File manager - Edit - /opt/alt/python35/share/doc/alt-python35-cryptography-1.8.1/docs/random-numbers.rst
Back
Random number generation ======================== When generating random data for use in cryptographic operations, such as an initialization vector for encryption in :class:`~cryptography.hazmat.primitives.ciphers.modes.CBC` mode, you do not want to use the standard :mod:`random` module APIs. This is because they do not provide a cryptographically secure random number generator, which can result in major security issues depending on the algorithms in use. Therefore, it is our recommendation to `always use your operating system's provided random number generator`_, which is available as :func:`os.urandom`. For example, if you need 16 bytes of random data for an initialization vector, you can obtain them with: .. doctest:: >>> import os >>> iv = os.urandom(16) This will use ``/dev/urandom`` on UNIX platforms, and ``CryptGenRandom`` on Windows. If you need your random number as an integer (for example, for :meth:`~cryptography.x509.CertificateBuilder.serial_number`), you can use ``int.from_bytes`` to convert the result of ``os.urandom``: .. code-block:: pycon >>> serial = int.from_bytes(os.urandom(20), byteorder="big") .. _`always use your operating system's provided random number generator`: https://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/
| ver. 1.4 |
Github
|
.
| PHP 7.3.33 | Generation time: 0.05 |
proxy
|
phpinfo
|
Settings