Add support for watch-only addresses

Changes:
* Add Add/Have WatchOnly methods to CKeyStore, and implementations
  in CBasicKeyStore.
* Add similar methods to CWallet, and support entries for it in
  CWalletDB.
* Make IsMine in script/wallet return a new enum 'isminetype',
  rather than a boolean. This allows distinguishing between
  spendable and unspendable coins.
* Add a field fSpendable to COutput (GetAvailableCoins' return type).
* Mark watchonly coins in listunspent as 'watchonly': true.
* Add 'watchonly' to validateaddress, suppressing script/pubkey/...
  in this case.

Based on a patch by Eric Lombrozo.

Conflicts:
	src/qt/walletmodel.cpp
	src/rpcserver.cpp
	src/wallet.cpp

Conflicts:
	src/script.h

Rebased-from: c898846 bitcoin#4045

src/keystore.cpp

@@ -59,3 +59,15 @@ bool CBasicKeyStore::GetCScript(const CScriptID &hash, CScript& redeemScriptOut)
     return false;
 }
 
+bool CBasicKeyStore::AddWatchOnly(const CTxDestination &dest)
+{
+    LOCK(cs_KeyStore);
+    setWatchOnly.insert(dest);
+    return true;
+}
+
+bool CBasicKeyStore::HaveWatchOnly(const CTxDestination &dest) const
+{
+    LOCK(cs_KeyStore);
+    return setWatchOnly.count(dest) > 0;
+}

src/keystore.h

@@ -8,11 +8,21 @@
 
 #include "key.h"
 #include "sync.h"
+#include "script.h"     // for CNoDestination
 
 #include <boost/signals2/signal.hpp>
+#include <boost/variant.hpp>
 
 class CScript;
 
+/** A txout script template with a specific destination. It is either:
+ *  * CNoDestination: no destination set
+ *  * CKeyID: TX_PUBKEYHASH destination
+ *  * CScriptID: TX_SCRIPTHASH destination
+ *  A CTxDestination is the internal data type encoded in a CBitcoinAddress
+ */
+typedef boost::variant<CNoDestination, CKeyID, CScriptID> CTxDestination;
+
 /** A virtual base class for key stores */
 class CKeyStore
 {
@@ -36,17 +46,23 @@ class CKeyStore
     virtual bool AddCScript(const CScript& redeemScript) =0;
     virtual bool HaveCScript(const CScriptID &hash) const =0;
     virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const =0;
+
+    // Support for Watch-only addresses
+    virtual bool AddWatchOnly(const CTxDestination &dest) =0;
+    virtual bool HaveWatchOnly(const CTxDestination &dest) const =0;
 };
 
 typedef std::map<CKeyID, CKey> KeyMap;
 typedef std::map<CScriptID, CScript > ScriptMap;
+typedef std::set<CTxDestination> WatchOnlySet;
 
 /** Basic key store, that keeps keys in an address->secret map */
 class CBasicKeyStore : public CKeyStore
 {
 protected:
     KeyMap mapKeys;
     ScriptMap mapScripts;
+    WatchOnlySet setWatchOnly;
 
 public:
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
@@ -88,6 +104,9 @@ class CBasicKeyStore : public CKeyStore
     virtual bool AddCScript(const CScript& redeemScript);
     virtual bool HaveCScript(const CScriptID &hash) const;
     virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const;
+
+    virtual bool AddWatchOnly(const CTxDestination &dest);
+    virtual bool HaveWatchOnly(const CTxDestination &dest) const;
 };
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;

src/qt/walletmodel.cpp

@@ -548,7 +548,7 @@ void WalletModel::getOutputs(const std::vector<COutPoint>& vOutpoints, std::vect
         if (!wallet->mapWallet.count(outpoint.hash)) continue;
         int nDepth = wallet->mapWallet[outpoint.hash].GetDepthInMainChain();
         if (nDepth < 0) continue;
-        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth);
+        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
         vOutputs.push_back(out);
     }
 }
@@ -575,7 +575,7 @@ void WalletModel::listCoins(std::map<QString, std::vector<COutput> >& mapCoins)
         if (!wallet->mapWallet.count(outpoint.hash)) continue;
         int nDepth = wallet->mapWallet[outpoint.hash].GetDepthInMainChain();
         if (nDepth < 0) continue;
-        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth);
+        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
         vCoins.push_back(out);
     }
 
