hs-tls/Network/TLS/Cipher.hs

-- |
-- Module      : Network.TLS.Cipher
-- License     : BSD-style
-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
-- Stability   : experimental
-- Portability : unknown
--
module Network.TLS.Cipher
	( CipherTypeFunctions(..)
	, CipherKeyExchangeType(..)
	, Cipher(..)
	, cipherExchangeNeedMoreData

	-- * builtin ciphers for ease of use, might move later to a tls-ciphers library
	, cipher_null_null
	, cipher_RC4_128_MD5
	, cipher_RC4_128_SHA1
	, cipher_AES128_SHA1
	, cipher_AES256_SHA1
	, cipher_AES128_SHA256
	, cipher_AES256_SHA256
	) where

import Data.Word
import Network.TLS.Struct (Version(..))

import qualified Crypto.Hash.SHA256 as SHA256
import qualified Crypto.Hash.SHA1 as SHA1
import qualified Crypto.Hash.MD5 as MD5

import qualified Data.Vector.Unboxed as Vector (fromList, toList)
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString as B

import qualified Codec.Crypto.AES as AES
import qualified Crypto.Cipher.RC4 as RC4

-- FIXME convert to newtype
type Key = B.ByteString
type IV = B.ByteString

data CipherTypeFunctions =
	  CipherNoneF -- special value for 0
	| CipherBlockF (Key -> IV -> B.ByteString -> B.ByteString)
	               (Key -> IV -> B.ByteString -> B.ByteString)
	| CipherStreamF (Key -> IV)
	                (IV -> B.ByteString -> (B.ByteString, IV))
	                (IV -> B.ByteString -> (B.ByteString, IV))

data CipherKeyExchangeType =
	  CipherKeyExchangeRSA
	| CipherKeyExchangeDHE_RSA
	| CipherKeyExchangeECDHE_RSA
	| CipherKeyExchangeDHE_DSS
	| CipherKeyExchangeDH_DSS
	| CipherKeyExchangeDH_RSA
	| CipherKeyExchangeECDH_ECDSA
	| CipherKeyExchangeECDH_RSA
	| CipherKeyExchangeECDHE_ECDSA

data Cipher = Cipher
	{ cipherID           :: Word16
	, cipherName         :: String
	, cipherDigestSize   :: Word8
	, cipherKeySize      :: Word8
	, cipherIVSize       :: Word8
	, cipherKeyBlockSize :: Word8
	, cipherPaddingSize  :: Word8
	, cipherKeyExchange  :: CipherKeyExchangeType
	, cipherMACHash      :: B.ByteString -> B.ByteString
	, cipherF            :: CipherTypeFunctions
	, cipherMinVer       :: Maybe Version
	}

instance Show Cipher where
	show c = cipherName c

instance Eq Cipher where
	(==) c1 c2 = cipherID c1 == cipherID c2

cipherExchangeNeedMoreData :: CipherKeyExchangeType -> Bool
cipherExchangeNeedMoreData CipherKeyExchangeRSA         = False
cipherExchangeNeedMoreData CipherKeyExchangeDHE_RSA     = True
cipherExchangeNeedMoreData CipherKeyExchangeECDHE_RSA   = True
cipherExchangeNeedMoreData CipherKeyExchangeDHE_DSS     = True
cipherExchangeNeedMoreData CipherKeyExchangeDH_DSS      = False
cipherExchangeNeedMoreData CipherKeyExchangeDH_RSA      = False
cipherExchangeNeedMoreData CipherKeyExchangeECDH_ECDSA  = True
cipherExchangeNeedMoreData CipherKeyExchangeECDH_RSA    = True
cipherExchangeNeedMoreData CipherKeyExchangeECDHE_ECDSA = True

repack :: Int -> B.ByteString -> [B.ByteString]
repack bs x =
	if B.length x > bs
		then
			let (c1, c2) = B.splitAt bs x in
			B.pack (B.unpack c1) : repack 16 c2
		else
			[ x ]

lazyToStrict :: L.ByteString -> B.ByteString
lazyToStrict = B.concat . L.toChunks

aes128_cbc_encrypt :: Key -> IV -> B.ByteString -> B.ByteString
aes128_cbc_encrypt key iv d = lazyToStrict $ AES.crypt AES.CBC key iv AES.Encrypt d16
	where d16 = L.fromChunks $ repack 16 d

