https://github.com/haskell/entropy

Easy entropy source for Haskell users.
https://github.com/haskell/entropy

Last synced: about 1 month ago
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Easy entropy source for Haskell users.

• Host: GitHub
• URL: https://github.com/haskell/entropy
• Owner: haskell
• License: other
• Created: 2013-05-12T19:21:56.000Z (over 11 years ago)
• Default Branch: main
• Last Pushed: 2023-03-24T20:32:35.000Z (over 1 year ago)
• Last Synced: 2024-04-16T00:49:06.888Z (7 months ago)
• Language: Haskell
• Size: 98.6 KB
• Stars: 23
• Watchers: 5
• Forks: 46
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Introduction

This package allows Haskell users to easily acquire entropy for use in critical

security applications by calling out to either windows crypto api, unix/linux's

`getrandom` and `/dev/urandom`. Hardware RNGs (currently RDRAND, patches

welcome) are supported via the `hardwareRNG` function.

## Quick Start

To simply get random bytes use `getEntropy`:

```

#!/usr/bin/env cabal

{- cabal:

    build-depends: base, entropy, bytestring

-}

import qualified Data.ByteString as BS

import           System.Entropy

main :: IO ()

main = print . BS.unpack =<< getEntropy 16

-- Example output: [241,191,215,193,225,27,121,244,16,155,252,41,131,38,6,100]

```

## Faster Randoms from Hardware

Most x86 systems include a hardware random number generator.  These can be

faster but require more trust in the platform:

```

import qualified Data.ByteString as B

import           System.Entropy

eitherRNG :: Int -> IO B.ByteString

eitherRNG sz = maybe (getEntropy sz) pure =<< getHardwareEntropy sz

main :: IO ()

main = print . B.unpack =<< eitherRNG 32

```

This package supports Windows, {li,u}nix, QNX, and has preliminary support for HaLVM.

Typically tested on Linux and OSX - testers are as welcome as patches.

[![Build Status](https://travis-ci.org/TomMD/entropy.svg?branch=master)](https://travis-ci.org/TomMD/entropy)