siphash
A Scheme implementation of the SipHash family of hash functions.
Description
SipHash is a cryptographically strong family of hash functions designed by Jean-Philippe Aumasson and Daniel J. Bernstein.
This library provides an implementation of these functions for CHICKEN Scheme.
Installation
When installing for CHICKEN Scheme, the numbers extension is required.
$ git clone git://bitbucket.org/evhan/siphash.git
$ cd siphash
$ chicken-install -test
Usage
Three functions are provided:
make-siphash
siphash-2-4
siphash-4-8
make-siphash
constructs a hashing function.
It takes two positive integer arguments c
and d
and returns a
hashing procedure of that number of compression and finalization rounds,
respectively.
(make-siphash c d) => (procedure key) => (procedure message) => integer
siphash-2-4
and siphash-4-8
are predefined hashing procedures.
Each takes one or two arguments, the key and message to hash, and
returns a positive integer. key
and message
may be strings or
bytevectors, and key
should have a length of 16 while message
may be
any length. If message
isn't given, a prekeyed hashing function is
returned.
The SipHash specification recommends SipHash-2-4 for performance and SipHash-4-8 for cryptographic security.
(siphash-2-4 key) => (procedure message) => integer (siphash-2-4 key message) => integer (siphash-4-8 key) => (procedure message) => integer (siphash-4-8 key message) => integer
Examples
> (define key (bytevector 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)) > (define msg (string->utf8 "The rain in Spain falls mainly on the plain.")) > (siphash-2-4 key msg) ; => 8751579407287093977 > ((siphash-4-8 key) msg) ; => 13472556437817646137 > ((make-siphash 8 16) key (string->utf8 "In Hertford, Hereford and Hampshire, hurricanes hardly ever happen.")) ; => 9275736844991428064
Author
Evan Hanson evhan@foldling.org
License
Copyright (c) 2013, Evan Hanson under a BSD-style license.
See LICENSE for full license information.