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Revision 1.30 by root, Sat Nov 30 16:19:59 2013 UTC vs.
Revision 1.78 by root, Tue Dec 8 08:29:44 2020 UTC

38with the added ability of supporting serialisation of Perl objects. (JSON 38with the added ability of supporting serialisation of Perl objects. (JSON
39often compresses better than CBOR though, so if you plan to compress the 39often compresses better than CBOR though, so if you plan to compress the
40data later and speed is less important you might want to compare both 40data later and speed is less important you might want to compare both
41formats first). 41formats first).
42 42
43The primary goal of this module is to be I<correct> and the secondary goal
44is to be I<fast>. To reach the latter goal it was written in C.
45
43To give you a general idea about speed, with texts in the megabyte range, 46To give you a general idea about speed, with texts in the megabyte range,
44C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or 47C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or
45L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the 48L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the
46data, the worse L<Storable> performs in comparison. 49data, the worse L<Storable> performs in comparison.
47 50
48Regarding compactness, C<CBOR::XS>-encoded data structures are usually 51Regarding compactness, C<CBOR::XS>-encoded data structures are usually
49about 20% smaller than the same data encoded as (compact) JSON or 52about 20% smaller than the same data encoded as (compact) JSON or
50L<Storable>. 53L<Storable>.
51 54
52In addition to the core CBOR data format, this module implements a 55In addition to the core CBOR data format, this module implements a
53number of extensions, to support cyclic and shared data structures (see 56number of extensions, to support cyclic and shared data structures
54C<allow_sharing>), string deduplication (see C<pack_strings>) and scalar 57(see C<allow_sharing> and C<allow_cycles>), string deduplication (see
55references (always enabled). 58C<pack_strings>) and scalar references (always enabled).
56
57The primary goal of this module is to be I<correct> and the secondary goal
58is to be I<fast>. To reach the latter goal it was written in C.
59 59
60See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and 60See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and
61vice versa. 61vice versa.
62 62
63=cut 63=cut
64 64
65package CBOR::XS; 65package CBOR::XS;
66 66
67use common::sense; 67use common::sense;
68 68
69our $VERSION = '1.0'; 69our $VERSION = 1.83;
70our @ISA = qw(Exporter); 70our @ISA = qw(Exporter);
71 71
72our @EXPORT = qw(encode_cbor decode_cbor); 72our @EXPORT = qw(encode_cbor decode_cbor);
73 73
74use Exporter; 74use Exporter;
112 112
113The mutators for flags all return the CBOR object again and thus calls can 113The mutators for flags all return the CBOR object again and thus calls can
114be chained: 114be chained:
115 115
116 my $cbor = CBOR::XS->new->encode ({a => [1,2]}); 116 my $cbor = CBOR::XS->new->encode ({a => [1,2]});
117
118=item $cbor = new_safe CBOR::XS
119
120Create a new, safe/secure CBOR::XS object. This is similar to C<new>,
121but configures the coder object to be safe to use with untrusted
122data. Currently, this is equivalent to:
123
124 my $cbor = CBOR::XS
125 ->new
126 ->forbid_objects
127 ->filter (\&CBOR::XS::safe_filter)
128 ->max_size (1e8);
129
130But is more future proof (it is better to crash because of a change than
131to be exploited in other ways).
132
133=cut
134
135sub new_safe {
136 CBOR::XS
137 ->new
138 ->forbid_objects
139 ->filter (\&CBOR::XS::safe_filter)
140 ->max_size (1e8)
141}
117 142
118=item $cbor = $cbor->max_depth ([$maximum_nesting_depth]) 143=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])
119 144
120=item $max_depth = $cbor->get_max_depth 145=item $max_depth = $cbor->get_max_depth
121 146
137 162
138Note that nesting is implemented by recursion in C. The default value has 163Note that nesting is implemented by recursion in C. The default value has
139been chosen to be as large as typical operating systems allow without 164been chosen to be as large as typical operating systems allow without
140crashing. 165crashing.
141 166
142See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 167See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
143 168
144=item $cbor = $cbor->max_size ([$maximum_string_size]) 169=item $cbor = $cbor->max_size ([$maximum_string_size])
145 170
146=item $max_size = $cbor->get_max_size 171=item $max_size = $cbor->get_max_size
147 172
152effect on C<encode> (yet). 177effect on C<encode> (yet).
153 178
154If no argument is given, the limit check will be deactivated (same as when 179If no argument is given, the limit check will be deactivated (same as when
155C<0> is specified). 180C<0> is specified).
156 181
157See SECURITY CONSIDERATIONS, below, for more info on why this is useful. 182See L<SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
158 183
159=item $cbor = $cbor->allow_unknown ([$enable]) 184=item $cbor = $cbor->allow_unknown ([$enable])
160 185
161=item $enabled = $cbor->get_allow_unknown 186=item $enabled = $cbor->get_allow_unknown
162 187
180reference to the earlier value. 205reference to the earlier value.
181 206
182This means that such values will only be encoded once, and will not result 207This means that such values will only be encoded once, and will not result
183in a deep cloning of the value on decode, in decoders supporting the value 208in a deep cloning of the value on decode, in decoders supporting the value
184sharing extension. This also makes it possible to encode cyclic data 209sharing extension. This also makes it possible to encode cyclic data
185structures. 210structures (which need C<allow_cycles> to be enabled to be decoded by this
211module).
186 212
187It is recommended to leave it off unless you know your 213It is recommended to leave it off unless you know your
188communication partner supports the value sharing extensions to CBOR 214communication partner supports the value sharing extensions to CBOR
189(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the 215(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the
190resulting data structure might be unusable. 216resulting data structure might be unusable.
191 217
192Detecting shared values incurs a runtime overhead when values are encoded 218Detecting shared values incurs a runtime overhead when values are encoded
193that have a reference counter large than one, and might unnecessarily 219that have a reference counter large than one, and might unnecessarily
194increase the encoded size, as potentially shared values are encode as 220increase the encoded size, as potentially shared values are encoded as
195sharable whether or not they are actually shared. 221shareable whether or not they are actually shared.