@@ -586,7 +586,7 @@ void WalletModel::listCoins(std::map<QString, std::vector<COutput> >& mapCoins)
         while (wallet->IsChange(cout.tx->vout[cout.i]) && cout.tx->vin.size() > 0 && wallet->IsMine(cout.tx->vin[0]))
         {
             if (!wallet->mapWallet.count(cout.tx->vin[0].prevout.hash)) break;
-            cout = COutput(&wallet->mapWallet[cout.tx->vin[0].prevout.hash], cout.tx->vin[0].prevout.n, 0);
+            cout = COutput(&wallet->mapWallet[cout.tx->vin[0].prevout.hash], cout.tx->vin[0].prevout.n, 0, true);
         }
 
         CTxDestination address;

src/rpcclient.cpp

@@ -149,6 +149,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "lockunspent", 0 },
     { "lockunspent", 1 },
     { "importprivkey", 2 },
+    { "importaddress", 2 },
     { "verifychain", 0 },
     { "verifychain", 1 },
     { "keypoolrefill", 0 },

src/rpcdump.cpp

@@ -133,6 +133,51 @@ Value importprivkey(const Array& params, bool fHelp)
     return Value::null;
 }
 
+Value importaddress(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1 || params.size() > 3)
+        throw runtime_error(
+            "importaddress <address> [label] [rescan=true]\n"
+            "Adds an address that can be watched as if it were in your wallet but cannot be used to spend.");
+
+    CBitcoinAddress address(params[0].get_str());
+    if (!address.IsValid())
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid Bitcoin address");
+    CTxDestination dest;
+    dest = address.Get();
+
+    string strLabel = "";
+    if (params.size() > 1)
+        strLabel = params[1].get_str();
+
+    // Whether to perform rescan after import
+    bool fRescan = true;
+    if (params.size() > 2)
+        fRescan = params[2].get_bool();
+
+    {
+        LOCK2(cs_main, pwalletMain->cs_wallet);
+
+        // Don't throw error in case an address is already there
+        if (pwalletMain->HaveWatchOnly(dest))
+            return Value::null;
+
+        pwalletMain->MarkDirty();
+        pwalletMain->SetAddressBook(dest, strLabel, "receive");
+
+        if (!pwalletMain->AddWatchOnly(dest))
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
+
+        if (fRescan)
+        {
+            pwalletMain->ScanForWalletTransactions(chainActive.Genesis(), true);
+            pwalletMain->ReacceptWalletTransactions();
+        }
+    }
+
+    return Value::null;
+}
+
 Value importwallet(const Array& params, bool fHelp)
 {
     if (fHelp || params.size() != 1)

src/rpcmisc.cpp

@@ -91,36 +91,45 @@ Value getinfo(const Array& params, bool fHelp)
 #ifdef ENABLE_WALLET
 class DescribeAddressVisitor : public boost::static_visitor<Object>
 {
+private:
+    isminetype mine;
+
 public:
+    DescribeAddressVisitor(isminetype mineIn) : mine(mineIn) {}
+
     Object operator()(const CNoDestination &dest) const { return Object(); }
 
     Object operator()(const CKeyID &keyID) const {
         Object obj;
         CPubKey vchPubKey;
-        pwalletMain->GetPubKey(keyID, vchPubKey);
         obj.push_back(Pair("isscript", false));
-        obj.push_back(Pair("pubkey", HexStr(vchPubKey)));
-        obj.push_back(Pair("iscompressed", vchPubKey.IsCompressed()));
+        if (mine == MINE_SPENDABLE) {
+            pwalletMain->GetPubKey(keyID, vchPubKey);
+            obj.push_back(Pair("pubkey", HexStr(vchPubKey)));
+            obj.push_back(Pair("iscompressed", vchPubKey.IsCompressed()));
+        }
         return obj;
     }
 
