Maintainer	Thomas.DuBuisson@gmail.com
Stability	beta
Portability	portable
Safe Haskell	None
Language	Haskell98

Control.Monad.CryptoRandom

Description

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

Synopsis

class CRandom a where
- crandom :: CryptoRandomGen g => g -> Either GenError (a, g)
- crandoms :: CryptoRandomGen g => g -> [a]
class CRandomR a where
- crandomR :: CryptoRandomGen g => (a, a) -> g -> Either GenError (a, g)
- crandomRs :: CryptoRandomGen g => (a, a) -> g -> [a]
class (ContainsGenError e, MonadError e m) => MonadCRandom e m where
- getCRandom :: CRandom a => m a
- getBytes :: Int -> m ByteString
- getBytesWithEntropy :: Int -> ByteString -> m ByteString
- doReseed :: ByteString -> m ()
class (ContainsGenError e, MonadError e m) => MonadCRandomR e m where
- getCRandomR :: CRandomR a => (a, a) -> m a
class ContainsGenError e where
- toGenError :: e -> Maybe GenError
- fromGenError :: GenError -> e
newtype CRandT g e m a = CRandT {
- unCRandT :: StateT g (ExceptT e m) a
}
type CRand g e = CRandT g e Identity
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 :: ContainsGenError e => CRand g e a -> g -> Either e (a, g)
evalCRand :: CRand g GenError a -> g -> Either GenError a
newGenCRand :: (CryptoRandomGen g, MonadCRandom GenError m, Functor m) => m g
liftCRand :: (g -> Either e (a, g)) -> CRand g e a
liftCRandT :: Monad m => (g -> Either e (a, g)) -> CRandT g e m a
data GenError
- = GenErrorOther String
- | RequestedTooManyBytes
- | RangeInvalid
- | NeedReseed
- | NotEnoughEntropy
- | NeedsInfiniteSeed
class CryptoRandomGen g where
- newGen :: ByteString -> Either GenError g
- genSeedLength :: Tagged g ByteLength
- genBytes :: ByteLength -> g -> Either GenError (ByteString, g)
- reseedInfo :: g -> ReseedInfo
- reseedPeriod :: g -> ReseedInfo
- genBytesWithEntropy :: ByteLength -> ByteString -> g -> Either GenError (ByteString, g)
- reseed :: ByteString -> g -> Either GenError g
- newGenIO :: IO g

Documentation

class CRandom a where Source #

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).

Minimal complete definition

crandom

Methods

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

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

Instances

Instances details

CRandom Bool Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Bool, g) Source # crandoms :: CryptoRandomGen g => g -> [Bool] Source #
CRandom Int Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Int, g) Source # crandoms :: CryptoRandomGen g => g -> [Int] Source #
CRandom Int8 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Int8, g) Source # crandoms :: CryptoRandomGen g => g -> [Int8] Source #
CRandom Int16 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Int16, g) Source # crandoms :: CryptoRandomGen g => g -> [Int16] Source #
CRandom Int32 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Int32, g) Source # crandoms :: CryptoRandomGen g => g -> [Int32] Source #
CRandom Int64 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Int64, g) Source # crandoms :: CryptoRandomGen g => g -> [Int64] Source #
CRandom Word8 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Word8, g) Source # crandoms :: CryptoRandomGen g => g -> [Word8] Source #
CRandom Word16 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Word16, g) Source # crandoms :: CryptoRandomGen g => g -> [Word16] Source #
CRandom Word32 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Word32, g) Source # crandoms :: CryptoRandomGen g => g -> [Word32] Source #
CRandom Word64 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandom :: CryptoRandomGen g => g -> Either GenError (Word64, g) Source # crandoms :: CryptoRandomGen g => g -> [Word64] Source #

