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a pure Python implementation of the hashing function BLAKE2
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blake2.py -- version 1 This pure Python implementation of BLAKE2 supports both BLAKE2b and BLAKE2s. It runs under both Python 2.7 and Python 3.3. For information about the BLAKE2 algorithm please see https://blake2.net blake2.py differs from the structure of the C reference version primarily by effecting classes (object orientation) and certain optimizations in the area of compress() and G(). The goal of these optimizations was to improve performance, and while a gain of about 50% was attained, this program is way too slow to be competitive with C implementations. This program can be useful, however, where a pure Python implementation is required, where the data to be hashed is small, and, of course, for educational purposes. Credit is given to Dmitry Chestnykh <email@example.com> for his work defining a Python API for pyblake2 and his excellent documentation of that interface. Please see http://pythonhosted.org/pyblake2/ I have adoped much of Dmitry's API and many of his data names. Here are a few known differences between blake2.py and pyblake2. - capitalization of BLAKE2b and BLAKE2s class names - digest() is an alias for final() - under Python 2.7 the returned digest is a str; under Python 3.3 the digest is a bytes object. Neither is a pyblake2 hash object. - hexdigest() returns a str under Pythons 2.7 and 3.3 - http://pythonhosted.org/pyblake2/module.html#pyblake2.hash.digest says "Return the digest of the data so far" which implies hashing may be resumed after a digest is retrieved at some arbitrary interim point. What really happens is that when final() is called, padding is added (if needed), and a final compress is performed on the last block. An intermediate digest value will NOT include a residual value left in the buffer (unless you just happen to be on an exact multiple of BLOCKSIZE). IMO, to resume hashing after "closing out" the state should NOT be permitted, hence blake2.py will throw an exception if resumption is attempted. Arguably, a better approach would be to make a deepcopy by calling copy() and then call digest() or hexdigest() on the copy, and resume hashing on the original. - digest() and hexdigest() may be called multiple times when finished hashing. Each calls final(), but final() performs the final compression only once. Other notes: - All data, key, salt, and person inputs are big endian bytes, NOT strings. Likewise, the final digest is big endian bytes. - blake2.py has been tested in sequential and tree modes; it has NOT been tested in parallel mode. - blake2.py is NOT a secure implementation. For example, keys are not securely overwritten after use. Use this implementation on a presumably secure platform only. Simple usage example: import blake2 digest = blake2.BLAKE2b(b'hello world').digest() Another, generating a 20-byte digest (in hex): from blake2 import BLAKE2b data1 = b'hello ' data2 = b'world' b2 = BLAKE2b(digest_size=20) b2.update(data1) b2.update(data2) hexdigest = b2.hexdigest() ----- "miniServer" BLAKE2b thruput (OSX 2.53GHz Core2Duo): MiB/sec 0.22 python 2.7, blake2.py v1 0.36 python 3.3, blake2.py v1 0.60 pypy 2.2 (python 2.7), blake2.py v1 0.35 python 2.7, cythonized blake2.py v1 0.59 python 3.3, cythonized blake2.py v1 1.99 python 2.7, cython + some cdef unsigned long long >>> 301.01 python 2.7, Dmitry's pyblake2 wrapper <<< "godspeed" BLAKE2b thruput (Ubuntu 12.4LTS 4.4GHz i5-3570K): MiB/sec 0.72 python 2.7, blake2.py v1 0.84 python 3.2, blake2.py v1 0.96 pypy 2.2 (python 2.7), blake2.py v1 ...still [very] slow. :-/ Consider using blake2.py when you need a pure Python implementation, and convert to Dmitry's pyblake2, with hopefully minimum effort, when more speed is required. ----- License: Copyright (c) 2009-2018 Larry Bugbee, Kent, WA, USA Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. (the ISC license, a minor tweak of the BSD license) Enjoy, Larry Bugbee December 2013 rev Mar 2014, Mar 2018 PS: If you are interested in a 100% Python implementation of the original BLAKE hash algorithm, predecessor to BLAKE2, submitted to and a finalist in the NIST SHA3 competition, go to: http://www.seanet.com/~bugbee/crypto/blake/