implement txId using CBOR encoders

cardano-foundation · Mar 6, 2019 · b31abd3 · b31abd3
1 parent 3358405
commit b31abd3
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Showing 4 changed files with 61 additions and 12 deletions.
diff --git a/cardano-wallet.cabal b/cardano-wallet.cabal
@@ -35,8 +35,10 @@ library
     , bytestring
     , cborg
     , containers
+    , cryptonite
     , deepseq
     , digest
+    , memory
   hs-source-dirs:
       src
   exposed-modules:

diff --git a/src/Cardano/Wallet/Binary.hs b/src/Cardano/Wallet/Binary.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE TypeApplications #-}
 
 -- |
 -- Copyright: © 2018-2019 IOHK
@@ -16,9 +17,11 @@ module Cardano.Wallet.Binary
     -- * Decoding
       decodeBlock
     , decodeBlockHeader
+    , decodeTx
 
     -- * Encoding
     , encodeTx
+    , txId
 
     -- * Helpers
     , inspectNextToken
@@ -40,6 +43,10 @@ import Cardano.Wallet.Primitive
     )
 import Control.Monad
     ( void )
+import Crypto.Hash
+    ( hash )
+import Crypto.Hash.Algorithms
+    ( Blake2b_256 )
 import Data.ByteString
     ( ByteString )
 import Data.Digest.CRC32
@@ -55,6 +62,7 @@ import qualified Codec.CBOR.Decoding as CBOR
 import qualified Codec.CBOR.Encoding as CBOR
 import qualified Codec.CBOR.Read as CBOR
 import qualified Codec.CBOR.Write as CBOR
+import qualified Data.ByteArray as BA
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.Set as Set
 
@@ -319,6 +327,16 @@ decodeSignature = do
         2 -> decodeProxySignature decodeHeavyIndex
         _ -> fail $ "decodeSignature: unknown signature constructor: " <> show t
 
+decodeSignedTx :: CBOR.Decoder s Tx
+decodeSignedTx = do
+    _ <- CBOR.decodeListLenCanonicalOf 2
+    _ <- CBOR.decodeListLenCanonicalOf 3
+    ins <- decodeListIndef decodeTxIn
+    outs <- decodeListIndef decodeTxOut
+    _ <- decodeAttributes
+    _ <- decodeList decodeTxWitness
+    return $ Tx ins outs
+
 decodeSharesProof :: CBOR.Decoder s ()
 decodeSharesProof = do
     _ <- CBOR.decodeBytes -- Shares Hash
@@ -341,16 +359,14 @@ decodeSoftwareVersion = do
 
 decodeTx :: CBOR.Decoder s Tx
 decodeTx = do
-    _ <- CBOR.decodeListLenCanonicalOf 2
     _ <- CBOR.decodeListLenCanonicalOf 3
     ins <- decodeListIndef decodeTxIn
     outs <- decodeListIndef decodeTxOut
     _ <- decodeAttributes
-    _ <- decodeList decodeTxWitness
     return $ Tx ins outs
 
 decodeTxPayload :: CBOR.Decoder s (Set Tx)
-decodeTxPayload = Set.fromList <$> decodeListIndef decodeTx
+decodeTxPayload = Set.fromList <$> decodeListIndef decodeSignedTx
 
 {-# ANN decodeTxIn ("HLint: ignore Use <$>" :: String) #-}
 decodeTxIn :: CBOR.Decoder s TxIn
@@ -407,6 +423,12 @@ decodeUpdateProof = do
 
 -- * Encoding
 
+-- | Compute a transaction id; assumed to be effectively injective.
+-- It returns an hex-encoded 64-byte hash.
+txId :: Tx -> Hash "Tx"
+txId =
+    Hash . BA.convert . hash @_ @Blake2b_256 . CBOR.toStrictByteString . encodeTx
+
 encodeAddressPayload :: ByteString -> CBOR.Encoding
 encodeAddressPayload payload = mempty
     <> CBOR.encodeListLen 2

diff --git a/src/Cardano/Wallet/Primitive.hs b/src/Cardano/Wallet/Primitive.hs
@@ -107,9 +107,9 @@ instance NFData Tx
 
