Implement Sapling tx decoding

librustzcash-wrapper/src/lib.rs

@@ -19,13 +19,17 @@ use haskell_ffi::{
 use zcash_primitives::{
     zip32::Scope as SaplingScope,
     transaction::components::sapling::{
+        read_zkproof,
         GrothProofBytes,
         OutputDescription,
         CompactOutputDescription
     },
     sapling::{
         value::ValueCommitment as SaplingValueCommitment,
-        keys::FullViewingKey as SaplingViewingKey,
+        keys::{
+            FullViewingKey as SaplingViewingKey,
+            PreparedIncomingViewingKey as SaplingPreparedIncomingViewingKey
+        },
         note_encryption::SaplingDomain,
         PaymentAddress,
         note::ExtractedNoteCommitment as SaplingExtractedNoteCommitment
@@ -311,35 +315,49 @@ pub extern "C" fn rust_wrapper_ufvk_decode(
     }
 }
 
-//#[no_mangle]
+#[no_mangle]
-//pub extern "C" fn rust_wrapper_sapling_note_decrypt(
+pub extern "C" fn rust_wrapper_sapling_note_decrypt(
-    //key: *const u8,
+    key: *const u8,
-    //key_len: usize,
+    key_len: usize,
-    //note: *const u8,
+    note: *const u8,
-    //note_len: usize,
+    note_len: usize,
-    //out: *mut u8,
+    out: *mut u8,
-    //out_len: &mut usize
+    out_len: &mut usize
-    //){
+    ){
-    //let evk: Vec<u8> = marshall_from_haskell_var(key, key_len, RW);
+    let evk: Vec<u8> = marshall_from_haskell_var(key, key_len, RW);
-    //let note_input: HshieldedOutput = marshall_from_haskell_var(note,note_len,RW);
+    let note_input: HshieldedOutput = marshall_from_haskell_var(note,note_len,RW);
-    //let svk = ExtendedFullViewingKey::read(&*evk);
+    let svk = ExtendedFullViewingKey::read(&*evk);
-    //match svk {
+    match svk {
-        //Ok(k) => {
+        Ok(k) => {
-            //let domain = SaplingDomain::for_height(MainNetwork, BlockHeight::from_u32(2000000));
+            let domain = SaplingDomain::for_height(MainNetwork, BlockHeight::from_u32(2000000));
-            //let action: CompactOutputDescription = CompactOutputDescription {
+            let mut action_bytes = vec![0];
-                //ephemeral_key: EphemeralKeyBytes(to_array(note_input.eph_key)),
+            action_bytes.extend(&note_input.cv);
-                //cmu: SaplingExtractedNoteCommitment::from_bytes(&to_array(note_input.cmu)).unwrap(),
+            action_bytes.extend(&note_input.cmu);
-                //enc_ciphertext: to_array(note_input.enc_txt)
+            action_bytes.extend(&note_input.eph_key);
-            //};
+            action_bytes.extend(&note_input.enc_txt);
-            //let fvk = k.to_diversifiable_full_viewing_key().to_ivk(SaplingScope::External);
+            action_bytes.extend(&note_input.out_txt);
-            //let result = zcash_note_encryption::try_note_decryption(&domain, &ivk, &action);
+            action_bytes.extend(&note_input.proof);
-        //}
+            let action2 = OutputDescription::read(&mut action_bytes.as_slice()).unwrap();
-        //Err(_e) => {
+            let fvk = k.to_diversifiable_full_viewing_key().to_ivk(SaplingScope::External);
-            //let hn0 = Hnote { note: 0, recipient: vec![0], memo: vec![0] };
+            let pivk = SaplingPreparedIncomingViewingKey::new(&fvk);
-            //marshall_to_haskell_var(&hn0, out, out_len, RW);
+            let result = zcash_note_encryption::try_note_decryption(&domain, &pivk, &action2);
-        //}
+            match result {
-    //}
+                Some((n, r, m)) => {
-//}
+                    let hn = Hnote {note: n.value().inner(), recipient: r.to_bytes().to_vec(), memo: m.as_slice().to_vec() };
+                    marshall_to_haskell_var(&hn, out, out_len, RW);
+                }
+                None => {
+                    let hn0 = Hnote { note: 0, recipient: vec![0], memo: vec![0] };
+                    marshall_to_haskell_var(&hn0, out, out_len, RW);
+                }
+            }
+        }
+        Err(_e) => {
+            let hn0 = Hnote { note: 0, recipient: vec![0], memo: vec![0] };
+            marshall_to_haskell_var(&hn0, out, out_len, RW);
+        }
+    }
+}
 
