-- Test Vectors for HKDF-SHA256

{-# LANGUAGE OverloadedStrings #-}

module HKDF where

import           Data.Base16.Types
import           Data.ByteString(ByteString)
import qualified Data.ByteString as B
import qualified Data.ByteString.Base16 as B
import qualified Data.ByteString.Short as SB
import           Data.Function((&))
import           Data.Int
import           Test.Tasty
import           Test.Tasty.HUnit

import           Crypto.HashString (HashString(..))
import qualified Crypto.HashString as HS
import           Crypto.Sha256.Hkdf

d :: ByteString -> ByteString
d = B.decodeBase16Lenient

tests :: [TestTree]
tests =
  [ testGroup "rfc5869 test vectors"
      [ testCase ("rfc5869-" ++ show n) (run x)
      | (n,x) <- zip [1..] testVectors
      ]
  ]
  where
    run x = HS.toBase16 (hkdf' (salt x) (ikm x) (info x) (B.length (out x))) @?= extractBase16 (B.encodeBase16' (out x))

testVectors :: [TestVector]
testVectors =
  [ rfc5869_testCase1
  , rfc5869_testCase2
  , rfc5869_testCase3
  ]

data TestVector = TestVector
  { salt :: !ByteString
  , ikm :: !ByteString
  , info :: !ByteString
  , out :: !ByteString
  }

rfc5869_testCase1 = TestVector
  { salt = d "000102030405060708090a0b0c"
  , ikm = d "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b"
  , info = d "f0f1f2f3f4f5f6f7f8f9"
  , out = d "3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865"
  }

rfc5869_testCase2 = TestVector
  { salt = d "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
  , ikm = d "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f"
  , info = d "b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"
  , out = d "b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87"
  }

rfc5869_testCase3 = TestVector
  { salt = ""
  , ikm = d "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b"
  , info = ""
  , out = d "8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8"
  }