     Object operator()(const CScriptID &scriptID) const {
         Object obj;
         obj.push_back(Pair("isscript", true));
-        CScript subscript;
-        pwalletMain->GetCScript(scriptID, subscript);
-        std::vector<CTxDestination> addresses;
-        txnouttype whichType;
-        int nRequired;
-        ExtractDestinations(subscript, whichType, addresses, nRequired);
-        obj.push_back(Pair("script", GetTxnOutputType(whichType)));
-        obj.push_back(Pair("hex", HexStr(subscript.begin(), subscript.end())));
-        Array a;
-        BOOST_FOREACH(const CTxDestination& addr, addresses)
-            a.push_back(CBitcoinAddress(addr).ToString());
-        obj.push_back(Pair("addresses", a));
-        if (whichType == TX_MULTISIG)
-            obj.push_back(Pair("sigsrequired", nRequired));
+        if (mine == MINE_SPENDABLE) {
+            CScript subscript;
+            pwalletMain->GetCScript(scriptID, subscript);
+            std::vector<CTxDestination> addresses;
+            txnouttype whichType;
+            int nRequired;
+            ExtractDestinations(subscript, whichType, addresses, nRequired);
+            obj.push_back(Pair("script", GetTxnOutputType(whichType)));
+            obj.push_back(Pair("hex", HexStr(subscript.begin(), subscript.end())));
+            Array a;
+            BOOST_FOREACH(const CTxDestination& addr, addresses)
+                a.push_back(CBitcoinAddress(addr).ToString());
+            obj.push_back(Pair("addresses", a));
+            if (whichType == TX_MULTISIG)
+                obj.push_back(Pair("sigsrequired", nRequired));
+        }
         return obj;
     }
 };
@@ -160,10 +169,11 @@ Value validateaddress(const Array& params, bool fHelp)
         string currentAddress = address.ToString();
         ret.push_back(Pair("address", currentAddress));
 #ifdef ENABLE_WALLET
-        bool fMine = pwalletMain ? IsMine(*pwalletMain, dest) : false;
-        ret.push_back(Pair("ismine", fMine));
-        if (fMine) {
-            Object detail = boost::apply_visitor(DescribeAddressVisitor(), dest);
+        isminetype mine = pwalletMain ? IsMine(*pwalletMain, dest) : MINE_NO;
+        ret.push_back(Pair("ismine", mine != MINE_NO));
+        if (mine != MINE_NO) {
+            ret.push_back(Pair("watchonly", mine == MINE_WATCH_ONLY));
+            Object detail = boost::apply_visitor(DescribeAddressVisitor(mine), dest);
             ret.insert(ret.end(), detail.begin(), detail.end());
         }
         if (pwalletMain && pwalletMain->mapAddressBook.count(dest))

src/rpcrawtransaction.cpp

@@ -304,6 +304,7 @@ Value listunspent(const Array& params, bool fHelp)
         }
         entry.push_back(Pair("amount",ValueFromAmount(nValue)));
         entry.push_back(Pair("confirmations",out.nDepth));
+        entry.push_back(Pair("spendable", out.fSpendable));
         results.push_back(entry);
     }
 

src/rpcserver.cpp

@@ -288,6 +288,7 @@ static const CRPCCommand vRPCCommands[] =
     { "getwalletinfo",          &getwalletinfo,          true,      false,      true },
     { "importprivkey",          &importprivkey,          false,     false,      true },
     { "importwallet",           &importwallet,           false,     false,      true },
+    { "importaddress",          &importaddress,          false,     false,      true },
     { "keypoolrefill",          &keypoolrefill,          true,      false,      true },
     { "listaccounts",           &listaccounts,           false,     false,      true },
     { "listaddressgroupings",   &listaddressgroupings,   false,     false,      true },

src/rpcserver.h

@@ -118,6 +118,7 @@ extern json_spirit::Value getnettotals(const json_spirit::Array& params, bool fH
 
 extern json_spirit::Value dumpprivkey(const json_spirit::Array& params, bool fHelp); // in rpcdump.cpp
 extern json_spirit::Value importprivkey(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value importaddress(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value dumpwallet(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value importwallet(const json_spirit::Array& params, bool fHelp);
 

src/script.cpp

@@ -1446,36 +1446,57 @@ class CKeyStoreIsMineVisitor : public boost::static_visitor<bool>
     bool operator()(const CScriptID &scriptID) const { return keystore->HaveCScript(scriptID); }
 };
 