196 222
197At the moment, only targets of references can be shared (e.g. scalars, 223At the moment, only targets of references can be shared (e.g. scalars,
198arrays or hashes pointed to by a reference). Weirder constructs, such as 224arrays or hashes pointed to by a reference). Weirder constructs, such as
199an array with multiple "copies" of the I<same> string, which are hard but 225an array with multiple "copies" of the I<same> string, which are hard but
200not impossible to create in Perl, are not supported (this is the same as 226not impossible to create in Perl, are not supported (this is the same as
205structures cannot be encoded in this mode. 231structures cannot be encoded in this mode.
206 232
207This option does not affect C<decode> in any way - shared values and 233This option does not affect C<decode> in any way - shared values and
208references will always be decoded properly if present. 234references will always be decoded properly if present.
209 235
236=item $cbor = $cbor->allow_cycles ([$enable])
237
238=item $enabled = $cbor->get_allow_cycles
239
240If C<$enable> is true (or missing), then C<decode> will happily decode
241self-referential (cyclic) data structures. By default these will not be
242decoded, as they need manual cleanup to avoid memory leaks, so code that
243isn't prepared for this will not leak memory.
244
245If C<$enable> is false (the default), then C<decode> will throw an error
246when it encounters a self-referential/cyclic data structure.
247
248FUTURE DIRECTION: the motivation behind this option is to avoid I<real>
249cycles - future versions of this module might chose to decode cyclic data
250structures using weak references when this option is off, instead of
251throwing an error.
252
253This option does not affect C<encode> in any way - shared values and
254references will always be encoded properly if present.
255
256=item $cbor = $cbor->forbid_objects ([$enable])
257
258=item $enabled = $cbor->get_forbid_objects
259
260Disables the use of the object serialiser protocol.
261
262If C<$enable> is true (or missing), then C<encode> will will throw an
263exception when it encounters perl objects that would be encoded using the
264perl-object tag (26). When C<decode> encounters such tags, it will fall
265back to the general filter/tagged logic as if this were an unknown tag (by
266default resulting in a C<CBOR::XC::Tagged> object).
267
268If C<$enable> is false (the default), then C<encode> will use the
269L<Types::Serialiser> object serialisation protocol to serialise objects
270into perl-object tags, and C<decode> will do the same to decode such tags.
271
272See L<SECURITY CONSIDERATIONS>, below, for more info on why forbidding this
273protocol can be useful.
274
210=item $cbor = $cbor->pack_strings ([$enable]) 275=item $cbor = $cbor->pack_strings ([$enable])
211 276
212=item $enabled = $cbor->get_pack_strings 277=item $enabled = $cbor->get_pack_strings
213 278
214If C<$enable> is true (or missing), then C<encode> will try not to encode 279If C<$enable> is true (or missing), then C<encode> will try not to encode
226the standard CBOR way. 291the standard CBOR way.
227 292
228This option does not affect C<decode> in any way - string references will 293This option does not affect C<decode> in any way - string references will
229always be decoded properly if present. 294always be decoded properly if present.
230 295
296=item $cbor = $cbor->text_keys ([$enable])
297
298=item $enabled = $cbor->get_text_keys
299
300If C<$enabled> is true (or missing), then C<encode> will encode all
301perl hash keys as CBOR text strings/UTF-8 string, upgrading them as needed.
302
303If C<$enable> is false (the default), then C<encode> will encode hash keys
304normally - upgraded perl strings (strings internally encoded as UTF-8) as
305CBOR text strings, and downgraded perl strings as CBOR byte strings.
306
307This option does not affect C<decode> in any way.
308
309This option is useful for interoperability with CBOR decoders that don't
310treat byte strings as a form of text. It is especially useful as Perl
311gives very little control over hash keys.
312
313Enabling this option can be slow, as all downgraded hash keys that are
314encoded need to be scanned and converted to UTF-8.
315
316=item $cbor = $cbor->text_strings ([$enable])
317
318=item $enabled = $cbor->get_text_strings
319
320This option works similar to C<text_keys>, above, but works on all strings
321(including hash keys), so C<text_keys> has no further effect after
322enabling C<text_strings>.
323
324If C<$enabled> is true (or missing), then C<encode> will encode all perl
325strings as CBOR text strings/UTF-8 strings, upgrading them as needed.
326
327If C<$enable> is false (the default), then C<encode> will encode strings
328normally (but see C<text_keys>) - upgraded perl strings (strings
329internally encoded as UTF-8) as CBOR text strings, and downgraded perl
330strings as CBOR byte strings.
331
332This option does not affect C<decode> in any way.
333
334This option has similar advantages and disadvantages as C<text_keys>. In
335addition, this option effectively removes the ability to automatically
336encode byte strings, which might break some C<FREEZE> and C<TO_CBOR>
337methods that rely on this.
338
339A workaround is to use explicit type casts, which are unaffected by this option.
340
341=item $cbor = $cbor->validate_utf8 ([$enable])
342
343=item $enabled = $cbor->get_validate_utf8
344
345If C<$enable> is true (or missing), then C<decode> will validate that
346elements (text strings) containing UTF-8 data in fact contain valid UTF-8
347data (instead of blindly accepting it). This validation obviously takes
348extra time during decoding.
349
350The concept of "valid UTF-8" used is perl's concept, which is a superset
351of the official UTF-8.
352
353If C<$enable> is false (the default), then C<decode> will blindly accept
354UTF-8 data, marking them as valid UTF-8 in the resulting data structure
355regardless of whether that's true or not.
356
357Perl isn't too happy about corrupted UTF-8 in strings, but should
358generally not crash or do similarly evil things. Extensions might be not
359so forgiving, so it's recommended to turn on this setting if you receive
360untrusted CBOR.
361
362This option does not affect C<encode> in any way - strings that are
363supposedly valid UTF-8 will simply be dumped into the resulting CBOR
364string without checking whether that is, in fact, true or not.
