diff --git a/Crypto/Tutorial.hs b/Crypto/Tutorial.hs index 83487c7..f0bdb97 100644 --- a/Crypto/Tutorial.hs +++ b/Crypto/Tutorial.hs @@ -1,34 +1,65 @@ -{-# OPTIONS_GHC -fno-warn-unused-imports #-} -{-# LANGUAGE OverloadedStrings #-} -{-| How to use @cryptonite@ +{- How to use @cryptonite@ with symmetric block ciphers -> -- | Beware MUST BE 256bits as we use AES256 -> import Data.ByteString (ByteString) -> import Crypto.Cipher.AES (AES256) -> import Crypto.Cipher.Types (BlockCipher(..), Cipher(..),nullIV) -> import Crypto.Error (CryptoFailable(..)) -> -> secretKey :: ByteString -> secretKey = "012-456-89A-CDE-012-456-89A-CDE-" -> -> encrypt :: ByteString -> ByteString -> ByteString -> encrypt secret = ctrCombine ctx nullIV -> where -> ctx = cipherInitNoErr (cipherMakeKey (undefined :: AES256) secret) -> cipherInitNoErr :: BlockCipher c => Key c -> c -> cipherInitNoErr (Key k) = case cipherInit k of -> CryptoPassed a -> a -> CryptoFailed e -> error (show e) -> cipherMakeKey :: Cipher cipher => cipher -> ByteString -> Key cipher -> cipherMakeKey _ = Key -- Yeah Lazyness!!!!!! -> -> -> decrypt :: ByteString -> ByteString -> ByteString +> {-# LANGUAGE OverloadedStrings #-} +> {-# LANGUAGE ScopedTypeVariables #-} +> {-# LANGUAGE GADTs #-} +> +> import Crypto.Cipher.AES (AES256) +> import Crypto.Cipher.Types (BlockCipher(..), Cipher(..), nullIV, KeySizeSpecifier(..), IV, makeIV) +> import Crypto.Error (CryptoFailable(..), CryptoError(..)) +> +> import qualified Crypto.Random.Types as CRT +> +> import Data.ByteArray (ByteArray) +> import Data.ByteString (ByteString) +> +> -- | Not required, but most general implementation +> data Key c a where +> Key :: (BlockCipher c, ByteArray a) => a -> Key c a +> +> -- | Generates a string of bytes (key) of a specific length for a given block cipher +> genSecretKey :: forall m c a. (CRT.MonadRandom m, BlockCipher c, ByteArray a) => c -> Int -> m (Key c a) +> genSecretKey _ = fmap Key . CRT.getRandomBytes +> +> -- | Generate a random initialization vector for a given block cipher +> genRandomIV :: forall m c. (CRT.MonadRandom m, BlockCipher c) => c -> m (Maybe (IV c)) +> genRandomIV _ = do +> bytes :: ByteString <- CRT.getRandomBytes $ blockSize (undefined :: c) +> return $ makeIV bytes +> +> -- | Initialize a block cipher +> initCipher :: (BlockCipher c, ByteArray a) => Key c a -> Either CryptoError c +> initCipher (Key k) = case cipherInit k of +> CryptoFailed e -> Left e +> CryptoPassed a -> Right a +> +> encrypt :: (BlockCipher c, ByteArray a) => Key c a -> IV c -> a -> Either CryptoError a +> encrypt secretKey initIV msg = +> case initCipher secretKey of +> Left e -> Left e +> Right c -> Right $ ctrCombine c initIV msg +> +> decrypt :: (BlockCipher c, ByteArray a) => Key c a -> IV c -> a -> Either CryptoError a > decrypt = encrypt +> +> exampleAES256 :: ByteString -> IO () +> exampleAES256 msg = do +> -- secret key needs 256 bits (32 * 8) +> secretKey <- genSecretKey (undefined :: AES256) 32 +> mInitIV <- genRandomIV (undefined :: AES256) +> case mInitIV of +> Nothing -> error "Failed to generate and initialization vector." +> Just initIV -> do +> let encryptedMsg = encrypt secretKey initIV msg +> decryptedMsg = decrypt secretKey initIV =<< encryptedMsg +> case (,) <$> encryptedMsg <*> decryptedMsg of +> Left err -> error $ show err +> Right (eMsg, dMsg) -> do +> putStrLn $ "Original Message: " ++ show msg +> putStrLn $ "Message after encryption: " ++ show eMsg +> putStrLn $ "Message after decryption: " ++ show dMsg |-} -module Crypto.Tutorial () where - -import Crypto.Cipher.Types +module Crypto.Tutorial where