File: Ed25519.hs

package info (click to toggle)
haskell-cryptonite 0.30-4
  • links: PTS, VCS
  • area: main
  • in suites: sid
  • size: 3,368 kB
  • sloc: ansic: 22,009; haskell: 18,423; makefile: 8
file content (150 lines) | stat: -rw-r--r-- 5,061 bytes parent folder | download | duplicates (5)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
-- |
-- Module      : Crypto.PubKey.Ed25519
-- License     : BSD-style
-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
-- Stability   : experimental
-- Portability : unknown
--
-- Ed25519 support
--
{-# LANGUAGE BangPatterns               #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
module Crypto.PubKey.Ed25519
    ( SecretKey
    , PublicKey
    , Signature
    -- * Size constants
    , publicKeySize
    , secretKeySize
    , signatureSize
    -- * Smart constructors
    , signature
    , publicKey
    , secretKey
    -- * Methods
    , toPublic
    , sign
    , verify
    , generateSecretKey
    ) where

import           Data.Word
import           Foreign.C.Types
import           Foreign.Ptr

import           Crypto.Error
import           Crypto.Internal.ByteArray (ByteArrayAccess, Bytes,
                                            ScrubbedBytes, withByteArray)
import qualified Crypto.Internal.ByteArray as B
import           Crypto.Internal.Compat
import           Crypto.Internal.Imports
import           Crypto.Random

-- | An Ed25519 Secret key
newtype SecretKey = SecretKey ScrubbedBytes
    deriving (Show,Eq,ByteArrayAccess,NFData)

-- | An Ed25519 public key
newtype PublicKey = PublicKey Bytes
    deriving (Show,Eq,ByteArrayAccess,NFData)

-- | An Ed25519 signature
newtype Signature = Signature Bytes
    deriving (Show,Eq,ByteArrayAccess,NFData)

-- | Try to build a public key from a bytearray
publicKey :: ByteArrayAccess ba => ba -> CryptoFailable PublicKey
publicKey bs
    | B.length bs == publicKeySize =
        CryptoPassed $ PublicKey $ B.copyAndFreeze bs (\_ -> return ())
    | otherwise =
        CryptoFailed $ CryptoError_PublicKeySizeInvalid

-- | Try to build a secret key from a bytearray
secretKey :: ByteArrayAccess ba => ba -> CryptoFailable SecretKey
secretKey bs
    | B.length bs == secretKeySize = unsafeDoIO $ withByteArray bs initialize
    | otherwise                    = CryptoFailed CryptoError_SecretKeyStructureInvalid
  where
        initialize inp = do
            valid <- isValidPtr inp
            if valid
                then (CryptoPassed . SecretKey) <$> B.copy bs (\_ -> return ())
                else return $ CryptoFailed CryptoError_SecretKeyStructureInvalid
        isValidPtr _ =
            return True
{-# NOINLINE secretKey #-}

-- | Try to build a signature from a bytearray
signature :: ByteArrayAccess ba => ba -> CryptoFailable Signature
signature bs
    | B.length bs == signatureSize =
        CryptoPassed $ Signature $ B.copyAndFreeze bs (\_ -> return ())
    | otherwise =
        CryptoFailed CryptoError_SecretKeyStructureInvalid

-- | Create a public key from a secret key
toPublic :: SecretKey -> PublicKey
toPublic (SecretKey sec) = PublicKey <$>
    B.allocAndFreeze publicKeySize $ \result ->
    withByteArray sec              $ \psec   ->
        ccryptonite_ed25519_publickey psec result
{-# NOINLINE toPublic #-}

-- | Sign a message using the key pair
sign :: ByteArrayAccess ba => SecretKey -> PublicKey -> ba -> Signature
sign secret public message =
    Signature $ B.allocAndFreeze signatureSize $ \sig ->
        withByteArray secret  $ \sec ->
        withByteArray public  $ \pub ->
        withByteArray message $ \msg ->
             ccryptonite_ed25519_sign msg (fromIntegral msgLen) sec pub sig
  where
    !msgLen = B.length message

-- | Verify a message
verify :: ByteArrayAccess ba => PublicKey -> ba -> Signature -> Bool
verify public message signatureVal = unsafeDoIO $
    withByteArray signatureVal $ \sig ->
    withByteArray public       $ \pub ->
    withByteArray message      $ \msg -> do
      r <- ccryptonite_ed25519_sign_open msg (fromIntegral msgLen) pub sig
      return (r == 0)
  where
    !msgLen = B.length message

-- | Generate a secret key
generateSecretKey :: MonadRandom m => m SecretKey
generateSecretKey = SecretKey <$> getRandomBytes secretKeySize

-- | A public key is 32 bytes
publicKeySize :: Int
publicKeySize = 32

-- | A secret key is 32 bytes
secretKeySize :: Int
secretKeySize = 32

-- | A signature is 64 bytes
signatureSize :: Int
signatureSize = 64

foreign import ccall "cryptonite_ed25519_publickey"
    ccryptonite_ed25519_publickey :: Ptr SecretKey -- secret key
                                  -> Ptr PublicKey -- public key
                                  -> IO ()

foreign import ccall "cryptonite_ed25519_sign_open"
    ccryptonite_ed25519_sign_open :: Ptr Word8     -- message
                                  -> CSize         -- message len
                                  -> Ptr PublicKey -- public
                                  -> Ptr Signature -- signature
                                  -> IO CInt

foreign import ccall "cryptonite_ed25519_sign"
    ccryptonite_ed25519_sign :: Ptr Word8     -- message
                             -> CSize         -- message len
                             -> Ptr SecretKey -- secret
                             -> Ptr PublicKey -- public
                             -> Ptr Signature -- signature
                             -> IO ()