365
231=item $cbor = $cbor->filter ([$cb->($tag, $value)]) 366=item $cbor = $cbor->filter ([$cb->($tag, $value)])
232 367
233=item $cb_or_undef = $cbor->get_filter 368=item $cb_or_undef = $cbor->get_filter
234 369
235Sets or replaces the tagged value decoding filter (when C<$cb> is 370Sets or replaces the tagged value decoding filter (when C<$cb> is
247replace the tagged value in the decoded data structure, or no values, 382replace the tagged value in the decoded data structure, or no values,
248which will result in default handling, which currently means the decoder 383which will result in default handling, which currently means the decoder
249creates a C<CBOR::XS::Tagged> object to hold the tag and the value. 384creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
250 385
251When the filter is cleared (the default state), the default filter 386When the filter is cleared (the default state), the default filter
252function, C<CBOR::XS::default_filter>, is used. This function simply looks 387function, C<CBOR::XS::default_filter>, is used. This function simply
253up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be 388looks up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists
254a code reference that is called with tag and value, and is responsible for 389it must be a code reference that is called with tag and value, and is
255decoding the value. If no entry exists, it returns no values. 390responsible for decoding the value. If no entry exists, it returns no
391values. C<CBOR::XS> provides a number of default filter functions already,
392the the C<%CBOR::XS::FILTER> hash can be freely extended with more.
393
394C<CBOR::XS> additionally provides an alternative filter function that is
395supposed to be safe to use with untrusted data (which the default filter
396might not), called C<CBOR::XS::safe_filter>, which works the same as
397the C<default_filter> but uses the C<%CBOR::XS::SAFE_FILTER> variable
398instead. It is prepopulated with the tag decoding functions that are
399deemed safe (basically the same as C<%CBOR::XS::FILTER> without all
400the bignum tags), and can be extended by user code as wlel, although,
401obviously, one should be very careful about adding decoding functions
402here, since the expectation is that they are safe to use on untrusted
403data, after all.
256 404
257Example: decode all tags not handled internally into C<CBOR::XS::Tagged> 405Example: decode all tags not handled internally into C<CBOR::XS::Tagged>
258objects, with no other special handling (useful when working with 406objects, with no other special handling (useful when working with
259potentially "unsafe" CBOR data). 407potentially "unsafe" CBOR data).
260 408
267 my ($tag, $value); 415 my ($tag, $value);
268 416
269 "tag 1347375694 value $value" 417 "tag 1347375694 value $value"
270 }; 418 };
271 419
420Example: provide your own filter function that looks up tags in your own
421hash:
422
423 my %my_filter = (
424 998347484 => sub {
425 my ($tag, $value);
426
427 "tag 998347484 value $value"
428 };
429 );
430
431 my $coder = CBOR::XS->new->filter (sub {
432 &{ $my_filter{$_[0]} or return }
433 });
434
435
436Example: use the safe filter function (see L<SECURITY CONSIDERATIONS> for
437more considerations on security).
438
439 CBOR::XS->new->filter (\&CBOR::XS::safe_filter)->decode ($cbor_data);
440
272=item $cbor_data = $cbor->encode ($perl_scalar) 441=item $cbor_data = $cbor->encode ($perl_scalar)
273 442
274Converts the given Perl data structure (a scalar value) to its CBOR 443Converts the given Perl data structure (a scalar value) to its CBOR
275representation. 444representation.
276 445
285when there is trailing garbage after the CBOR string, it will silently 454when there is trailing garbage after the CBOR string, it will silently
286stop parsing there and return the number of characters consumed so far. 455stop parsing there and return the number of characters consumed so far.
287 456
288This is useful if your CBOR texts are not delimited by an outer protocol 457This is useful if your CBOR texts are not delimited by an outer protocol
289and you need to know where the first CBOR string ends amd the next one 458and you need to know where the first CBOR string ends amd the next one
290starts. 459starts - CBOR strings are self-delimited, so it is possible to concatenate
460CBOR strings without any delimiters or size fields and recover their data.
291 461
292 CBOR::XS->new->decode_prefix ("......") 462 CBOR::XS->new->decode_prefix ("......")
293 => ("...", 3) 463 => ("...", 3)
464
465=back
466
467=head2 INCREMENTAL PARSING
468
469In some cases, there is the need for incremental parsing of JSON
470texts. While this module always has to keep both CBOR text and resulting
471Perl data structure in memory at one time, it does allow you to parse a
472CBOR stream incrementally, using a similar to using "decode_prefix" to see
473if a full CBOR object is available, but is much more efficient.
474
475It basically works by parsing as much of a CBOR string as possible - if
476the CBOR data is not complete yet, the pasrer will remember where it was,
477to be able to restart when more data has been accumulated. Once enough
478data is available to either decode a complete CBOR value or raise an
479error, a real decode will be attempted.
480
481A typical use case would be a network protocol that consists of sending
482and receiving CBOR-encoded messages. The solution that works with CBOR and
483about anything else is by prepending a length to every CBOR value, so the
484receiver knows how many octets to read. More compact (and slightly slower)
485would be to just send CBOR values back-to-back, as C<CBOR::XS> knows where
486a CBOR value ends, and doesn't need an explicit length.
487
488The following methods help with this:
489
490=over 4
491
492=item @decoded = $cbor->incr_parse ($buffer)
493
494This method attempts to decode exactly one CBOR value from the beginning
495of the given C<$buffer>. The value is removed from the C<$buffer> on
496success. When C<$buffer> doesn't contain a complete value yet, it returns
497nothing. Finally, when the C<$buffer> doesn't start with something
498that could ever be a valid CBOR value, it raises an exception, just as
499C<decode> would. In the latter case the decoder state is undefined and
500must be reset before being able to parse further.
501
502This method modifies the C<$buffer> in place. When no CBOR value can be
503decoded, the decoder stores the current string offset. On the next call,
504continues decoding at the place where it stopped before. For this to make
505sense, the C<$buffer> must begin with the same octets as on previous
506unsuccessful calls.
