Auto merge of #3392 - arcalinea:sapling_z_importexport_keys, r=bitcartel

Add Sapling support to z_importkey, z_exportkey

Add Sapling support to `z_importkey` and `z_exportkey`

src/test/rpc_wallet_tests.cpp

@@ -564,7 +564,7 @@ BOOST_AUTO_TEST_CASE(rpc_wallet_z_importexport)
 
     // verify import and export key
     for (int i = 0; i < n1; i++) {
-        // create a random key locally
+        // create a random Sprout key locally
         auto testSpendingKey = libzcash::SproutSpendingKey::random();
         auto testPaymentAddress = testSpendingKey.address();
         std::string testAddr = EncodePaymentAddress(testPaymentAddress);
@@ -572,6 +572,15 @@ BOOST_AUTO_TEST_CASE(rpc_wallet_z_importexport)
         BOOST_CHECK_NO_THROW(CallRPC(string("z_importkey ") + testKey));
         BOOST_CHECK_NO_THROW(retValue = CallRPC(string("z_exportkey ") + testAddr));
         BOOST_CHECK_EQUAL(retValue.get_str(), testKey);
+        
+        // create a random Sapling key locally
+        auto testSaplingSpendingKey = libzcash::SaplingSpendingKey::random();
+        auto testSaplingPaymentAddress = testSaplingSpendingKey.default_address();
+        std::string testSaplingAddr = EncodePaymentAddress(testSaplingPaymentAddress);
+        std::string testSaplingKey = EncodeSpendingKey(testSaplingSpendingKey);
+        BOOST_CHECK_NO_THROW(CallRPC(string("z_importkey ") + testSaplingKey));
+        BOOST_CHECK_NO_THROW(retValue = CallRPC(string("z_exportkey ") + testSaplingAddr));
+        BOOST_CHECK_EQUAL(retValue.get_str(), testSaplingKey);
     }
 
     // Verify we can list the keys imported

src/wallet/rpcdump.cpp

@@ -550,6 +550,58 @@ UniValue dumpwallet_impl(const UniValue& params, bool fHelp, bool fDumpZKeys)
     return exportfilepath.string();
 }
 
+class AddSpendingKeyToWallet : public boost::static_visitor<bool>
+{
+private:
+    CWallet *m_wallet;
+public: 
+    AddSpendingKeyToWallet(CWallet *wallet) : m_wallet(wallet) {}
+
+    bool operator()(const libzcash::SproutSpendingKey &sk) const {
+        auto addr = sk.address();
+        // Don't throw error in case a key is already there
+        if (m_wallet->HaveSpendingKey(addr)) {
+            return true;
+        } else {
+            m_wallet->MarkDirty();
+
+            if (!m_wallet-> AddZKey(sk)) {
+                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding spending key to wallet");
+            }
+
+            m_wallet->mapZKeyMetadata[addr].nCreateTime = 1;
+            
+            return false;
+        }
+    }
+    
+    bool operator()(const libzcash::SaplingSpendingKey &sk) const {
+        auto fvk = sk.full_viewing_key();
+        auto addr = sk.default_address();
+        {
+            // Don't throw error in case a key is already there
+            if (m_wallet->HaveSaplingSpendingKey(fvk)) {
+                return true;
+            } else {
+                m_wallet->MarkDirty();
+    
+                if (!m_wallet-> AddSaplingZKey(sk)) {
+                    throw JSONRPCError(RPC_WALLET_ERROR, "Error adding spending key to wallet");
+                }
+    
+                m_wallet->mapSaplingZKeyMetadata[addr].nCreateTime = 1;
+                
+                return false;
+            }    
+        }
+    }
+    
+    bool operator()(const libzcash::InvalidEncoding& no) const { 
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid spending key");
+    }
+    
+};
+
 