 #[no_mangle]
 pub extern "C" fn rust_wrapper_orchard_note_decrypt(

src/C/Zcash.chs

@@ -72,6 +72,14 @@ import ZcashHaskell.Types
   -> `Bool'
 #}
 
+{# fun unsafe rust_wrapper_sapling_note_decrypt as rustWrapperSaplingNoteDecode
+    { toBorshVar* `BS.ByteString'&
+    , toBorshVar* `ShieldedOutput'&
+    , getVarBuffer `Buffer DecodedNote'&
+    }
+  -> `()'
+#}
+
 {# fun unsafe rust_wrapper_ufvk_decode as rustWrapperUfvkDecode
      { toBorshVar* `BS.ByteString'&
      , getVarBuffer `Buffer UnifiedFullViewingKey'&
@@ -82,7 +90,7 @@ import ZcashHaskell.Types
 {# fun unsafe rust_wrapper_orchard_note_decrypt as rustWrapperOrchardNoteDecode
      { toBorshVar* `BS.ByteString'&
      , toBorshVar* `OrchardAction'&
-     , getVarBuffer `Buffer OrchardDecodedAction'&
+     , getVarBuffer `Buffer DecodedNote'&
      }
   -> `()'
-  #}
+#}

src/ZcashHaskell/Orchard.hs

@@ -35,7 +35,7 @@ decodeUfvk str =
 
 -- | Attempts to decode the given @OrchardAction@ using the given @UnifiedFullViewingKey@.
 decryptOrchardAction ::
-     OrchardAction -> UnifiedFullViewingKey -> Maybe OrchardDecodedAction
+     OrchardAction -> UnifiedFullViewingKey -> Maybe DecodedNote
 decryptOrchardAction encAction key =
   case a_value decodedAction of
     0 -> Nothing

src/ZcashHaskell/Sapling.hs

@@ -3,9 +3,12 @@ module ZcashHaskell.Sapling where
 import C.Zcash
   ( rustWrapperIsShielded
   , rustWrapperSaplingCheck
+  , rustWrapperSaplingNoteDecode
   , rustWrapperSaplingVkDecode
   )
 import qualified Data.ByteString as BS
+import Foreign.Rust.Marshall.Variable (withPureBorshVarBuffer)
+import ZcashHaskell.Types (DecodedNote(..), ShieldedOutput)
 
 -- | Check if given bytesting is a valid encoded shielded address
 isValidShieldedAddress :: BS.ByteString -> Bool
@@ -18,3 +21,13 @@ isValidSaplingViewingKey = rustWrapperSaplingVkDecode
 -- | Check if the given bytestring for the Sapling viewing key matches the second bytestring for the address
 matchSaplingAddress :: BS.ByteString -> BS.ByteString -> Bool
 matchSaplingAddress = rustWrapperSaplingCheck
+
+-- | Attempt to decode the given Sapling raw output with the given Sapling viewing key
+decodeSaplingOutput :: BS.ByteString -> ShieldedOutput -> Maybe DecodedNote
+decodeSaplingOutput key out =
+  case a_value decodedAction of
+    0 -> Nothing
+    _ -> Just decodedAction
+  where
+    decodedAction =
+      withPureBorshVarBuffer $ rustWrapperSaplingNoteDecode key out

src/ZcashHaskell/Types.hs

@@ -153,15 +153,15 @@ instance FromJSON OrchardAction where
           (decodeHexText cval)
           (decodeHexText a)
 
--- | Type to represent a decoded Orchard Action
+-- | Type to represent a decoded note
-data OrchardDecodedAction = OrchardDecodedAction
+data DecodedNote = DecodedNote
   { a_value :: Int64 -- ^ The amount of the transaction in _zatoshis_.
   , a_recipient :: BS.ByteString -- ^ The recipient Orchard receiver.
   , a_memo :: BS.ByteString -- ^ The decoded shielded memo field.
   } deriving stock (Eq, Prelude.Show, GHC.Generic)
     deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
     deriving anyclass (Data.Structured.Show)
-    deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct OrchardDecodedAction
+    deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct DecodedNote
 
