Commit Graph
22 Commits
Author SHA1 Message Date
Niels Lohmann 44f8ec30e9 Bound UBJSON optimized arrays of a valueless type (#5504)
* Bound UBJSON optimized arrays of a valueless type

An element of type 'Z' (null), 'T' (true) or 'F' (false) is encoded by its
type marker alone, so an optimized UBJSON array of one of those has no
payload: reading an element consumes no input at all. Its declared count is
therefore the only thing that decides how much is allocated, and nothing
bounded it. "[$Z#l" and a four-byte count is nine bytes of input describing
two billion values; #2793 reports 35 GB and 150 seconds from ten bytes, and
OSS-Fuzz has an out-of-memory and a timeout report for the same shape.

Every other type costs at least one byte per element, so the end of the input
bounds it. 'N' (no-op) is already skipped rather than stored. Objects are not
affected either: each element is preceded by its key, which costs bytes. And
BJData already refuses these markers as an optimized type, so this is a plain
UBJSON matter.

Reject a count above 1,048,576 elements for those three types with
out_of_range.408, the code this reader already uses for a declared size it
will not honour. The check runs before the SAX start event, so no container
is opened and then abandoned.

Rejecting on the read side alone would break the guarantee that anything
to_ubjson() writes can be read back, and would trip the round-trip assertion
in fuzzer-parse_ubjson.cpp. So the writer falls back to the unoptimized
encoding, one byte per element, for arrays of these types above the same
limit. Its decision depends only on the array's size, which is identical for
a value and for anything parsed back from it, so the round trip is stable.

No existing test changes: the largest such count in the test suite is 65,793.
The excessive-size test that already used this shape still passes, now
rejected a little earlier than by the max_size() check it used to reach.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Note the 1,048,576 valueless-array limit as (1 << 20) in the docs

Addresses review feedback from @gregmarr on PR #5504: spell out the
binary/hex form next to the decimal count so it reads as the round
power-of-two it is, matching how include/nlohmann/detail/input/binary_reader.hpp
defines max_valueless_container_size. Applied in both docs/exceptions.md
and ubjson.md, as requested.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-11 08:34:42 +02:00
Niels Lohmann 8c38e270b5 Reject JSON Patch move when from is a proper prefix of path (#5497)
* Reject JSON Patch move when from is a proper prefix of path

RFC 6902 (section 4.4) forbids "from" from being a proper prefix of
"path" for a "move" operation: "a location cannot be moved into one
of its children." "move" is implemented as remove-then-add with no
check for this. For object targets, the subsequent "add" happened to
throw as a side effect of resolving through the now-removed parent,
but for array targets, removing the "from" element shifts subsequent
indices, so "path" silently re-resolves to a different element and
the operation "succeeds" with a silently corrupted document.

Add a check, before performing the remove/add, for whether "from" is
a proper prefix of "path" at the reference-token level. This compares
json_pointer's already-unescaped reference_tokens vectors (basic_json
is a friend of json_pointer) rather than the raw pointer strings, so
that tokens containing escaped '/' or '~' characters are compared
correctly, and a token that merely looks like a string prefix (e.g.
"/ab" vs "/abc/x") is not mistaken for a pointer-token prefix. When
"from" is a proper prefix of "path", throw out_of_range.414.

Fixes #5397.

Stacked on top of the fix for #5396 (branch
issue-5396-patch-remove-primitive-parent), since both touch the same
patch_inplace move/remove handling in include/nlohmann/json.hpp.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Add root-pointer and array-append-token edge case tests for the move prefix check

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Replace std::equal with an explicitly-bounded loop in the move prefix check

The three-iterator std::equal(first1, last1, first2) form has no
explicit end iterator for the second range, which a static analyzer
(Flawfinder, CWE-126) flags as a potential over-read even though the
preceding size comparison already guarantees the second range is long
enough. Rather than argue the point, make the bound visible in the code
itself via an explicit loop -- every access to ptr.reference_tokens is
now guarded by the same index the loop condition bounds against
from_size.

