librustzcash-wrapper/src/lib.rs

@@ -61,7 +61,8 @@ use zcash_address::{
 use zcash_client_backend::keys::sapling::{
     spending_key,
     ExtendedFullViewingKey,
-    ExtendedSpendingKey
+    ExtendedSpendingKey,
+    DiversifiableFullViewingKey
 };
 
 use zcash_primitives::zip32::DiversifierIndex;
@@ -676,6 +677,29 @@ 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
+    ){
+    let vexspk: Vec<u8> = marshall_from_haskell_var(extspk, extspk_len, RW);
+    let vexspkp = &vexspk;
+    let extspku8 : &[u8] = &vexspkp;
+    let extspk =  match ExtendedSpendingKey::from_bytes(&extspku8) {
+        Ok( k ) => k,
+        Err( e ) => {
+            // error recovering ExtendedSpendingKey
+            marshall_to_haskell_var(&vec![0], out, out_len, RW);
+            return
+        }
+    };
+    let dfvk = extspk.to_diversifiable_full_viewing_key();
+    let ( divIx, cPmtAddress ) = dfvk.change_address();
+    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

@@ -151,6 +151,13 @@ 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

@@ -20,6 +20,7 @@ module ZcashHaskell.Sapling where
 import C.Zcash
   ( rustWrapperIsShielded
   , rustWrapperSaplingCheck
+  , rustWrapperSaplingChgPaymentAddress
   , rustWrapperSaplingNoteDecode
   , rustWrapperSaplingPaymentAddress
   , rustWrapperSaplingSpendingkey
@@ -124,4 +125,10 @@ genSaplingPaymentAddress i extspk =
 
 -- | Generate an internal Sapling address
 genSaplingInternalAddress :: SaplingSpendingKey -> Maybe SaplingReceiver
-genSaplingInternalAddress sk = undefined
+genSaplingInternalAddress sk =
+  if BS.length res > 0
+    then Just $ SaplingReceiver res
+    else Nothing
+  where
+    res =
+      withPureBorshVarBuffer (rustWrapperSaplingChgPaymentAddress $ getBytes sk)

src/ZcashHaskell/Transparent.hs

@@ -17,28 +17,30 @@ module ZcashHaskell.Transparent where
 
 import Control.Exception (throwIO)
 import Crypto.Hash
+import Crypto.Secp256k1
 import qualified Data.ByteArray as BA
 import qualified Data.ByteString as BS
 import Data.ByteString.Base58 (bitcoinAlphabet, encodeBase58)
+import Data.HexString
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as E
+import Data.Word
+import Haskoin.Address (Address(..))
+import qualified Haskoin.Crypto.Hash as H
+import Haskoin.Crypto.Keys.Extended
 import ZcashHaskell.Types
   ( AccountId
+  , CoinType(..)
+  , Scope(..)
   , Seed(..)
   , ToBytes(..)
   , TransparentAddress(..)
   , TransparentType(..)
   , ZcashNet(..)
   , getTransparentPrefix
+  , getValue
   )
 
-import Crypto.Secp256k1
-import Data.HexString
-import Data.Word
-import Haskoin.Address (Address(..))
-import qualified Haskoin.Crypto.Hash as H
-import Haskoin.Crypto.Keys.Extended
-
 encodeTransparent :: ZcashNet -> TransparentAddress -> T.Text
 encodeTransparent zNet t =
   encodeTransparent' (getTransparentPrefix zNet (ta_type t)) $
@@ -53,19 +55,36 @@ encodeTransparent zNet t =
         digest = BS.pack [a, b] <> h
         checksum = sha256 $ sha256 digest
 
--- | Attempts to generate an Extended Private Key from a known HDSeed.
+-- | Generate an Extended Private Key from a known HDSeed.
-genTransparentPrvKey :: Seed -> AccountId -> IO XPrvKey
+genTransparentPrvKey :: Seed -> CoinType -> AccountId -> IO XPrvKey
-genTransparentPrvKey hdseed i = do
+genTransparentPrvKey hdseed ctype accid = do
-  let prvKey = makeXPrvKey $ getBytes hdseed
+  let coin = getValue ctype
   ioCtx <- createContext
-  return $ hardSubKey ioCtx prvKey (fromIntegral i)
+  let path = Deriv :| 44 :| coin :| fromIntegral accid :: DerivPath
+  let prvKey = makeXPrvKey $ getBytes hdseed
+  return $ derivePath ioCtx path prvKey
+
+genTransparentPubKey :: XPrvKey -> IO XPubKey
+genTransparentPubKey xPrvKey = do
+  ioCtx <- createContext
+  return $ deriveXPubKey ioCtx xPrvKey
+
+genTransparentPubAddress :: XPubKey -> IO Address
+genTransparentPubAddress xPubKey = do
+  ioCtx <- createContext
+  return $ xPubAddr ioCtx xPubKey
 
