From bf0f464ab62d2e69ebfacd80fad2de46e862fcbc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Krier?= Date: Fri, 26 Feb 2016 18:40:20 +0100 Subject: Added support for padding ANSI X.923 --- docs/hazmat/primitives/padding.rst | 41 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'docs/hazmat') diff --git a/docs/hazmat/primitives/padding.rst b/docs/hazmat/primitives/padding.rst index a60f5ac8..37e4252d 100644 --- a/docs/hazmat/primitives/padding.rst +++ b/docs/hazmat/primitives/padding.rst @@ -54,6 +54,47 @@ multiple of the block size. provider. +.. class:: ANSIX923(block_size) + + ANSI X.923 padding works by appending ``N-1`` bytes with the value of ``0`` + and a last byte with the value of ``chr(N)``, where ``N`` is the number of + bytes required to make the final block of data the same size as the block + size. A simple example of padding is: + + .. doctest:: + + >>> padder = padding.ANSIX923(128).padder() + >>> padded_data = padder.update(b"11111111111111112222222222") + >>> padded_data + '1111111111111111' + >>> padded_data += padder.finalize() + >>> padded_data + '11111111111111112222222222\x00\x00\x00\x00\x00\x06' + >>> unpadder = padding.ANSIX923(128).unpadder() + >>> data = unpadder.update(padded_data) + >>> data + '1111111111111111' + >>> data + unpadder.finalize() + '11111111111111112222222222' + + :param block_size: The size of the block in bits that the data is being + padded to. + :raises ValueError: Raised if block size is not a multiple of 8 or is not + between 0 and 256. + + .. method:: padder() + + :returns: A padding + :class:`~cryptography.hazmat.primitives.padding.PaddingContext` + provider + + .. method:: unpadder() + + :returns: An unpadding + :class:`~cryptography.hazmat.primitives.padding.PaddingContext` + provider. + + .. class:: PaddingContext When calling ``padder()`` or ``unpadder()`` the result will conform to the -- cgit v1.2.3