diff --git a/Crypto/Classes.hs b/Crypto/Classes.hs --- a/Crypto/Classes.hs +++ b/Crypto/Classes.hs @@ -80,14 +80,18 @@ remlen = B.length msg - (B.length msg `rem` bLen) bLen = blockLength `for` res `div` 8 --- |Obtain a lazy hash function from a digest +-- |Obtain a lazy hash function whose result is the same type +-- as the given digest, which is discarded. If the type is already inferred then +-- consider using the 'hash' function instead. hashFunc :: Hash c d => d -> (L.ByteString -> d) hashFunc d = f where f = hash a = f undefined `asTypeOf` d --- |Obtain a strict hash function from a digest +-- |Obtain a strict hash function whose result is the same type +-- as the given digest, which is discarded. If the type is already inferred then +-- consider using the 'hash'' function instead. hashFunc' :: Hash c d => d -> (B.ByteString -> d) hashFunc' d = f where diff --git a/Crypto/Random.hs b/Crypto/Random.hs --- a/Crypto/Random.hs +++ b/Crypto/Random.hs @@ -22,38 +22,48 @@ -} module Crypto.Random - ( -- * Basic Interface - CryptoRandomGen(..) - , GenError (..) - -- * Helper functions and expanded interface - , splitGen - -- * Instances - , SystemRandom - ) where + ( -- * Basic Interface + CryptoRandomGen(..) + , GenError (..) + -- * Helper functions and expanded interface + , splitGen + -- * Instances + , SystemRandom + ) where -import System.Entropy -import Crypto.Types import Control.Monad (liftM) -import qualified Data.ByteString as B -import qualified Data.ByteString.Lazy as L -import Data.Tagged +import Crypto.Types import Data.Bits (xor, setBit, shiftR, shiftL, (.&.)) import Data.List (foldl') +import Data.Tagged +import System.Entropy import System.IO.Unsafe(unsafeInterleaveIO) +import qualified Data.ByteString as B +import qualified Data.ByteString.Lazy as L import qualified Foreign.ForeignPtr as FP #if MIN_VERSION_tagged(0,2,0) import Data.Proxy #endif --- |many generators have these error conditions in common +-- |Generator failures should always return the appropriate GenError. data GenError = 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') + | 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') deriving (Eq, Ord, Show) -- |A class of random bit generators that allows for the possibility @@ -128,7 +138,9 @@ newGenIO :: IO g newGenIO = go 0 where - go 1000 = error "The generator instance requested by newGenIO never instantiates (1000 tries). It must be broken." + go 1000 = error $ "The generator instance requested by" ++ + "newGenIO never instantiates (1000 tries). " ++ + "It must be broken." go i = do let p = Proxy getTypedGen :: (CryptoRandomGen g) => Proxy g -> IO (Either GenError g) @@ -164,17 +176,18 @@ data SystemRandom = SysRandom L.ByteString instance CryptoRandomGen SystemRandom where - newGen _ = Left NeedsInfiniteSeed - genSeedLength = Tagged maxBound - genBytes req (SysRandom bs) = - let reqI = fromIntegral req - rnd = L.take reqI bs - rest = L.drop reqI bs - in if L.length rnd == reqI - then Right (B.concat $ L.toChunks rnd, SysRandom rest) - else Left $ GenErrorOther "Error obtaining enough bytes from system random for given request" - reseed _ _ = Left NeedsInfiniteSeed - newGenIO = getSystemGen + newGen _ = Left NeedsInfiniteSeed + genSeedLength = Tagged maxBound + genBytes req (SysRandom bs) = + let reqI = fromIntegral req + rnd = L.take reqI bs + rest = L.drop reqI bs + in if L.length rnd == reqI + then Right (B.concat $ L.toChunks rnd, SysRandom rest) + else Left $ GenErrorOther "Error obtaining enough bytes \ + \from system random for given request" + reseed _ _ = Left NeedsInfiniteSeed + newGenIO = getSystemGen -- | While the safety and wisdom of a splitting function depends on the -- properties of the generator being split, several arguments from @@ -182,14 +195,14 @@ -- generators. (see libraries\@haskell.org discussion around Sept, Oct -- 2010) splitGen :: CryptoRandomGen g => g -> Either GenError (g,g) -splitGen g = do - let e = genBytes (genSeedLength `for` g) g - case e of +splitGen g = + let e = genBytes (genSeedLength `for` g) g + in case e of + Left e -> Left e + Right (ent,g') -> + case newGen ent of + Right new -> Right (g',new) Left e -> Left e - Right (ent,g') -> - case newGen ent of - Right new -> Right (g',new) - Left e -> Left e -- |Obtain a tagged value for a particular instantiated type. for :: Tagged a b -> a -> b diff --git a/crypto-api.cabal b/crypto-api.cabal --- a/crypto-api.cabal +++ b/crypto-api.cabal @@ -1,5 +1,5 @@ name: crypto-api -version: 0.6.3 +version: 0.6.4 license: BSD3 license-file: LICENSE copyright: Thomas DuBuisson , Francisco Blas Izquierdo Riera (klondike) (see AUTHORS) @@ -54,7 +54,7 @@ cereal >= 0.2 && < 0.4, tagged >= 0.1 && < 0.3, largeword >= 1.0.0, array, entropy - ghc-options: -O2 + ghc-options: hs-source-dirs: exposed-modules: Crypto.Classes, Crypto.Types, Crypto.HMAC, Crypto.Modes, Crypto.Random, Crypto.Padding, System.Crypto.Random other-modules: Crypto.Util, Crypto.CPoly