class CRandomR a where Source #

Minimal complete definition

crandomR

Methods

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

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

Instances

Instances details

CRandomR Int Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Int, Int) -> g -> Either GenError (Int, g) Source # crandomRs :: CryptoRandomGen g => (Int, Int) -> g -> [Int] Source #
CRandomR Int8 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Int8, Int8) -> g -> Either GenError (Int8, g) Source # crandomRs :: CryptoRandomGen g => (Int8, Int8) -> g -> [Int8] Source #
CRandomR Int16 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Int16, Int16) -> g -> Either GenError (Int16, g) Source # crandomRs :: CryptoRandomGen g => (Int16, Int16) -> g -> [Int16] Source #
CRandomR Int32 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Int32, Int32) -> g -> Either GenError (Int32, g) Source # crandomRs :: CryptoRandomGen g => (Int32, Int32) -> g -> [Int32] Source #
CRandomR Int64 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Int64, Int64) -> g -> Either GenError (Int64, g) Source # crandomRs :: CryptoRandomGen g => (Int64, Int64) -> g -> [Int64] Source #
CRandomR Integer Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Integer, Integer) -> g -> Either GenError (Integer, g) Source # crandomRs :: CryptoRandomGen g => (Integer, Integer) -> g -> [Integer] Source #
CRandomR Word8 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Word8, Word8) -> g -> Either GenError (Word8, g) Source # crandomRs :: CryptoRandomGen g => (Word8, Word8) -> g -> [Word8] Source #
CRandomR Word16 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Word16, Word16) -> g -> Either GenError (Word16, g) Source # crandomRs :: CryptoRandomGen g => (Word16, Word16) -> g -> [Word16] Source #
CRandomR Word32 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Word32, Word32) -> g -> Either GenError (Word32, g) Source # crandomRs :: CryptoRandomGen g => (Word32, Word32) -> g -> [Word32] Source #
CRandomR Word64 Source #
Instance details Defined in Control.Monad.CryptoRandom Methods crandomR :: CryptoRandomGen g => (Word64, Word64) -> g -> Either GenError (Word64, g) Source # crandomRs :: CryptoRandomGen g => (Word64, Word64) -> g -> [Word64] Source #

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

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 Source #

getBytes :: Int -> m ByteString Source #

getBytesWithEntropy :: Int -> ByteString -> m ByteString Source #

doReseed :: ByteString -> m () Source #

Instances

Instances details

MonadCRandom e m => MonadCRandom e (ReaderT r m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => ReaderT r m a Source # getBytes :: Int -> ReaderT r m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> ReaderT r m ByteString Source # doReseed :: ByteString -> ReaderT r m () Source #
(Monoid w, MonadCRandom e m) => MonadCRandom e (WriterT w m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => WriterT w m a Source # getBytes :: Int -> WriterT w m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> WriterT w m ByteString Source # doReseed :: ByteString -> WriterT w m () Source #
(Monoid w, MonadCRandom e m) => MonadCRandom e (WriterT w m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => WriterT w m a Source # getBytes :: Int -> WriterT w m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> WriterT w m ByteString Source # doReseed :: ByteString -> WriterT w m () Source #
MonadCRandom e m => MonadCRandom e (StateT s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => StateT s m a Source # getBytes :: Int -> StateT s m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> StateT s m ByteString Source # doReseed :: ByteString -> StateT s m () Source #
MonadCRandom e m => MonadCRandom e (StateT s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => StateT s m a Source # getBytes :: Int -> StateT s m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> StateT s m ByteString Source # doReseed :: ByteString -> StateT s m () Source #
(ContainsGenError e, Monad m, CryptoRandomGen g) => MonadCRandom e (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => CRandT g e m a Source # getBytes :: Int -> CRandT g e m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> CRandT g e m ByteString Source # doReseed :: ByteString -> CRandT g e m () Source #
(Monoid w, MonadCRandom e m) => MonadCRandom e (RWST r w s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => RWST r w s m a Source # getBytes :: Int -> RWST r w s m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> RWST r w s m ByteString Source # doReseed :: ByteString -> RWST r w s m () Source #
(Monoid w, MonadCRandom e m) => MonadCRandom e (RWST r w s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => RWST r w s m a Source # getBytes :: Int -> RWST r w s m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> RWST r w s m ByteString Source # doReseed :: ByteString -> RWST r w s m () Source #

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

Methods

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

Instances

Instances details

MonadCRandomR e m => MonadCRandomR e (ReaderT r m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> ReaderT r m a Source #
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (WriterT w m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> WriterT w m a Source #
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (WriterT w m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> WriterT w m a Source #
MonadCRandomR e m => MonadCRandomR e (StateT s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> StateT s m a Source #
MonadCRandomR e m => MonadCRandomR e (StateT s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> StateT s m a Source #
(ContainsGenError e, Monad m, CryptoRandomGen g) => MonadCRandomR e (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> CRandT g e m a Source #
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (RWST r w s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> RWST r w s m a Source #
(MonadCRandomR e m, Monoid w) => MonadCRandomR e (RWST r w s m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> RWST r w s m a Source #

class ContainsGenError e where Source #

Methods

toGenError :: e -> Maybe GenError Source #

fromGenError :: GenError -> e Source #

Instances

Instances details

ContainsGenError GenError Source #
Instance details Defined in Control.Monad.CryptoRandom Methods toGenError :: GenError -> Maybe GenError Source # fromGenError :: GenError -> GenError Source #

newtype CRandT g e m a Source #

CRandT is the transformer suggested for MonadCRandom.

