wallet/rpc: add 'avoid_reuse' option to RPC commands

createwallet, getbalance, getwalletinfo, listunspent, sendtoaddress

rpc/wallet: listunspent include reused flag and show reused utxos by default

Author: kallewoof

src/rpc/client.cpp

@@ -36,6 +36,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "sendtoaddress", 4, "subtractfeefromamount" },
     { "sendtoaddress", 5 , "replaceable" },
     { "sendtoaddress", 6 , "conf_target" },
+    { "sendtoaddress", 8, "avoid_reuse" },
     { "settxfee", 0, "amount" },
     { "sethdseed", 0, "newkeypool" },
     { "getreceivedbyaddress", 1, "minconf" },
@@ -48,6 +49,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "listreceivedbylabel", 2, "include_watchonly" },
     { "getbalance", 1, "minconf" },
     { "getbalance", 2, "include_watchonly" },
+    { "getbalance", 3, "avoid_reuse" },
     { "getblockhash", 0, "height" },
     { "waitforblockheight", 0, "height" },
     { "waitforblockheight", 1, "timeout" },
@@ -163,6 +165,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "rescanblockchain", 1, "stop_height"},
     { "createwallet", 1, "disable_private_keys"},
     { "createwallet", 2, "blank"},
+    { "createwallet", 4, "avoid_reuse"},
     { "getnodeaddresses", 0, "count"},
     { "stop", 0, "wait" },
 };

src/wallet/rpcwallet.cpp

@@ -321,7 +321,7 @@ static UniValue setlabel(const JSONRPCRequest& request)
 
 static CTransactionRef SendMoney(interfaces::Chain::Lock& locked_chain, CWallet * const pwallet, const CTxDestination &address, CAmount nValue, bool fSubtractFeeFromAmount, const CCoinControl& coin_control, mapValue_t mapValue)
 {
-    CAmount curBalance = pwallet->GetBalance().m_mine_trusted;
+    CAmount curBalance = pwallet->GetBalance(0, coin_control.m_avoid_address_reuse).m_mine_trusted;
 
     // Check amount
     if (nValue <= 0)
@@ -368,7 +368,7 @@ static UniValue sendtoaddress(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || request.params.size() < 2 || request.params.size() > 8)
+    if (request.fHelp || request.params.size() < 2 || request.params.size() > 9)
         throw std::runtime_error(
             RPCHelpMan{"sendtoaddress",
                 "\nSend an amount to a given address." +
@@ -389,6 +389,8 @@ static UniValue sendtoaddress(const JSONRPCRequest& request)
             "       \"UNSET\"\n"
             "       \"ECONOMICAL\"\n"
             "       \"CONSERVATIVE\""},
+                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) ? "true" : "unavailable", "Avoid spending from dirty addresses; addresses are considered\n"
+            "                             dirty if they have previously been used in a transaction."},
                 },
                 RPCResult{
             "\"txid\"                  (string) The transaction id.\n"
@@ -445,6 +447,7 @@ static UniValue sendtoaddress(const JSONRPCRequest& request)
         }
     }
 
+    coin_control.m_avoid_address_reuse = GetAvoidReuseFlag(pwallet, request.params[8]);
 
     EnsureWalletIsUnlocked(pwallet);
 
@@ -734,7 +737,7 @@ static UniValue getbalance(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || (request.params.size() > 3 ))
+    if (request.fHelp || request.params.size() > 4)
         throw std::runtime_error(
             RPCHelpMan{"getbalance",
                 "\nReturns the total available balance.\n"
@@ -744,6 +747,7 @@ static UniValue getbalance(const JSONRPCRequest& request)
                     {"dummy", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "Remains for backward compatibility. Must be excluded or set to \"*\"."},
                     {"minconf", RPCArg::Type::NUM, /* default */ "0", "Only include transactions confirmed at least this many times."},
                     {"include_watchonly", RPCArg::Type::BOOL, /* default */ "false", "Also include balance in watch-only addresses (see 'importaddress')"},
+                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) ? "true" : "unavailable", "Do not include balance in dirty outputs; addresses are considered dirty if they have previously been used in a transaction."},
                 },
                 RPCResult{
             "amount              (numeric) The total amount in " + CURRENCY_UNIT + " received for this wallet.\n"
@@ -780,7 +784,9 @@ static UniValue getbalance(const JSONRPCRequest& request)
         include_watchonly = true;
     }
 
