Add -confchange=0 option.
[novacoin.git] / src / wallet.cpp
index 7715419..85262f7 100644 (file)
@@ -3,17 +3,19 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "txdb.h"
 #include "wallet.h"
 #include "walletdb.h"
 #include "crypter.h"
 #include "ui_interface.h"
 #include "base58.h"
 #include "kernel.h"
+#include "coincontrol.h"
+#include <boost/algorithm/string/replace.hpp>
 
 using namespace std;
 extern int nStakeMaxAge;
 
-
 //////////////////////////////////////////////////////////////////////////////
 //
 // mapWallet
@@ -40,6 +42,14 @@ CPubKey CWallet::GenerateNewKey()
     if (fCompressed)
         SetMinVersion(FEATURE_COMPRPUBKEY);
 
+    CPubKey pubkey = key.GetPubKey();
+
+    // Create new metadata
+    int64 nCreationTime = GetTime();
+    mapKeyMetadata[pubkey.GetID()] = CKeyMetadata(nCreationTime);
+    if (!nTimeFirstKey || nCreationTime < nTimeFirstKey)
+        nTimeFirstKey = nCreationTime;
+
     if (!AddKey(key))
         throw std::runtime_error("CWallet::GenerateNewKey() : AddKey failed");
     return key.GetPubKey();
@@ -47,12 +57,14 @@ CPubKey CWallet::GenerateNewKey()
 
 bool CWallet::AddKey(const CKey& key)
 {
+    CPubKey pubkey = key.GetPubKey();
+
     if (!CCryptoKeyStore::AddKey(key))
         return false;
     if (!fFileBacked)
         return true;
     if (!IsCrypted())
-        return CWalletDB(strWalletFile).WriteKey(key.GetPubKey(), key.GetPrivKey());
+        return CWalletDB(strWalletFile).WriteKey(pubkey, key.GetPrivKey(), mapKeyMetadata[pubkey.GetID()]);
     return true;
 }
 
@@ -65,13 +77,22 @@ bool CWallet::AddCryptedKey(const CPubKey &vchPubKey, const vector<unsigned char
     {
         LOCK(cs_wallet);
         if (pwalletdbEncryption)
-            return pwalletdbEncryption->WriteCryptedKey(vchPubKey, vchCryptedSecret);
+            return pwalletdbEncryption->WriteCryptedKey(vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
         else
-            return CWalletDB(strWalletFile).WriteCryptedKey(vchPubKey, vchCryptedSecret);
+            return CWalletDB(strWalletFile).WriteCryptedKey(vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
     }
     return false;
 }
 
+bool CWallet::LoadKeyMetadata(const CPubKey &pubkey, const CKeyMetadata &meta)
+{
+    if (meta.nCreateTime && (!nTimeFirstKey || meta.nCreateTime < nTimeFirstKey))
+        nTimeFirstKey = meta.nCreateTime;
+
+    mapKeyMetadata[pubkey.GetID()] = meta;
+    return true;
+}
+
 bool CWallet::AddCScript(const CScript& redeemScript)
 {
     if (!CCryptoKeyStore::AddCScript(redeemScript))
@@ -227,7 +248,7 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
     vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
     RAND_bytes(&vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
 
-    CMasterKey kMasterKey;
+    CMasterKey kMasterKey(nDerivationMethodIndex);
 
     RandAddSeedPerfmon();
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
@@ -332,7 +353,7 @@ CWallet::TxItems CWallet::OrderedTxItems(std::list<CAccountingEntry>& acentries,
     return txOrdered;
 }
 
-void CWallet::WalletUpdateSpent(const CTransaction &tx)
+void CWallet::WalletUpdateSpent(const CTransaction &tx, bool fBlock)
 {
     // Anytime a signature is successfully verified, it's proof the outpoint is spent.
     // Update the wallet spent flag if it doesn't know due to wallet.dat being
@@ -356,6 +377,24 @@ void CWallet::WalletUpdateSpent(const CTransaction &tx)
                 }
             }
         }
+
+        if (fBlock)
+        {
+            uint256 hash = tx.GetHash();
+            map<uint256, CWalletTx>::iterator mi = mapWallet.find(hash);
+            CWalletTx& wtx = (*mi).second;
+
+            BOOST_FOREACH(const CTxOut& txout, tx.vout)
+            {
+                if (IsMine(txout))
+                {
+                    wtx.MarkUnspent(&txout - &tx.vout[0]);
+                    wtx.WriteToDisk();
+                    NotifyTransactionChanged(this, hash, CT_UPDATED);
+                }
+            }
+        }
+
     }
 }
 
