librustzcash-wrapper/src/lib.rs

@@ -649,8 +649,48 @@ pub extern "C" fn rust_wrapper_sapling_paymentaddress(
     out: *mut u8,
     out_len: &mut usize
     ){
-    let divIx : u32 = 2;
-    println!("Starting paymentAddress generation....");
+//    println!("Starting paymentAddress generation....");
+    let extspkb: Vec<u8> = marshall_from_haskell_var(extspk, extspk_len, RW);
+    if ( extspkb.len() != 169 ) {
+        // invalid ExtendedSpenndingKey Array length 
+        println!("Invalid ExtendedSpendingKey....");
+        marshall_to_haskell_var(&vec![0], out, out_len, RW);
+    } else {
+        // Process 
+//        println!("Extended Spending Key validated, continue ....");
+        let extspkbu8 = &extspkb;
+        let xsku8 : &[u8] = &extspkbu8;
+        let xsk = match sapling::ExtendedSpendingKey::from_bytes(&xsku8) {
+                Ok ( x ) => x, 
+                Err ( err ) => {
+                    // Error recovering ExtendedSpendingKey from bytes
+                    marshall_to_haskell_var(&vec![0], out, out_len, RW);
+                    return        
+                }
+            };
+        // Obtain the DiversifiableFullViewingKey from ExtendedSpendingKey   
+        let dfvk = xsk.to_diversifiable_full_viewing_key();
+        // Obtain the Address from the DiversifiableFullViewingKey
+//        println!("dfvk -> \n{:?}", dfvk);
+//        let divIndex : DiversifierIndex  = divIx.into();
+//        println!("divIndex -> {:?}", divIndex);
+        let (divIx, paddress) = dfvk.default_address();
+//        println!("Rust pmtAddress - \n{:?}\n\nRust Diversifier - \n{:?}\n", paddress, divIx);
+        let pmtAddress = paddress.to_bytes();
+//        println!("\nRust pntAddress as byte array -\n{:?}\n", pmtAddress);
+        marshall_to_haskell_var(&pmtAddress.to_vec(), out, out_len, RW);
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn rust_wrapper_sapling_find_paymentaddress(
+    extspk: *const u8,
+    extspk_len: usize,
+    divIx: u32,
+    out: *mut u8,
+    out_len: &mut usize
+    ){
+    println!("Starting paymentAddress generation using Find_Address()....");
     let extspkb: Vec<u8> = marshall_from_haskell_var(extspk, extspk_len, RW);
     if ( extspkb.len() != 169 ) {
         // invalid ExtendedSpenndingKey Array length 
@@ -669,20 +709,30 @@ pub extern "C" fn rust_wrapper_sapling_paymentaddress(
                     return        
                 }
             };
+        println!("Obtain a DiversifierIndex from u32 parameter {:?}....",divIx);
+        let diversifierIndex : DiversifierIndex = divIx.into();
         // Obtain the DiversifiableFullViewingKey from ExtendedSpendingKey   
         let dfvk = xsk.to_diversifiable_full_viewing_key();
         // Obtain the Address from the DiversifiableFullViewingKey
 //        println!("dfvk -> \n{:?}", dfvk);
 //        let divIndex : DiversifierIndex  = divIx.into();
 //        println!("divIndex -> {:?}", divIndex);
-        let (divIx, paddress) = dfvk.default_address();
+        let result = dfvk.find_address(diversifierIndex) 
+                    .map (|(divIx,paddress) | {
                             println!("Rust pmtAddress - \n{:?}\n\nRust Diversifier - \n{:?}\n", paddress, divIx);
                             let pmtAddress = paddress.to_bytes();
                             println!("\nRust pntAddress as byte array -\n{:?}\n", pmtAddress);
                             marshall_to_haskell_var(&pmtAddress.to_vec(), out, out_len, RW);
+//                                 
+                    })
+                    .unwrap_or_else(|| {
+                        // Handle the case where the function returns None
+                        println!("Rust - Error finding payment address.... ");
+                        marshall_to_haskell_var(&vec![0], out, out_len, RW);
+                        return        
+                    });
     }
 }
-
 #[no_mangle]
 pub extern "C" fn rust_wrapper_derive_orchard_spending_key(
     seed: *const u8,

