… | |
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101 | |
101 | |
102 | package JSON::XS; |
102 | package JSON::XS; |
103 | |
103 | |
104 | use common::sense; |
104 | use common::sense; |
105 | |
105 | |
106 | our $VERSION = 3.01; |
106 | our $VERSION = 3.02; |
107 | our @ISA = qw(Exporter); |
107 | our @ISA = qw(Exporter); |
108 | |
108 | |
109 | our @EXPORT = qw(encode_json decode_json); |
109 | our @EXPORT = qw(encode_json decode_json); |
110 | |
110 | |
111 | use Exporter; |
111 | use Exporter; |
… | |
… | |
402 | character, after which more white-space and comments are allowed. |
402 | character, after which more white-space and comments are allowed. |
403 | |
403 | |
404 | [ |
404 | [ |
405 | 1, # this comment not allowed in JSON |
405 | 1, # this comment not allowed in JSON |
406 | # neither this one... |
406 | # neither this one... |
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407 | ] |
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408 | |
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409 | =item * literal ASCII TAB characters in strings |
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410 | |
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411 | Literal ASCII TAB characters are now allowed in strings (and treated as |
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412 | C<\t>). |
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413 | |
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414 | [ |
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415 | "Hello\tWorld", |
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416 | "Hello<TAB>World", # literal <TAB> would not normally be allowed |
407 | ] |
417 | ] |
408 | |
418 | |
409 | =back |
419 | =back |
410 | |
420 | |
411 | =item $json = $json->canonical ([$enable]) |
421 | =item $json = $json->canonical ([$enable]) |
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… | |
687 | |
697 | |
688 | This is useful if your JSON texts are not delimited by an outer protocol |
698 | This is useful if your JSON texts are not delimited by an outer protocol |
689 | and you need to know where the JSON text ends. |
699 | and you need to know where the JSON text ends. |
690 | |
700 | |
691 | JSON::XS->new->decode_prefix ("[1] the tail") |
701 | JSON::XS->new->decode_prefix ("[1] the tail") |
692 | => ([], 3) |
702 | => ([1], 3) |
693 | |
703 | |
694 | =back |
704 | =back |
695 | |
705 | |
696 | |
706 | |
697 | =head1 INCREMENTAL PARSING |
707 | =head1 INCREMENTAL PARSING |
… | |
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1553 | are browser design bugs, but it is still you who will have to deal with |
1563 | are browser design bugs, but it is still you who will have to deal with |
1554 | it, as major browser developers care only for features, not about getting |
1564 | it, as major browser developers care only for features, not about getting |
1555 | security right). |
1565 | security right). |
1556 | |
1566 | |
1557 | |
1567 | |
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1568 | =head1 "OLD" VS. "NEW" JSON (RFC 4627 VS. RFC 7159) |
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1569 | |
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1570 | TL;DR: Due to security concerns, JSON::XS will not allow scalar data in |
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1571 | JSON texts by default - you need to create your own JSON::XS object and |
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1572 | enable C<allow_nonref>: |
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1573 | |
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1574 | |
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1575 | my $json = JSON::XS->new->allow_nonref; |
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1576 | |
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1577 | $text = $json->encode ($data); |
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1578 | $data = $json->decode ($text); |
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1579 | |
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1580 | The long version: JSON being an important and supposedly stable format, |
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1581 | the IETF standardised it as RFC 4627 in 2006. Unfortunately, the inventor |
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1582 | of JSON, Dougles Crockford, unilaterally changed the definition of JSON in |
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1583 | javascript. Rather than create a fork, the IETF decided to standardise the |
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1584 | new syntax (apparently, so Iw as told, without finding it very amusing). |
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1585 | |
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1586 | The biggest difference between thed original JSON and the new JSON is that |
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1587 | the new JSON supports scalars (anything other than arrays and objects) at |
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1588 | the toplevel of a JSON text. While this is strictly backwards compatible |
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1589 | to older versions, it breaks a number of protocols that relied on sending |
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1590 | JSON back-to-back, and is a minor security concern. |
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1591 | |
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1592 | For example, imagine you have two banks communicating, and on one side, |
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1593 | trhe JSON coder gets upgraded. Two messages, such as C<10> and C<1000> |
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1594 | might then be confused to mean C<101000>, something that couldn't happen |
