Utils.hs

{-# LANGUAGE OverloadedStrings #-}

module Network.QUIC.Crypto.Utils (
    tagLength,
    sampleLength,
    bsXOR,
    calculateIntegrityTag,
) where

import qualified Data.ByteArray as Byte (xor)
import qualified Data.ByteString as BS
import qualified Data.ByteString.Short as Short
import Network.TLS hiding (Version)

import Network.QUIC.Crypto.Nite
import Network.QUIC.Crypto.Types
import Network.QUIC.Imports
import Network.QUIC.Types

----------------------------------------------------------------

bsXOR :: ByteString -> ByteString -> ByteString
bsXOR = Byte.xor

----------------------------------------------------------------

tagLength :: Cipher -> Int
tagLength cipher
    | supportedCipher cipher = 16
    | otherwise = unsupportedCipher "tagLength" cipher

sampleLength :: Cipher -> Int
sampleLength cipher
    | supportedCipher cipher = 16
    | otherwise = unsupportedCipher "sampleLength" cipher

----------------------------------------------------------------

calculateIntegrityTag :: Version -> CID -> ByteString -> ByteString
calculateIntegrityTag ver oCID pseudo0 =
    case aes128gcmEncrypt (key ver) (nonce ver) "" (AssDat pseudo) of
        Nothing -> ""
        Just (hdr, bdy) -> hdr `BS.append` bdy
  where
    (ocid, ocidlen) = unpackCID oCID
    pseudo =
        BS.concat
            [ BS.singleton ocidlen
            , Short.fromShort ocid
            , pseudo0
            ]
    key Draft29 = Key "\xcc\xce\x18\x7e\xd0\x9a\x09\xd0\x57\x28\x15\x5a\x6c\xb9\x6b\xe1"
    key Version1 = Key "\xbe\x0c\x69\x0b\x9f\x66\x57\x5a\x1d\x76\x6b\x54\xe3\x68\xc8\x4e"
    key Version2 = Key "\x8f\xb4\xb0\x1b\x56\xac\x48\xe2\x60\xfb\xcb\xce\xad\x7c\xcc\x92"
    key _ = Key "not supported"
    nonce Draft29 = Nonce "\xe5\x49\x30\xf9\x7f\x21\x36\xf0\x53\x0a\x8c\x1c"
    nonce Version1 = Nonce "\x46\x15\x99\xd3\x5d\x63\x2b\xf2\x23\x98\x25\xbb"
    nonce Version2 = Nonce "\xd8\x69\x69\xbc\x2d\x7c\x6d\x99\x90\xef\xb0\x4a"
    nonce _ = Nonce "not supported"