 -- | Generate a transparent receiver
-genTransparentReceiver :: Int -> XPrvKey -> IO TransparentAddress
+genTransparentReceiver :: Int -> Scope -> XPrvKey -> IO TransparentAddress
-genTransparentReceiver i xprvk = do
+genTransparentReceiver i scope xprvk = do
   ioCtx <- createContext
-  let rootPubKey = deriveXPubKey ioCtx xprvk
+  let s =
-  let childPubKey = pubSubKey ioCtx rootPubKey (fromIntegral i)
+        case scope of
+          External -> 0
+          Internal -> 1
+  let path = Deriv :/ s :/ fromIntegral i :: DerivPath
+  let childPrvKey = derivePath ioCtx path xprvk
+  let childPubKey = deriveXPubKey ioCtx childPrvKey
   let x = xPubAddr ioCtx childPubKey
   case x of
     PubKeyAddress k -> return $ TransparentAddress P2PKH $ fromBinary k

test/Spec.hs

@@ -33,7 +33,6 @@ import qualified Data.Text as T
 import qualified Data.Text.Encoding as E
 import qualified Data.Text.Lazy.Encoding as LE
 import qualified Data.Text.Lazy.IO as LTIO
-
 import GHC.Float.RealFracMethods (properFractionDoubleInteger)
 import Test.Hspec
 import Test.Hspec.QuickCheck
@@ -42,6 +41,7 @@ import ZcashHaskell.Keys (generateWalletSeedPhrase, getWalletSeed)
 import ZcashHaskell.Orchard
 import ZcashHaskell.Sapling
   ( decodeSaplingOutput
+  , genSaplingInternalAddress
   , genSaplingPaymentAddress
   , genSaplingSpendingKey
   , getShieldedOutputs
@@ -60,6 +60,7 @@ import ZcashHaskell.Types
   , Phrase(..)
   , RawData(..)
   , RawTxResponse(..)
+  , SaplingReceiver(..)
   , SaplingSpendingKey(..)
   , Scope(..)
   , Seed(..)
@@ -503,7 +504,7 @@ main = do
                   maybe "No transparent" (encodeTransparent (ua_net u)) $
                   t_rec u
         msg `shouldBe` "t1LPWuQnjCRH7JAeEErSXKixcUteLJRJjKD"
-      it "Recover UA from YWallet:" $
+      it "Recover UA from YWallet" $
         ioProperty $ do
           let p =
                 Phrase
@@ -517,10 +518,10 @@ main = do
             Just s' -> do
               let oK = genOrchardSpendingKey s' MainNetCoin 0
               let sK = genSaplingSpendingKey s' MainNetCoin 0
-              let tK = genTransparentPrvKey s' 0
+              let tK = genTransparentPrvKey s' MainNetCoin 0
               let oR = genOrchardReceiver 0 External =<< oK
               let sR = genSaplingPaymentAddress 0 =<< sK
-              tR <- genTransparentReceiver 0 =<< tK
+              tR <- genTransparentReceiver 0 External =<< tK
               let newUA = UnifiedAddress MainNet oR sR $ Just tR
               return $ Just newUA `shouldBe` targetUA
       it "Recover UA from Zingo:" $
@@ -537,12 +538,233 @@ main = do
             Just s' -> do
               let oK = genOrchardSpendingKey s' MainNetCoin 0
               let sK = genSaplingSpendingKey s' MainNetCoin 0
-              let tK = genTransparentPrvKey s' 0
+              let tK = genTransparentPrvKey s' MainNetCoin 0
               let oR = genOrchardReceiver 0 External =<< oK
               let sR = genSaplingPaymentAddress 0 =<< sK
-              tR <- genTransparentReceiver 0 =<< tK
+              tR <- genTransparentReceiver 0 External =<< tK
               let newUA = UnifiedAddress MainNet oR sR $ Just tR
               return $ Just newUA `shouldBe` targetUA
+    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
+              , 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 = SaplingReceiver $ BS.pack cAdr
+        let ca = genSaplingInternalAddress (SaplingSpendingKey $ BS.pack sk)
+        fromMaybe (SaplingReceiver "") ca `shouldBe` bscAdr
 
 -- | Properties
 prop_PhraseLength :: Property
@@ -604,18 +826,18 @@ prop_OrchardRecRepeated s c (NonNegative i) (NonNegative j) scope =
     scope
     (fromMaybe (OrchardSpendingKey "") $ genOrchardSpendingKey s c i)
 
-prop_TransparentSpendingKey :: Seed -> NonNegative Int -> Property
+prop_TransparentSpendingKey :: Seed -> CoinType -> NonNegative Int -> Property
-prop_TransparentSpendingKey s (NonNegative i) =
+prop_TransparentSpendingKey s coinType (NonNegative i) =
   ioProperty $ do
-    k <- genTransparentPrvKey s i
+    k <- genTransparentPrvKey s coinType i
     return $ xPrvChild k == fromIntegral i
 
 prop_TransparentReceiver ::
-     Seed -> NonNegative Int -> NonNegative Int -> Property
+     Seed -> CoinType -> Scope -> NonNegative Int -> NonNegative Int -> Property
-prop_TransparentReceiver s (NonNegative i) (NonNegative j) =
+prop_TransparentReceiver s coinType scope (NonNegative i) (NonNegative j) =
   ioProperty $ do
-    k <- genTransparentPrvKey s i
+    k <- genTransparentPrvKey s coinType i
-    r <- genTransparentReceiver j k
+    r <- genTransparentReceiver j scope k
     return $ ta_type r == P2PKH
 
 -- | Generators