 UniValue z_importkey(const UniValue& params, bool fHelp)
 {
@@ -620,33 +672,19 @@ UniValue z_importkey(const UniValue& params, bool fHelp)
     if (!IsValidSpendingKey(spendingkey)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid spending key");
     }
-    // TODO: Add Sapling support. For now, ensure we can freely convert.
+    
-    assert(boost::get<libzcash::SproutSpendingKey>(&spendingkey) != nullptr);
+    // Sapling support
-    auto key = boost::get<libzcash::SproutSpendingKey>(spendingkey);
+    auto keyAlreadyExists = boost::apply_visitor(AddSpendingKeyToWallet(pwalletMain), spendingkey);
-    auto addr = key.address();
+    if (keyAlreadyExists && fIgnoreExistingKey) {
-
+        return NullUniValue;
-    {
+    }
-        // Don't throw error in case a key is already there
+    
-        if (pwalletMain->HaveSpendingKey(addr)) {
+    // whenever a key is imported, we need to scan the whole chain
-            if (fIgnoreExistingKey) {
+    pwalletMain->nTimeFirstKey = 1; // 0 would be considered 'no value'
-                return NullUniValue;
+    
-            }
+    // We want to scan for transactions and notes
-        } else {
+    if (fRescan) {
-            pwalletMain->MarkDirty();
+        pwalletMain->ScanForWalletTransactions(chainActive[nRescanHeight], true);
-
-            if (!pwalletMain-> AddZKey(key))
-                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding spending key to wallet");
-
-            pwalletMain->mapZKeyMetadata[addr].nCreateTime = 1;
-        }
-
-        // whenever a key is imported, we need to scan the whole chain
-        pwalletMain->nTimeFirstKey = 1; // 0 would be considered 'no value'
-
-        // We want to scan for transactions and notes
-        if (fRescan) {
-            pwalletMain->ScanForWalletTransactions(chainActive[nRescanHeight], true);
-        }
     }
 
     return NullUniValue;
@@ -746,6 +784,41 @@ UniValue z_importviewingkey(const UniValue& params, bool fHelp)
     return NullUniValue;
 }
 
+class GetSpendingKeyForPaymentAddress : public boost::static_visitor<libzcash::SpendingKey>
+{
+private:
+    CWallet *m_wallet;
+public:
+    GetSpendingKeyForPaymentAddress(CWallet *wallet) : m_wallet(wallet) {}
+
+    libzcash::SpendingKey operator()(const libzcash::SproutPaymentAddress &zaddr) const
+    {
+        libzcash::SproutSpendingKey k;
+        if (!pwalletMain->GetSpendingKey(zaddr, k)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Wallet does not hold private zkey for this zaddr");
+        }
+        return k;
+    }
+
+    libzcash::SpendingKey operator()(const libzcash::SaplingPaymentAddress &zaddr) const 
+    {
+        libzcash::SaplingIncomingViewingKey ivk;
+        libzcash::SaplingFullViewingKey fvk;
+        libzcash::SaplingSpendingKey sk;
+
+        if (!pwalletMain->GetSaplingIncomingViewingKey(zaddr, ivk) ||
+            !pwalletMain->GetSaplingFullViewingKey(ivk, fvk) ||
+            !pwalletMain->GetSaplingSpendingKey(fvk, sk)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Wallet does not hold private zkey for this zaddr");
+        }
+        return sk;
+    }
+    
+    libzcash::SpendingKey operator()(const libzcash::InvalidEncoding& no) const { 
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid zaddr");
+    }
+};
+
 UniValue z_exportkey(const UniValue& params, bool fHelp)
 {
     if (!EnsureWalletIsAvailable(fHelp))
@@ -776,15 +849,10 @@ UniValue z_exportkey(const UniValue& params, bool fHelp)
     if (!IsValidPaymentAddress(address)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid zaddr");
     }
-    // TODO: Add Sapling support. For now, ensure we can freely convert.
-    assert(boost::get<libzcash::SproutPaymentAddress>(&address) != nullptr);
-    auto addr = boost::get<libzcash::SproutPaymentAddress>(address);
 
-    libzcash::SproutSpendingKey k;
+    // Sapling support
-    if (!pwalletMain->GetSpendingKey(addr, k))
+    auto sk = boost::apply_visitor(GetSpendingKeyForPaymentAddress(pwalletMain), address);
-        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet does not hold private zkey for this zaddr");
+    return EncodeSpendingKey(sk);
-
-    return EncodeSpendingKey(k);
 }
 
 UniValue z_exportviewingkey(const UniValue& params, bool fHelp)