@@ -478,10 +517,20 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn)
         }
 #endif
         // since AddToWallet is called directly for self-originating transactions, check for consumption of own coins
-        WalletUpdateSpent(wtx);
+        WalletUpdateSpent(wtx, (wtxIn.hashBlock != 0));
 
         // Notify UI of new or updated transaction
         NotifyTransactionChanged(this, hash, fInsertedNew ? CT_NEW : CT_UPDATED);
+
+        // notify an external script when a wallet transaction comes in or is updated
+        std::string strCmd = GetArg("-walletnotify", "");
+
+        if ( !strCmd.empty())
+        {
+            boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
+            boost::thread t(runCommand, strCmd); // thread runs free
+        }
+
     }
     return true;
 }
@@ -672,9 +721,10 @@ void CWalletTx::GetAmounts(int64& nGeneratedImmature, int64& nGeneratedMature, l
 void CWalletTx::GetAccountAmounts(const string& strAccount, int64& nGenerated, int64& nReceived,
                                   int64& nSent, int64& nFee) const
 {
-    nReceived = nSent = nFee = 0;
+    nGenerated = nReceived = nSent = nFee = 0;
 
     int64 allGeneratedImmature, allGeneratedMature, allFee;
+    allGeneratedImmature = allGeneratedMature = allFee = 0;
     string strSentAccount;
     list<pair<CTxDestination, int64> > listReceived;
     list<pair<CTxDestination, int64> > listSent;
@@ -872,7 +922,7 @@ void CWalletTx::RelayWalletTransaction(CTxDB& txdb)
         {
             uint256 hash = tx.GetHash();
             if (!txdb.ContainsTx(hash))
-                RelayMessage(CInv(MSG_TX, hash), (CTransaction)tx);
+                RelayTransaction((CTransaction)tx, hash);
         }
     }
     if (!(IsCoinBase() || IsCoinStake()))
@@ -881,7 +931,7 @@ void CWalletTx::RelayWalletTransaction(CTxDB& txdb)
         if (!txdb.ContainsTx(hash))
         {
             printf("Relaying wtx %s\n", hash.ToString().substr(0,10).c_str());
-            RelayMessage(CInv(MSG_TX, hash), (CTransaction)*this);
+            RelayTransaction((CTransaction)*this, hash);
         }
     }
 }
@@ -955,7 +1005,7 @@ int64 CWallet::GetBalance() const
         for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
         {
             const CWalletTx* pcoin = &(*it).second;
-            if (pcoin->IsFinal() && pcoin->IsConfirmed())
+            if (pcoin->IsConfirmed())
                 nTotal += pcoin->GetAvailableCredit();
         }
     }
@@ -994,7 +1044,7 @@ int64 CWallet::GetImmatureBalance() const
 }
 
 // populate vCoins with vector of spendable COutputs
-void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed) const
+void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed, const CCoinControl *coinControl) const
 {
     vCoins.clear();
 
@@ -1013,8 +1063,36 @@ void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed) const
             if (pcoin->IsCoinBase() && pcoin->GetBlocksToMaturity() > 0)
                 continue;
 
+            if(pcoin->IsCoinStake() && pcoin->GetBlocksToMaturity() > 0)
+                continue;
+
             for (unsigned int i = 0; i < pcoin->vout.size(); i++)
-                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue > 0)
+                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue >= nMinimumInputValue &&
+                (!coinControl || !coinControl->HasSelected() || coinControl->IsSelected((*it).first, i)))
+                    vCoins.push_back(COutput(pcoin, i, pcoin->GetDepthInMainChain()));
+
+        }
+    }
+}
+
+void CWallet::AvailableCoinsMinConf(vector<COutput>& vCoins, int nConf) const
+{
+    vCoins.clear();
+
+    {
+        LOCK(cs_wallet);
+        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        {
+            const CWalletTx* pcoin = &(*it).second;
+
+            if (!pcoin->IsFinal())
+                continue;
+
+            if(pcoin->GetDepthInMainChain() < nConf)
+                continue;
+
+            for (unsigned int i = 0; i < pcoin->vout.size(); i++)
+                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue >= nMinimumInputValue)
                     vCoins.push_back(COutput(pcoin, i, pcoin->GetDepthInMainChain()));
         }
     }
@@ -1108,8 +1186,9 @@ bool CWallet::SelectCoinsMinConf(int64 nTargetValue, unsigned int nSpendTime, in
 
         int i = output.i;
 
