Add z_validateviewingkey and start to write some tests

src/rpcserver.cpp

@@ -406,6 +406,7 @@ static const CRPCCommand vRPCCommands[] =
     { "wallet",             "z_listaddresses",        &z_listaddresses,        true  },
     { "wallet",             "z_exportkey",            &z_exportkey,            true  },
     { "wallet",             "z_importkey",            &z_importkey,            true  },
+    { "wallet",             "z_validateviewingkey",   &z_validateviewingkey,   true  },
     { "wallet",             "z_exportviewingkey",     &z_exportviewingkey,     true  },
     { "wallet",             "z_importviewingkey",     &z_importviewingkey,     true  },
     { "wallet",             "z_exportwallet",         &z_exportwallet,         true  },

src/rpcserver.h

@@ -291,6 +291,7 @@ extern UniValue getblocksubsidy(const UniValue& params, bool fHelp);
 
 extern UniValue z_exportkey(const UniValue& params, bool fHelp); // in rpcdump.cpp
 extern UniValue z_importkey(const UniValue& params, bool fHelp); // in rpcdump.cpp
+extern UniValue z_validateviewingkey(const UniValue& params, bool fHelp); // in rpcdump.cpp
 extern UniValue z_exportviewingkey(const UniValue& params, bool fHelp); // in rpcdump.cpp
 extern UniValue z_importviewingkey(const UniValue& params, bool fHelp); // in rpcdump.cpp
 extern UniValue z_getnewaddress(const UniValue& params, bool fHelp); // in rpcwallet.cpp

src/test/rpc_wallet_tests.cpp

@@ -314,6 +314,29 @@ BOOST_AUTO_TEST_CASE(rpc_wallet_getbalance)
     BOOST_CHECK_THROW(CallRPC("z_listreceivedbyaddress tnRZ8bPq2pff3xBWhTJhNkVUkm2uhzksDeW5PvEa7aFKGT9Qi3YgTALZfjaY4jU3HLVKBtHdSXxoPoLA3naMPcHBcY88FcF 1"), runtime_error);
 }
 
+/**
+ * This test covers RPC command z_validateviewingkey
+ */
+BOOST_AUTO_TEST_CASE(rpc_wallet_z_validateviewingkey)
+{
+    SelectParams(CBaseChainParams::MAIN);
+
+    LOCK2(cs_main, pwalletMain->cs_wallet);
+
+    UniValue retValue;
+
+    // Check number of args
+    BOOST_CHECK_THROW(CallRPC("z_validateviewingkey"), runtime_error);
+    BOOST_CHECK_THROW(CallRPC("z_validateviewingkey toomany args"), runtime_error);
+
+    BOOST_CHECK_NO_THROW(retValue = CallRPC("z_validateviewingkey VKstuff"));
+    UniValue resultObj = retValue.get_obj();
+    bool b = find_value(resultObj, "isvalid").get_bool();
+    BOOST_CHECK_EQUAL(b, false);
+    b = find_value(resultObj, "ismine").get_bool();
+    BOOST_CHECK_EQUAL(b, false);
+}
+
 /**
  * This test covers RPC command z_validateaddress
  */

src/wallet/rpcdump.cpp

@@ -649,6 +649,51 @@ UniValue z_importkey(const UniValue& params, bool fHelp)
     return NullUniValue;
 }
 
+UniValue z_validateviewingkey(const UniValue& params, bool fHelp)
+{
+    if (!EnsureWalletIsAvailable(fHelp))
+        return NullUniValue;
+
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "z_validateviewingkey \"vkey\"\n"
+            "\nReturn information about the given Zcash viewing key.\n"
+            "\nArguments:\n"
+            "1. \"vkey\"             (string, required) The viewing key (see z_exportviewingkey)\n"
+            "\nExamples:\n"
+            "\nValidate a viewing key\n"
+            + HelpExampleCli("z_validateviewingkey", "\"vkey\"") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("z_validateviewingkey", "\"vkey\"")
+        );
+
+    LOCK2(cs_main, pwalletMain->cs_wallet);
+
+    EnsureWalletIsUnlocked();
+
+    string strVKey  = params[0].get_str();
+    auto viewingkey = DecodeViewingKey(strVKey);
+
+    // TODO: Add Sapling support. For now, ensure we can freely convert.
+    assert(boost::get<libzcash::SproutViewingKey>(&viewingkey) != nullptr);
+
+    auto vkey       = boost::get<libzcash::SproutViewingKey>(viewingkey);
+    auto addr       = vkey.address();
+    bool isValid    = IsValidViewingKey(viewingkey);
+    bool isMine     = pwalletMain->HaveSpendingKey(addr);
+
+    UniValue ret(UniValue::VOBJ);
+    ret.push_back(Pair("isvalid", isValid));
+
+    if (isValid) {
+	ret.push_back(Pair("address", addr.GetHash().ToString() ));
+	ret.push_back(Pair("viewingkey", strVKey));
+	ret.push_back(Pair("ismine", isMine));
+    }
+
+    return ret;
+}
+
 UniValue z_importviewingkey(const UniValue& params, bool fHelp)
 {
     if (!EnsureWalletIsAvailable(fHelp))