commit 769f94dcd712b2f1903c322f1544dd0bcb7d05ec
parent 46476d6f71955fc525cd73e1d529d7569e498977
Author: Jared Tobin <jared@jtobin.io>
Date: Thu, 1 Jun 2023 20:29:27 +0400
Add single-byte XOR deciphering utility.
Diffstat:
4 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/cryptopals.cabal b/cryptopals.cabal
@@ -49,6 +49,7 @@ executable break-single-byte-xor
hs-source-dirs: src
build-depends:
base
+ , base16
, bytestring
, cryptopals
, optparse-applicative
diff --git a/lib/Cryptopals/Util.hs b/lib/Cryptopals/Util.hs
@@ -30,8 +30,6 @@ hexToB64 (Hex b) = do
fixedXor :: BS.ByteString -> BS.ByteString -> BS.ByteString
fixedXor l r = BS.pack $ BS.zipWith B.xor l r
-singleByteXor :: Word8 -> Hex -> Either T.Text Hex
-singleByteXor byt (Hex bs) = do
- s <- B16.decodeBase16 bs
- pure $ Hex (B16.encodeBase16' . BS.map (B.xor byt) $ s)
+singleByteXor :: Word8 -> BS.ByteString -> BS.ByteString
+singleByteXor byt = BS.map (B.xor byt)
diff --git a/lib/Cryptopals/Util/Similarity.hs b/lib/Cryptopals/Util/Similarity.hs
@@ -13,7 +13,7 @@ mse :: IMS.IntMap Double -> IMS.IntMap Double -> Double
mse ref tar =
let res = IMS.foldlWithKey' alg mempty ref
siz = IMS.size res
- in IMS.foldl' (\acc val -> (acc + val) / fromIntegral siz) 0 res
+ in IMS.foldl' (\acc val -> acc + val / fromIntegral siz) 0 res
where
alg acc key val = case IMS.lookup key tar of
Nothing -> acc
@@ -35,7 +35,7 @@ normalize m =
-- | Observed frequency distribution of bytes in English corpora.
english :: IMS.IntMap Double
-english = IMS.fromList [
+english = IMS.fromAscList [
(9, 0.000057)
, (23, 0.000000)
, (32, 0.171662)
diff --git a/src/BreakSingleByteXor.hs b/src/BreakSingleByteXor.hs
@@ -3,15 +3,16 @@
module Main where
-import Control.Monad (unless)
import qualified Cryptopals.Util as CU
import qualified Data.ByteString as BS
+import qualified Data.ByteString.Base16 as B16
import Data.List (foldl')
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import qualified Data.Text.Encoding as TE
import GHC.Word (Word8)
import qualified Options.Applicative as O
+import qualified System.Exit as SE
import qualified System.IO as SIO
data Args = Args { argsInp :: T.Text }
@@ -28,29 +29,33 @@ best s = foldl' alg (0, CU.score s, s) [32..126] where
then (b, sc, xo)
else acc
-render :: Show a => a -> T.Text
-render = T.pack. show
-
decipher :: Args -> IO ()
decipher Args {..} = do
- let s = TE.encodeUtf8 argsInp
+ let render :: Show a => a -> T.Text
+ render = T.pack . show
+
+ err = TIO.hPutStrLn SIO.stderr
+ out = TIO.hPutStrLn SIO.stdout
- TIO.hPutStrLn SIO.stderr $
- "cryptopals: input similarity score is " <> render (CU.score s)
+ args = B16.decodeBase16 $ TE.encodeUtf8 argsInp
- let (byt, bsc, b) = best s
+ case args of
+ Left e -> do
+ err $ "cryptopals: " <> e
+ SE.exitFailure
- unless (b == s) $ do
+ Right s -> do
+ err $ "cryptopals: input similarity score is " <> render (CU.score s)
- TIO.hPutStrLn SIO.stderr (
- "cryptopals: xor-ing with " <> render byt <>
- " yields score " <> render bsc
- )
+ let (byt, bsc, b) = best s
- TIO.hPutStrLn SIO.stderr $
- "cryptopals: result"
+ err (
+ "cryptopals: xor-ing with " <> render byt <>
+ " yields " <> render bsc
+ )
- TIO.hPutStrLn SIO.stdout $ TE.decodeUtf8 b
+ err $ "cryptopals: result"
+ out . TE.decodeUtf8 . B16.encodeBase16' $ b
main :: IO ()
main = do