+        // Follow the timestamp rules
         if (pcoin->nTime > nSpendTime)
-            continue;  // ppcoin: timestamp must not exceed spend time
+            continue;
 
         int64 n = pcoin->vout[i].nValue;
 
@@ -1190,20 +1269,72 @@ bool CWallet::SelectCoinsMinConf(int64 nTargetValue, unsigned int nSpendTime, in
     return true;
 }
 
-bool CWallet::SelectCoins(int64 nTargetValue, unsigned int nSpendTime, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet) const
+bool CWallet::SelectCoins(int64 nTargetValue, unsigned int nSpendTime, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet, const CCoinControl* coinControl) const
 {
     vector<COutput> vCoins;
-    AvailableCoins(vCoins);
+    AvailableCoins(vCoins, true, coinControl);
+
+    // coin control -> return all selected outputs (we want all selected to go into the transaction for sure)
+    if (coinControl && coinControl->HasSelected())
+    {
+        BOOST_FOREACH(const COutput& out, vCoins)
+        {
+            nValueRet += out.tx->vout[out.i].nValue;
+            setCoinsRet.insert(make_pair(out.tx, out.i));
+        }
+        return (nValueRet >= nTargetValue);
+    }
 
     return (SelectCoinsMinConf(nTargetValue, nSpendTime, 1, 6, vCoins, setCoinsRet, nValueRet) ||
             SelectCoinsMinConf(nTargetValue, nSpendTime, 1, 1, vCoins, setCoinsRet, nValueRet) ||
             SelectCoinsMinConf(nTargetValue, nSpendTime, 0, 1, vCoins, setCoinsRet, nValueRet));
 }
 
+// Select some coins without random shuffle or best subset approximation
+bool CWallet::SelectCoinsSimple(int64 nTargetValue, unsigned int nSpendTime, int nMinConf, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet) const
+{
+    vector<COutput> vCoins;
+    AvailableCoinsMinConf(vCoins, nMinConf);
+
+    setCoinsRet.clear();
+    nValueRet = 0;
+
+    BOOST_FOREACH(COutput output, vCoins)
+    {
+        const CWalletTx *pcoin = output.tx;
+        int i = output.i;
 
+        // Stop if we've chosen enough inputs
+        if (nValueRet >= nTargetValue)
+            break;
+
+        // Follow the timestamp rules
+        if (pcoin->nTime > nSpendTime)
+            continue;
+
+        int64 n = pcoin->vout[i].nValue;
+
+        pair<int64,pair<const CWalletTx*,unsigned int> > coin = make_pair(n,make_pair(pcoin, i));
+
+        if (n >= nTargetValue)
+        {
+            // If input value is greater or equal to target then simply insert
+            //    it into the current subset and exit
+            setCoinsRet.insert(coin.second);
+            nValueRet += coin.first;
+            break;
+        }
+        else if (n < nTargetValue + CENT)
+        {
+            setCoinsRet.insert(coin.second);
+            nValueRet += coin.first;
+        }
+    }
 