src/C/Zcash.chs

@@ -148,6 +148,14 @@ import ZcashHaskell.Types
   -> `()'
 #}
 
+{# fun unsafe rust_wrapper_sapling_find_paymentaddress as rustWrapperFindPaymentAddress
+     { toBorshVar* `BS.ByteString'&
+     , `Word32'
+     , getVarBuffer `Buffer (BS.ByteString)'&
+     }
+  -> `()'
+#}
+
 {# fun unsafe rust_wrapper_derive_orchard_spending_key as rustWrapperGenOrchardSpendKey
      { toBorshVar* `BS.ByteString'&
      , `Word32'

src/ZcashHaskell/Sapling.hs

@@ -23,6 +23,7 @@ import C.Zcash
   , rustWrapperSaplingNoteDecode
   , rustWrapperSaplingSpendingkey
   , rustWrapperPaymentAddress
+  , rustWrapperFindPaymentAddress
   , rustWrapperSaplingVkDecode
   , rustWrapperTxParse
   )
@@ -99,8 +100,14 @@ genSaplingSpendingKey seed = do
       res
 --
 -- | Attempts to generate a sapling Payment Address using an ExtendedSpendingKey 
--- | and a Diversifier Index 
 genSaplingPaymentAddress :: BS.ByteString -> BS.ByteString
 genSaplingPaymentAddress extspk = do
       let pmtaddress = withPureBorshVarBuffer (rustWrapperPaymentAddress extspk )
       pmtaddress
+
+--
+-- | Attempts to generate a sapling Payment Address using an ExtendedSpendingKey 
+genSaplingFindPaymentAddress :: BS.ByteString -> Word32 -> BS.ByteString
+genSaplingFindPaymentAddress extspk divIx = do
+      let pmtaddress = withPureBorshVarBuffer (rustWrapperFindPaymentAddress extspk divIx)
+      pmtaddress

test/Spec.hs

@@ -47,6 +47,7 @@ import ZcashHaskell.Sapling
   , matchSaplingAddress
   , genSaplingSpendingKey
   , genSaplingPaymentAddress
+  , genSaplingFindPaymentAddress
   )
 import ZcashHaskell.Transparent 
   --(encodeTransparent)
@@ -532,9 +533,7 @@ main = do
                   ] :: [Word8]
           let msg = genSaplingSpendingKey (word8ArrayToByteString hdseed)
           let msgArr = BS.unpack msg
-          if (length msgArr) == 169
-                  then True
-                  else False
+          length msgArr `shouldBe` 169
     describe "Sapling Payment Address generation test" $ do
         it "Call genSaplingPaymentAddress" $ do
           let hdseed1 =  [206, 61, 120, 38,
@@ -557,9 +556,30 @@ main = do
           let msg1 = genSaplingSpendingKey (word8ArrayToByteString hdseed1)
           let pmtaddress = genSaplingPaymentAddress  msg1 --(word8ArrayToByteString hdseed1)
           let msgArr = BS.unpack pmtaddress
-          if (length msgArr) == 43
-                  then True
-                  else False
+          length msgArr `shouldBe` 43
+    describe "Sapling Payment Find Address generation test" $ do
+        it "Call genSaplingFindPaymentAddress" $ do
+          let hdseed1 =  [206, 61, 120, 38,
+                   206, 40, 201, 62,
+                   83, 175, 151, 131,
+                   218, 141, 206, 254,
+                   28, 244, 172, 213,
+                   128, 248, 156, 45,
+                   204, 44, 169, 3,
+                   162, 188, 16, 173,
+                   192, 164, 96, 148,
+                   91, 52, 244, 83,
+                   149, 169, 82, 196,
+                   199, 53, 177, 170,
+                   1, 6, 0, 120,
+                   170, 2, 238, 219,
+                   241, 243, 172, 178,
+                   104, 81, 159, 144
+                  ] :: [Word8]
+          let msg1 = genSaplingSpendingKey (word8ArrayToByteString hdseed1)
+          let pmtaddress = genSaplingFindPaymentAddress msg1 0 --(word8ArrayToByteString hdseed1)
+          let msgArr = BS.unpack pmtaddress
+          length msgArr `shouldBe` 42
 
 -- | Properties
 prop_PhraseLength :: Int -> Property