 
 data TxIn = TxIn
-    { txId
+    { inputId
         :: !(Hash "Tx")
-    , txIx
+    , inputIx
         :: !Word32
     } deriving (Show, Generic, Eq, Ord)
 

diff --git a/test/unit/Cardano/Wallet/BinarySpec.hs b/test/unit/Cardano/Wallet/BinarySpec.hs
@@ -5,7 +5,7 @@ module Cardano.Wallet.BinarySpec (spec) where
 import Prelude
 
 import Cardano.Wallet.Binary
-    ( decodeBlock, decodeBlockHeader )
+    ( decodeBlock, decodeBlockHeader, decodeTx, encodeTx, txId )
 import Cardano.Wallet.Primitive
     ( Address (..)
     , Block (..)
@@ -27,11 +27,13 @@ import Test.Hspec
 
 import qualified Codec.CBOR.Decoding as CBOR
 import qualified Codec.CBOR.Read as CBOR
+import qualified Codec.CBOR.Write as CBOR
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.ByteString.Lazy.Char8 as L8
 import qualified Data.Set as Set
 
 
+{-# ANN spec ("HLint: ignore Use head" :: String) #-}
 spec :: Spec
 spec = do
     describe "Decoding blocks" $ do
@@ -55,6 +57,29 @@ spec = do
             let decoded = unsafeDeserialiseFromBytes decodeBlock bs
             decoded `shouldBe` block3
 
+    describe "Encoding Tx" $ do
+        let txs = Set.toList (transactions block2 <> transactions block3)
+        let roundTripTx tx = do
+                let bytes = CBOR.toLazyByteString (encodeTx tx)
+                let tx' = unsafeDeserialiseFromBytes decodeTx bytes
+                tx `shouldBe` tx'
+
+        it "encode . decode = pure (1)" $ do
+            roundTripTx (txs !! 0)
+
+        it "encode . decode = pure (2)" $ do
+            roundTripTx (txs !! 1)
+
+        it "should compute correct txId (1)" $ do
+            let hash = txId (txs !! 0)
+            let hash' = hash16 "c470563001e448e61ff1268c2a6eb458ace1d04011a02cb262b6d709d66c23d0"
+            hash `shouldBe` hash'
+
+        it "should compute correct txId (2)" $ do
+            let hash = txId (txs !! 1)
+            let hash' = hash16 "d30d37f1f8674c6c33052826fdc5bc198e3e95c150364fd775d4bc663ae6a9e6"
+            hash `shouldBe` hash'
+
 
 -- A mainnet block header
 blockHeader1 :: BlockHeader
@@ -87,8 +112,8 @@ block2 = Block
         [ Tx
             { inputs =
                 [ TxIn
-                    { txId = hash16 "60dbb2679ee920540c18195a3d92ee9be50aee6ed5f891d92d51db8a76b02cd2"
-                    , txIx = 3
+                    { inputId = hash16 "60dbb2679ee920540c18195a3d92ee9be50aee6ed5f891d92d51db8a76b02cd2"
+                    , inputIx = 3
                     }
                 ]
             , outputs =
@@ -117,11 +142,11 @@ block3 = Block
         [ Tx
             { inputs =
                 [ TxIn
-                    { txId = hash16 "6967e2b5c3ad5ae07a9bd8d888f1836195a04f7a1cb4b6d083261870068fab1b"
-                    , txIx = 1}
+                    { inputId = hash16 "6967e2b5c3ad5ae07a9bd8d888f1836195a04f7a1cb4b6d083261870068fab1b"
+                    , inputIx = 1}
                 , TxIn
-                    { txId = hash16 "7064addc0968bccd7d57d2e7aa1e9c2f666d8387042483fc1e87200cfb96c8f1"
-                    , txIx = 0} ]
+                    { inputId = hash16 "7064addc0968bccd7d57d2e7aa1e9c2f666d8387042483fc1e87200cfb96c8f1"
+                    , inputIx = 0} ]
             , outputs =
                 [ TxOut
                     { address = addr58 "37btjrVyb4KBsw2f3V76ntfwqDPgyf3QmmdsrTSmCnuTGYtS9JgVXzxeQEsKjgWurKoyw9BDNEtLxWtU9znK49SC8bLTirk6YqcAESFxXJkSyXhQKL"