Persist Sapling payment address to IVK map

This ensures we remember any diversified addresses manually generated
outside the wallet.

src/wallet/gtest/test_wallet_zkeys.cpp

@@ -11,7 +11,9 @@
  * This test covers Sapling methods on CWallet
  * GenerateNewSaplingZKey()
  * AddSaplingZKey()
+ * AddSaplingIncomingViewingKey()
  * LoadSaplingZKey()
+ * LoadSaplingIncomingViewingKey()
  * LoadSaplingZKeyMetadata()
  */
 TEST(wallet_zkeys_tests, StoreAndLoadSaplingZkeys) {
@@ -62,6 +64,24 @@ TEST(wallet_zkeys_tests, StoreAndLoadSaplingZkeys) {
     EXPECT_EQ(1, addrs.count(address));
     EXPECT_EQ(1, addrs.count(sk.DefaultAddress()));
 
+    // Generate a diversified address different to the default
+    // If we can't get an early diversified address, we are very unlucky
+    blob88 diversifier;
+    diversifier.begin()[0] = 10;
+    auto dpa = sk.ToXFVK().Address(diversifier).get().second;
+
+    // verify wallet only has the default address
+    EXPECT_TRUE(wallet.HaveSaplingIncomingViewingKey(sk.DefaultAddress()));
+    EXPECT_FALSE(wallet.HaveSaplingIncomingViewingKey(dpa));
+
+    // manually add a diversified address
+    auto ivk = fvk.in_viewing_key();
+    EXPECT_TRUE(wallet.AddSaplingIncomingViewingKey(ivk, dpa));
+
+    // verify wallet did add it
+    EXPECT_TRUE(wallet.HaveSaplingIncomingViewingKey(sk.DefaultAddress()));
+    EXPECT_TRUE(wallet.HaveSaplingIncomingViewingKey(dpa));
+
     // Load a third key into the wallet
     auto sk2 = m.Derive(1);
     ASSERT_TRUE(wallet.LoadSaplingZKey(sk2));
@@ -74,6 +94,13 @@ TEST(wallet_zkeys_tests, StoreAndLoadSaplingZkeys) {
 
     // check metadata is the same
     ASSERT_EQ(wallet.mapSaplingZKeyMetadata[ivk2].nCreateTime, now);
+
+    // Load a diversified address for the third key into the wallet
+    auto dpa2 = sk2.ToXFVK().Address(diversifier).get().second;
+    EXPECT_TRUE(wallet.HaveSaplingIncomingViewingKey(sk2.DefaultAddress()));
+    EXPECT_FALSE(wallet.HaveSaplingIncomingViewingKey(dpa2));
+    EXPECT_TRUE(wallet.LoadSaplingPaymentAddress(dpa2, ivk2));
+    EXPECT_TRUE(wallet.HaveSaplingIncomingViewingKey(dpa2));
 }
 
 /**
@@ -413,6 +440,18 @@ TEST(wallet_zkeys_tests, WriteCryptedSaplingZkeyDirectToDb) {
     wallet.GetSaplingPaymentAddresses(addrs);
     ASSERT_EQ(1, addrs.size());
 
+    // Generate a diversified address different to the default
+    // If we can't get an early diversified address, we are very unlucky
+    libzcash::SaplingExtendedSpendingKey extsk;
+    EXPECT_TRUE(wallet.GetSaplingExtendedSpendingKey(address, extsk));
+    blob88 diversifier;
+    diversifier.begin()[0] = 10;
+    auto dpa = extsk.ToXFVK().Address(diversifier).get().second;
+
+    // Add diversified address to the wallet
+    auto ivk = extsk.expsk.full_viewing_key().in_viewing_key();
+    EXPECT_TRUE(wallet.AddSaplingIncomingViewingKey(ivk, dpa));
+
     // encrypt wallet
     SecureString strWalletPass;
     strWalletPass.reserve(100);
@@ -434,19 +473,25 @@ TEST(wallet_zkeys_tests, WriteCryptedSaplingZkeyDirectToDb) {
     ASSERT_TRUE(&wallet != &wallet2);
     ASSERT_TRUE(wallet2.HaveHDSeed());
 
-    // wallet should have two keys
+    // wallet should have three addresses
     wallet2.GetSaplingPaymentAddresses(addrs);
-    ASSERT_EQ(2, addrs.size());
+    ASSERT_EQ(3, addrs.size());
 
     //check we have entries for our payment addresses
     ASSERT_TRUE(addrs.count(address));
     ASSERT_TRUE(addrs.count(address2));
+    ASSERT_TRUE(addrs.count(dpa));
 
     // spending key is crypted, so we can't extract valid payment address
     libzcash::SaplingExtendedSpendingKey keyOut;
     EXPECT_FALSE(wallet2.GetSaplingExtendedSpendingKey(address, keyOut));
     ASSERT_FALSE(address == keyOut.DefaultAddress());
 
+    // address -> ivk mapping is not crypted
+    libzcash::SaplingIncomingViewingKey ivkOut;
+    EXPECT_TRUE(wallet2.GetSaplingIncomingViewingKey(dpa, ivkOut));
+    EXPECT_EQ(ivk, ivkOut);
+
     // unlock wallet to get spending keys and verify payment addresses
     wallet2.Unlock(strWalletPass);
 

src/wallet/wallet.cpp

@@ -174,6 +174,28 @@ bool CWallet::AddSaplingZKey(
     return true;
 }
 
+// Add payment address -> incoming viewing key map entry
+bool CWallet::AddSaplingIncomingViewingKey(
+    const libzcash::SaplingIncomingViewingKey &ivk,
+    const libzcash::SaplingPaymentAddress &addr)
+{
+    AssertLockHeld(cs_wallet); // mapSaplingZKeyMetadata
+
+    if (!CCryptoKeyStore::AddSaplingIncomingViewingKey(ivk, addr)) {
+        return false;
+    }
+
+    if (!fFileBacked) {
+        return true;
+    }
+
+    if (!IsCrypted()) {
+        return CWalletDB(strWalletFile).WriteSaplingPaymentAddress(addr, ivk);
+    }
+
+    return true;
+}
+
 