507
508You can call this method in scalar context, in which case it either
509returns a decoded value or C<undef>. This makes it impossible to
510distinguish between CBOR null values (which decode to C<undef>) and an
511unsuccessful decode, which is often acceptable.
512
513=item @decoded = $cbor->incr_parse_multiple ($buffer)
514
515Same as C<incr_parse>, but attempts to decode as many CBOR values as
516possible in one go, instead of at most one. Calls to C<incr_parse> and
517C<incr_parse_multiple> can be interleaved.
518
519=item $cbor->incr_reset
520
521Resets the incremental decoder. This throws away any saved state, so that
522subsequent calls to C<incr_parse> or C<incr_parse_multiple> start to parse
523a new CBOR value from the beginning of the C<$buffer> again.
524
525This method can be called at any time, but it I<must> be called if you want
526to change your C<$buffer> or there was a decoding error and you want to
527reuse the C<$cbor> object for future incremental parsings.
294 528
295=back 529=back
296 530
297 531
298=head1 MAPPING 532=head1 MAPPING
371 605
372=item hash references 606=item hash references
373 607
374Perl hash references become CBOR maps. As there is no inherent ordering in 608Perl hash references become CBOR maps. As there is no inherent ordering in
375hash keys (or CBOR maps), they will usually be encoded in a pseudo-random 609hash keys (or CBOR maps), they will usually be encoded in a pseudo-random
376order. This order can be different each time a hahs is encoded. 610order. This order can be different each time a hash is encoded.
377 611
378Currently, tied hashes will use the indefinite-length format, while normal 612Currently, tied hashes will use the indefinite-length format, while normal
379hashes will use the fixed-length format. 613hashes will use the fixed-length format.
380 614
381=item array references 615=item array references
434 my $x = 3.1; # some variable containing a number 668 my $x = 3.1; # some variable containing a number
435 "$x"; # stringified 669 "$x"; # stringified
436 $x .= ""; # another, more awkward way to stringify 670 $x .= ""; # another, more awkward way to stringify
437 print $x; # perl does it for you, too, quite often 671 print $x; # perl does it for you, too, quite often
438 672
439You can force whether a string ie encoded as byte or text string by using 673You can force whether a string is encoded as byte or text string by using
440C<utf8::upgrade> and C<utf8::downgrade>): 674C<utf8::upgrade> and C<utf8::downgrade> (if C<text_strings> is disabled).
441 675
442 utf8::upgrade $x; # encode $x as text string 676 utf8::upgrade $x; # encode $x as text string
443 utf8::downgrade $x; # encode $x as byte string 677 utf8::downgrade $x; # encode $x as byte string
444 678
679More options are available, see L<TYPE CASTS>, below, and the C<text_keys>
680and C<text_strings> options.
681
445Perl doesn't define what operations up- and downgrade strings, so if the 682Perl doesn't define what operations up- and downgrade strings, so if the
446difference between byte and text is important, you should up- or downgrade 683difference between byte and text is important, you should up- or downgrade
447your string as late as possible before encoding. 684your string as late as possible before encoding. You can also force the
685use of CBOR text strings by using C<text_keys> or C<text_strings>.
448 686
449You can force the type to be a CBOR number by numifying it: 687You can force the type to be a CBOR number by numifying it:
450 688
451 my $x = "3"; # some variable containing a string 689 my $x = "3"; # some variable containing a string
452 $x += 0; # numify it, ensuring it will be dumped as a number 690 $x += 0; # numify it, ensuring it will be dumped as a number
463represent numerical values are supported, but might suffer loss of 701represent numerical values are supported, but might suffer loss of
464precision. 702precision.
465 703
466=back 704=back
467 705
706=head2 TYPE CASTS
707
708B<EXPERIMENTAL>: As an experimental extension, C<CBOR::XS> allows you to
709force specific cbor types to be used when encoding. That allows you to
710encode types not normally accessible (e.g. half floats) as well as force
711string types even when C<text_strings> is in effect.
712
713Type forcing is done by calling a special "cast" function which keeps a
714copy of the value and returns a new value that can be handed over to any
715CBOR encoder function.
716
717The following casts are currently available (all of which are unary operators):
718
719=over
720
721=item CBOR::XS::as_int $value
722
723Forces the value to be encoded as some form of (basic, not bignum) integer
724type.
725
726=item CBOR::XS::as_text $value
727
728Forces the value to be encoded as (UTF-8) text values.
729
730=item CBOR::XS::as_bytes $value
731
732Forces the value to be encoded as a (binary) string value.
733
734Example: encode a perl string as binary even though C<text_strings> is in
735effect.
736
737 CBOR::XS->new->text_strings->encode ([4, "text", CBOR::XS::bytes "bytevalue"]);
738
739=item CBOR::XS::as_bool $value
740
741Converts a Perl boolean (which can be any kind of scalar) into a CBOR
742boolean. Strictly the same, but shorter to write, than:
743
744 $value ? Types::Serialiser::true : Types::Serialiser::false
745
746=item CBOR::XS::as_float16 $value
747
748Forces half-float (IEEE 754 binary16) encoding of the given value.
749
750=item CBOR::XS::as_float32 $value
751
752Forces single-float (IEEE 754 binary32) encoding of the given value.
753
754=item CBOR::XS::as_float64 $value
755
756Forces double-float (IEEE 754 binary64) encoding of the given value.
757
758=item CBOR::XS::as_cbor $cbor_text
759
760Not a type cast per-se, this type cast forces the argument to eb encoded
761as-is. This can be used to embed pre-encoded CBOR data.
762
763Note that no checking on the validity of the C<$cbor_text> is done - it's
764the callers responsibility to correctly encode values.
765
766=item CBOR::XS::as_map [key => value...]
767
768Treat the array reference as key value pairs and output a CBOR map. This
769allows you to generate CBOR maps with arbitrary key types (or, if you
770don't care about semantics, duplicate keys or prairs in a custom order),
771which is otherwise hard to do with Perl.
