Introduce wrappers around CZCViewingKey

src/base58.cpp

@@ -379,6 +379,21 @@ boost::optional<libzcash::PaymentAddress> DecodePaymentAddress(const std::string
     }
 }
 
+std::string EncodeViewingKey(const libzcash::ViewingKey& vk)
+{
+    return CZCViewingKey(vk).ToString();
+}
+
+boost::optional<libzcash::ViewingKey> DecodeViewingKey(const std::string& str)
+{
+    CZCViewingKey vk(str);
+    try {
+        return vk.Get();
+    } catch (const std::runtime_error&) {
+        return boost::none;
+    }
+}
+
 std::string EncodeSpendingKey(const libzcash::SpendingKey& zkey)
 {
     return CZCSpendingKey(zkey).ToString();

src/base58.h

@@ -182,6 +182,9 @@ bool IsValidDestinationString(const std::string& str, const CChainParams& params
 std::string EncodePaymentAddress(const libzcash::PaymentAddress& zaddr);
 boost::optional<libzcash::PaymentAddress> DecodePaymentAddress(const std::string& str);
 
+std::string EncodeViewingKey(const libzcash::ViewingKey& vk);
+boost::optional<libzcash::ViewingKey> DecodeViewingKey(const std::string& str);
+
 std::string EncodeSpendingKey(const libzcash::SpendingKey& zkey);
 boost::optional<libzcash::SpendingKey> DecodeSpendingKey(const std::string& str);
 

src/wallet/rpcdump.cpp

@@ -705,8 +705,11 @@ UniValue z_importviewingkey(const UniValue& params, bool fHelp)
     }
 
     string strVKey = params[0].get_str();
-    CZCViewingKey viewingkey(strVKey);
-    auto vkey = viewingkey.Get();
+    auto viewingkey = DecodeViewingKey(strVKey);
+    if (!viewingkey) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid viewing key");
+    }
+    auto vkey = *viewingkey;
     auto addr = vkey.address();
 
     {
@@ -815,6 +818,5 @@ UniValue z_exportviewingkey(const UniValue& params, bool fHelp)
         vk = k.viewing_key();
     }
 
-    CZCViewingKey viewingkey(vk);
-    return viewingkey.ToString();
+    return EncodeViewingKey(vk);
 }

src/wallet/rpcwallet.cpp

@@ -3067,12 +3067,10 @@ UniValue zc_raw_keygen(const UniValue& params, bool fHelp)
     auto addr = k.address();
     auto viewing_key = k.viewing_key();
 
-    CZCViewingKey viewingkey(viewing_key);
-
     UniValue result(UniValue::VOBJ);
     result.push_back(Pair("zcaddress", EncodePaymentAddress(addr)));
     result.push_back(Pair("zcsecretkey", EncodeSpendingKey(k)));
-    result.push_back(Pair("zcviewingkey", viewingkey.ToString()));
+    result.push_back(Pair("zcviewingkey", EncodeViewingKey(viewing_key)));
     return result;
 }