librustzcash-wrapper/src/lib.rs

@@ -54,7 +54,7 @@ use zcash_client_backend::keys::{
     sapling::ExtendedFullViewingKey,
     sapling::ExtendedSpendingKey};
 
-use zcash_primitives::zip32::AccountId;
+use zcash_primitives::zip32::{ AccountId, DiversifierIndex };
 use std::slice;
 
 use orchard::{
@@ -621,27 +621,68 @@ pub extern "C" fn rust_wrapper_recover_seed(
 pub extern "C" fn rust_wrapper_sapling_spendingkey(
     iseed: *const u8,
     iseed_len: usize,
-    coin_type: u32,
-    acc_id: u32,
     out: *mut u8,
     out_len: &mut usize
     ){
-        println!("From Rust\n=========");
+    println!("Starting extended spending key generation....");
     let seed: Vec<u8> = marshall_from_haskell_var(iseed, iseed_len, RW);
-    if  ( seed.len() <= 0 ) {
-        println!("Seed error, returning a null vector...");
+    if  ( seed.len() != 64 ) {
+        // invalid seed length 
         marshall_to_haskell_var(&vec![0], out, out_len, RW);
     } else {
-        println!("Seed in rust : {:?}\n", seed);
-        println!("Coin Type -> {}\nAccount Id -> {}",coin_type,acc_id);
+        // Obtain the ExtendedSpendingKey using the seed
+        // Returns a byte array (169 bytes)
         let su8 = &seed;
         let seedu8 : &[u8] = &su8;
+        println!("Seed : {:?}\n", &seedu8);
         let extsk: ExtendedSpendingKey = sapling::ExtendedSpendingKey::master(&seedu8); 
         let extsk_bytes = extsk.to_bytes().to_vec(); 
         marshall_to_haskell_var(&extsk_bytes, out, out_len, RW);
     }
 }
 
+#[no_mangle]
+pub extern "C" fn rust_wrapper_sapling_paymentaddress(
+    extspk: *const u8,
+    extspk_len: usize,
+//    divIx: u32,
+    out: *mut u8,
+    out_len: &mut usize
+    ){
+    let divIx : u32 = 2;
+    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_derive_orchard_spending_key(
     seed: *const u8,

src/C/Zcash.chs

@@ -136,8 +136,13 @@ import ZcashHaskell.Types
 
 {# fun unsafe rust_wrapper_sapling_spendingkey as rustWrapperSaplingSpendingkey
      { toBorshVar* `BS.ByteString'&
-     , `Word32'
-     , `Word32'
+     , getVarBuffer `Buffer (BS.ByteString)'&
+     }
+  -> `()'
+#}
+
+{# fun unsafe rust_wrapper_sapling_paymentaddress as rustWrapperPaymentAddress
+     { toBorshVar* `BS.ByteString'&
      , getVarBuffer `Buffer (BS.ByteString)'&
      }
   -> `()'

src/ZcashHaskell/Sapling.hs

@@ -22,6 +22,7 @@ import C.Zcash
   , rustWrapperSaplingCheck
   , rustWrapperSaplingNoteDecode
   , rustWrapperSaplingSpendingkey
+  , rustWrapperPaymentAddress
   , rustWrapperSaplingVkDecode
   , rustWrapperTxParse
   )
@@ -92,7 +93,14 @@ instance FromJSON RawTxResponse where
           pure $ RawTxResponse i h (getShieldedOutputs h) a ht c b
 --
 -- | Attempts to obtain a sapling SpendinKey using a HDSeed, a Coin Type and an Account ID
-genSaplingSpendingKey :: BS.ByteString -> Word32-> AccountId -> BS.ByteString
-genSaplingSpendingKey seed coin_type account_id = do
-      let res = withPureBorshVarBuffer (rustWrapperSaplingSpendingkey seed (fromIntegral coin_type) (fromIntegral account_id) )
+genSaplingSpendingKey :: BS.ByteString -> BS.ByteString
+genSaplingSpendingKey seed = do
+      let res = withPureBorshVarBuffer (rustWrapperSaplingSpendingkey seed )
       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

test/Spec.hs

@@ -43,6 +43,7 @@ import ZcashHaskell.Sapling
   , isValidShieldedAddress
   , matchSaplingAddress
   , genSaplingSpendingKey
+  , genSaplingPaymentAddress 
   )
 import ZcashHaskell.Transparent 
   --(encodeTransparent)
@@ -531,11 +532,33 @@ main = do
                    241, 243, 172, 178,
                    104, 81, 159, 144
                   ] :: [Word8]
-          let cointype  =  getValue TestNetCoin
-          let account = 0 :: AccountId
-          let msg = genSaplingSpendingKey (word8ArrayToByteString hdseed) cointype account
+          let msg = genSaplingSpendingKey (word8ArrayToByteString hdseed)
           let msgArr = BS.unpack msg
           if (length msgArr) == 169
                   then True
                   else False
---          msgArr `shouldBe` "It's working."
+    describe "Sapling Payment Address generation test" $ do
+        it "Call genSaplingPaymentAddress" $ 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 = genSaplingPaymentAddress  msg1 --(word8ArrayToByteString hdseed1)
+          let msgArr = BS.unpack pmtaddress
+          if (length msgArr) == 43
+                  then True
+                  else False