772
773The single argument must be an array reference with an even number of
774elements.
775
776Example: encode a CBOR map with a string and an integer as keys.
777
778 encode_cbor CBOR::XS::as_map [string => "value", 5 => "value"]
779
780=back
781
782=cut
783
784sub CBOR::XS::as_cbor ($) { bless [$_[0], 0, undef], CBOR::XS::Tagged:: }
785sub CBOR::XS::as_int ($) { bless [$_[0], 1, undef], CBOR::XS::Tagged:: }
786sub CBOR::XS::as_bytes ($) { bless [$_[0], 2, undef], CBOR::XS::Tagged:: }
787sub CBOR::XS::as_text ($) { bless [$_[0], 3, undef], CBOR::XS::Tagged:: }
788sub CBOR::XS::as_float16 ($) { bless [$_[0], 4, undef], CBOR::XS::Tagged:: }
789sub CBOR::XS::as_float32 ($) { bless [$_[0], 5, undef], CBOR::XS::Tagged:: }
790sub CBOR::XS::as_float64 ($) { bless [$_[0], 6, undef], CBOR::XS::Tagged:: }
791
792sub CBOR::XS::as_bool ($) { $_[0] ? $Types::Serialiser::true : $Types::Serialiser::false }
793
794sub CBOR::XS::as_map ($) {
795 ARRAY:: eq ref $_[0]
796 and $#{ $_[0] } & 1
797 or do { require Carp; Carp::croak ("CBOR::XS::as_map only acepts array references with an even number of elements, caught") };
798
799 bless [$_[0], 7, undef], CBOR::XS::Tagged::
800}
801
468=head2 OBJECT SERIALISATION 802=head2 OBJECT SERIALISATION
469 803
470This module implements both a CBOR-specific and the generic 804This module implements both a CBOR-specific and the generic
471L<Types::Serialier> object serialisation protocol. The following 805L<Types::Serialier> object serialisation protocol. The following
472subsections explain both methods. 806subsections explain both methods.
553 "$self" # encode url string 887 "$self" # encode url string
554 } 888 }
555 889
556 sub URI::THAW { 890 sub URI::THAW {
557 my ($class, $serialiser, $uri) = @_; 891 my ($class, $serialiser, $uri) = @_;
558
559 $class->new ($uri) 892 $class->new ($uri)
560 } 893 }
561 894
562Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For 895Unlike C<TO_CBOR>, multiple values can be returned by C<FREEZE>. For
563example, a C<FREEZE> method that returns "type", "id" and "variant" values 896example, a C<FREEZE> method that returns "type", "id" and "variant" values
694additional tags (such as base64url). 1027additional tags (such as base64url).
695 1028
696=head2 ENFORCED TAGS 1029=head2 ENFORCED TAGS
697 1030
698These tags are always handled when decoding, and their handling cannot be 1031These tags are always handled when decoding, and their handling cannot be
699overriden by the user. 1032overridden by the user.
700 1033
701=over 4 1034=over 4
702 1035
703=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>) 1036=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>)
704 1037
705These tags are automatically created (and decoded) for serialisable 1038These tags are automatically created (and decoded) for serialisable
706objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object 1039objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
707serialisation protocol). See L<OBJECT SERIALISATION> for details. 1040serialisation protocol). See L<OBJECT SERIALISATION> for details.
708 1041
709=item 28, 29 (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) 1042=item 28, 29 (shareable, sharedref, L<http://cbor.schmorp.de/value-sharing>)
710 1043
711These tags are automatically decoded when encountered, resulting in 1044These tags are automatically decoded when encountered (and they do not
1045result in a cyclic data structure, see C<allow_cycles>), resulting in
712shared values in the decoded object. They are only encoded, however, when 1046shared values in the decoded object. They are only encoded, however, when
713C<allow_sharable> is enabled. 1047C<allow_sharing> is enabled.
714 1048
1049Not all shared values can be successfully decoded: values that reference
1050themselves will I<currently> decode as C<undef> (this is not the same
1051as a reference pointing to itself, which will be represented as a value
1052that contains an indirect reference to itself - these will be decoded
1053properly).
1054
1055Note that considerably more shared value data structures can be decoded
1056than will be encoded - currently, only values pointed to by references
1057will be shared, others will not. While non-reference shared values can be
1058generated in Perl with some effort, they were considered too unimportant
1059to be supported in the encoder. The decoder, however, will decode these
1060values as shared values.
1061
715=item 256, 25 (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>) 1062=item 256, 25 (stringref-namespace, stringref, L<http://cbor.schmorp.de/stringref>)
716 1063
717These tags are automatically decoded when encountered. They are only 1064These tags are automatically decoded when encountered. They are only
718encoded, however, when C<pack_strings> is enabled. 1065encoded, however, when C<pack_strings> is enabled.
719 1066
720=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>) 1067=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
721 1068
722This tag is automatically generated when a reference are encountered (with 1069This tag is automatically generated when a reference are encountered (with
723the exception of hash and array refernces). It is converted to a reference 1070the exception of hash and array references). It is converted to a reference
724when decoding. 1071when decoding.
725 1072
726=item 55799 (self-describe CBOR, RFC 7049) 1073=item 55799 (self-describe CBOR, RFC 7049)
727 1074
728This value is not generated on encoding (unless explicitly requested by 1075This value is not generated on encoding (unless explicitly requested by
731=back 1078=back
732 1079
733=head2 NON-ENFORCED TAGS 1080=head2 NON-ENFORCED TAGS
734 1081
735These tags have default filters provided when decoding. Their handling can 1082These 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 1083be overridden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
737providing a custom C<filter> callback when decoding. 1084providing a custom C<filter> callback when decoding.
738 1085
739When they result in decoding into a specific Perl class, the module 1086When they result in decoding into a specific Perl class, the module
740usually provides a corresponding C<TO_CBOR> method as well. 1087usually provides a corresponding C<TO_CBOR> method as well.
