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|
-- |
-- Module : Crypto.Random.Generator
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : Good
--
module Crypto.Random.Generator
( CPRG(..)
) where
import Data.ByteString (ByteString)
import Crypto.Random.Entropy (EntropyPool)
-- | Cryptographic Pseudo Random Generator
class CPRG gen where
-- | Create a new CPRG using an object of the CryptoGenerator class
-- and with an explicit reference to an EntropyPool.
cprgCreate :: EntropyPool -> gen
-- | Give the ability to set a threshold of byte generated that after
-- being exceeded will result in a reseed with some stateful entropy
-- after a call to 'cprgGenerate'
--
-- If this threshold is exceeded during the set operation, the
-- rng should be reseeded here.
--
-- If this value is set to 0, no reseeding will be done and the
-- output will be completely predicable. This is not a recommended
-- level except for debugging and testing purpose.
cprgSetReseedThreshold :: Int -> gen -> gen
-- | Fork a CPRG into a new independent CPRG.
--
-- As entropy is mixed to generate safely a new generator,
-- 2 calls with the same CPRG will not produce the same output.
cprgFork :: gen -> (gen, gen)
-- | Generate a number of bytes using the CPRG.
--
-- Given one CPRG, the generated bytes will always be the same.
--
-- However the returned CPRG might have been reseeded with entropy bits,
-- so 2 calls with the same CPRG will not necessarily result in the same next CPRG.
cprgGenerate :: Int -> gen -> (ByteString, gen)
-- | Similar to cprgGenerate except that the random data is mixed with pure entropy,
-- so the result is not reproducible after use, but it provides more guarantee,
-- theorically speaking, in term of the randomness generated.
cprgGenerateWithEntropy :: Int -> gen -> (ByteString, gen)
|
