 1253of 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 1254CBOR 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 1255temporary). If that is exceeded, the program crashes. To be conservative,
860conservative, 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
861has a smaller stack, you should adjust this setting accordingly with the 1257stack, you should adjust this setting accordingly with the C<max_depth>
862C<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...
863 1276
864Something 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
865case, 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...
866 1279
867Also keep in mind that CBOR::XS might leak contents of your Perl data 1280=back
868structures in its error messages, so when you serialise sensitive 1281
869information you might want to make sure that exceptions thrown by CBOR::XS 1282
870will 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
871 1314
872=head1 CBOR IMPLEMENTATION NOTES 1315=head1 CBOR IMPLEMENTATION NOTES
873 1316
874This section contains some random implementation notes. They do not 1317This section contains some random implementation notes. They do not
875describe guaranteed behaviour, but merely behaviour as-is implemented 1318describe guaranteed behaviour, but merely behaviour as-is implemented
884Only the double data type is supported for NV data types - when Perl uses 1327Only the double data type is supported for NV data types - when Perl uses
885long double to represent floating point values, they might not be encoded 1328long double to represent floating point values, they might not be encoded
886properly. Half precision types are accepted, but not encoded. 1329properly. Half precision types are accepted, but not encoded.
887 1330
888Strict mode and canonical mode are not implemented. 1331Strict mode and canonical mode are not implemented.
1332
1333
1334=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT
1335
1336On perls that were built without 64 bit integer support (these are rare
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
1339value in CBOR is very limited - most likely, these 64 bit values will
1340be truncated, corrupted, or otherwise not decoded correctly. This also
1341includes string, float, array and map sizes that are stored as 64 bit
1342integers.
889 1343
890 1344
891=head1 THREADS 1345=head1 THREADS
892 1346
893This 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
907Please refrain from using rt.cpan.org or any other bug reporting 1361Please refrain from using rt.cpan.org or any other bug reporting
908service. I put the contact address into my modules for a reason. 1362service. I put the contact address into my modules for a reason.
909 1363
910=cut 1364=cut
911 1365
1366# clumsy and slow hv_store-in-hash helper function
1367sub _hv_store {
1368 $_[0]{$_[1]} = $_[2];
1369}
1370
912our %FILTER = ( 1371our %FILTER = (
913 # 0 # rfc4287 datetime, utf-8 1372 0 => sub { # rfc4287 datetime, utf-8
914 # 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 },
915 1399
916 2 => sub { # pos bigint 1400 2 => sub { # pos bigint
917 require Math::BigInt; 1401 require Math::BigInt;
918 Math::BigInt->new ("0x" . unpack "H*", pop) 1402 Math::BigInt->new ("0x" . unpack "H*", pop)
919 }, 1403 },
926 4 => sub { # decimal fraction, array 1410 4 => sub { # decimal fraction, array
927 require Math::BigFloat; 1411 require Math::BigFloat;
928 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0]) 1412 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
929 }, 1413 },
930 1414
1415 264 => sub { # decimal fraction with arbitrary exponent
1416 require Math::BigFloat;
1417 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
1418 },
1419
931 5 => sub { # bigfloat, array 1420 5 => sub { # bigfloat, array
932 require Math::BigFloat; 1421 require Math::BigFloat;
933 scalar Math::BigFloat->new ($_[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
934 }, 1433 },
935 1434
936 21 => sub { pop }, # expected conversion to base64url encoding 1435 21 => sub { pop }, # expected conversion to base64url encoding
937 22 => sub { pop }, # expected conversion to base64 encoding 1436 22 => sub { pop }, # expected conversion to base64 encoding
938 23 => sub { pop }, # expected conversion to base16 encoding 1437 23 => sub { pop }, # expected conversion to base16 encoding
948 # 34 # base64 rfc46484, utf-8 1447 # 34 # base64 rfc46484, utf-8
949 # 35 # regex pcre/ecma262, utf-8 1448 # 35 # regex pcre/ecma262, utf-8
950 # 36 # mime message rfc2045, utf-8 1449 # 36 # mime message rfc2045, utf-8
951); 1450);
952 1451
953sub CBOR::XS::default_filter { 1452sub default_filter {
954 &{ $FILTER{$_[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 }
955} 1460}
956 1461
957sub URI::TO_CBOR { 1462sub URI::TO_CBOR {
958 my $uri = $_[0]->as_string; 1463 my $uri = $_[0]->as_string;
959 utf8::upgrade $uri; 1464 utf8::upgrade $uri;
960 CBOR::XS::tag 32, $uri 1465 tag 32, $uri
961} 1466}
962 1467
963sub Math::BigInt::TO_CBOR { 1468sub Math::BigInt::TO_CBOR {
964 if ($_[0] >= -2147483648 && $_[0] <= 2147483647) { 1469 if (-2147483648 <= $_[0] && $_[0] <= 2147483647) {
965 $_[0]->numify 1470 $_[0]->numify
966 } else { 1471 } else {
967 my $hex = substr $_[0]->as_hex, 2; 1472 my $hex = substr $_[0]->as_hex, 2;
968 $hex = "0$hex" if 1 & length $hex; # sigh 1473 $hex = "0$hex" if 1 & length $hex; # sigh
969 CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex 1474 tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
970 } 1475 }
971} 1476}
972 1477
973sub Math::BigFloat::TO_CBOR { 1478sub Math::BigFloat::TO_CBOR {
974 my ($m, $e) = $_[0]->parts; 1479 my ($m, $e) = $_[0]->parts;
1480
1481 -9223372036854775808 <= $e && $e <= 18446744073709551615
975 CBOR::XS::tag 4, [$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
976} 1498}
977 1499
978XSLoader::load "CBOR::XS", $VERSION; 1500XSLoader::load "CBOR::XS", $VERSION;
979 1501
980=head1 SEE ALSO 1502=head1 SEE ALSO

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