cryptonite/Crypto/PubKey/ECC/DH.hs
2015-05-20 06:07:31 +01:00

47 lines
1.3 KiB
Haskell

-- |
-- Module : Crypto.PubKey.ECC.DH
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : unknown
--
-- Elliptic curve Diffie Hellman
--
module Crypto.PubKey.ECC.DH
(
Curve
, PublicPoint
, PrivateNumber
, SharedKey(..)
, generatePrivate
, calculatePublic
, getShared
) where
import Crypto.Number.Generate (generateMax)
import Crypto.PubKey.ECC.Prim (pointMul)
import Crypto.Random.Types
import Crypto.PubKey.DH (SharedKey(..))
import Crypto.PubKey.ECC.Types (PublicPoint, PrivateNumber, Curve, Point(..))
import Crypto.PubKey.ECC.Types (ecc_n, ecc_g, common_curve)
-- | Generating a private number d.
generatePrivate :: MonadRandom m => Curve -> m PrivateNumber
generatePrivate curve = generateMax n
where
n = ecc_n $ common_curve curve
-- | Generating a public point Q.
calculatePublic :: Curve -> PrivateNumber -> PublicPoint
calculatePublic curve d = q
where
g = ecc_g $ common_curve curve
q = pointMul curve d g
-- | Generating a shared key using our private number and
-- the other party public point.
getShared :: Curve -> PrivateNumber -> PublicPoint -> SharedKey
getShared curve db qa = SharedKey x
where
Point x _ = pointMul curve db qa