Commit first version of genSaplingInternalAddress function

librustzcash-wrapper/src/lib.rs

@@ -59,7 +59,8 @@ use zcash_address::{
 
 use zcash_client_backend::keys::sapling::{
     ExtendedFullViewingKey,
-    ExtendedSpendingKey
+    ExtendedSpendingKey,
+    DiversifiableFullViewingKey
 };
 
 use zcash_primitives::zip32::{ AccountId, DiversifierIndex };
@@ -632,7 +633,7 @@ pub extern "C" fn rust_wrapper_sapling_spendingkey(
     out_len: &mut usize
     ){
     let seed: Vec<u8> = marshall_from_haskell_var(iseed, iseed_len, RW);
-    if  ( seed.len() != 64 ) {
+    if  seed.len() != 64  {
         // invalid seed length 
         marshall_to_haskell_var(&vec![0], out, out_len, RW);
     } else {
@@ -669,6 +670,36 @@ pub extern "C" fn rust_wrapper_sapling_paymentaddress(
     }
 }
 
+#[no_mangle]
+pub extern "C" fn rust_wrapper_sapling_chgpaymentaddress(
+    extspk: *const u8,
+    extspk_len: usize,
+    out: *mut u8,
+    out_len: &mut usize
+    ){
+    println!("Entering ChangeAddress generation....");
+    let vexspk: Vec<u8> = marshall_from_haskell_var(extspk, extspk_len, RW);
+    let vexspkp = &vexspk;
+    let extspku8 : &[u8] = &vexspkp;
+    println!("Received ExtendedSpendingKey in Bytes...\n{:?}\n",extspku8);
+    let extspk =  match ExtendedSpendingKey::from_bytes(&extspku8) {
+        Ok( k ) => k,
+        Err( e ) => {
+            // error recovering ExtendedSpendingKey
+            println!("\n>>>> Error generating ExtendedSpendingKey");
+            marshall_to_haskell_var(&vec![0], out, out_len, RW);
+            return
+        }
+    };
+    println!("ExtendedSpendingKey -> {:?}",extspk);
+    let dfvk = extspk.to_diversifiable_full_viewing_key();
+    let ( divIx, cPmtAddress ) = dfvk.change_address();
+    println!("\nDiversifierIndex > {:?}\n\nChange Payment Address -> {:?}\n ", 
+             divIx, cPmtAddress);
+    println!("Change Payment Address in bytes : \n{:?}",cPmtAddress.to_bytes());
+    marshall_to_haskell_var(&cPmtAddress.to_bytes().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

@@ -149,6 +149,13 @@ import ZcashHaskell.Types
   -> `()'
 #}
 
+{# fun unsafe rust_wrapper_sapling_chgpaymentaddress as rustWrapperSaplingChgPaymentAddress
+     { toBorshVar* `BS.ByteString'&
+     , getVarBuffer `Buffer (BS.ByteString)'&
+     }
+  -> `()'
+#}
+
 {# fun unsafe rust_wrapper_derive_orchard_spending_key as rustWrapperGenOrchardSpendKey
      { toBorshVar* `BS.ByteString'&
      , `Word32'

src/ZcashHaskell/Sapling.hs

@@ -22,6 +22,7 @@ import C.Zcash
   , rustWrapperSaplingCheck
   , rustWrapperSaplingNoteDecode
   , rustWrapperSaplingPaymentAddress
+  , rustWrapperSaplingChgPaymentAddress
   , rustWrapperSaplingSpendingkey
   , rustWrapperSaplingVkDecode
   , rustWrapperTxParse
@@ -115,5 +116,6 @@ genSaplingPaymentAddress extspk i =
         (rustWrapperSaplingPaymentAddress extspk (fromIntegral i))
 
 -- | Generate an internal Sapling address
-genSaplingInternalAddress :: SaplingSpendingKey -> Maybe SaplingInternalReceiver
+genSaplingInternalAddress :: SaplingSpendingKey -> BS.ByteString -- SaplingInternalReceiver
-genSaplingInternalAddress sk = undefined
+genSaplingInternalAddress sk =  withPureBorshVarBuffer (rustWrapperSaplingChgPaymentAddress sk)
+  

