1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
|
Use of OpenSSL
==============
``cryptography`` depends on the `OpenSSL`_ C library for all cryptographic
operation. OpenSSL is the de facto standard for cryptographic libraries and
provides high performance along with various certifications that may be
relevant to developers.
A list of supported versions can be found in our :doc:`/installation`
documentation.
In general the backend should be considered an internal implementation detail
of the project, but there are some public methods available for debugging
purposes.
.. data:: cryptography.hazmat.backends.openssl.backend
.. method:: openssl_version_text()
:return text: The friendly string name of the loaded OpenSSL library.
This is not necessarily the same version as it was compiled against.
.. method:: openssl_version_number()
.. versionadded:: 1.8
:return int: The integer version of the loaded OpenSSL library. This is
defined in ``opensslv.h`` as ``OPENSSL_VERSION_NUMBER`` and is
typically shown in hexadecimal (e.g. ``0x1010003f``). This is
not necessarily the same version as it was compiled against.
.. _legacy-provider:
Legacy provider in OpenSSL 3.x
------------------------------
.. versionadded:: 39.0.0
Users can set ``CRYPTOGRAPHY_OPENSSL_NO_LEGACY`` environment variable to
disable the legacy provider in OpenSSL 3.x. This will disable legacy
cryptographic algorithms, including ``Blowfish``, ``CAST5``, ``SEED``,
``ARC4``, and ``RC2`` (which is used by some encrypted serialization formats).
.. _`OpenSSL`: https://www.openssl.org/
|