Implements low-level transparent components (#45)

This PR includes components for the deserialization of low-level part of transparent components.

Reviewed-on: #45
Co-authored-by: Rene Vergara <rene@vergara.network>
Co-committed-by: Rene Vergara <rene@vergara.network>

librustzcash-wrapper/src/lib.rs

@@ -36,6 +36,7 @@ use zcash_primitives::{
             Bundle as TransparentBundle,
             TxIn,
             TxOut,
+            OutPoint,
             Authorized
         },
         sapling::{
@@ -246,6 +247,7 @@ impl<RW> ToHaskell<RW> for Htx {
 
 #[derive(BorshSerialize, BorshDeserialize)]
 pub struct HTBundle {
+    empty: bool,
     vin: Vec<HTxIn>,
     vout: Vec<HTxOut>,
     coinbase: bool
@@ -260,13 +262,13 @@ impl<RW> ToHaskell<RW> for HTBundle {
 
 impl HTBundle {
     pub fn from_bundle(b: &TransparentBundle<Authorized>) -> HTBundle {
-        HTBundle { vin: b.vin.iter().map(HTxIn::pack).collect() , vout: b.vout.iter().map(HTxOut::pack).collect(), coinbase: b.is_coinbase()}
+        HTBundle {empty: false, vin: b.vin.iter().map(HTxIn::pack).collect() , vout: b.vout.iter().map(HTxOut::pack).collect(), coinbase: b.is_coinbase()}
     }
 }
 
 #[derive(BorshSerialize, BorshDeserialize)]
 pub struct HTxIn {
-    outpoint: u32,
+    outpoint: Houtpoint,
     script: Vec<u8>,
     sequence: u32
 }
@@ -280,7 +282,7 @@ impl<RW> ToHaskell<RW> for HTxIn {
 
 impl HTxIn {
     pub fn pack(t: &TxIn<Authorized>) -> HTxIn {
-        return HTxIn { outpoint: t.prevout.n(), script: t.script_sig.0.clone(), sequence: t.sequence}
+        return HTxIn { outpoint: Houtpoint::pack(&t.prevout), script: t.script_sig.0.clone(), sequence: t.sequence}
     }
 }
 
@@ -303,6 +305,25 @@ impl HTxOut {
     }
 }
 
+#[derive(BorshSerialize, BorshDeserialize)]
+pub struct Houtpoint {
+    hash: Vec<u8>,
+    index: u32
+}
+
+impl<RW> ToHaskell<RW> for Houtpoint {
+    fn to_haskell<W: Write>(&self, writer: &mut W, _tag: PhantomData<RW>) -> Result<()> {
+        self.serialize(writer)?;
+        Ok(())
+    }
+}
+
+impl Houtpoint {
+    pub fn pack(o: &OutPoint) -> Houtpoint {
+        return Houtpoint {hash: o.hash().to_vec() , index: o.n() }
+    }
+}
+
 #[derive(BorshSerialize, BorshDeserialize)]
 pub struct Hufvk {
     net: u8,
@@ -651,11 +672,20 @@ pub extern "C" fn rust_wrapper_tx_read(
     let parsed_tx = Transaction::read(&mut tx_reader, Nu5);
     match parsed_tx {
         Ok(t) => {
-            let h = Htx {txid: t.txid().as_ref().to_vec(), locktime: t.lock_time(), expiry: u32::from(t.expiry_height()), t_bundle: HTBundle::from_bundle(t.transparent_bundle().unwrap()) };
+            let tb = t.transparent_bundle();
+            match tb {
+                Some(my_tb) => {
+                    let h = Htx {txid: t.txid().as_ref().to_vec(), locktime: t.lock_time(), expiry: u32::from(t.expiry_height()), t_bundle: HTBundle::from_bundle(my_tb) };
                     marshall_to_haskell_var(&h, out, out_len, RW);
                 },
+                None => {
+                    let h0 = Htx {txid: t.txid().as_ref().to_vec(), locktime: t.lock_time(), expiry: u32::from(t.expiry_height()), t_bundle: HTBundle {empty: true, vin: vec![HTxIn {outpoint: Houtpoint {hash: vec![0], index: 0}, script: vec![0], sequence: 0}], vout: vec![HTxOut {amt: 0, script: vec![0]}], coinbase: true} };
+                    marshall_to_haskell_var(&h0, out, out_len, RW);
+                }
+            }
+        },
         Err(_e) => {
-            let h0 = Htx {txid: vec![0], locktime: 0, expiry: 0, t_bundle: HTBundle {vin: vec![HTxIn {outpoint: 0, script: vec![0], sequence: 0}], vout: vec![HTxOut {amt: 0, script: vec![0]}], coinbase: true} };
+            let h0 = Htx {txid: vec![0], locktime: 0, expiry: 0, t_bundle: HTBundle {empty: true, vin: vec![HTxIn {outpoint: Houtpoint {hash: vec![0], index: 0}, script: vec![0], sequence: 0}], vout: vec![HTxOut {amt: 0, script: vec![0]}], coinbase: true} };
             marshall_to_haskell_var(&h0, out, out_len, RW);
         }
     }

