{-# LANGUAGE OverloadedStrings, GeneralizedNewtypeDeriving, MultiParamTypeClasses, FlexibleInstances #-}

{- Copyright 2016 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU AGPL version 3 or higher.
 -}

module Types where

import Types.Cost
import Entropy
import qualified Data.ByteString as B
import Data.String

-- | keysafe stores secret keys.
newtype SecretKey = SecretKey B.ByteString

-- | The secret key, encrypted with a password.
data EncryptedSecretKey = EncryptedSecretKey B.ByteString (CostCalc BruteForceOp UnknownPassword)

instance Show EncryptedSecretKey where
	show (EncryptedSecretKey b _) = show b

instance Bruteforceable EncryptedSecretKey UnknownPassword where
	getBruteCostCalc (EncryptedSecretKey _ cc) = cc

-- | Objects stored on a keysafe server are (probably) a shard of an
-- encrypted secret key.
newtype StorableObject = StorableObject { fromStorableObject :: B.ByteString }
	deriving (Show)

-- | An identifier for a StorableObject
newtype StorableObjectIdent = StorableObjectIdent B.ByteString
	deriving (Show)

-- | A shard, with a known number (N of M).
data Shard = Shard ShardNum StorableObject

type ShardNum = Int

-- | A password used to encrypt a key stored in keysafe.
newtype Password = Password B.ByteString
	deriving (IsString)

-- | Naive calculation of the entropy of a password.
-- Does not take common passwords and password generation patterns into
-- account, so this is an overestimation of how hard a password
-- is to crack.
passwordEntropy :: Password -> Entropy UnknownPassword
passwordEntropy (Password p) = Entropy $ floor $ totalEntropy p

-- | A name associated with a key stored in keysafe.
newtype Name = Name B.ByteString
	deriving (Show)

-- | Very naive calculation of the entropy of a name.
-- Assumes that the attacker is not targeting a particular list of names.
nameEntropy :: Name -> Entropy UnknownName
nameEntropy (Name n) = Entropy $ floor $ totalEntropy n

-- | The type of the key that is stored in keysafe.
newtype KeyType = KeyType B.ByteString
	deriving (Show)

gpgKey :: KeyType
gpgKey = KeyType "gpg"

-- | The keyid is any value that is unique to a private key, and can be
-- looked up somehow without knowing the private key.
--
-- A gpg keyid is the obvious example.
data KeyId = KeyId KeyType B.ByteString
	deriving (Show)

data Benchmark t = Benchmark { expectedBenchmark :: t, actualBenchmark :: t }
	deriving (Show)