[ChaCha] only need ByteArrayAccess for initialization

2017-07-07 17:31:30 +01:00 · 2017-07-07 17:31:30 +01:00 · f559c7bd9d
commit f559c7bd9d
parent cb293eb6db
1 changed files with 4 additions and 2 deletions
--- a/Crypto/Cipher/ChaCha.hs
+++ b/Crypto/Cipher/ChaCha.hs
@ -54,11 +54,13 @@ initialize nbRounds key nonce
        nonceLen = B.length nonce

 -- | Initialize simple ChaCha State
-initializeSimple :: ByteArray seed
+--
+-- The seed need to be at least 40 bytes long
+initializeSimple :: ByteArrayAccess seed
                 => seed -- ^ a 40 bytes long seed
                 -> StateSimple
 initializeSimple seed
-    | sLen /= 40 = error "ChaCha Random: seed length should be 40 bytes"
+    | sLen < 40 = error "ChaCha Random: seed length should be 40 bytes"
    | otherwise = unsafeDoIO $ do
        stPtr <- B.alloc 64 $ \stPtr ->
                    B.withByteArray seed $ \seedPtr ->