Skex

Overview

Skex is a NIF wrapper around Skein hashing functions. It is a port of the Erlang Skerl library, by Basho.

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

iex> bits = 256
256
iex> data = "foobarbazquux"
<<"foobarbazquux">>
iex> {:ok, hash} = Skex.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,
      ...>>}
iex> bit_size(hash)
256

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

iex> hex_hash = Skex.hexhash(bits, data)      
<<"ce24af6ca85b7c0bb56c90a424d8826ef1c562b4417838e101ff3627dcc000bc">>

Documentation for this repo can be found here

Installation

The package can be installed by adding skex to your list of dependencies in mix.exs:

def deps do
  [
    {:skex, "~> 0.1.1"}
  ]
end

The Skein Hash

The underlying hashing code in Skex 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 Skex from the community.

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

git clone [email protected]:yourusername/skex.git
# or
git remote add mine [email protected]:yourusername/skex.git

3. Create a topic branch for your change.

git checkout -b some-topic-branch

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

git push mine some-topic-branch

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