aes128_cbc_decrypt :: Key -> IV -> B.ByteString -> B.ByteString
aes128_cbc_decrypt key iv d = lazyToStrict $ AES.crypt AES.CBC key iv AES.Decrypt d16
	where d16 = L.fromChunks $ repack 16 d

aes256_cbc_encrypt :: Key -> IV -> B.ByteString -> B.ByteString
aes256_cbc_encrypt key iv d = lazyToStrict $ AES.crypt AES.CBC key iv AES.Encrypt d16
	where d16 = L.fromChunks $ repack 16 d

aes256_cbc_decrypt :: Key -> IV -> B.ByteString -> B.ByteString
aes256_cbc_decrypt key iv d = lazyToStrict $ AES.crypt AES.CBC key iv AES.Decrypt d16
	where d16 = L.fromChunks $ repack 32 d

toIV :: RC4.Ctx -> IV
toIV (v, x, y) = B.pack (x : y : Vector.toList v)

toCtx :: IV -> RC4.Ctx
toCtx iv =
	case B.unpack iv of
		x:y:l -> (Vector.fromList l, x, y)
		_     -> (Vector.fromList [], 0, 0)

initF_rc4 :: Key -> IV
initF_rc4 key     = toIV $ RC4.initCtx (B.unpack key)

encryptF_rc4 :: IV -> B.ByteString -> (B.ByteString, IV)
encryptF_rc4 iv d = (\(ctx, e) -> (e, toIV ctx)) $ RC4.encrypt (toCtx iv) d

decryptF_rc4 :: IV -> B.ByteString -> (B.ByteString, IV)
decryptF_rc4 iv e = (\(ctx, d) -> (d, toIV ctx)) $ RC4.decrypt (toCtx iv) e

{-
TLS 1.0 ciphers definition

CipherSuite TLS_NULL_WITH_NULL_NULL               = { 0x00,0x00 };
CipherSuite TLS_RSA_WITH_NULL_MD5                 = { 0x00,0x01 };
CipherSuite TLS_RSA_WITH_NULL_SHA                 = { 0x00,0x02 };
CipherSuite TLS_RSA_EXPORT_WITH_RC4_40_MD5        = { 0x00,0x03 };
CipherSuite TLS_RSA_WITH_RC4_128_MD5              = { 0x00,0x04 };
CipherSuite TLS_RSA_WITH_RC4_128_SHA              = { 0x00,0x05 };
CipherSuite TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5    = { 0x00,0x06 };
CipherSuite TLS_RSA_WITH_IDEA_CBC_SHA             = { 0x00,0x07 };
CipherSuite TLS_RSA_EXPORT_WITH_DES40_CBC_SHA     = { 0x00,0x08 };
CipherSuite TLS_RSA_WITH_DES_CBC_SHA              = { 0x00,0x09 };
CipherSuite TLS_RSA_WITH_3DES_EDE_CBC_SHA         = { 0x00,0x0A };
CipherSuite TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA  = { 0x00,0x0B };
CipherSuite TLS_DH_DSS_WITH_DES_CBC_SHA           = { 0x00,0x0C };
CipherSuite TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA      = { 0x00,0x0D };
CipherSuite TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA  = { 0x00,0x0E };
CipherSuite TLS_DH_RSA_WITH_DES_CBC_SHA           = { 0x00,0x0F };
CipherSuite TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA      = { 0x00,0x10 };
CipherSuite TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA = { 0x00,0x11 };
CipherSuite TLS_DHE_DSS_WITH_DES_CBC_SHA          = { 0x00,0x12 };
CipherSuite TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x13 };
CipherSuite TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA = { 0x00,0x14 };
CipherSuite TLS_DHE_RSA_WITH_DES_CBC_SHA          = { 0x00,0x15 };
CipherSuite TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x16 };
CipherSuite TLS_DH_anon_EXPORT_WITH_RC4_40_MD5    = { 0x00,0x17 };
CipherSuite TLS_DH_anon_WITH_RC4_128_MD5          = { 0x00,0x18 };
CipherSuite TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA = { 0x00,0x19 };
CipherSuite TLS_DH_anon_WITH_DES_CBC_SHA          = { 0x00,0x1A };
CipherSuite TLS_DH_anon_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x1B };
-}