741 1088
744provide these modules. The decoding usually fails with an exception if the 1091provide these modules. The decoding usually fails with an exception if the
745required module cannot be loaded. 1092required module cannot be loaded.
746 1093
747=over 4 1094=over 4
748 1095
1096=item 0, 1 (date/time string, seconds since the epoch)
1097
1098These tags are decoded into L<Time::Piece> objects. The corresponding
1099C<Time::Piece::TO_CBOR> method always encodes into tag 1 values currently.
1100
1101The L<Time::Piece> API is generally surprisingly bad, and fractional
1102seconds are only accidentally kept intact, so watch out. On the plus side,
1103the module comes with perl since 5.10, which has to count for something.
1104
749=item 2, 3 (positive/negative bignum) 1105=item 2, 3 (positive/negative bignum)
750 1106
751These tags are decoded into L<Math::BigInt> objects. The corresponding 1107These tags are decoded into L<Math::BigInt> objects. The corresponding
752C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR 1108C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
753integers, and others into positive/negative CBOR bignums. 1109integers, and others into positive/negative CBOR bignums.
754 1110
755=item 4, 5 (decimal fraction/bigfloat) 1111=item 4, 5, 264, 265 (decimal fraction/bigfloat)
756 1112
757Both decimal fractions and bigfloats are decoded into L<Math::BigFloat> 1113Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
758objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always> 1114objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
759encodes into a decimal fraction. 1115encodes into a decimal fraction (either tag 4 or 264).
760 1116
761CBOR cannot represent bigfloats with I<very> large exponents - conversion 1117NaN and infinities are not encoded properly, as they cannot be represented
762of such big float objects is undefined. 1118in CBOR.
763 1119
764Also, NaN and infinities are not encoded properly. 1120See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
1121
1122=item 30 (rational numbers)
1123
1124These tags are decoded into L<Math::BigRat> objects. The corresponding
1125C<Math::BigRat::TO_CBOR> method encodes rational numbers with denominator
1126C<1> via their numerator only, i.e., they become normal integers or
1127C<bignums>.
1128
1129See L<BIGNUM SECURITY CONSIDERATIONS> for more info.
765 1130
766=item 21, 22, 23 (expected later JSON conversion) 1131=item 21, 22, 23 (expected later JSON conversion)
767 1132
768CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these 1133CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
769tags. 1134tags.
774C<URI::TO_CBOR> method again results in a CBOR URI value. 1139C<URI::TO_CBOR> method again results in a CBOR URI value.
775 1140
776=back 1141=back
777 1142
778=cut 1143=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 1144
822=head1 CBOR and JSON 1145=head1 CBOR and JSON
823 1146
824CBOR is supposed to implement a superset of the JSON data model, and is, 1147CBOR 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 1148with some coercion, able to represent all JSON texts (something that other
834CBOR intact. 1157CBOR intact.
835 1158
836 1159
837=head1 SECURITY CONSIDERATIONS 1160=head1 SECURITY CONSIDERATIONS
838 1161
839When you are using CBOR in a protocol, talking to untrusted potentially 1162Tl;dr... if you want to decode or encode CBOR from untrusted sources, you
840hostile creatures requires relatively few measures. 1163should start with a coder object created via C<new_safe> (which implements
1164the mitigations explained below):
841 1165
1166 my $coder = CBOR::XS->new_safe;
1167
1168 my $data = $coder->decode ($cbor_text);
1169 my $cbor = $coder->encode ($data);
1170
1171Longer version: When you are using CBOR in a protocol, talking to
1172untrusted potentially hostile creatures requires some thought:
1173
1174=over 4
1175
1176=item Security of the CBOR decoder itself
1177
842First of all, your CBOR decoder should be secure, that is, should not have 1178First and foremost, your CBOR decoder should be secure, that is, should
1179not have any buffer overflows or similar bugs that could potentially be
843any buffer overflows. Obviously, this module should ensure that and I am 1180exploited. Obviously, this module should ensure that and I am trying hard
844trying hard on making that true, but you never know. 1181on making that true, but you never know.
845 1182
1183=item CBOR::XS can invoke almost arbitrary callbacks during decoding
1184
1185CBOR::XS supports object serialisation - decoding CBOR can cause calls
1186to I<any> C<THAW> method in I<any> package that exists in your process
1187(that is, CBOR::XS will not try to load modules, but any existing C<THAW>
1188method or function can be called, so they all have to be secure).
1189
1190Less obviously, it will also invoke C<TO_CBOR> and C<FREEZE> methods -
1191even if all your C<THAW> methods are secure, encoding data structures from
1192untrusted sources can invoke those and trigger bugs in those.
1193
1194So, if you are not sure about the security of all the modules you
1195have loaded (you shouldn't), you should disable this part using
1196C<forbid_objects> or using C<new_safe>.
1197
1198=item CBOR can be extended with tags that call library code
1199
1200CBOR can be extended with tags, and C<CBOR::XS> has a registry of
1201conversion functions for many existing tags that can be extended via
1202third-party modules (see the C<filter> method).
1203
1204If you don't trust these, you should configure the "safe" filter function,
1205C<CBOR::XS::safe_filter> (C<new_safe> does this), which by default only
1206includes conversion functions that are considered "safe" by the author
1207(but again, they can be extended by third party modules).
1208
1209Depending on your level of paranoia, you can use the "safe" filter:
1210
1211 $cbor->filter (\&CBOR::XS::safe_filter);
1212
1213... your own filter...
1214
1215 $cbor->filter (sub { ... do your stuffs here ... });
1216
1217... or even no filter at all, disabling all tag decoding:
1218
1219 $cbor->filter (sub { });
1220
1221This is never a problem for encoding, as the tag mechanism only exists in
1222CBOR texts.
1223
1224=item Resource-starving attacks: object memory usage
1225
846Second, you need to avoid resource-starving attacks. That means you should 1226You 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 1227the 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 1228run 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 1229crash 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 1230indication 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 1231structure. 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 1232C<max_size> - done by C<new_safe>), it might be too late when you already
853the size before you accept the string. 1233have it in memory, so you might want to check the size before you accept
1234the string.
