pysha3 0.3

pysha3
======

SHA-3 wrapper (keccak) for Python. The package is a wrapper around the
optimized reference implementation from http://keccak.noekeon.org/ . Only
the optimizations for 32 and 64bit platforms are used. The optimized SSE and
ARM assembly variants are ignored for now.

The module is a standalone version of the SHA-3 implemention of Python 3.4
(currently under development). The code in sha3module.c has been modified to
be compatible with Python 2.6 to 3.4. Python 2.5 and earlier are not
supported.


Platforms
=========

pysha3 has been successfully tested on several platforms and architectures:

- Linux (GCC 4.3, GCC 4.6, clang 3.0) on X86, X86_64 and ARMv6
- Windows (VS 2008, VS 2010) on X86 and X86_64
- FreeBSD (clang) on X86 and X86_64
- HP-UX (HP C/aC++) on IA64
- Solaris 10 (Oracle Solaris Studio 12.3) on SPARC (big endian)
- AIX (XLC 12.1) on PowerPC (big endian)

Thank you very much to Trent Nelson for the Snakebite network.


Usage
=====

The `sha3` module contains several constructors for hash objects with a
PEP 247 compatible interface. The module provides `sha3_228()`, `sha3_256()`,
`sha3_384()`, and `sha3_512()`.

The `sha3` module monkey patches the `hashlib` module . The monkey patch is
automatically activated with the first import of the `sha3` module. The
`hashlib` module of Python 3.4 will support the four SHA-3 algorithms
on all platforms. Therefore you shouldn't use the sha3 module directly
and rather go through the `hashlib` interface::

>>> import sys
>>> import hashlib
>>> if sys.version_info < (3, 4):
... import sha3
>>> s = hashlib.new("sha3_512")
>>> s = hashlib.sha3_512() # alternative
>>> s.name
'sha3_512'
>>> s.digest_size
64
>>> s.update(b"data")
>>> s.hexdigest()
'1065aceeded3a5e4412e2187e919bffeadf815f5bd73d37fe00d384fe29f55f08462fdabe1007b993ce5b8119630e7db93101d9425d6e352e22ffe3dcb56b825'

**Don't use SHA-3 for HMAC!** HMAC hasn't been specified for SHA-3 yet and no
test vectors are available, too.


Comments from sha3module header
===============================

The code is based on KeccakReferenceAndOptimized-3.2.zip from 29 May 2012.

The reference implementation is altered in this points:
- C++ comments are converted to ANSI C comments.
- All functions and globals are declared static.
- The typedef for UINT64 is commented out.
- brg_endian.h is removed.
- KeccakF-1600-opt[32|64]-settings.h are commented out
- Some unused functions are commented out to silence compiler warnings.

In order to avoid name clashes with other software I have to declare all
Keccak functions and global data as static. The C code is directly
included into this file in order to access the static functions.

Keccak can be tuned with several paramenters. I try to explain all options
as far as I understand them. The reference implementation also contains
assembler code for ARM platforms (NEON instructions).

Common
------

`Unrolling`
loop unrolling (24, 12, 8, 6, 4, 3, 2, 1)

`UseBebigokimisa`
lane complementing

64bit platforms
---------------

default settings of common options

`Unrolling`
24
`UseBebigokimisa`
enabled

Additional optimiation instructions (disabled by default):

`UseSSE`
use Stream SIMD extensions

`UseOnlySIMD64`
limit to 64bit instructions, otherwise 128bit

`w/o UseOnlySIMD64`
requires compiler argument `-mssse3` or `-mtune=core2` or better

`UseMMX`
use 64bit MMX instructions

`UseXOP`
use AMD's eXtended Operations (128bit SSE extension)

When neither `UseSSE`, `UseMMX` nor `UseXOP` is configured, `ROL64`
(rotate left 64) is implemented as:

Windows
_rotl64()

`UseSHLD`
use shld (shift left) asm optimization

otherwise
shift and xor

`UseBebigokimisa` can't be used in combination with `UseSSE`, `UseMMX` or
`UseXOP`. `UseOnlySIMD64` has no effect unless UseSSE is specified.

Tests have shown that `UseSSE` + `UseOnlySIMD64` is about three to four
times SLOWER than `UseBebigokimisa`. `UseSSE` and `UseMMX` are about two
times slower. (tested by CH and AP)

32bit platforms
---------------

default settings of common options

`Unrolling`
2
`UseBebigokimisa`
disabled

`UseSchedule`
`1`
unknown

`2`
unknown

`3` [default]
unknown, no `UseBebigokimisa`, `Unrolling` must be 2

`UseInterleaveTables`
use two 64k lookup tables for (de)interleaving (disabled by default)


Changelog
=========

pysha3 0.3
----------

*Release date: 14-Oct-2012*

- Fix 64bit big endian support

- Add workaround for alignment error on 64bit SPARC machine by using the opt32
implementation.

- block_size now returns NotImplemented to prevent users from using pysha3
with the hmac module.


pysha3 0.2.2
------------

*Release date: 07-Oct-2012*

- Re-add brg_endian.h to fix issue on Solaris (big endian platform)


pysha3 0.2.1
------------

*Release date: 06-Oct-2012*

- Fix MANIFEST.in to include Makefile and tests.py

- Add setup.py test command with hack for inplace builds

- Enhance README.txt and fixed its markup


pysha3 0.2
----------

*Release date: 06-Oct-2012*

- Change directory struct to use the same directory layout as Python 3.4.

- Remove C++ comments from Keccak sources for ANSI C compatibility.

- Declare all Keccak functions and globals as static to avoid name clashes.

- Remove alias sha3() for sha3_512().

- Add block_size attribute. Keccak has a internal sponge size of 1600 bits.

- Release GIL around SHA3_update() calls.

- Monkey patch the hashlib module to support, e.g. hashlib.sha3_512() and
hashlib.new("sha3_512")

- Release GIL around SHA3_update() when the data exceeds a certain size.

- Fix build on platforms with an unsigned 64bit integer type (uint64_t). The
module falls back to 32bit implementation of Keccak with interleave tables.


pysha3 0.1
----------

*Release date: 04-Oct-2012*

- first release

- based on KeccakReferenceAndOptimized-3.2.zip