{-
 - some builtin ciphers description
 -}

cipher_null_null :: Cipher
cipher_null_null = Cipher
	{ cipherID           = 0x0
	, cipherName         = "null-null"
	, cipherDigestSize   = 0
	, cipherKeySize      = 0
	, cipherIVSize       = 0
	, cipherKeyBlockSize = 0
	, cipherPaddingSize  = 0
	, cipherMACHash      = (const B.empty)
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherNoneF
	, cipherMinVer       = Nothing
	}

cipher_RC4_128_MD5 :: Cipher
cipher_RC4_128_MD5 = Cipher
	{ cipherID           = 0x04
	, cipherName         = "RSA-rc4-128-md5"
	, cipherDigestSize   = 16
	, cipherKeySize      = 16
	, cipherIVSize       = 0
	, cipherKeyBlockSize = 2 * (16 + 16 + 0)
	, cipherPaddingSize  = 0
	, cipherMACHash      = MD5.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherStreamF initF_rc4 encryptF_rc4 decryptF_rc4
	, cipherMinVer       = Nothing
	}

cipher_RC4_128_SHA1 :: Cipher
cipher_RC4_128_SHA1 = Cipher
	{ cipherID           = 0x05
	, cipherName         = "RSA-rc4-128-sha1"
	, cipherDigestSize   = 20
	, cipherKeySize      = 16
	, cipherIVSize       = 0
	, cipherKeyBlockSize = 2 * (20 + 16 + 0)
	, cipherPaddingSize  = 0
	, cipherMACHash      = SHA1.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherStreamF initF_rc4 encryptF_rc4 decryptF_rc4
	, cipherMinVer       = Nothing
	}

cipher_AES128_SHA1 :: Cipher
cipher_AES128_SHA1 = Cipher
	{ cipherID           = 0x2f
	, cipherName         = "RSA-aes128-sha1"
	, cipherDigestSize   = 20
	, cipherKeySize      = 16
	, cipherIVSize       = 16
	, cipherKeyBlockSize = 2 * (20 + 16 + 16)
	, cipherPaddingSize  = 16
	, cipherMACHash      = SHA1.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherBlockF aes128_cbc_encrypt aes128_cbc_decrypt
	, cipherMinVer       = Just SSL3
	}

cipher_AES256_SHA1 :: Cipher
cipher_AES256_SHA1 = Cipher
	{ cipherID           = 0x35
	, cipherName         = "RSA-aes256-sha1"
	, cipherDigestSize   = 20
	, cipherKeySize      = 32
	, cipherIVSize       = 16
	, cipherKeyBlockSize = 2 * (20 + 32 + 16)
	, cipherPaddingSize  = 16
	, cipherMACHash      = SHA1.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherBlockF aes256_cbc_encrypt aes256_cbc_decrypt
	, cipherMinVer       = Just SSL3
	}

cipher_AES128_SHA256 :: Cipher
cipher_AES128_SHA256 = Cipher
	{ cipherID           = 0x3c
	, cipherName         = "RSA-aes128-sha256"
	, cipherDigestSize   = 32
	, cipherKeySize      = 16
	, cipherIVSize       = 16
	, cipherKeyBlockSize = 2 * (32 + 16 + 16)
	, cipherPaddingSize  = 16
	, cipherMACHash      = SHA256.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherBlockF aes128_cbc_encrypt aes128_cbc_decrypt
	, cipherMinVer       = Just TLS12
	}

cipher_AES256_SHA256 :: Cipher
cipher_AES256_SHA256 = Cipher
	{ cipherID           = 0x3d
	, cipherName         = "RSA-aes256-sha256"
	, cipherDigestSize   = 32
	, cipherKeySize      = 32
	, cipherIVSize       = 16
	, cipherKeyBlockSize = 2 * (32 + 32 + 16)
	, cipherPaddingSize  = 16
	, cipherMACHash      = SHA256.hash
	, cipherKeyExchange  = CipherKeyExchangeRSA
	, cipherF            = CipherBlockF aes256_cbc_encrypt aes256_cbc_decrypt
	, cipherMinVer       = Just TLS12
	}