(The C++14 four-iterator std::equal(first1, last1, first2, last2) form
was tried first as a more minimal fix, but this codebase targets C++11
and that overload is not safely usable under -std=c++11 with all
supported standard library implementations.)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Extract the move prefix check into a named helper lambda

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Account for JSON_DIAGNOSTIC_POSITIONS in the move-prefix-check error messages

out_of_range::create() includes a "(bytes X-Y)" position annotation when
JSON_DIAGNOSTIC_POSITIONS is enabled, which the ci_test_diagnostic_positions
CI job builds the whole suite with. The five new out_of_range.414
assertions only checked the annotation-free message. Confirmed
JSON_DIAGNOSTICS produces the same (annotation-free) message as the
default build for this particular throw site (its path-based annotation
is empty at the root, where &result always points here), so only two
message variants are needed, not three.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-09 09:49:12 +02:00
Niels Lohmann c9477ccf91 Throw when JSON Patch remove's target path resolves through a primitive or null parent (#5496)
RFC 6902 (section 4.2) requires the target location of a "remove"
operation to exist. operation_remove handled parent.is_object() and
parent.is_array(), but had no final else branch: when the resolved
parent was a primitive value or null, neither branch matched and the
operation silently did nothing instead of failing.

Add the missing else branch, throwing out_of_range.413 with wording
that matches the existing out_of_range.411 thrown by the analogous
"add" case (operation_add) for the same kind of invalid parent.

Fixes #5396.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-09 09:49:12 +02:00
Krishnanand G 2f025f401e Throw other_error.502 when UBJSON use_type is set without use_size (#5380)
* Throw other_error.502 when UBJSON use_type is set without use_size

Fixes #5321

Signed-off-by: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>

* Scope UBJSON use_type check to container branches and expand tests

Signed-off-by: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>

* Re-amalgamate single_include/json.hpp

The previous commit updated the split headers but the amalgamated
file didn't go back through astyle before I committed it, so CI's
amalgamation check caught formatting drift in json_fwd.hpp and a
few noexcept clauses in basic_json, plus one doc example. None of
it touches the UBJSON logic. Applied the patch CI generated to
bring single_include back in sync.

Signed-off-by: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>

---------

Signed-off-by: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>
2026-08-25 07:16:10 +01:00
Niels Lohmann 173f2a7407 Documentation review: exceptions from binary-format hardening, and tuple reference types (#5359)
* 📝 Document exceptions newly thrown by the binary-format hardening

A round of binary-format input validation (#5274, #5284, #5287, #5332)
added new failure modes without updating exceptions.md, and left two
descriptions factually narrower than the code:

- parse_error.110 said "CBOR or MessagePack"; BSON and UBJSON also
  throw it. Generalized, and added the BSON EOF example (#5332).
- parse_error.112: added the BSON document-size mismatch example
  (#5287).
- parse_error.113 said "while parsing a map key", but its own existing
  UBJSON char example already contradicted that. Broadened to cover
  invalid length specifications, and added the negative-string-length
  example (#5284).
- out_of_range.408 said "of an UBJSON array or object"; CBOR now throws
  it too (#5274). Generalized and added both CBOR examples.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* 📝 Correct which types may be referenced in a tuple extraction

The note added in #5271 said a referenced type must be one the library
stores "or an arithmetic type it can convert to/from". The parenthetical
is wrong: is_compatible_reference_type requires an exact match against
the stored types, so std::tuple<int&> is rejected by static_assert even
though int converts fine as a value. Only the value case is permissive.

Spell out the eight admissible types, give the int& counter-example, and
separate the reference restriction from by-value conversion.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-08-04 08:45:18 +02:00
Luke Banicevic 2e23687092 to_bson() silently emits corrupt documents when a length exceeds INT32_MAX (#5314) 2026-07-28 09:08:57 +00:00
Niels Lohmann 521a084827 Documentation review (#5257)
* 📝 Fix documentation gaps for 3.13.0 release (todos 138-142)

- Todo 138: Add "Known issues" section to modules.md with compiler-specific troubleshooting (GCC redefinition, MSVC symbol export). Add pointer note to quality_assurance.md.
- Todo 139: Document CBOR/MessagePack half-precision float encoding for NaN/Infinity (0xF9/0xCA with exact byte sequences). Explain pre-3.13.0 double-precision bug mechanism without issue citations.
- Todo 140: Document CBOR negative-integer-overflow rejection (parse_error.112) for magnitudes exceeding int64_t range (already implemented in rev 1).
- Todo 141: Update version history in value.md and operator[].md with behavior-change details, removing issue citations per citation policy (prose is self-contained).
- Todo 142: Global sed replace of 3.12.x → 3.13.0 placeholder across all 20 documentation files.