Constructors

CRandT
Fields unCRandT :: StateT g (ExceptT e m) a

Instances

Instances details

Monad m => MonadError e (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods throwError :: e -> CRandT g e m a catchError :: CRandT g e m a -> (e -> CRandT g e m a) -> CRandT g e m a
MonadReader r m => MonadReader r (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods ask :: CRandT g e m r local :: (r -> r) -> CRandT g e m a -> CRandT g e m a reader :: (r -> a) -> CRandT g e m a
MonadState s m => MonadState s (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods get :: CRandT g e m s put :: s -> CRandT g e m () state :: (s -> (a, s)) -> CRandT g e m a
MonadWriter w m => MonadWriter w (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods writer :: (a, w) -> CRandT g e m a tell :: w -> CRandT g e m () listen :: CRandT g e m a -> CRandT g e m (a, w) pass :: CRandT g e m (a, w -> w) -> CRandT g e m a
(ContainsGenError e, Monad m, CryptoRandomGen g) => MonadCRandomR e (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandomR :: CRandomR a => (a, a) -> CRandT g e m a Source #
(ContainsGenError e, Monad m, CryptoRandomGen g) => MonadCRandom e (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods getCRandom :: CRandom a => CRandT g e m a Source # getBytes :: Int -> CRandT g e m ByteString Source # getBytesWithEntropy :: Int -> ByteString -> CRandT g e m ByteString Source # doReseed :: ByteString -> CRandT g e m () Source #
MonadTrans (CRandT g e) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods lift :: Monad m => m a -> CRandT g e m a
Monad m => Monad (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods (>>=) :: CRandT g e m a -> (a -> CRandT g e m b) -> CRandT g e m b (>>) :: CRandT g e m a -> CRandT g e m b -> CRandT g e m b return :: a -> CRandT g e m a
Functor m => Functor (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods fmap :: (a -> b) -> CRandT g e m a -> CRandT g e m b (<$) :: a -> CRandT g e m b -> CRandT g e m a
MonadFix m => MonadFix (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods mfix :: (a -> CRandT g e m a) -> CRandT g e m a
Monad m => Applicative (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods pure :: a -> CRandT g e m a (<>) :: CRandT g e m (a -> b) -> CRandT g e m a -> CRandT g e m b liftA2 :: (a -> b -> c) -> CRandT g e m a -> CRandT g e m b -> CRandT g e m c (>) :: CRandT g e m a -> CRandT g e m b -> CRandT g e m b (<*) :: CRandT g e m a -> CRandT g e m b -> CRandT g e m a
MonadThrow m => MonadThrow (CRandT g e m) Source #	Throws exceptions into the base monad. Since: 0.7.1
Instance details Defined in Control.Monad.CryptoRandom Methods throwM :: Exception e0 => e0 -> CRandT g e m a Source #
MonadCatch m => MonadCatch (CRandT g e m) Source #	Catches exceptions from the base monad. Since: 0.7.1
Instance details Defined in Control.Monad.CryptoRandom Methods catch :: Exception e0 => CRandT g e m a -> (e0 -> CRandT g e m a) -> CRandT g e m a Source #
MonadIO m => MonadIO (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods liftIO :: IO a -> CRandT g e m a
MonadCont m => MonadCont (CRandT g e m) Source #
Instance details Defined in Control.Monad.CryptoRandom Methods callCC :: ((a -> CRandT g e m b) -> CRandT g e m a) -> CRandT g e m a

type CRand g e = CRandT g e Identity Source #

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)) Source #

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

runCRand :: ContainsGenError e => CRand g e a -> g -> Either e (a, g) Source #

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

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

liftCRand :: (g -> Either e (a, g)) -> CRand g e a Source #

liftCRandT :: Monad m => (g -> Either e (a, g)) -> CRandT g e m a Source #

data GenError Source #

Generator failures should always return the appropriate GenError. Note GenError in an instance of exception but wether or not an exception is thrown depends on if the selected generator (read: if you don't want execptions from code that uses throw then pass in a generator that never has an error for the used functions)

Constructors

GenErrorOther String	Misc
RequestedTooManyBytes	Requested more bytes than a single pass can generate (The maximum request is generator dependent)
RangeInvalid	When using `genInteger g (l,h)` and `logBase 2 (h - l) > (maxBound :: Int)`.
NeedReseed	Some generators cease operation after too high a count without a reseed (ex: NIST SP 800-90)
NotEnoughEntropy	For instantiating new generators (or reseeding)
NeedsInfiniteSeed	This generator can not be instantiated or reseeded with a finite seed (ex: `SystemRandom`)