-bool IsMine(const CKeyStore &keystore, const CTxDestination &dest)
+isminetype IsMine(const CKeyStore &keystore, const CTxDestination &dest)
 {
-    return boost::apply_visitor(CKeyStoreIsMineVisitor(&keystore), dest);
+    if (boost::apply_visitor(CKeyStoreIsMineVisitor(&keystore), dest))
+        return MINE_SPENDABLE;
+    if (keystore.HaveWatchOnly(dest))
+        return MINE_WATCH_ONLY;
+    return MINE_NO;
 }
 
-bool IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
+isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
 {
     vector<valtype> vSolutions;
     txnouttype whichType;
-    if (!Solver(scriptPubKey, whichType, vSolutions))
-        return false;
+    if (!Solver(scriptPubKey, whichType, vSolutions)) {
+        if (keystore.HaveWatchOnly(scriptPubKey.GetID()))
+            return MINE_WATCH_ONLY;
+        return MINE_NO;
+    }
 
     CKeyID keyID;
     switch (whichType)
     {
     case TX_NONSTANDARD:
     case TX_NULL_DATA:
-        return false;
+        break;
     case TX_PUBKEY:
         keyID = CPubKey(vSolutions[0]).GetID();
-        return keystore.HaveKey(keyID);
+        if (keystore.HaveKey(keyID))
+            return MINE_SPENDABLE;
+        if (keystore.HaveWatchOnly(keyID))
+            return MINE_WATCH_ONLY;
+        break;
     case TX_PUBKEYHASH:
         keyID = CKeyID(uint160(vSolutions[0]));
-        return keystore.HaveKey(keyID);
+        if (keystore.HaveKey(keyID))
+            return MINE_SPENDABLE;
+        if (keystore.HaveWatchOnly(keyID))
+            return MINE_WATCH_ONLY;
+        break;
     case TX_SCRIPTHASH:
     {
+        CScriptID scriptID = CScriptID(uint160(vSolutions[0]));
         CScript subscript;
-        if (!keystore.GetCScript(CScriptID(uint160(vSolutions[0])), subscript))
-            return false;
-        return IsMine(keystore, subscript);
+        if (keystore.GetCScript(scriptID, subscript)) {
+            isminetype ret = IsMine(keystore, subscript);
+            if (ret)
+                return ret;
+        }
+        if (keystore.HaveWatchOnly(scriptID))
+            return MINE_WATCH_ONLY;
+        break;
     }
     case TX_MULTISIG:
     {
@@ -1485,10 +1506,15 @@ bool IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
         // them) enable spend-out-from-under-you attacks, especially
         // in shared-wallet situations.
         vector<valtype> keys(vSolutions.begin()+1, vSolutions.begin()+vSolutions.size()-1);
-        return HaveKeys(keys, keystore) == keys.size();
+        if (HaveKeys(keys, keystore) == keys.size())
+            return MINE_SPENDABLE;
+        break;
     }
     }
-    return false;
+
+    if (keystore.HaveWatchOnly(scriptPubKey.GetID()))
+        return MINE_WATCH_ONLY;
+    return MINE_NO;
 }
 
 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)

src/script.h

@@ -192,6 +192,14 @@ enum
     SCRIPT_VERIFY_NOCACHE   = (1U << 3), // do not store results in signature cache (but do query it)
 };
 
+/** IsMine() return codes */
+enum isminetype
+{
+    MINE_NO = 0,
+    MINE_WATCH_ONLY = 1,
+    MINE_SPENDABLE = 2,
+};
+
 enum txnouttype
 {
     TX_NONSTANDARD,
@@ -791,8 +799,8 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
 bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
 int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
 bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
-bool IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
-bool IsMine(const CKeyStore& keystore, const CTxDestination &dest);
+isminetype IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
+isminetype IsMine(const CKeyStore& keystore, const CTxDestination &dest);
 void ExtractAffectedKeys(const CKeyStore &keystore, const CScript& scriptPubKey, std::vector<CKeyID> &vKeys);
 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);
 bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);

src/test/wallet_tests.cpp

@@ -44,7 +44,7 @@ static void add_coin(int64_t nValue, int nAge = 6*24, bool fIsFromMe = false, in
         wtx->fDebitCached = true;
         wtx->nDebitCached = 1;
     }
-    COutput output(wtx, nInput, nAge);
+    COutput output(wtx, nInput, nAge, true);
     vCoins.push_back(output);
 }