src/ZcashHaskell/Types.hs

@@ -30,6 +30,7 @@ import Data.Aeson
 import qualified Data.ByteArray as BA
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Char8 as C
+import qualified Data.ByteString.Lazy.UTF8 as US
 import Data.HexString
 import Data.Int
 import Data.Maybe (fromMaybe)
@@ -135,6 +136,29 @@ data TransparentBundle = TransparentBundle
   , tb_coinbase :: !Bool
   } deriving (Eq, Prelude.Show, Read)
 
+-- | Read a raw transparent bundle into the Haskell type
+fromRawTBundle :: RawTBundle -> Maybe TransparentBundle
+fromRawTBundle rtb =
+  if ztb_empty rtb
+    then Nothing
+    else Just $
+         TransparentBundle
+           (map fromRawTxIn $ ztb_vin rtb)
+           (map fromRawTxOut $ ztb_vout rtb)
+           (ztb_coinbase rtb)
+
+fromRawTxIn :: RawTxIn -> H.TxIn
+fromRawTxIn t =
+  H.TxIn
+    (H.OutPoint
+       (read $ US.toString $ C.fromStrict $ rop_hash $ rti_outpoint t)
+       (rop_n $ rti_outpoint t))
+    (rti_script t)
+    (rti_seq t)
+
+fromRawTxOut :: RawTxOut -> H.TxOut
+fromRawTxOut t = H.TxOut (rto_amt t) (rto_script t)
+
 -- *** Constants for Sapling Human-readable part
 sapExtSpendingKeyHrp = "secret-extended-key-main" :: String
 
@@ -262,7 +286,8 @@ data RawZebraTx = RawZebraTx
 
 -- | Type for a raw deserialized Zebra transparent bundle
 data RawTBundle = RawTBundle
-  { ztb_vin :: ![RawTxIn]
+  { ztb_empty :: !Bool
+  , ztb_vin :: ![RawTxIn]
   , ztb_vout :: ![RawTxOut]
   , ztb_coinbase :: !Bool
   } deriving stock (Eq, Prelude.Show, GHC.Generic)
@@ -323,7 +348,7 @@ data TransparentAddress = TransparentAddress
 
 -- | Wrapper types for transparent elements
 data RawTxIn = RawTxIn
-  { rti_outpoint :: !Word32
+  { rti_outpoint :: !RawOutPoint
   , rti_script :: !BS.ByteString
   , rti_seq :: !Word32
   } deriving stock (Eq, Prelude.Show, GHC.Generic)
@@ -339,6 +364,14 @@ data RawTxOut = RawTxOut
     deriving anyclass (Data.Structured.Show)
     deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct RawTxOut
 
+data RawOutPoint = RawOutPoint
+  { rop_hash :: !BS.ByteString
+  , rop_n :: !Word32
+  } deriving stock (Eq, Prelude.Show, GHC.Generic)
+    deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
+    deriving anyclass (Data.Structured.Show)
+    deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct RawOutPoint
+
 -- * Sapling
 -- | A spending key for Sapling
 newtype SaplingSpendingKey =

zcash-haskell.cabal

@@ -58,6 +58,7 @@ library
     , text
     , haskoin-core
     , secp256k1-haskell
+    , utf8-string
   build-tool-depends:
     c2hs:c2hs
   default-language: Haskell2010