 -- * Helpers
 -- | Helper function to turn a hex-encoded string to bytestring

test/Spec.hs

@@ -11,17 +11,18 @@ import Data.Word
 import Test.Hspec
 import ZcashHaskell.Orchard
 import ZcashHaskell.Sapling
-  ( isValidSaplingViewingKey
+  ( decodeSaplingOutput
+  , isValidSaplingViewingKey
   , isValidShieldedAddress
   , matchSaplingAddress
   )
 import ZcashHaskell.Types
   ( BlockResponse(..)
+  , DecodedNote(..)
   , OrchardAction(..)
-  , OrchardDecodedAction(..)
   , RawData(..)
   , RawTxResponse(..)
-  , ShieldedOutput(s_cmu)
+  , ShieldedOutput(ShieldedOutput, s_cmu)
   , UnifiedFullViewingKey(..)
   , decodeHexText
   )
@@ -313,7 +314,25 @@ main = do
     describe "Decode Sapling tx" $ do
       let svk =
             "zxviews1qvapd723qqqqpqq09ldgykvyusthmkky2w062esx5xg3nz4m29qxcvndyx6grrhrdepu4ns88sjr3u6mfp2hhwj5hfd6y24r0f64uwq65vjrmsh9mr568kenk33fcumag6djcjywkm5v295egjuk3qdd47atprs0j33nhaaqep3uqspzp5kg4mthugvug0sc3gc83atkrgmguw9g7gkvh82tugrntf66lnvyeh6ufh4j2xt0xr2r4zujtm3qvrmd3vvnulycuwqtetg2jk384"
-      it "succeeds with correct key" pending
+      it "succeeds with correct key" $ do
+        let rawKey = decodeBech32 svk
+        let rawNote =
+              ShieldedOutput
+                (decodeHexText
+                   "a2853a37316dfc32301dfcae2583797a6dab0aaba8b08e9bd052d2d65bc66c14")
+                (decodeHexText
+                   "65dc83588d7fa63510391505b2b57455d8740a29bce1ad20f798a647b4163a5a")
+                (decodeHexText
+                   "3c9748817d696cf1e540d0ffa759092740e23c2b07415d326f9d007ba1a43bea")
+                (decodeHexText
+                   "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")
+                (decodeHexText
+                   "01c4ed60fa283994fd712aab17ca6360256fd5aef0ebc48f0256e3eda5894b53981d0d46768aefdc85b48c1525b7f134dce5d4ec2d76c03c821513f1652d9671219d744bdce5e69b9a74ca0c7c837668")
+                (decodeHexText
+                   "9534b3d594e1609b3bace18608750b35a066c57f85e291d194400cb351430bbbe212abba32be071e747b7310863bd5fd989855a6567a351b288144b6e9f838c6a517db94673246ef0010b65f9c0be8aca654f6f57b83d893663cfd389ab96ce50e8077fe588c16b1b5989c6cc262e6658efb9b88ac800e49e9e5999e2651b8fff28fa77071d63790df155ed8344e2581ac5205b31d4f17bd748fcf60e35a9d6048d23c94c7aca8d4e541fda497aa268df9c173af5877a5da56d8fa2a42166900")
+        print rawNote
+        let a = decodeSaplingOutput (bytes rawKey) rawNote
+        maybe 0 a_value a `shouldNotBe` 0
     describe "Decode Orchard tx" $ do
       let uvk =
             "uview1u833rp8yykd7h4druwht6xp6k8krle45fx8hqsw6vzw63n24atxpcatws82z092kryazuu6d7rayyut8m36wm4wpjy2z8r9hj48fx5pf49gw4sjrq8503qpz3vqj5hg0vg9vsqeasg5qjuyh94uyfm7v76udqcm2m0wfc25hcyqswcn56xxduq3xkgxkr0l73cjy88fdvf90eq5fda9g6x7yv7d0uckpevxg6540wc76xrc4axxvlt03ptaa2a0rektglmdy68656f3uzcdgqqyu0t7wk5cvwghyyvgqc0rp3vgu5ye4nd236ml57rjh083a2755qemf6dk6pw0qrnfm7246s8eg2hhzkzpf9h73chhng7xhmyem2sjh8rs2m9nhfcslsgenm"