argon2-cffi 15.0.0

=====================================
CFFI-based Argon2 Bindings for Python
=====================================

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.. teaser-begin

`Argon2 <https://github.com/p-h-c/phc-winner-argon2>`_ won the `Password Hashing Competition <https://password-hashing.net/>`_ and ``argon2_cffi`` is the simplest way to use it in Python and PyPy:

.. code-block:: pycon

>>> import argon2
>>> hash = argon2.hash_password(b"secret")
>>> hash # doctest: +SKIP
b'$argon2i$m=512,t=2,p=2$c29tZXNhbHQ$2IdoNVglVTxb9w4YVJqW8w'
>>> argon2.verify_password(hash, b"secret")
True
>>> argon2.verify_password(hash, b"wrong")
Traceback (most recent call last):
...
argon2.exceptions.VerificationError: Decoding failed


``argon2_cffi``\ ’s documentation lives at `Read the Docs <https://argon2-cffi.readthedocs.org/>`_, the code on `GitHub <https://github.com/hynek/argon2_cffi>`_.
It’s rigorously tested on Python 2.6, 2.7, 3.3+, and PyPy.


Credits & License
=================

``argon2_cffi`` is maintained by Hynek Schlawack and released under the `MIT license <https://github.com/hynek/argon2_cffi/blob/master/LICENSE>`_.

The development is kindly supported by `Variomedia AG <https://www.variomedia.de/>`_.

A full list of contributors can be found on `GitHub <https://github.com/hynek/argon2_cffi/graphs/contributors>`_.


Vendored Code
-------------

Argon2
^^^^^^

The original Argon2 repo can be found at https://github.com/P-H-C/phc-winner-argon2/.

Except for the components listed below, the Argon2 code in this repository is copyright (c) 2015 Daniel Dinu, Dmitry Khovratovich (main authors), Jean-Philippe Aumasson and Samuel Neves, and under CC0_ license.

The string encoding routines in src/encoding.c are copyright (c) 2015 Thomas Pornin, and under CC0_ license.

The `BLAKE2 <https://blake2.net>`_ code in ``src/blake2/`` is copyright (c) Samuel Neves, 2013-2015, and under CC0_ license.

The authors of Argon2 also were very helpful to get the library to compile on ancient versions of Visual Studio for ancient versions of Python.

The documentation also quotes frequently from the Argon2 paper_ to avoid mistakes by rephrasing.

.. _CC0: https://creativecommons.org/publicdomain/zero/1.0/
.. _paper: https://password-hashing.net/argon2-specs.pdf

msinttypes
^^^^^^^^^^

In order to be able to compile on Visual Studio 2008 and Visual Studio 2010 which are required for Python 2.6/2.7 and 3.3/3.4 respectively, we also ship two C headers with integer types.
They are from the `msinttypes project <https://code.google.com/p/msinttypes/>`_ (`auto-import on GitHub <https://github.com/chemeris/msinttypes>`_) and licensed under New BSD:

Copyright (c) 2006-2013 Alexander Chemeris

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name of the product nor the names of its contributors may
be used to endorse or promote products derived from this software
without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


Changelog
=========

Versions are year-based with a strict backward compatibility policy.
The third digit is only for regressions.


15.0.0 (2015-12-18)
-------------------

Vendoring ``argon2`` @ `4fe0d8cda37691228dd5a96a310be57369403a4b <https://github.com/P-H-C/phc-winner-argon2/tree/4fe0d8cda37691228dd5a96a310be57369403a4b>`_.

Changes:
^^^^^^^^

- ``verify_password()`` doesn't guess the hash type if passed ``None`` anymore.
Supporting this resulted in measurable overhead (~ 0.6ms vs 0.8ms on my notebook) since it had to happen in Python.
That means that naïve usage of the API would give attackers an edge.
The new behavior is that it has the same default value as ``hash_password()`` such that ``verify_password(hash_password(b"password"), b"password")`` still works.
- Conditionally use the `SSE2 <https://en.wikipedia.org/wiki/SSE2>`_-optimized version of ``argon2`` on x86 architectures.
- More packaging fixes.
Most notably compilation on Visual Studio 2010 for Python 3.3 and 3.4.
- Tweaked default parameters to more reasonable values.
Verification should take between 0.5ms and 1ms on recent-ish hardware.


15.0.0b5 (2015-12-10)
---------------------

Vendoring ``argon2`` @ `4fe0d8cda37691228dd5a96a310be57369403a4b <https://github.com/P-H-C/phc-winner-argon2/tree/4fe0d8cda37691228dd5a96a310be57369403a4b>`_.

Initial work.
Previous betas were only for fixing Windows packaging.
The authors of ``argon2`` were kind enough to `help me <https://github.com/P-H-C/phc-winner-argon2/issues/44>`_ to get it building under Visual Studio 2008 that we’re forced to use for Python 2.7 on Windows.