+    return true;
+}
 
-bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet)
+bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet, const CCoinControl* coinControl)
 {
     int64 nValue = 0;
     BOOST_FOREACH (const PAIRTYPE(CScript, int64)& s, vecSend)
@@ -1223,7 +1354,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
         CTxDB txdb("r");
         {
             nFeeRet = nTransactionFee;
-            loop
+            while (true)
             {
                 wtxNew.vin.clear();
                 wtxNew.vout.clear();
@@ -1238,7 +1369,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
                 // Choose coins to use
                 set<pair<const CWalletTx*,unsigned int> > setCoins;
                 int64 nValueIn = 0;
-                if (!SelectCoins(nTotalValue, wtxNew.nTime, setCoins, nValueIn))
+                if (!SelectCoins(nTotalValue, wtxNew.nTime, setCoins, nValueIn, coinControl))
                     return false;
                 BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
                 {
@@ -1266,22 +1397,30 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
                 if (nChange > 0)
                 {
-                    // Note: We use a new key here to keep it from being obvious which side is the change.
-                    //  The drawback is that by not reusing a previous key, the change may be lost if a
-                    //  backup is restored, if the backup doesn't have the new private key for the change.
-                    //  If we reused the old key, it would be possible to add code to look for and
-                    //  rediscover unknown transactions that were written with keys of ours to recover
-                    //  post-backup change.
-
-                    // Reserve a new key pair from key pool
-                    CPubKey vchPubKey = reservekey.GetReservedKey();
-                    // assert(mapKeys.count(vchPubKey));
-
                     // Fill a vout to ourself
                     // TODO: pass in scriptChange instead of reservekey so
                     // change transaction isn't always pay-to-bitcoin-address
                     CScript scriptChange;
-                    scriptChange.SetDestination(vchPubKey.GetID());
+
+                    // coin control: send change to custom address
+                    if (coinControl && !boost::get<CNoDestination>(&coinControl->destChange))
+                        scriptChange.SetDestination(coinControl->destChange);
+
+                    // no coin control: send change to newly generated address
+                    else
+                    {
+                        // Note: We use a new key here to keep it from being obvious which side is the change.
+                        //  The drawback is that by not reusing a previous key, the change may be lost if a
+                        //  backup is restored, if the backup doesn't have the new private key for the change.
+                        //  If we reused the old key, it would be possible to add code to look for and
+                        //  rediscover unknown transactions that were written with keys of ours to recover
+                        //  post-backup change.
+
+                        // Reserve a new key pair from key pool
+                        CPubKey vchPubKey = reservekey.GetReservedKey();
+
+                        scriptChange.SetDestination(vchPubKey.GetID());
+                    }
 
                     // Insert change txn at random position:
                     vector<CTxOut>::iterator position = wtxNew.vout.begin()+GetRandInt(wtxNew.vout.size());
@@ -1308,7 +1447,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
                 // Check that enough fee is included
                 int64 nPayFee = nTransactionFee * (1 + (int64)nBytes / 1000);
-                int64 nMinFee = wtxNew.GetMinFee(1, false, GMF_SEND);
+                int64 nMinFee = wtxNew.GetMinFee(1, false, GMF_SEND, nBytes);
 
                 if (nFeeRet < max(nPayFee, nMinFee))
                 {
@@ -1327,58 +1466,174 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
     return true;
 }
 
