improve types

2 files changed, 12 insertions, 2 deletions

diff --git a/Cost.hs b/Cost.hs
index 0425707..5fd003f 100644
--- a/Cost.hs
+++ b/Cost.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving, MultiParamTypeClasses #-}
 
 module Cost where
 
@@ -74,3 +74,10 @@ data UnknownPassword
 bruteForceLinearSearch :: Cost step -> CostCalc BruteForceOp t
 bruteForceLinearSearch stepcost e = 
 	castCost stepcost `raiseCostPower` reduceEntropy e 1
+
+-- | Things that can be brute-forced expose a CostCalc.
+class Bruteforceable t a where
+	getBruteCostCalc :: t -> CostCalc BruteForceOp a
+
+estimateBruteforceOf :: Bruteforceable t a => t -> Entropy a -> Cost BruteForceOp
+estimateBruteforceOf t e = getBruteCostCalc t e
diff --git a/Encryption.hs b/Encryption.hs
index 98afdfd..23da288 100644
--- a/Encryption.hs
+++ b/Encryption.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings, MultiParamTypeClasses #-}
 
 module Encryption where
 
@@ -19,6 +19,9 @@ data KeyEncryptionKey = KeyEncryptionKey
 	(Cost DecryptionOp) 
 	(CostCalc BruteForceOp UnknownPassword)
 
+instance Bruteforceable KeyEncryptionKey UnknownPassword where
+	getBruteCostCalc (KeyEncryptionKey _ _ c) = c
+
 -- | The ExpensiveHash of the Password is combined with a 
 -- RandomObstacle to form the AES key. Combination method is logical OR.
 genKeyEncryptionKey :: Tunables -> KeyIdent -> Password -> KeyEncryptionKey