Instances

Instances details

Eq GenError
Instance details Defined in Crypto.Random Methods (==) :: GenError -> GenError -> Bool (/=) :: GenError -> GenError -> Bool
Data GenError
Instance details Defined in Crypto.Random Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> GenError -> c GenError gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c GenError toConstr :: GenError -> Constr dataTypeOf :: GenError -> DataType dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c GenError) dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c GenError) gmapT :: (forall b. Data b => b -> b) -> GenError -> GenError gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> GenError -> r gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> GenError -> r gmapQ :: (forall d. Data d => d -> u) -> GenError -> [u] gmapQi :: Int -> (forall d. Data d => d -> u) -> GenError -> u gmapM :: Monad m => (forall d. Data d => d -> m d) -> GenError -> m GenError gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> GenError -> m GenError gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> GenError -> m GenError
Ord GenError
Instance details Defined in Crypto.Random Methods compare :: GenError -> GenError -> Ordering (<) :: GenError -> GenError -> Bool (<=) :: GenError -> GenError -> Bool (>) :: GenError -> GenError -> Bool (>=) :: GenError -> GenError -> Bool max :: GenError -> GenError -> GenError min :: GenError -> GenError -> GenError
Read GenError
Instance details Defined in Crypto.Random Methods readsPrec :: Int -> ReadS GenError readList :: ReadS [GenError] readPrec :: ReadPrec GenError readListPrec :: ReadPrec [GenError]
Show GenError
Instance details Defined in Crypto.Random Methods showsPrec :: Int -> GenError -> ShowS show :: GenError -> String showList :: [GenError] -> ShowS
Exception GenError
Instance details Defined in Crypto.Random Methods toException :: GenError -> SomeException # fromException :: SomeException -> Maybe GenError # displayException :: GenError -> String #
ContainsGenError GenError Source #
Instance details Defined in Control.Monad.CryptoRandom Methods toGenError :: GenError -> Maybe GenError Source # fromGenError :: GenError -> GenError Source #

class CryptoRandomGen g where Source #

A class of random bit generators that allows for the possibility of failure, reseeding, providing entropy at the same time as requesting bytes

Minimum complete definition: newGen, genSeedLength, genBytes, reseed, reseedInfo, reseedPeriod.

Minimal complete definition

newGen, genSeedLength, genBytes, reseedInfo, reseedPeriod, reseed

Methods

newGen :: ByteString -> Either GenError g Source #

Instantiate a new random bit generator. The provided bytestring should be of length >= genSeedLength. If the bytestring is shorter then the call may fail (suggested error: NotEnoughEntropy). If the bytestring is of sufficent length the call should always succeed.

genSeedLength :: Tagged g ByteLength Source #

Length of input entropy necessary to instantiate or reseed a generator

genBytes :: ByteLength -> g -> Either GenError (ByteString, g) Source #

genBytes len g generates a random ByteString of length len and new generator. The MonadCryptoRandom package has routines useful for converting the ByteString to commonly needed values (but "cereal" or other deserialization libraries would also work).

This routine can fail if the generator has gone too long without a reseed (usually this is in the ball-park of 2^48 requests). Suggested error in this cases is NeedReseed

reseedInfo :: g -> ReseedInfo Source #

Indicates how soon a reseed is needed

reseedPeriod :: g -> ReseedInfo Source #

Indicates the period between reseeds (constant for most generators).

genBytesWithEntropy :: ByteLength -> ByteString -> g -> Either GenError (ByteString, g) Source #

genBytesWithEntropy g i entropy generates i random bytes and use the additional input entropy in the generation of the requested data to increase the confidence our generated data is a secure random stream.

Some generators use entropy to perturb the state of the generator, meaning:

    (_,g2') <- genBytesWithEntropy len g1 ent
    (_,g2 ) <- genBytes len g1
    g2 /= g2'

But this is not required.

Default:

    genBytesWithEntropy g bytes entropy = xor entropy (genBytes g bytes)

reseed :: ByteString -> g -> Either GenError g Source #

If the generator has produced too many random bytes on its existing seed it will return NeedReseed. In that case, reseed the generator using this function and a new high-entropy seed of length >= genSeedLength. Using bytestrings that are too short can result in an error (NotEnoughEntropy).

newGenIO :: IO g Source #

By default this uses System.Entropy to obtain entropy for newGen. WARNING: The default implementation opens a file handle which will never be closed!

Instances

Instances details

CryptoRandomGen SystemRandom

Instance details

Defined in Crypto.Random

Methods

newGen :: ByteString -> Either GenError SystemRandom Source #

genSeedLength :: Tagged SystemRandom ByteLength Source #

genBytes :: ByteLength -> SystemRandom -> Either GenError (ByteString, SystemRandom) Source #

reseedInfo :: SystemRandom -> ReseedInfo Source #

reseedPeriod :: SystemRandom -> ReseedInfo Source #

genBytesWithEntropy :: ByteLength -> ByteString -> SystemRandom -> Either GenError (ByteString, SystemRandom) Source #

reseed :: ByteString -> SystemRandom -> Either GenError SystemRandom Source #

newGenIO :: IO SystemRandom Source #