 // Add spending key to keystore and persist to disk
 bool CWallet::AddSproutZKey(const libzcash::SproutSpendingKey &key)
@@ -365,6 +387,13 @@ bool CWallet::LoadSaplingZKey(const libzcash::SaplingExtendedSpendingKey &key)
     return CCryptoKeyStore::AddSaplingSpendingKey(key, key.DefaultAddress());
 }
 
+bool CWallet::LoadSaplingPaymentAddress(
+    const libzcash::SaplingPaymentAddress &addr,
+    const libzcash::SaplingIncomingViewingKey &ivk)
+{
+    return CCryptoKeyStore::AddSaplingIncomingViewingKey(ivk, addr);
+}
+
 bool CWallet::LoadZKey(const libzcash::SproutSpendingKey &key)
 {
     return CCryptoKeyStore::AddSproutSpendingKey(key);

src/wallet/wallet.h

@@ -1075,6 +1075,9 @@ public:
     bool AddSaplingZKey(
         const libzcash::SaplingExtendedSpendingKey &key,
         const libzcash::SaplingPaymentAddress &defaultAddr);
+    bool AddSaplingIncomingViewingKey(
+        const libzcash::SaplingIncomingViewingKey &ivk,
+        const libzcash::SaplingPaymentAddress &addr);
     bool AddCryptedSaplingSpendingKey(
         const libzcash::SaplingExtendedFullViewingKey &extfvk,
         const std::vector<unsigned char> &vchCryptedSecret,
@@ -1083,6 +1086,11 @@ public:
     bool LoadSaplingZKey(const libzcash::SaplingExtendedSpendingKey &key);
     //! Load spending key metadata (used by LoadWallet)
     bool LoadSaplingZKeyMetadata(const libzcash::SaplingIncomingViewingKey &ivk, const CKeyMetadata &meta);
+    //! Adds a Sapling payment address -> incoming viewing key map entry,
+    //! without saving it to disk (used by LoadWallet)
+    bool LoadSaplingPaymentAddress(
+        const libzcash::SaplingPaymentAddress &addr,
+        const libzcash::SaplingIncomingViewingKey &ivk);
     //! Adds an encrypted spending key to the store, without saving it to disk (used by LoadWallet)
     bool LoadCryptedSaplingZKey(const libzcash::SaplingExtendedFullViewingKey &extfvk,
                                 const std::vector<unsigned char> &vchCryptedSecret);

src/wallet/walletdb.cpp

@@ -175,6 +175,15 @@ bool CWalletDB::WriteSaplingZKey(const libzcash::SaplingIncomingViewingKey &ivk,
     return Write(std::make_pair(std::string("sapzkey"), ivk), key, false);
 }
 
+bool CWalletDB::WriteSaplingPaymentAddress(
+    const libzcash::SaplingPaymentAddress &addr,
+    const libzcash::SaplingIncomingViewingKey &ivk)
+{
+    nWalletDBUpdated++;
+
+    return Write(std::make_pair(std::string("sapzaddr"), addr), ivk, false);
+}
+
 bool CWalletDB::WriteSproutViewingKey(const libzcash::SproutViewingKey &vk)
 {
     nWalletDBUpdated++;
@@ -416,13 +425,14 @@ public:
     unsigned int nZKeys;
     unsigned int nCZKeys;
     unsigned int nZKeyMeta;
+    unsigned int nSapZAddrs;
     bool fIsEncrypted;
     bool fAnyUnordered;
     int nFileVersion;
     vector<uint256> vWalletUpgrade;
 
     CWalletScanState() {
-        nKeys = nCKeys = nKeyMeta = nZKeys = nCZKeys = nZKeyMeta = 0;
+        nKeys = nCKeys = nKeyMeta = nZKeys = nCZKeys = nZKeyMeta = nSapZAddrs = 0;
         fIsEncrypted = false;
         fAnyUnordered = false;
         nFileVersion = 0;
@@ -729,6 +739,21 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
 
             pwallet->LoadSaplingZKeyMetadata(ivk, keyMeta);
         }
+        else if (strType == "sapzaddr")
+        {
+            libzcash::SaplingPaymentAddress addr;
+            ssKey >> addr;
+            libzcash::SaplingIncomingViewingKey ivk;
+            ssValue >> ivk;
+
+            wss.nSapZAddrs++;
+
+            if (!pwallet->LoadSaplingPaymentAddress(addr, ivk))
+            {
+                strErr = "Error reading wallet database: LoadSaplingPaymentAddress failed";
+                return false;
+            }
+        }
         else if (strType == "defaultkey")
         {
             ssValue >> pwallet->vchDefaultKey;

src/wallet/walletdb.h

@@ -187,6 +187,8 @@ public:
     bool WriteSaplingZKey(const libzcash::SaplingIncomingViewingKey &ivk,
                           const libzcash::SaplingExtendedSpendingKey &key,
                           const CKeyMetadata  &keyMeta);
+    bool WriteSaplingPaymentAddress(const libzcash::SaplingPaymentAddress &addr,
+                                    const libzcash::SaplingIncomingViewingKey &ivk);
     bool WriteCryptedZKey(const libzcash::SproutPaymentAddress & addr,
                           const libzcash::ReceivingKey & rk,
                           const std::vector<unsigned char>& vchCryptedSecret,