Revision 2 incorporates feedback to reduce changelog-like issue citations. Only citations that add unique troubleshooting value are retained (#5103 for GCC workaround, #3970 for MSVC symbol export). "Known issues" section follows PR #5252's visual pattern (info admonition with bold-bullet format).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* 📝 Document integer type selection, type_name() invalid value, and std::optional get() fix

- number_handling.md: clarify that positive/negative integers select
  unsigned/signed storage based on the leading minus sign (todo 143).
- type_name.md: document the new "invalid" return value for corrupted
  JSON values (todo 145).
- get.md: note that get<std::optional<T>>() was unreachable in every
  configuration prior to 3.13.0 due to an internal macro-guard bug,
  unrelated to JSON_USE_IMPLICIT_CONVERSIONS's actual effect (todo 144).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-09 17:24:19 +02:00
Niels Lohmann 730b57775d 🐛 avoid assertion in patch (#5222) 2026-07-01 06:47:24 +02:00
Niels Lohmann c5b2b26fdc 📝 fix docs (#5217) 2026-06-29 22:15:18 +02:00
Caillin NugentandNiels Lohmann 58cfecf7f7 Serialize enum (#5151)
* Added NLOHNMANN_JSON_SERIALIZE_ENUM_STRICT
- duplicate of NLOHMANN_JSON_SERIALIZE_ENUM

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* Added failing tests for NLOHMANN_JSON_SERIALIZE_ENUM_STRICT

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* modified NLOHMANN_JSON_SERIALIZE_STRICT to throw

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* added documentation and changed readme to include NLOHMANN_JSON_SERIALIZE_ENUM_STRICT

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* ran amalgamate

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* docs(macros): add page for JSON_SERIALIZE_ENUM_STRICT
- added page to nav
- added links to new page where appropriate

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* refactor(macros): make JSON_SERIALIZE_ENUM_STRICT use JSON_THROW
- added templated wrapper function to fix scope error in calling JSON_THROW

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* refactor(macros): make NLOHMANN_SERIALIZE_ENUM_STRICT use error code 410
- added error code 410 to docs

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* tests(macros): add test for to_json with enum value not mentioned
	       in mapping for NLOHMANN_JSON_SERIALIZE_ENUM_STRICT

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* Apply suggestions from code review

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
Signed-off-by: Caillin Nugent <nugentcaillin@gmail.com>

* fix(macro): prevent compilation error with -Werror and -Wunused-parameter
            with NLOHMANN_JSON_SERIALIZE_ENUM_STRICT
- casted exception to void to avoid warning

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* fix(docs): add link to NLOHMANN_SERIALIZE_ENUM_STRICT docs to exception page

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* docs(macros): add example of exception throwing for NLOHMANN_JSON_SERIALIZE_ENUM_STRICT

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

* refactor(macros): add more in-depth error message to NLOHMANN_JSON_SERIALIZE_ENUM_STRICT
- changed error message to follow style of nlohmann/json#4989
- made description of throw wrapper more general
- updated tests and example of exceptions

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>

---------

Signed-off-by: Caillin Nugent <caillinn@student.unimelb.edu.au>
Signed-off-by: Caillin Nugent <nugentcaillin@gmail.com>
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
2026-05-18 20:37:07 +02:00
risa2000andRichard Musil fd17b0889e Remove nullptr safety check from sax_parse functions (#5139)
PR #4873 introduced a safety check in sax_parse functions to catch
nullptr passed as SAX parser object, which had been already annotated by
JSON_HEDLEY_NON_NULL macro.

Compilers (e.g. clang) which respected the non-null annotation tended to
eliminate the safety check completely in optimized builds, while
compilers which did not, compiled the safety check in. This led to
different behaviors accross different compilers/platforms  and/or build
types (debug, release).

This commit reverts PR #4873 to remove this discrepancy. Passing null to
non-null annotated parameter is considered to be undefined behavior.

