ACIL FM

Pilih semua

Nama	Ukuran	Aksi
asymmetric	-	Open
mac	-	Open
aead.rst	13 MB	View DL Edit
constant-time.rst	1.55 MB	View DL Edit
cryptographic-hashes.rst	9.19 MB	View DL Edit
index.rst	246 B	View DL Edit
key-derivation-functions.rst	41.99 MB	View DL Edit
keywrap.rst	2.17 MB	View DL Edit
padding.rst	4.56 MB	View DL Edit
symmetric-encryption.rst	31.06 MB	View DL Edit
twofactor.rst	9.65 MB	View DL Edit

Edit file: /usr/share/doc/python3-cryptography/docs/hazmat/primitives/constant-time.rst

.. hazmat::

Constant time functions
=======================

.. currentmodule:: cryptography.hazmat.primitives.constant_time

This module contains functions for operating with secret data in a way that
does not leak information about that data through how long it takes to perform
the operation. These functions should be used whenever operating on secret data
along with data that is user supplied.

An example would be comparing a HMAC signature received from a client to the
one generated by the server code for authentication purposes.

For more information about this sort of issue, see `Coda Hale's blog post`_
about the timing attacks on KeyCzar and Java's ``MessageDigest.isEqual()``.

.. function:: bytes_eq(a, b)

Compares ``a`` and ``b`` with one another. If ``a`` and ``b`` have
    different lengths, this returns ``False`` immediately. Otherwise it
    compares them in a way that takes the same amount of time, regardless of
    how many characters are the same between the two.

.. doctest::

>>> from cryptography.hazmat.primitives import constant_time
        >>> constant_time.bytes_eq(b"foo", b"foo")
        True
        >>> constant_time.bytes_eq(b"foo", b"bar")
        False

:param bytes a: The left-hand side.
    :param bytes b: The right-hand side.
    :returns bool: ``True`` if ``a`` has the same bytes as ``b``, otherwise
                   ``False``.
    :raises TypeError: This exception is raised if ``a`` or ``b`` is not
                       ``bytes``.

.. _`Coda Hale's blog post`: https://codahale.com/a-lesson-in-timing-attacks/

Batal

Isi Zip:

Create