https://github.com/zacharyvoase/python-csiphash
The SipHash-2-4 C reference implementation, CFFI-wrapped for Python
https://github.com/zacharyvoase/python-csiphash
cffi crypto cryptographic-hash-functions digest djb python siphash
Last synced: 3 months ago
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The SipHash-2-4 C reference implementation, CFFI-wrapped for Python
- Host: GitHub
- URL: https://github.com/zacharyvoase/python-csiphash
- Owner: zacharyvoase
- License: unlicense
- Created: 2016-09-22T22:55:27.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2017-04-27T09:33:45.000Z (over 8 years ago)
- Last Synced: 2024-11-11T12:38:25.817Z (11 months ago)
- Topics: cffi, crypto, cryptographic-hash-functions, digest, djb, python, siphash
- Language: Python
- Size: 23.4 KB
- Stars: 12
- Watchers: 2
- Forks: 2
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
csiphash.py
===========
[SipHash][] is a hash function and message authentication code that is secure,
fast and simple. It accepts a 128-bit secret key and a variable-length message,
and returns a 64-bit hash. It performs better than most cryptographic hash
function-based MACs (especially for short inputs), and offers much better
security than non-cryptographic hash functions, providing resistance against
hash-flooding DoS attacks. As a result, it is now used as the hash function of
choice for hash tables in Python, Ruby, Rust and Redis.
This Python package is the SipHash-2-4 [C reference implementation][siphash-c],
wrapped with [CFFI][]. It's incredibly fast: amortized hashing times tested as
follows on a mid-2015 MacBook Pro:
| Message Size | Time per Hash (Amortized over 1M) |
| ------------ | --------------------------------- |
| 43 bytes | 3.17 microseconds |
| 256 bytes | 3.39 microseconds |
| 1500 bytes | 4.40 microseconds |
| 1 MiB | 0.74 milliseconds |
[siphash]: https://131002.net/siphash/
[siphash-c]: https://github.com/veorq/SipHash
[cffi]: http://cffi.readthedocs.io
Installation
------------
You can get this library with pip:
pip install csiphash
Usage
-----
Currently there's just a single function, `siphash24()`, that accepts a secret
key bytestring of length 16 and an arbitrary length bytestring for the message,
and returns an 8-byte digest bytestring:
```pycon
>>> from csiphash import siphash24
>>> siphash24(b'\x00' * 16, b'hello, world!\n')
b'\xf1G4\x95\xa5\xaa\xc2b'
```
If you want to specify keys in hexadecimal, use `.decode('hex')`:
```pycon
>>> siphash24('abcdef01234567899876543210fedcba'.decode('hex'), b'hello, world!\n')
'\xd3\xd4N\x1dk\x1f$='
```
If you want digests in hexadecimal, use `.encode('hex')`:
```pycon
>>> siphash24(b'\x00' * 16, b'hello, world!\n').encode('hex')
'f1473495a5aac262'
```
License
-------
The reference C implementation of SipHash is bundled with this library. It was
written by Jean-Philippe Aumasson and Daniel J. Bernstein, and is released
under the [CC0][].
[Six][] is bundled with this library. It was written by Benjamin Peterson, and
is licensed under the [MIT License][].
All other software in this library is released under the [UNLICENSE][]:
> This is free and unencumbered software released into the public domain.
>
> Anyone is free to copy, modify, publish, use, compile, sell, or
> distribute this software, either in source code form or as a compiled
> binary, for any purpose, commercial or non-commercial, and by any
> means.
>
> In jurisdictions that recognize copyright laws, the author or authors
> of this software dedicate any and all copyright interest in the
> software to the public domain. We make this dedication for the benefit
> of the public at large and to the detriment of our heirs and
> successors. We intend this dedication to be an overt act of
> relinquishment in perpetuity of all present and future rights to this
> software under copyright law.
>
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
> IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> OTHER DEALINGS IN THE SOFTWARE.
>
> For more information, please refer to
[cc0]: https://creativecommons.org/publicdomain/zero/1.0/
[six]: https://pythonhosted.org/six/
[mit license]: https://bitbucket.org/gutworth/six/raw/ca4580a5a648fc75abc568907e81abc80b05d58c/LICENSE
[unlicense]: https://unlicense.org/