{-# LANGUAGE OverloadedStrings #-}

module SpecCrypto (
    tests,
) where

import Crypto.Cipher.AES128 (
    AESKey128,
 )
import Crypto.Classes (
    buildKey,
    keyLength,
 )
import Crypto.Types (ByteLength)
import qualified Data.ByteString as B
import Data.Char (
    ord,
 )
import Data.Tagged (Tagged, untag)
import Tahoe.CHK.Crypto (
    convergenceEncryptionTag,
    convergenceSecretLength,
    sha256,
    sha256d,
    storageIndexHash,
    taggedHash,
    taggedPairHash,
 )
import Tahoe.CHK.Types (
    Parameters (..),
 )
import Test.Tasty (
    TestTree,
    testGroup,
 )
import Test.Tasty.HUnit (
    assertEqual,
    testCase,
 )

tests :: TestTree
tests =
    testGroup
        "Crypto"
        [ testGroup
            "sha256"
            [ testCase "sha256" $
                assertEqual
                    "known value"
                    "\x23\xfb\xe2\x1e\x2f\xae\xde\xb5\x44\x92\xcb\x7a\xc6\x0e\x04\x4a\xbb\x47\x3f\xcb\x13\x1a\x65\x8e\xd2\x5c\xd0\x17\x06\xc3\xf3\x98"
                    (sha256 "4:tag1,value")
            , testCase "sha256d" $
                assertEqual
                    "known value"
                    "\x6b\xd0\xdc\xb0\x2f\x11\x0a\xe1\xe9\x41\x1f\x12\x52\x07\x03\x66\xfe\xaa\xcb\xc9\xda\xdb\x66\xa4\xa9\xa0\xc0\xdd\x85\x49\x5d\xc4"
                    (sha256d "4:tag1,value")
            , testCase "storage index tagged hash" $
                -- Adapted from allmydata.test.test_hashutil.HashUtilTests.test_known_answers
                assertEqual
                    "known value"
                    (Just "\xb5\x4c\x60\xc5\xb1\x26\x46\xf0\x77\x0\xc4\x4c\x8b\x75\xb9\x48")
                    (storageIndexHash <$> xKey)
            , testCase "tagged hash length" $ do
                -- The length of the result equals the given size.
                let expected = 17
                assertEqual "taggedHash result length /= expected" expected (B.length $ taggedHash expected "tag" "hello world")
                assertEqual "taggedPairHash result length /= expected" expected (B.length $ taggedPairHash expected "tag" "hello" "world")
            , testCase "convergence hasher tag" $
                -- See allmydata.test.test_hashutil.HashUtilTests.test_convergence_hasher_tag
                let convergenceSecret = B.replicate convergenceSecretLength 0x42
                    params =
                        Parameters
                            { paramSegmentSize = 1024
                            , paramTotalShares = 10
                            , paramHappyShares = undefined
                            , paramRequiredShares = 3
                            }
                 in assertEqual
                        "known value"
                        ( mconcat
                            [ "allmydata_immutable_content_to_key_with_added_secret_v1+"
                            , "16:\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42\x42,"
                            , "9:3,10,1024,"
                            ]
                        )
                        (convergenceEncryptionTag convergenceSecret params)
            ]
        ]
  where
    xKey = buildKey (B.replicate (untag (keyLength :: Tagged AESKey128 ByteLength)) . fromIntegral . ord $ 'x') :: Maybe AESKey128