-    const auto bal = pwallet->GetBalance(min_depth);
+    bool avoid_reuse = GetAvoidReuseFlag(pwallet, request.params[3]);
+
+    const auto bal = pwallet->GetBalance(min_depth, avoid_reuse);
 
     return ValueFromAmount(bal.m_mine_trusted + (include_watchonly ? bal.m_watchonly_trusted : 0));
 }
@@ -2474,6 +2480,7 @@ static UniValue getwalletinfo(const JSONRPCRequest& request)
             "  \"paytxfee\": x.xxxx,                (numeric) the transaction fee configuration, set in " + CURRENCY_UNIT + "/kB\n"
             "  \"hdseedid\": \"<hash160>\"            (string, optional) the Hash160 of the HD seed (only present when HD is enabled)\n"
             "  \"private_keys_enabled\": true|false (boolean) false if privatekeys are disabled for this wallet (enforced watch-only wallet)\n"
+            "  \"avoid_reuse\": true|false          (boolean) whether this wallet tracks clean/dirty coins in terms of reuse\n"
             "  \"scanning\":                        (json object) current scanning details, or false if no scan is in progress\n"
             "    {\n"
             "      \"duration\" : xxxx              (numeric) elapsed seconds since scan start\n"
@@ -2522,6 +2529,7 @@ static UniValue getwalletinfo(const JSONRPCRequest& request)
         obj.pushKV("hdseedid", seed_id.GetHex());
     }
     obj.pushKV("private_keys_enabled", !pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
+    obj.pushKV("avoid_reuse", pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE));
     if (pwallet->IsScanning()) {
         UniValue scanning(UniValue::VOBJ);
         scanning.pushKV("duration", pwallet->ScanningDuration() / 1000);
@@ -2730,6 +2738,7 @@ static UniValue createwallet(const JSONRPCRequest& request)
             {"disable_private_keys", RPCArg::Type::BOOL, /* default */ "false", "Disable the possibility of private keys (only watchonlys are possible in this mode)."},
             {"blank", RPCArg::Type::BOOL, /* default */ "false", "Create a blank wallet. A blank wallet has no keys or HD seed. One can be set using sethdseed."},
             {"passphrase", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Encrypt the wallet with this passphrase."},
+            {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "false", "Keep track of coin reuse, and treat dirty and clean coins differently with privacy considerations in mind."},
         },
         RPCResult{
             "{\n"
@@ -2771,6 +2780,10 @@ static UniValue createwallet(const JSONRPCRequest& request)
         flags |= WALLET_FLAG_BLANK_WALLET;
     }
 
+    if (!request.params[4].isNull() && request.params[4].get_bool()) {
+        flags |= WALLET_FLAG_AVOID_REUSE;
+    }
+
     WalletLocation location(request.params[0].get_str());
     if (location.Exists()) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet " + location.GetName() + " already exists.");
@@ -2872,6 +2885,8 @@ static UniValue listunspent(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
+    bool avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
+
     if (request.fHelp || request.params.size() > 5)
         throw std::runtime_error(
             RPCHelpMan{"listunspent",
@@ -2911,6 +2926,9 @@ static UniValue listunspent(const JSONRPCRequest& request)
             "    \"witnessScript\" : \"script\" (string) witnessScript if the scriptPubKey is P2WSH or P2SH-P2WSH\n"
             "    \"spendable\" : xxx,        (bool) Whether we have the private keys to spend this output\n"
             "    \"solvable\" : xxx,         (bool) Whether we know how to spend this output, ignoring the lack of keys\n"
+            + (avoid_reuse ?
+            "    \"reused\" : xxx,           (bool) Whether this output is reused/dirty (sent to an address that was previously spent from)\n" :
+            "") +
             "    \"desc\" : xxx,             (string, only when solvable) A descriptor for spending this output\n"
             "    \"safe\" : xxx              (bool) Whether this output is considered safe to spend. Unconfirmed transactions\n"
             "                              from outside keys and unconfirmed replacement transactions are considered unsafe\n"
@@ -2990,9 +3008,11 @@ static UniValue listunspent(const JSONRPCRequest& request)
     UniValue results(UniValue::VARR);
     std::vector<COutput> vecOutputs;
     {
+        CCoinControl cctl;
+        cctl.m_avoid_address_reuse = false;
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
-        pwallet->AvailableCoins(*locked_chain, vecOutputs, !include_unsafe, nullptr, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount, nMinDepth, nMaxDepth);
+        pwallet->AvailableCoins(*locked_chain, vecOutputs, !include_unsafe, &cctl, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount, nMinDepth, nMaxDepth);
     }
 
