secp256k1

Wycheproof.hs (5538B)

---

 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ViewPatterns #-}
 
 module Wycheproof (
     Wycheproof(..)
   , execute_group
   ) where
 
 import Crypto.Curve.Secp256k1
 import Data.Aeson ((.:))
 import qualified Data.Aeson as A
 import qualified Data.Attoparsec.ByteString as AT
 import qualified Data.Bits as B
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Base16 as B16
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import qualified GHC.Num.Integer as I
 import Test.Tasty (TestTree, testGroup)
 import Test.Tasty.HUnit (assertBool, testCase)
 
 decodeLenient :: BS.ByteString -> BS.ByteString
 decodeLenient bs = case B16.decode bs of
   Nothing -> error "bang"
   Just b -> b
 
 fi :: (Integral a, Num b) => a -> b
 fi = fromIntegral
 {-# INLINE fi #-}
 
 -- big-endian bytestring decoding
 roll :: BS.ByteString -> Integer
 roll = BS.foldl' unstep 0 where
   unstep a (fi -> b) = (a `I.integerShiftL` 8) `I.integerOr` b
 
 execute_group :: Context -> SigType -> EcdsaTestGroup -> TestTree
 execute_group tex ty EcdsaTestGroup {..} =
     testGroup msg (fmap (execute tex ty pk_uncompressed) etg_tests)
   where
     msg = "wycheproof (" <> T.unpack etg_type <> ", " <> T.unpack etg_sha <> ")"
     PublicKey {..} = etg_publicKey
 
 execute :: Context -> SigType -> Projective -> EcdsaVerifyTest -> TestTree
 execute tex ty pub EcdsaVerifyTest {..} = testCase report $ do
     let msg = decodeLenient (TE.encodeUtf8 t_msg)
         sig = toEcdsa t_sig
     case sig of
       Left _  -> assertBool mempty (t_result == "invalid")
       Right s -> do
         let ver = case ty of
               LowS -> verify_ecdsa msg pub s && verify_ecdsa' tex msg pub s
               Unrestricted -> verify_ecdsa_unrestricted msg pub s
                            && verify_ecdsa_unrestricted' tex msg pub s
         if   t_result == "invalid"
         then assertBool mempty (not ver)
         else assertBool mempty ver
   where
     report = "wycheproof (" <> show ty <> ") " <> show t_tcId
 
 parse_der_sig :: AT.Parser ECDSA
 parse_der_sig = do
     _ <- AT.word8 0x30
     len <- fmap fi AT.anyWord8
     content <- AT.take len
     etc <- AT.takeByteString
     if   BS.length content /= len || etc /= mempty
     then fail "invalid content"
     else case AT.parseOnly (meat len) content of
       Left _  -> fail "invalid content"
       Right v -> pure v
   where
     meat len = do
       (lr, bs_r) <- parseAsnInt
       (ls, bs_s) <- parseAsnInt
       let r = fi (roll bs_r)
           s = fi (roll bs_s)
           checks = lr + ls == len
       rest <- AT.takeByteString
       if   rest == mempty && checks
       then pure (ECDSA r s)
       else fail "input remaining or length mismatch"
 
 parseAsnInt :: AT.Parser (Int, BS.ByteString)
 parseAsnInt = do
   _       <- AT.word8 0x02
   len     <- fmap fi AT.anyWord8
   content <- AT.take len
   if   BS.length content /= len
   then fail "invalid length"
   else if   len == 1
        then pure (len + 2, content) -- + tag byt + len byt
        else case BS.uncons content of
          Nothing -> fail "invalid content"
          Just (h0, t0)
            | B.testBit h0 7 -> fail "negative value"
            | otherwise -> case BS.uncons t0 of
                Nothing -> fail "invalid content"
                Just (h1, _)
                  | h0 == 0x00 && not (B.testBit h1 7) -> fail "invalid padding"
                  | otherwise -> case BS.unsnoc content of
                      Nothing -> fail "invalid content"
                      Just (_, tn)
                        | tn == 0x00 -> fail "invalid padding"
                        | otherwise  -> pure (len + 2, content)
 
 data Wycheproof = Wycheproof {
     wp_algorithm        :: !T.Text
   , wp_generatorVersion :: !T.Text
   , wp_numberOfTests    :: !Int
   , wp_testGroups       :: ![EcdsaTestGroup]
   } deriving Show
 
 instance A.FromJSON Wycheproof where
   parseJSON = A.withObject "Wycheproof" $ \m -> Wycheproof
     <$> m .: "algorithm"
     <*> m .: "generatorVersion"
     <*> m .: "numberOfTests"
     <*> m .: "testGroups"
 
 data EcdsaTestGroup = EcdsaTestGroup {
     etg_type      :: !T.Text
   , etg_publicKey :: !PublicKey
   , etg_sha       :: !T.Text
   , etg_tests     :: ![EcdsaVerifyTest]
   } deriving Show
 
 instance A.FromJSON EcdsaTestGroup where
   parseJSON = A.withObject "EcdsaTestGroup" $ \m -> EcdsaTestGroup
     <$> m .: "type"
     <*> m .: "publicKey"
     <*> m .: "sha"
     <*> m .: "tests"
 
 data PublicKey = PublicKey {
     pk_type         :: !T.Text
   , pk_curve        :: !T.Text
   , pk_keySize      :: !Int
   , pk_uncompressed :: !Projective
   } deriving Show
 
 toProjective :: T.Text -> Projective
 toProjective (decodeLenient . TE.encodeUtf8 -> bs) = case parse_point bs of
   Nothing -> error "wycheproof: couldn't parse pubkey"
   Just p -> p
 
 instance A.FromJSON PublicKey where
   parseJSON = A.withObject "PublicKey" $ \m -> PublicKey
     <$> m .: "type"
     <*> m .: "curve"
     <*> m .: "keySize"
     <*> fmap toProjective (m .: "uncompressed")
 
 toEcdsa :: T.Text -> Either String ECDSA
 toEcdsa (decodeLenient . TE.encodeUtf8 -> bs) =
   AT.parseOnly parse_der_sig bs
 
 data EcdsaVerifyTest = EcdsaVerifyTest {
     t_tcId    :: !Int
   , t_comment :: !T.Text
   , t_msg     :: !T.Text
   , t_sig     :: !T.Text
   , t_result  :: !T.Text
   } deriving Show
 
 instance A.FromJSON EcdsaVerifyTest where
   parseJSON = A.withObject "EcdsaVerifyTest" $ \m -> EcdsaVerifyTest
     <$> m .: "tcId"
     <*> m .: "comment"
     <*> m .: "msg"
     <*> m .: "sig"
     <*> m .: "result"