d7e26e34ee
It decomposes the drgNew call that was gathering entropy then initializing a ChaChaDRG, into 2 new calls seedNew and drgNewSeed. drgNew remains unchanged. The integer importing capability, should be used when wanting to bring reproducibility to a debugging problem or for testing, otherwise it's probably a bad idea to use.
83 lines
2.3 KiB
Haskell
83 lines
2.3 KiB
Haskell
-- |
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-- Module : Crypto.Random
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-- License : BSD-style
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-- Maintainer : Vincent Hanquez <vincent@snarc.org>
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-- Stability : stable
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-- Portability : good
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--
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{-# LANGUAGE GeneralizedNewtypeDeriving #-}
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module Crypto.Random
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(
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-- * Deterministic instances
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ChaChaDRG
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, SystemDRG
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, Seed
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-- * Seed
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, seedNew
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, seedFromInteger
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, seedToInteger
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-- * Deterministic Random class
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, getSystemDRG
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, drgNew
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, drgNewSeed
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, drgNewTest
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, withDRG
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, withRandomBytes
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, DRG(..)
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-- * Random abstraction
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, MonadRandom(..)
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, MonadPseudoRandom
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) where
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import Crypto.Random.Types
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import Crypto.Random.ChaChaDRG
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import Crypto.Random.SystemDRG
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import Data.ByteArray (ByteArray, ByteArrayAccess, ScrubbedBytes)
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import Crypto.Internal.Imports
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import qualified Crypto.Number.Serialize as Serialize
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newtype Seed = Seed ScrubbedBytes
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deriving (ByteArrayAccess)
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-- Length for ChaCha DRG seed
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seedLength :: Int
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seedLength = 40
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-- | Create a new Seed from system entropy
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seedNew :: MonadRandom randomly => randomly Seed
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seedNew = Seed `fmap` getRandomBytes seedLength
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-- | Convert a Seed to an integer
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seedToInteger :: Seed -> Integer
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seedToInteger (Seed b) = Serialize.os2ip b
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-- | Convert an integer to a Seed
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seedFromInteger :: Integer -> Seed
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seedFromInteger i = Seed $ Serialize.i2ospOf_ seedLength (i `mod` 2^(seedLength * 8))
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-- | Create a new DRG from system entropy
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drgNew :: MonadRandom randomly => randomly ChaChaDRG
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drgNew = drgNewSeed `fmap` seedNew
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-- | Create a new DRG from a seed
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drgNewSeed :: Seed -> ChaChaDRG
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drgNewSeed (Seed seed) = initialize seed
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-- | Create a new DRG from 5 Word64.
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--
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-- This is a convenient interface to create deterministic interface
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-- for quickcheck style testing.
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--
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-- It can also be used in other contexts provided the input
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-- has been properly randomly generated.
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drgNewTest :: (Word64, Word64, Word64, Word64, Word64) -> ChaChaDRG
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drgNewTest = initializeWords
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-- | Generate @len random bytes and mapped the bytes to the function @f.
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--
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-- This is equivalent to use Control.Arrow 'first' with 'randomBytesGenerate'
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withRandomBytes :: (ByteArray ba, DRG g) => g -> Int -> (ba -> a) -> (a, g)
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withRandomBytes rng len f = (f bs, rng')
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where (bs, rng') = randomBytesGenerate len rng
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