-bool CWallet::CreateTransaction(CScript scriptPubKey, int64 nValue, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet)
+bool CWallet::CreateTransaction(CScript scriptPubKey, int64 nValue, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet, const CCoinControl* coinControl)
 {
     vector< pair<CScript, int64> > vecSend;
     vecSend.push_back(make_pair(scriptPubKey, nValue));
-    return CreateTransaction(vecSend, wtxNew, reservekey, nFeeRet);
+    return CreateTransaction(vecSend, wtxNew, reservekey, nFeeRet, coinControl);
+}
+
+// NovaCoin: get current stake weight
+bool CWallet::GetStakeWeight(const CKeyStore& keystore, uint64& nMinWeight, uint64& nMaxWeight, uint64& nWeight)
+{
+    // Choose coins to use
+    int64 nBalance = GetBalance();
+    int64 nReserveBalance = 0;
+
+    if (mapArgs.count("-reservebalance") && !ParseMoney(mapArgs["-reservebalance"], nReserveBalance))
+    {
+        error("GetStakeWeight : invalid reserve balance amount");
+        return false;
+    }
+
+    if (nBalance <= nReserveBalance)
+        return false;
+
+    vector<const CWalletTx*> vwtxPrev;
+
+/*
+ * TODO: performance comparison
+
+    static set<pair<const CWalletTx*,unsigned int> > setCoins;
+    static uint256 hashPrevBlock;
+    static int64 nValueIn = 0;
+
+    // Cache outputs unless best block changed
+    if (hashPrevBlock != pindexBest->GetBlockHash())
+    {
+        if (!SelectCoinsSimple(nBalance - nReserveBalance, GetAdjustedTime(), nCoinbaseMaturity * 10, setCoins, nValueIn))
+            return false;
+
+        if (setCoins.empty())
+            return false;
+
+        hashPrevBlock == pindexBest->GetBlockHash();
+    }
+*/
+
+    set<pair<const CWalletTx*,unsigned int> > setCoins;
+    int64 nValueIn = 0;
+
+    if (!SelectCoinsSimple(nBalance - nReserveBalance, GetTime(), nCoinbaseMaturity * 10, setCoins, nValueIn))
+        return false;
+
+    if (setCoins.empty())
+        return false;
+
+    CTxDB txdb("r");
+    BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
+    {
+        CTxIndex txindex;
+        {
+            LOCK2(cs_main, cs_wallet);
+            if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
+                continue;
+        }
+
+        int64 nTimeWeight = GetWeight((int64)pcoin.first->nTime, (int64)GetTime());
+        CBigNum bnCoinDayWeight = CBigNum(pcoin.first->vout[pcoin.second].nValue) * nTimeWeight / COIN / (24 * 60 * 60);
+
+        // Weight is greater than zero
+        if (nTimeWeight > 0)
+        {
+            nWeight += bnCoinDayWeight.getuint64();
+        }
+
+        // Weight is greater than zero, but the maximum value isn't reached yet
+        if (nTimeWeight > 0 && nTimeWeight < nStakeMaxAge)
+        {
+            nMinWeight += bnCoinDayWeight.getuint64();
+        }
+
+        // Maximum weight was reached
+        if (nTimeWeight == nStakeMaxAge)
+        {
+            nMaxWeight += bnCoinDayWeight.getuint64();
+        }
+    }
+
+    return true;
 }
 
-// ppcoin: create coin stake transaction
-bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int64 nSearchInterval, CTransaction& txNew)
+bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int64 nSearchInterval, CTransaction& txNew, CKey& key)
 {
-    // The following split & combine thresholds are important to security
+    // The following combine threshold is important to security
     // Should not be adjusted if you don't understand the consequences
-    static unsigned int nStakeSplitAge = (60 * 60 * 24 * 90);
     int64 nCombineThreshold = GetProofOfWorkReward(GetLastBlockIndex(pindexBest, false)->nBits) / 3;
 
     CBigNum bnTargetPerCoinDay;
     bnTargetPerCoinDay.SetCompact(nBits);
 
-    LOCK2(cs_main, cs_wallet);
     txNew.vin.clear();
     txNew.vout.clear();
+
     // Mark coin stake transaction
     CScript scriptEmpty;
     scriptEmpty.clear();
     txNew.vout.push_back(CTxOut(0, scriptEmpty));
+
     // Choose coins to use
     int64 nBalance = GetBalance();
     int64 nReserveBalance = 0;
+
     if (mapArgs.count("-reservebalance") && !ParseMoney(mapArgs["-reservebalance"], nReserveBalance))
         return error("CreateCoinStake : invalid reserve balance amount");
+
     if (nBalance <= nReserveBalance)
         return false;
-    set<pair<const CWalletTx*,unsigned int> > setCoins;
+
     vector<const CWalletTx*> vwtxPrev;
+
+/*
+ * TODO: performance comparison
+
+    static set<pair<const CWalletTx*,unsigned int> > setCoins;
+    static uint256 hashPrevBlock;
+    static int64 nValueIn = 0;
+
+    // Cache outputs unless best block changed
+    if (hashPrevBlock != pindexBest->GetBlockHash())
+    {
+        if (!SelectCoinsSimple(nBalance - nReserveBalance, txNew.nTime, nCoinbaseMaturity * 10, setCoins, nValueIn))
+            return false;
+
+        if (setCoins.empty())
+            return false;
+
+        hashPrevBlock == pindexBest->GetBlockHash();
+    }
+*/
+
+    set<pair<const CWalletTx*,unsigned int> > setCoins;
     int64 nValueIn = 0;
-    if (!SelectCoins(nBalance - nReserveBalance, txNew.nTime, setCoins, nValueIn))
+
+    // Select coins with suitable depth
+    if (!SelectCoinsSimple(nBalance - nReserveBalance, txNew.nTime, nCoinbaseMaturity * 10, setCoins, nValueIn))
         return false;
+
     if (setCoins.empty())
         return false;
+
     int64 nCredit = 0;
     CScript scriptPubKeyKernel;
+    CTxDB txdb("r");
     BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
     {
-        CTxDB txdb("r");
         CTxIndex txindex;
-        if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
-            continue;
+        {
+            LOCK2(cs_main, cs_wallet);
+            if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
+                continue;
+        }
 