854 1235
1236As for encoding, it is possible to construct data structures that are
1237relatively small but result in large CBOR texts (for example by having an
1238array full of references to the same big data structure, which will all be
1239deep-cloned during encoding by default). This is rarely an actual issue
1240(and the worst case is still just running out of memory), but you can
1241reduce this risk by using C<allow_sharing>.
1242
1243=item Resource-starving attacks: stack overflows
1244
855Third, CBOR::XS recurses using the C stack when decoding objects and 1245CBOR::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 1246C 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 1247of 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 1248CBOR 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 1249temporary). If that is exceeded, the program crashes. To be conservative,
860conservative, the default nesting limit is set to 512. If your process 1250the 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 1251stack, you should adjust this setting accordingly with the C<max_depth>
862C<max_depth> method. 1252method.
1253
1254=item Resource-starving attacks: CPU en-/decoding complexity
1255
1256CBOR::XS will use the L<Math::BigInt>, L<Math::BigFloat> and
1257L<Math::BigRat> libraries to represent encode/decode bignums. These can be
1258very slow (as in, centuries of CPU time) and can even crash your program
1259(and are generally not very trustworthy). See the next section on bignum
1260security for details.
1261
1262=item Data breaches: leaking information in error messages
1263
1264CBOR::XS might leak contents of your Perl data structures in its error
1265messages, so when you serialise sensitive information you might want to
1266make sure that exceptions thrown by CBOR::XS will not end up in front of
1267untrusted eyes.
1268
1269=item Something else...
863 1270
864Something else could bomb you, too, that I forgot to think of. In that 1271Something 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... 1272case, you get to keep the pieces. I am always open for hints, though...
866 1273
867Also keep in mind that CBOR::XS might leak contents of your Perl data 1274=back
868structures in its error messages, so when you serialise sensitive 1275
869information you might want to make sure that exceptions thrown by CBOR::XS 1276
870will not end up in front of untrusted eyes. 1277=head1 BIGNUM SECURITY CONSIDERATIONS
1278
1279CBOR::XS provides a C<TO_CBOR> method for both L<Math::BigInt> and
1280L<Math::BigFloat> that tries to encode the number in the simplest possible
1281way, that is, either a CBOR integer, a CBOR bigint/decimal fraction (tag
12824) or an arbitrary-exponent decimal fraction (tag 264). Rational numbers
1283(L<Math::BigRat>, tag 30) can also contain bignums as members.
1284
1285CBOR::XS will also understand base-2 bigfloat or arbitrary-exponent
1286bigfloats (tags 5 and 265), but it will never generate these on its own.
1287
1288Using the built-in L<Math::BigInt::Calc> support, encoding and decoding
1289decimal fractions is generally fast. Decoding bigints can be slow for very
1290big numbers (tens of thousands of digits, something that could potentially
1291be caught by limiting the size of CBOR texts), and decoding bigfloats or
1292arbitrary-exponent bigfloats can be I<extremely> slow (minutes, decades)
1293for large exponents (roughly 40 bit and longer).
1294
1295Additionally, L<Math::BigInt> can take advantage of other bignum
1296libraries, such as L<Math::GMP>, which cannot handle big floats with large
1297exponents, and might simply abort or crash your program, due to their code
1298quality.
1299
1300This can be a concern if you want to parse untrusted CBOR. If it is, you
1301might want to disable decoding of tag 2 (bigint) and 3 (negative bigint)
1302types. You should also disable types 5 and 265, as these can be slow even
1303without bigints.
1304
1305Disabling bigints will also partially or fully disable types that rely on
1306them, e.g. rational numbers that use bignums.
1307
871 1308
872=head1 CBOR IMPLEMENTATION NOTES 1309=head1 CBOR IMPLEMENTATION NOTES
873 1310
874This section contains some random implementation notes. They do not 1311This section contains some random implementation notes. They do not
875describe guaranteed behaviour, but merely behaviour as-is implemented 1312describe guaranteed behaviour, but merely behaviour as-is implemented
889 1326
890 1327
891=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT 1328=head1 LIMITATIONS ON PERLS WITHOUT 64-BIT INTEGER SUPPORT
892 1329
893On perls that were built without 64 bit integer support (these are rare 1330On perls that were built without 64 bit integer support (these are rare
894nowadays, even on 32 bit architectures), support for any kind of 64 bit 1331nowadays, even on 32 bit architectures, as all major Perl distributions
1332are built with 64 bit integer support), support for any kind of 64 bit
895integer in CBOR is very limited - most likely, these 64 bit values will 1333value in CBOR is very limited - most likely, these 64 bit values will
896be truncated, corrupted, or otherwise not decoded correctly. This also 1334be truncated, corrupted, or otherwise not decoded correctly. This also
897includes string, array and map sizes that are stored as 64 bit integers. 1335includes string, float, array and map sizes that are stored as 64 bit
1336integers.
898 1337
899 1338
900=head1 THREADS 1339=head1 THREADS
901 1340
902This module is I<not> guaranteed to be thread safe and there are no 1341This module is I<not> guaranteed to be thread safe and there are no
916Please refrain from using rt.cpan.org or any other bug reporting 1355Please refrain from using rt.cpan.org or any other bug reporting
917service. I put the contact address into my modules for a reason. 1356service. I put the contact address into my modules for a reason.
918 1357
919=cut 1358=cut
920 1359
1360# clumsy and slow hv_store-in-hash helper function
1361sub _hv_store {
1362 $_[0]{$_[1]} = $_[2];
1363}
1364
921our %FILTER = ( 1365our %FILTER = (
922 # 0 # rfc4287 datetime, utf-8 1366 0 => sub { # rfc4287 datetime, utf-8
923 # 1 # unix timestamp, any 1367 require Time::Piece;
1368 # Time::Piece::Strptime uses the "incredibly flexible date parsing routine"
1369 # from FreeBSD, which can't parse ISO 8601, RFC3339, RFC4287 or much of anything
1370 # else either. Whats incredibe over standard strptime totally escapes me.
