-- | -- 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)