From c84acf079e65f3feebab73c9fe1bdde8dd81aab1 Mon Sep 17 00:00:00 2001
From: Vincent Hanquez <vincent@snarc.org>
Date: Sun, 27 Jul 2014 11:09:45 -0700
Subject: [PATCH] add Scrypt placeholder

---
 Crypto/KDF/Scrypt.hs | 41 +++++++++++++++++++++++++++++++++++++++++
 cryptonite.cabal     |  1 +
 2 files changed, 42 insertions(+)
 create mode 100644 Crypto/KDF/Scrypt.hs

diff --git a/Crypto/KDF/Scrypt.hs b/Crypto/KDF/Scrypt.hs
new file mode 100644
index 0000000..693c1dd
--- /dev/null
+++ b/Crypto/KDF/Scrypt.hs
@@ -0,0 +1,41 @@
+-- |
+-- Module      : Crypto.KDF.Scrypt
+-- License     : BSD-style
+-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
+-- Stability   : experimental
+-- Portability : unknown
+--
+-- Scrypt key derivation function as defined in Colin Percival's paper "Stronger Key Derivation via Sequential Memory-Hard Functions" <http://www.tarsnap.com/scrypt/scrypt.pdf>.
+--
+{-# LANGUAGE BangPatterns #-}
+module Crypto.KDF.Scrypt
+    ( Parameters(..)
+    , generate
+    ) where
+
+import Data.Word
+import Data.Bits
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as B
+import qualified Data.ByteString.Internal as B (unsafeCreate, memset)
+import Data.Byteable
+import Foreign.Storable
+import Foreign.Ptr (Ptr, plusPtr)
+import Control.Applicative
+import Control.Monad (forM_, void)
+
+import qualified Crypto.KDF.PBKDF2 as PBKDF2
+
+-- | Parameters for Scrypt
+data Parameters = Parameters
+    { password     :: ByteString -- ^ Password (bytes encoded)
+    , salt         :: ByteString -- ^ Salt (bytes encoded)
+    , n            :: Int        -- ^ Cpu/Memory cost ratio. must be a power of 2 greater than 1
+    , r            :: Int        -- ^ Must satisfy r * p < 2^30
+    , p            :: Int        -- ^ Must satisfy r * p < 2^30
+    , outputLength :: Int        -- ^ the number of bytes to generate out of Scrypt
+    }
+
+-- | Generate the scrypt key derivation data
+generate :: Parameters -> B.ByteString
+generate params = undefined
diff --git a/cryptonite.cabal b/cryptonite.cabal
index 7066e1f..196e3b9 100644
--- a/cryptonite.cabal
+++ b/cryptonite.cabal
@@ -48,6 +48,7 @@ Library
   Other-modules:     Crypto.Hash.Internal
                    , Crypto.Hash.Utils
                    , Crypto.Hash.Types
+                   , Crypto.KDF.Scrypt
                    , Crypto.Random.Entropy.Source
   Build-depends:     base >= 4 && < 5
                    , bytestring