1371 # doesn't do fractional times, either. sigh.
1372 # In fact, it's all a lie, it uses whatever strptime it wants, and of course,
1373 # they are all incompatible. The openbsd one simply ignores %z (but according to the
1374 # docs, it would be much more incredibly flexible indeed. If it worked, that is.).
1375 scalar eval {
1376 my $s = $_[1];
1377
1378 $s =~ s/Z$/+00:00/;
1379 $s =~ s/(\.[0-9]+)?([+-][0-9][0-9]):([0-9][0-9])$//
1380 or die;
1381
1382 my $b = $1 - ($2 * 60 + $3) * 60; # fractional part + offset. hopefully
1383 my $d = Time::Piece->strptime ($s, "%Y-%m-%dT%H:%M:%S");
1384
1385 Time::Piece::gmtime ($d->epoch + $b)
1386 } || die "corrupted CBOR date/time string ($_[0])";
1387 },
1388
1389 1 => sub { # seconds since the epoch, possibly fractional
1390 require Time::Piece;
1391 scalar Time::Piece::gmtime (pop)
1392 },
924 1393
925 2 => sub { # pos bigint 1394 2 => sub { # pos bigint
926 require Math::BigInt; 1395 require Math::BigInt;
927 Math::BigInt->new ("0x" . unpack "H*", pop) 1396 Math::BigInt->new ("0x" . unpack "H*", pop)
928 }, 1397 },
935 4 => sub { # decimal fraction, array 1404 4 => sub { # decimal fraction, array
936 require Math::BigFloat; 1405 require Math::BigFloat;
937 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0]) 1406 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
938 }, 1407 },
939 1408
1409 264 => sub { # decimal fraction with arbitrary exponent
1410 require Math::BigFloat;
1411 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
1412 },
1413
940 5 => sub { # bigfloat, array 1414 5 => sub { # bigfloat, array
941 require Math::BigFloat; 1415 require Math::BigFloat;
942 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2) 1416 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1417 },
1418
1419 265 => sub { # bigfloat with arbitrary exponent
1420 require Math::BigFloat;
1421 scalar Math::BigFloat->new ($_[1][1]) * Math::BigFloat->new (2)->bpow ($_[1][0])
1422 },
1423
1424 30 => sub { # rational number
1425 require Math::BigRat;
1426 Math::BigRat->new ("$_[1][0]/$_[1][1]") # separate parameters only work in recent versons
943 }, 1427 },
944 1428
945 21 => sub { pop }, # expected conversion to base64url encoding 1429 21 => sub { pop }, # expected conversion to base64url encoding
946 22 => sub { pop }, # expected conversion to base64 encoding 1430 22 => sub { pop }, # expected conversion to base64 encoding
947 23 => sub { pop }, # expected conversion to base16 encoding 1431 23 => sub { pop }, # expected conversion to base16 encoding
957 # 34 # base64 rfc46484, utf-8 1441 # 34 # base64 rfc46484, utf-8
958 # 35 # regex pcre/ecma262, utf-8 1442 # 35 # regex pcre/ecma262, utf-8
959 # 36 # mime message rfc2045, utf-8 1443 # 36 # mime message rfc2045, utf-8
960); 1444);
961 1445
962sub CBOR::XS::default_filter { 1446sub default_filter {
963 &{ $FILTER{$_[0]} or return } 1447 &{ $FILTER{$_[0]} or return }
1448}
1449
1450our %SAFE_FILTER = map { $_ => $FILTER{$_} } 0, 1, 21, 22, 23, 32;
1451
1452sub safe_filter {
1453 &{ $SAFE_FILTER{$_[0]} or return }
964} 1454}
965 1455
966sub URI::TO_CBOR { 1456sub URI::TO_CBOR {
967 my $uri = $_[0]->as_string; 1457 my $uri = $_[0]->as_string;
968 utf8::upgrade $uri; 1458 utf8::upgrade $uri;
969 CBOR::XS::tag 32, $uri 1459 tag 32, $uri
970} 1460}
971 1461
972sub Math::BigInt::TO_CBOR { 1462sub Math::BigInt::TO_CBOR {
973 if ($_[0] >= -2147483648 && $_[0] <= 2147483647) { 1463 if (-2147483648 <= $_[0] && $_[0] <= 2147483647) {
974 $_[0]->numify 1464 $_[0]->numify
975 } else { 1465 } else {
976 my $hex = substr $_[0]->as_hex, 2; 1466 my $hex = substr $_[0]->as_hex, 2;
977 $hex = "0$hex" if 1 & length $hex; # sigh 1467 $hex = "0$hex" if 1 & length $hex; # sigh
978 CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex 1468 tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
979 } 1469 }
980} 1470}
981 1471
982sub Math::BigFloat::TO_CBOR { 1472sub Math::BigFloat::TO_CBOR {
983 my ($m, $e) = $_[0]->parts; 1473 my ($m, $e) = $_[0]->parts;
1474
1475 -9223372036854775808 <= $e && $e <= 18446744073709551615
984 CBOR::XS::tag 4, [$e->numify, $m] 1476 ? tag 4, [$e->numify, $m]
1477 : tag 264, [$e, $m]
1478}
1479
1480sub Math::BigRat::TO_CBOR {
1481 my ($n, $d) = $_[0]->parts;
1482
1483 # older versions of BigRat need *1, as they not always return numbers
1484
1485 $d*1 == 1
1486 ? $n*1
1487 : tag 30, [$n*1, $d*1]
1488}
1489
1490sub Time::Piece::TO_CBOR {
1491 tag 1, 0 + $_[0]->epoch
985} 1492}
986 1493
987XSLoader::load "CBOR::XS", $VERSION; 1494XSLoader::load "CBOR::XS", $VERSION;
988 1495
989=head1 SEE ALSO 1496=head1 SEE ALSO

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