     LOCK(pwallet->cs_wallet);
@@ -3001,6 +3021,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
         CTxDestination address;
         const CScript& scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;
         bool fValidAddress = ExtractDestination(scriptPubKey, address);
+        bool reused = avoid_reuse && pwallet->IsUsedDestination(address);
 
         if (destinations.size() && (!fValidAddress || !destinations.count(address)))
             continue;
@@ -3057,6 +3078,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
             auto descriptor = InferDescriptor(scriptPubKey, *pwallet);
             entry.pushKV("desc", descriptor->ToString());
         }
+        if (avoid_reuse) entry.pushKV("reused", reused);
         entry.pushKV("safe", out.fSafe);
         results.push_back(entry);
     }
@@ -4261,13 +4283,13 @@ static const CRPCCommand commands[] =
     { "wallet",             "addmultisigaddress",               &addmultisigaddress,            {"nrequired","keys","label","address_type"} },
     { "wallet",             "backupwallet",                     &backupwallet,                  {"destination"} },
     { "wallet",             "bumpfee",                          &bumpfee,                       {"txid", "options"} },
-    { "wallet",             "createwallet",                     &createwallet,                  {"wallet_name", "disable_private_keys", "blank", "passphrase"} },
+    { "wallet",             "createwallet",                     &createwallet,                  {"wallet_name", "disable_private_keys", "blank", "passphrase", "avoid_reuse"} },
     { "wallet",             "dumpprivkey",                      &dumpprivkey,                   {"address"}  },
     { "wallet",             "dumpwallet",                       &dumpwallet,                    {"filename"} },
     { "wallet",             "encryptwallet",                    &encryptwallet,                 {"passphrase"} },
     { "wallet",             "getaddressesbylabel",              &getaddressesbylabel,           {"label"} },
     { "wallet",             "getaddressinfo",                   &getaddressinfo,                {"address"} },
-    { "wallet",             "getbalance",                       &getbalance,                    {"dummy","minconf","include_watchonly"} },
+    { "wallet",             "getbalance",                       &getbalance,                    {"dummy","minconf","include_watchonly","avoid_reuse"} },
     { "wallet",             "getnewaddress",                    &getnewaddress,                 {"label","address_type"} },
     { "wallet",             "getrawchangeaddress",              &getrawchangeaddress,           {"address_type"} },
     { "wallet",             "getreceivedbyaddress",             &getreceivedbyaddress,          {"address","minconf"} },
@@ -4298,7 +4320,7 @@ static const CRPCCommand commands[] =
     { "wallet",             "removeprunedfunds",                &removeprunedfunds,             {"txid"} },
     { "wallet",             "rescanblockchain",                 &rescanblockchain,              {"start_height", "stop_height"} },
     { "wallet",             "sendmany",                         &sendmany,                      {"dummy","amounts","minconf","comment","subtractfeefrom","replaceable","conf_target","estimate_mode"} },
-    { "wallet",             "sendtoaddress",                    &sendtoaddress,                 {"address","amount","comment","comment_to","subtractfeefromamount","replaceable","conf_target","estimate_mode"} },
+    { "wallet",             "sendtoaddress",                    &sendtoaddress,                 {"address","amount","comment","comment_to","subtractfeefromamount","replaceable","conf_target","estimate_mode","avoid_reuse"} },
     { "wallet",             "sethdseed",                        &sethdseed,                     {"newkeypool","seed"} },
     { "wallet",             "setlabel",                         &setlabel,                      {"address","label"} },
     { "wallet",             "settxfee",                         &settxfee,                      {"amount"} },