# Changes

## Version 2.2.0

Released 2024-04-16

- Drop support for Python 3.7. #372

- Use modern packaging metadata with `pyproject.toml` instead of `setup.cfg`. #326

- Use `flit_core` instead of `setuptools` as build backend.

- Deprecate the `__version__` attribute. Use feature detection, or `importlib.metadata.version("itsdangerous")`, instead. #371

- `Serializer` and the return type of `dumps` is generic for type checking. By default it is `Serializer[str]` and `dumps` returns a `str`. If a different `serializer` argument is given, it will try to infer the return type of its `dumps` method. #347

- The default `hashlib.sha1` may not be available in FIPS builds. Don’t access it at import time so the developer has time to change the default. #375

## Version 2.1.2

Released 2022-03-24

- Handle date overflow in timed unsign on 32-bit systems. #299

## Version 2.1.1

Released 2022-03-09

- Handle date overflow in timed unsign. #296

## Version 2.1.0

Released 2022-02-17

- Drop support for Python 3.6. #272

- Remove previously deprecated code. #273

  - JWS functionality: Use a dedicated library such as Authlib instead.

  - `import itsdangerous.json`: Import `json` from the standard library instead.

## Version 2.0.1

Released 2021-05-18

- Mark top-level names as exported so type checking understands imports in user projects. #240

- The `salt` argument to `Serializer` and `Signer` can be `None` again. #237

## Version 2.0.0

Released 2021-05-11

- Drop support for Python 2 and 3.5.

- JWS support (`JSONWebSignatureSerializer`, `TimedJSONWebSignatureSerializer`) is deprecated. Use a dedicated JWS/JWT library such as authlib instead. #129

- Importing `itsdangerous.json` is deprecated. Import Python’s `json` module instead. #152

- Simplejson is no longer used if it is installed. To use a different library, pass it as `Serializer(serializer=...)`. #146

- `datetime` values are timezone-aware with `timezone.utc`. Code using `TimestampSigner.unsign(return_timestamp=True)` or `BadTimeSignature.date_signed` may need to change. #150

- If a signature has an age less than 0, it will raise `SignatureExpired` rather than appearing valid. This can happen if the timestamp offset is changed. #126

- `BadTimeSignature.date_signed` is always a `datetime` object rather than an `int` in some cases. #124

- Added support for key rotation. A list of keys can be passed as `secret_key`, oldest to newest. The newest key is used for signing, all keys are tried for unsigning. #141

- Removed the default SHA-512 fallback signer from `default_fallback_signers`. #155

- Add type information for static typing tools. #186

## Version 1.1.0

Released 2018-10-26

- Change default signing algorithm back to SHA-1. #113

- Added a default SHA-512 fallback for users who used the yanked 1.0.0 release which defaulted to SHA-512. #114

- Add support for fallback algorithms during deserialization to support changing the default in the future without breaking existing signatures. #113

- Changed capitalization of packages back to lowercase as the change in capitalization broke some tooling. #113

## Version 1.0.0

Released 2018-10-18

YANKED

Note: This release was yanked from PyPI because it changed the default algorithm to SHA-512. This decision was reverted in 1.1.0 and it remains at SHA1.

- Drop support for Python 2.6 and 3.3.

- Refactor code from a single module to a package. Any object in the API docs is still importable from the top-level `itsdangerous` name, but other imports will need to be changed. A future release will remove many of these compatibility imports. #107

- Optimize how timestamps are serialized and deserialized. #13

- `base64_decode` raises `BadData` when it is passed invalid data. #27

- Ensure value is bytes when signing to avoid a `TypeError` on Python 3. #29

- Add a `serializer_kwargs` argument to `Serializer`, which is passed to `dumps` during `dump_payload`. #36

- More compact JSON dumps for unicode strings. #38

- Use the full timestamp rather than an offset, allowing dates before 2011. #46

  To retain compatibility with signers from previous versions, consider using this shim when unsigning.

- Detect a `sep` character that may show up in the signature itself and raise a `ValueError`. #62

- Use a consistent signature for keyword arguments for `Serializer.load_payload` in subclasses. #74, #75

- Change default intermediate hash from SHA-1 to SHA-512. #80

- Convert JWS exp header to an int when loading. #99

## Version 0.24

Released 2014-03-28

- Added a `BadHeader` exception that is used for bad headers that replaces the old `BadPayload` exception that was reused in those cases.

## Version 0.23

Released 2013-08-08

- Fixed a packaging mistake that caused the tests and license files to not be included.

## Version 0.22

Released 2013-07-03

- Added support for `TimedJSONWebSignatureSerializer`.

- Made it possible to override the signature verification function to allow implementing asymmetrical algorithms.

## Version 0.21

Released 2013-05-26

- Fixed an issue on Python 3 which caused invalid errors to be generated.

## Version 0.20

Released 2013-05-23

- Fixed an incorrect call into `want_bytes` that broke some uses of ItsDangerous on Python 2.6.

## Version 0.19

Released 2013-05-21

- Dropped support for 2.5 and added support for 3.3.

## Version 0.18

Released 2013-05-03

- Added support for JSON Web Signatures (JWS).

## Version 0.17

Released 2012-08-10

- Fixed a name error when overriding the digest method.

## Version 0.16

Released 2012-07-11

- Made it possible to pass unicode values to `load_payload` to make it easier to debug certain things.

## Version 0.15

Released 2012-07-11

- Made standalone `load_payload` more robust by raising one specific error if something goes wrong.

- Refactored exceptions to catch more cases individually, added more attributes.

- Fixed an issue that caused `load_payload` not work in some situations with timestamp based serializers

- Added an `loads_unsafe` method.

## Version 0.14

Released 2012-06-29

- API refactoring to support different key derivations.

- Added attributes to exceptions so that you can inspect the data even if the signature check failed.

## Version 0.13

Released 2012-06-10

- Small API change that enables customization of the digest module.

## Version 0.12

Released 2012-02-22

- Fixed a problem with the local timezone being used for the epoch calculation. This might invalidate some of your signatures if you were not running in UTC timezone. You can revert to the old behavior by monkey patching `itsdangerous.EPOCH`.

## Version 0.11

Released 2011-07-07

- Fixed an uncaught value error.

## Version 0.10

Released 2011-06-25

- Refactored interface that the underlying serializers can be swapped by passing in a module instead of having to override the payload loaders and dumpers. This makes the interface more compatible with Django’s recent changes.