test/Spec.hs

@@ -42,6 +42,7 @@ import ZcashHaskell.Orchard
 import ZcashHaskell.Sapling
   ( decodeSaplingOutput
   , genSaplingPaymentAddress
+  , genSaplingInternalAddress
   , genSaplingSpendingKey
   , getShieldedOutputs
   , isValidSaplingViewingKey
@@ -481,7 +482,7 @@ main = do
                 Nothing -> "Bad UA"
                 Just u -> maybe "No transparent" encodeTransparent $ t_rec u
         msg `shouldBe` "t1LPWuQnjCRH7JAeEErSXKixcUteLJRJjKD"
-    describe "Transparent Private and Publicc Key Generation" $ do
+    describe "Transparent Private and Public Key Generation" $ do
       it "Obtain a transparent extended private key from HDSeed" $ do
         let hdseed =
               [ 206
@@ -589,6 +590,191 @@ main = do
         genSaplingPaymentAddress (fromMaybe "" s) 0 `shouldNotBe` Nothing
       prop "Sapling receivers are valid" $
         forAll genSapArgs $ \i -> prop_SaplingReceiver i
+    describe "Sapling Change Payment Address generation test" $ do
+      it "Call genSaplingInternalAddress" $ do
+        let sk =  [ 3
+                  , 183
+                  , 26
+                  , 151
+                  , 89
+                  , 0
+                  , 0
+                  , 0
+                  , 128
+                  , 199
+                  , 189
+                  , 33
+                  , 169
+                  , 114
+                  , 194
+                  , 50
+                  , 0
+                  , 139
+                  , 140
+                  , 162
+                  , 100
+                  , 100
+                  , 35
+                  , 58
+                  , 226
+                  , 6
+                  , 47
+                  , 232
+                  , 34
+                  , 214
+                  , 11
+                  , 173
+                  , 142
+                  , 40
+                  , 45
+                  , 163
+                  , 190
+                  , 207
+                  , 49
+                  , 130
+                  , 158
+                  , 113
+                  , 232
+                  , 251
+                  , 79
+                  , 98
+                  , 77
+                  , 195
+                  , 196
+                  , 40
+                  , 42
+                  , 113
+                  , 133
+                  , 35
+                  , 211
+                  , 68
+                  , 146
+                  , 104
+                  , 5
+                  , 56
+                  , 244
+                  , 162
+                  , 55
+                  , 239
+                  , 55
+                  , 112
+                  , 37
+                  , 38
+                  , 189
+                  , 183
+                  , 121
+                  , 201
+                  , 1
+                  , 60
+                  , 158
+                  , 151
+                  , 141
+                  , 123
+                  , 250
+                  , 95
+                  , 169
+                  , 123
+                  , 208
+                  , 56
+                  , 103
+                  , 74
+                  , 85
+                  , 49
+                  , 152
+                  , 207
+                  , 245
+                  , 216
+                  , 58
+                  , 37
+                  , 0
+                  , 127
+                  , 186
+                  , 245
+                  , 234
+                  , 47
+                  , 68
+                  , 11
+                  , 78
+                  , 76
+                  , 12
+                  , 171
+                  , 37
+                  , 63
+                  , 172
+                  , 90
+                  , 111
+                  , 94
+                  , 88
+                  , 152
+                  , 211
+                  , 53
+                  , 243
+                  , 142
+                  , 16
+                  , 195
+                  , 142
+                  , 50
+                  , 14
+                  , 13
+                  , 32
+                  , 91
+                  , 5
+                  , 82
+                  , 182
+                  , 121
+                  , 136
+                  , 109
+                  , 125
+                  , 165
+                  , 125
+                  , 123
+                  , 226
+                  , 54
+                  , 60
+                  , 34
+                  , 62
+                  , 111
+                  , 167
+                  , 88
+                  , 254
+                  , 113
+                  , 204
+                  , 47
+                  , 181
+                  , 97
+                  , 18
+                  , 220
+                  , 46
+                  , 51
+                  , 160
+                  , 62
+                  , 16
+                  , 199
+                  , 143
+                  , 184
+                  , 200
+                  , 209
+                  , 124
+                  , 154
+                  , 175
+                  , 29
+                  , 216
+                  , 48
+                  , 201] :: [Word8]
+        let cAdr = [31, 232, 31, 17, 195,  -- 196
+                    178, 208, 227, 206, 
+                    199, 105, 55, 147, 
+                    23, 151, 206, 117, 
+                    59, 249, 162, 218, 
+                    140, 189, 17, 60, 
+                    116, 106, 56, 64, 
+                    203, 152, 52, 155, 
+                    133, 179, 118, 47, 
+                    161, 70, 155, 21, 
+                    22, 41] :: [Word8]
+        let bscAdr = BS.pack cAdr
+        let ca = genSaplingInternalAddress (BS.pack sk)
+        ca `shouldBe` bscAdr
 
 -- | Properties
 prop_PhraseLength :: Int -> Property