sha3 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).
>>> import sha3 >>> s = sha3.sha3_512() >>> s.name 'sha3_512' >>> s.digest_size 64 >>> s.update(b"data") >>> s.hexdigest() '1065aceeded3a5e4412e2187e919bffeadf815f5bd73d37fe00d384fe29f55f08462fdabe1007b993ce5b8119630e7db93101d9425d6e352e22ffe3dcb56b825'
The module contains the constructors sha3_228(), sha3_256(), sha3_384 and sha3_512().
The sha3 module monkey patches the hashlib module:
>>> import hashlib >>> s = hashlib.new("sha3_512") Traceback (most recent call last): ... ValueError: unsupported hash type sha3_512>>> import sha3 >>> s = hashlib.new("sha3_512") >>> s = hashlib.sha3_512()
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).
- UseBebigokimisa, Unrolling
- Unrolling: loop unrolling (24, 12, 8, 6, 4, 3, 2, 1)
- UseBebigokimisa: lane complementing
- Additional options:
- UseSSE, UseOnlySIMD64, UseMMX, UseXOP, UseSHLD
- Optimized instructions (disabled by default):
- UseSSE: use Stream SIMD extensions o UseOnlySIMD64: limit to 64bit instructions, otherwise 128bit o w/o UseOnlySIMD64: requires compiler agument -mssse3 or -mtune
- UseMMX: use 64bit MMX instructions
- UseXOP: use AMD's eXtended Operations (128bit SSE extension)
- Unrolling: default 24
- UseBebigokimisa: default 1
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)
- Additional options:
- Unrolling: default 2
- UseBebigokimisa: default n/a
- UseSchedule: ???, (1, 2, 3; default 3)
- UseInterleaveTables: use two 64k lookup tables for (de)interleaving default: n/a
- 3: no UseBebigokimisa, Unrolling must be 2
- 2 + 1: ???