Implemented RPC calls z_importkey, z_exportkey, z_getnewaddress.

Modified RPC calls dumpwallet and importwallet to include spending keys.

src/wallet/rpcdump.cpp

@@ -265,6 +265,32 @@ Value importwallet(const Array& params, bool fHelp)
         boost::split(vstr, line, boost::is_any_of(" "));
         if (vstr.size() < 2)
             continue;
+
+        // Let's see if the address is a valid Zcash spending key
+        try {
+            CZCSpendingKey spendingkey(vstr[0]);
+            libzcash::SpendingKey key = spendingkey.Get();
+            libzcash::PaymentAddress addr = key.address();
+            if (pwalletMain->HaveSpendingKey(addr)) {
+                LogPrintf("Skipping import of zaddr %s (key already present)\n", CZCPaymentAddress(addr).ToString());
+                continue;
+            }
+            int64_t nTime = DecodeDumpTime(vstr[1]);
+            LogPrintf("Importing zaddr %s...\n", CZCPaymentAddress(addr).ToString());
+            if (!pwalletMain->AddZKey(key)) {
+                // Something went wrong
+                fGood = false;
+                continue;
+            }
+            // Successfully imported zaddr.  Now import the metadata.
+            pwalletMain->mapZKeyMetadata[addr].nCreateTime = nTime;
+            continue;
+        }
+        catch (...) {
+            // Not a valid spending key, so carry on and see if it's a Bitcoin style address.
+        }
+
+
         CBitcoinSecret vchSecret;
         if (!vchSecret.SetString(vstr[0]))
             continue;
@@ -419,7 +445,124 @@ Value dumpwallet(const Array& params, bool fHelp)
         }
     }
     file << "\n";
+
+    // dump the zkeys
+    std::set<libzcash::PaymentAddress> addresses;
+    pwalletMain->GetPaymentAddresses(addresses);
+    file << "\n";
+    file << "# Zkeys\n";
+    file << "\n";
+    for (auto addr : addresses ) {
+        libzcash::SpendingKey key;
+        if (pwalletMain->GetSpendingKey(addr, key)) {
+            std::string strTime = EncodeDumpTime(pwalletMain->mapZKeyMetadata[addr].nCreateTime);
+            file << strprintf("%s %s # zaddr=%s\n", CZCSpendingKey(key).ToString(), strTime, CZCPaymentAddress(addr).ToString());
+        }
+    }
+    file << "\n";
+
     file << "# End of dump\n";
     file.close();
     return Value::null;
 }
+
+
+Value z_importkey(const Array& params, bool fHelp)
+{
+    if (!EnsureWalletIsAvailable(fHelp))
+        return Value::null;
+
+    if (fHelp || params.size() < 1 || params.size() > 3)
+        throw runtime_error(
+            "z_importkey \"zkey\" ( \"label\" rescan )\n"
+            "\nAdds a zkey (as returned by z_exportkey) to your wallet.\n"
+            "\nArguments:\n"
+            "1. \"zkey\"             (string, required) The zkey (see z_exportkey)\n"
+            "2. rescan             (boolean, optional, default=true) Rescan the wallet for transactions\n"
+            "\nNote: This call can take minutes to complete if rescan is true.\n"
+            "\nExamples:\n"
+            "\nExport a zkey\n"
+            + HelpExampleCli("z_exportkey", "\"myaddress\"") +
+            "\nImport the zkey with rescan\n"
+            + HelpExampleCli("z_importkey", "\"mykey\"") +
+            "\nImport using a label and without rescan\n"
+            + HelpExampleCli("z_importkey", "\"mykey\" \"testing\" false") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("z_importkey", "\"mykey\", \"testing\", false")
+        );
+
+    LOCK2(cs_main, pwalletMain->cs_wallet);
+
+    EnsureWalletIsUnlocked();
+
+    // Whether to perform rescan after import
+    bool fRescan = true;
+    if (params.size() > 1)
+        fRescan = params[1].get_bool();
+
+    string strSecret = params[0].get_str();
+    CZCSpendingKey spendingkey(strSecret);
+    auto key = spendingkey.Get();
+    auto addr = key.address();
+
+    {
+        pwalletMain->MarkDirty();
+
+        // Don't throw error in case a key is already there
+        if (pwalletMain->HaveSpendingKey(addr))
+            return Value::null;
+
+        if (!pwalletMain-> AddZKey(key))
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding spending key to wallet");
+
+        pwalletMain->mapZKeyMetadata[addr].nCreateTime = 1;
+
+        // We want to scan for transactions and notes
+        if (fRescan) {
+            pwalletMain->ScanForWalletTransactions(chainActive.Genesis(), true);
+        }
+    }
+
+    return Value::null;
+}
+
+
+Value z_exportkey(const Array& params, bool fHelp)
+{
+    if (!EnsureWalletIsAvailable(fHelp))
+        return Value::null;
+
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "z_exportkey \"zaddr\"\n"
+            "\nReveals the zkey corresponding to 'zaddr'.\n"
+            "Then the z_importkey can be used with this output\n"
+            "\nArguments:\n"
+            "1. \"zaddr\"   (string, required) The zaddr for the private key\n"
+            "\nResult:\n"
+            "\"key\"                  (string) The private key\n"
+            "\nExamples:\n"
+            + HelpExampleCli("z_exportkey", "\"myaddress\"")
+            + HelpExampleCli("z_importkey", "\"mykey\"")
+            + HelpExampleRpc("z_exportkey", "\"myaddress\"")
+        );
+
+    LOCK2(cs_main, pwalletMain->cs_wallet);
+
+    EnsureWalletIsUnlocked();
+
+    string strAddress = params[0].get_str();
+
+    CZCPaymentAddress address(strAddress);
+    auto addr = address.Get();
+    if (!pwalletMain->HaveSpendingKey(addr))
+        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet does not hold private zkey for this zaddr");
+
+    libzcash::SpendingKey k;
+    if (!pwalletMain->GetSpendingKey(addr, k))
+        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet does not hold private zkey for this zaddr");
+
+    CZCSpendingKey spendingkey(k);
+    return spendingkey.ToString();
+}
+