Fixes #5048

Signed-off-by: Richard Musil <risa2000x@gmail.com>
Co-authored-by: Richard Musil <risa2000x@gmail.com>
2026-05-08 07:55:02 +02:00
Niels Lohmann e00484f866 📝 update sax_parse documentation (#4878) 2025-08-03 11:21:05 +02:00
Nikhil efcf9efb4f Fixes #4854 Explicitly handle nullptr in sax_parse (#4873)
* handle nullptr explicitly

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* add test

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* make amalgamate

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* Fix formatting

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* move sax parse test to relevant unit test file

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* extend exceptions.md to include other_error.502

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* Better exception messages

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* link sax_parse function

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* fix string

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* amalgamate

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* fix clang-tidy checks

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* cover valid handler with no throw

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* Add tests for other two overloads

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* cover overload with valid sax handler

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* pass an rvalue

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* ignore -Wtautological-pointer-compare

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* ignore clang-analyzer-core.NonNullParamChecker

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* ignore gcc -Wnonnull-compare

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* ignore undefined-behaviour-sanitizer

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* nest directives to ignore sanitizer errors

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

* use elif

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>

---------

Signed-off-by: Nikhil <nikhilreddydev@gmail.com>
2025-08-02 21:06:01 +02:00
Niels Lohmann 9110918cf8 Fix typos (#4748)
* ✏️ fix typos

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* ✏️ address review comments

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* ✏️ address review comments

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-05-04 10:28:24 +02:00
Niels Lohmann 4424a0fcc1 📝 update documentation (#4723)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-05 18:54:35 +02:00
Niels Lohmann 26cfec34be Clean up and document project files (#4560) 2025-01-17 06:53:35 +01:00
Michael Valladolid 2d42229f4d Support BSON uint64 de/serialization (#4590)
* Support BSON uint64 de/serialization

Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com>

* Treat 0x11 as uint64 and not timestamp specific

Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com>

---------

Signed-off-by: Michael Valladolid <mikevalladolid@gmail.com>
2025-01-10 14:59:55 +01:00
Niels Lohmann 549c79ba7e Overwork documentation (#4516) 2024-12-09 23:02:30 +01:00
Colby Haskell 59da644db4 Add more specific error message when attempting to parse empty input (#4180) 2023-10-31 20:17:43 +01:00
Florian Albrechtskirchinger d3e347bd2d More documentation updates for 3.11.0 (#3553)
* mkdocs: add string_view examples

* mkdocs: reference underlying operators

* mkdocs: add operator<=> examples

* mkdocs: fix style check issues

* mkdocs: tweak BJData page

* mkdocs: add CMake option hints to macros

* mkdocs: fix JSON_DISABLE_ENUM_SERIALIZATION definition

* mkdocs: fix link to unit-udt.cpp

* mkdocs: fix "Arbitrary Type Conversions" title

* mkdocs: link to api/macros/*.md instead of features/macros.md

* mkdocs: document JSON_DisableEnumSerialization CMake option

* mkdocs: encode required C++ standard in example files

* docset: detect gsed/sed

* docset: update index

* docset: fix CSS patching

* docset: add list_missing_pages make target

* docset: add list_removed_paths make target

* docset: replace page titles with name from index

* docset: add install target for Zeal docset browser

* Use GCC_TOOL in ci_test_documentation target
2022-07-31 14:05:58 +02:00
6a7392058e Complete documentation for 3.11.0 (#3464)
* 👥 update contributor and sponsor list

* 🚧 document BJData format

* 🚧 document BJData format

* 📝 clarified documentation of [json.exception.parse_error.112]

* ✏️ adjust titles

* 📝 add more examples

* 🚨 adjust warnings for index.md files

* 📝 add more examples

* 🔥 remove example for deprecated code

* 📝 add missing enum entry

* 📝 overwork table for binary formats

*  add test to create table for binary formats

* 📝 fix wording in example

* 📝 add more examples

* Update iterators.md (#3481)

*  add check for overloads to linter #3455

* 👥 update contributor list

* 📝 add more examples

* 📝 fix documentation

* 📝 add more examples

* 🎨 fix indentation

* 🔥 remove example for destructor

* 📝 overwork documentation

* Updated BJData documentation, #3464 (#3493)

* update bjdata.md for #3464

* Minor edit

* Fix URL typo

* Add info on demoting ND array to a 1-D optimized array when singleton dimension

Co-authored-by: Chaoqi Zhang <prncoprs@163.com>
Co-authored-by: Qianqian Fang <fangqq@gmail.com>
2022-05-17 13:08:56 +02:00
Niels Lohmann b21c345179 Reorganize directories (#3462)
* 🚚 move files
* 🚚 rename doc folder to docs
* 🚚 rename test folder to tests
2022-05-01 09:41:50 +02:00