entropy: A platform independent entropy source

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A mostly platform independent method to obtain cryptographically strong entropy (RDRAND, urandom, CryptAPI, and patches welcome) Users looking for cryptographically strong (number-theoretically sound) PRNGs should see the DRBG package too.

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Versions 0.1, 0.2, 0.2.1, 0.2.2,,,,, 0.3, 0.3.1, 0.3.2, 0.3.3, 0.3.4,, 0.3.5, 0.3.6, 0.3.7, 0.3.8, 0.4, 0.4.1,,,,,,,,,,
Change log None available
Dependencies base (>=4.8 && <5), bytestring, ghcjs-dom, jsaddle, unix, Win32 (>=2.5) [details]
License BSD-3-Clause
Copyright Thomas DuBuisson <thomas.dubuisson@gmail.com>
Author Thomas DuBuisson <thomas.dubuisson@gmail.com>
Maintainer Thomas DuBuisson <thomas.dubuisson@gmail.com>
Category Data, Cryptography
Home page https://github.com/TomMD/entropy
Bug tracker https://github.com/TomMD/entropy/issues
Source repo head: git clone https://github.com/TomMD/entropy
Uploaded by ThomasDuBuisson at 2019-09-06T20:30:30Z


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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 /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.

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