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1595 | in the original JSON, because niether of these messages would be valid |
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1596 | JSON. |
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1597 | |
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1598 | If one side accepts these messages, then an upgrade in the coder on either |
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1599 | side could result in this becoming exploitable. |
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1600 | |
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1601 | This module has always allowed these messages as an optional extension, by |
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1602 | default disabled. The security concerns are the reason why the default is |
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1603 | still disabled, but future versions might/will likely upgrade to the newer |
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1604 | RFC as default format, so you are advised to check your implementation |
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1605 | and/or override the default with C<< ->allow_nonref (0) >> to ensure that |
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1606 | future versions are safe. |
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1607 | |
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1608 | |
1558 | =head1 INTEROPERABILITY WITH OTHER MODULES |
1609 | =head1 INTEROPERABILITY WITH OTHER MODULES |
1559 | |
1610 | |
1560 | C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean |
1611 | C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean |
1561 | constants. That means that the JSON true and false values will be |
1612 | constants. That means that the JSON true and false values will be |
1562 | comaptible to true and false values of iother modules that do the same, |
1613 | comaptible to true and false values of iother modules that do the same, |
… | |
… | |
1612 | |
1663 | |
1613 | And after decoding the JSON text, you could walk the data |
1664 | And after decoding the JSON text, you could walk the data |
1614 | structure looking for arrays with a first element of |
1665 | structure looking for arrays with a first element of |
1615 | C<XU1peReLzT4ggEllLanBYq4G9VzliwKF>. |
1666 | C<XU1peReLzT4ggEllLanBYq4G9VzliwKF>. |
1616 | |
1667 | |
1617 | The same approach cna be used to create the tagged format with another |
1668 | The same approach can be used to create the tagged format with another |
1618 | encoder. First, you create an array with the magic string as first member, |
1669 | encoder. First, you create an array with the magic string as first member, |
1619 | the classname as second, and constructor arguments last, encode it as part |
1670 | the classname as second, and constructor arguments last, encode it as part |
1620 | of your JSON structure, and then: |
1671 | of your JSON structure, and then: |
1621 | |
1672 | |
1622 | $json =~ s/\[\s*"XU1peReLzT4ggEllLanBYq4G9VzliwKF"\s*,\s*("([^\\":,]+|\\.|::)*")\s*,/($1)[/g; |
1673 | $json =~ s/\[\s*"XU1peReLzT4ggEllLanBYq4G9VzliwKF"\s*,\s*("([^\\":,]+|\\.|::)*")\s*,/($1)[/g; |
1623 | |
1674 | |
1624 | Again, this has some limitations - the magic string must not be encoded |
1675 | Again, this has some limitations - the magic string must not be encoded |
1625 | with character escapes, and the constructor arguments must be non-empty. |
1676 | with character escapes, and the constructor arguments must be non-empty. |
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1677 | |
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1678 | |
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1679 | =head1 RFC7159 |
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1680 | |
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1681 | Since this module was written, Google has written a new JSON RFC, RFC 7159 |
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1682 | (and RFC7158). Unfortunately, this RFC breaks compatibility with both the |
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1683 | original JSON specification on www.json.org and RFC4627. |
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1684 | |
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1685 | As far as I can see, you can get partial compatibility when parsing by |
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1686 | using C<< ->allow_nonref >>. However, consider thew security implications |
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1687 | of doing so. |
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1688 | |
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1689 | I haven't decided yet when to break compatibility with RFC4627 by default |
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1690 | (and potentially leave applications insecure) and change the default to |
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1691 | follow RFC7159, but application authors are well advised to call C<< |
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1692 | ->allow_nonref(0) >> even if this is the current default, if they cannot |
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1693 | handle non-reference values, in preparation for the day when the4 default |
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1694 | will change. |
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1695 | |
1626 | |
1696 | |
1627 | =head1 THREADS |
1697 | =head1 THREADS |
1628 | |
1698 | |
1629 | This module is I<not> guaranteed to be thread safe and there are no |
1699 | This module is I<not> guaranteed to be thread safe and there are no |
1630 | plans to change this until Perl gets thread support (as opposed to the |
1700 | plans to change this until Perl gets thread support (as opposed to the |