Portability	portable
Stability	beta
Maintainer	Thomas.DuBuisson@gmail.com
Safe Haskell	None

Control.Monad.CryptoRandom

Description

Much like the MonadRandom package (Control.Monad.Random), this module provides plumbing for the CryptoRandomGen generators.

Synopsis

Documentation

class CRandom a where

CRandom a is much like the Random class from the System.Random module in the random package. The main difference is CRandom builds on crypto-api's CryptoRandomGen, so it allows explicit failure.

crandomR (low,high) g as typically instantiated will generate a value between [low, high] inclusively, swapping the pair if high < low.

Provided instances for crandom g generates randoms between the bounds and between +/- 2^256 for Integer.

The crandomR function has degraded (theoretically unbounded, probabilistically decent) performance the closer your range size (high - low) is to 2^n (from the top).

Methods

crandom :: CryptoRandomGen g => g -> Either GenError (a, g)

crandoms :: CryptoRandomGen g => g -> [a]

Instances

CRandom Int
CRandom Int8
CRandom Int16
CRandom Int32
CRandom Int64
CRandom Word8
CRandom Word16
CRandom Word32
CRandom Word64

class CRandomR a where

Methods

crandomR :: CryptoRandomGen g => (a, a) -> g -> Either GenError (a, g)

crandomRs :: CryptoRandomGen g => (a, a) -> g -> [a]

Instances

CRandomR Int
CRandomR Int8
CRandomR Int16
CRandomR Int32
CRandomR Int64
CRandomR Integer
CRandomR Word8
CRandomR Word16
CRandomR Word32
CRandomR Word64

class (ContainsGenError e, MonadError e m) => MonadCRandom e m where

MonadCRandom m represents a monad that can produce random values (or fail with a GenError). It is suggested you use the CRandT transformer in your monad stack.

Methods

getCRandom :: CRandom a => m a

getBytes :: Int -> m ByteString

getBytesWithEntropy :: Int -> ByteString -> m ByteString

doReseed :: ByteString -> m ()

Instances

MonadCRandom e m => MonadCRandom e (ReaderT r m)
(Monoid w, MonadCRandom e m) => MonadCRandom e (WriterT w m)
(Monoid w, MonadCRandom e m) => MonadCRandom e (WriterT w m)
MonadCRandom e m => MonadCRandom e (StateT s m)
MonadCRandom e m => MonadCRandom e (StateT s m)
(ContainsGenError e, Error e, Monad m, CryptoRandomGen g) => MonadCRandom e (CRandT g e m)
(Monoid w, MonadCRandom e m) => MonadCRandom e (RWST r w s m)
(Monoid w, MonadCRandom e m) => MonadCRandom e (RWST r w s m)

class (ContainsGenError e, MonadError e m) => MonadCRandomR e m where

Methods

getCRandomR :: CRandomR a => (a, a) -> m a

Instances

MonadCRandomR e m => MonadCRandomR e (ReaderT r m)
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (WriterT w m)
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (WriterT w m)
MonadCRandomR e m => MonadCRandomR e (StateT s m)
MonadCRandomR e m => MonadCRandomR e (StateT s m)
(ContainsGenError e, Error e, Monad m, CryptoRandomGen g) => MonadCRandomR e (CRandT g e m)
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (RWST r w s m)
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (RWST r w s m)

class ContainsGenError e where

Methods

toGenError :: e -> Maybe GenError

fromGenError :: GenError -> e

Instances

ContainsGenError GenError

data CRandT g e m a

CRandT is the transformer suggested for MonadCRandom.

Instances

(Monad m, Error e) => MonadError e (CRandT g e m)
(MonadReader r m, Error e) => MonadReader r (CRandT g e m)
(MonadState s m, Error e) => MonadState s (CRandT g e m)
(MonadWriter w m, Error e) => MonadWriter w (CRandT g e m)
(ContainsGenError e, Error e, Monad m, CryptoRandomGen g) => MonadCRandomR e (CRandT g e m)
(ContainsGenError e, Error e, Monad m, CryptoRandomGen g) => MonadCRandom e (CRandT g e m)
Error e => MonadTrans (CRandT g e)
(Monad m, Error e) => Monad (CRandT g e m)
Functor m => Functor (CRandT g e m)
(MonadFix m, Error e) => MonadFix (CRandT g e m)
(Functor m, Monad m, Error e) => Applicative (CRandT g e m)
(MonadIO m, Error e) => MonadIO (CRandT g e m)
(MonadCont m, Error e) => MonadCont (CRandT g e m)

type CRand g e = CRandT g e Identity

Simple users of generators can use CRand for quick and easy generation of randoms. See below for a simple use of newGenIO (from crypto-api), getCRandom, getBytes, and runCRandom.

getRandPair = do
   int <- getCRandom
   bytes <- getBytes 100
   return (int, bytes)

func = do
   g <- newGenIO
   case runCRand getRandPair g of
       Right ((int,bytes), g') -> useRandomVals (int,bytes)
       Left x -> handleGenError x

runCRandT :: ContainsGenError e => CRandT g e m a -> g -> m (Either e (a, g))

evalCRandT :: (ContainsGenError e, Monad m) => CRandT g e m a -> g -> m (Either e a)

runCRand :: CRand g GenError a -> g -> Either GenError (a, g)

evalCRand :: CRand g GenError a -> g -> Either GenError a

newGenCRand :: (CryptoRandomGen g, MonadCRandom GenError m, Functor m) => m g

module Crypto.Random