skerl

Overview

skerl is a NIF wrapper around Skein hashing functions

Quick Start

You must have Erlang/OTP R13B04 or later and a GNU-style build system to compile and run skerl.

git clone git://github.com/basho/skerl.git
cd skerl
make

Start up an Erlang shell with the path to skerl included.

cd path/to/skerl/ebin
erl

Hash a binary by calling skerl:hash/2 with the desired number of bits for the resulting hash:

1> Bits = 256.
256
2> Data = <<"foobarbazquux">>.
<<"foobarbazquux">>
3> {ok, Hash} = skerl:hash(Bits, Data).
{ok,<<206,36,175,108,168,91,124,11,181,108,144,164,36,
      216,130,110,241,197,98,180,65,120,56,225,1,255,54,
      ...>>}
4> bit_size(Hash).
256

You may find skerl:hexhash/2 more useful, as it returns a hexadecimal-encoded string representing the hash:

5> HexHash = skerl:hexhash(Bits, Data).      
<<"ce24af6ca85b7c0bb56c90a424d8826ef1c562b4417838e101ff3627dcc000bc">>

The Skein Hash

The underlying hashing code in Skerl is the reference implementation of Skein from the official NIST submission.

Skein is a finalist candidate in the NIST competition to become SHA-3.

It is a hash function designed by Niels Ferguson, Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, and Jesse Walker.

Details on the algorithm as submitted and known analysis can be found at ecrypt.

A full paper on Skein by the designers has been published.

The official Skein page uses the headline:

Fast, Secure, Simple, Flexible, Efficient. And it rhymes with “rain.”

Contributing

We encourage contributions to skerl from the community.

1. Fork the skerl repository on Github.
2. Clone your fork or add the remote if you already have a clone of the repository.

git clone git@github.com:yourusername/skerl.git
# or
git remote add mine git@github.com:yourusername/skerl.git

1. Create a topic branch for your change.

git checkout -b some-topic-branch

1. Make your change and commit. Use a clear and descriptive commit message, spanning multiple lines if detailed explanation is needed.
2. Push to your fork of the repository and then send a pull-request through Github.

git push mine some-topic-branch

1. A Basho engineer or community maintainer will review your patch and merge it into the main repository or send you feedback.