         // Read block header
         CBlock block;
-        if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
-            continue;
+        {
+            LOCK2(cs_main, cs_wallet);
+            if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
+                continue;
+        }
+
         static int nMaxStakeSearchInterval = 60;
         if (block.GetBlockTime() + nStakeMinAge > txNew.nTime - nMaxStakeSearchInterval)
             continue; // only count coins meeting min age requirement
@@ -1388,9 +1643,9 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
         {
             // Search backward in time from the given txNew timestamp 
             // Search nSearchInterval seconds back up to nMaxStakeSearchInterval
-            uint256 hashProofOfStake = 0;
+            uint256 hashProofOfStake = 0, targetProofOfStake = 0;
             COutPoint prevoutStake = COutPoint(pcoin.first->GetHash(), pcoin.second);
-            if (CheckStakeKernelHash(nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, *pcoin.first, prevoutStake, txNew.nTime - n, hashProofOfStake))
+            if (CheckStakeKernelHash(nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, *pcoin.first, prevoutStake, txNew.nTime - n, hashProofOfStake, targetProofOfStake))
             {
                 // Found a kernel
                 if (fDebug && GetBoolArg("-printcoinstake"))
@@ -1416,7 +1671,6 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                 if (whichType == TX_PUBKEYHASH) // pay to address type
                 {
                     // convert to pay to public key type
-                    CKey key;
                     if (!keystore.GetKey(uint160(vSolutions[0]), key))
                     {
                         if (fDebug && GetBoolArg("-printcoinstake"))
@@ -1425,15 +1679,33 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                     }
                     scriptPubKeyOut << key.GetPubKey() << OP_CHECKSIG;
                 }
-                else
+                if (whichType == TX_PUBKEY)
+                {
+                    valtype& vchPubKey = vSolutions[0];
+                    if (!keystore.GetKey(Hash160(vchPubKey), key))
+                    {
+                        if (fDebug && GetBoolArg("-printcoinstake"))
+                            printf("CreateCoinStake : failed to get key for kernel type=%d\n", whichType);
+                        break;  // unable to find corresponding public key
+                    }
+
+                if (key.GetPubKey() != vchPubKey)
+                {
+                    if (fDebug && GetBoolArg("-printcoinstake"))
+                        printf("CreateCoinStake : invalid key for kernel type=%d\n", whichType);
+                        break; // keys mismatch
+                    }
+
                     scriptPubKeyOut = scriptPubKeyKernel;
+                }
 
-                txNew.nTime -= n; 
+                txNew.nTime -= n;
                 txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
                 nCredit += pcoin.first->vout[pcoin.second].nValue;
                 vwtxPrev.push_back(pcoin.first);
                 txNew.vout.push_back(CTxOut(0, scriptPubKeyOut));
-                if (block.GetBlockTime() + nStakeSplitAge > txNew.nTime)
+
+                if (GetWeight(block.GetBlockTime(), (int64)txNew.nTime) < nStakeMaxAge)
                     txNew.vout.push_back(CTxOut(0, scriptPubKeyOut)); //split stake
                 if (fDebug && GetBoolArg("-printcoinstake"))
                     printf("CreateCoinStake : added kernel type=%d\n", whichType);
@@ -1441,11 +1713,14 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                 break;
             }
         }
+
         if (fKernelFound || fShutdown)
             break; // if kernel is found stop searching
     }
+
     if (nCredit == 0 || nCredit > nBalance - nReserveBalance)
         return false;
+
     BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
     {
         // Attempt to add more inputs
@@ -1453,6 +1728,8 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
         if (txNew.vout.size() == 2 && ((pcoin.first->vout[pcoin.second].scriptPubKey == scriptPubKeyKernel || pcoin.first->vout[pcoin.second].scriptPubKey == txNew.vout[1].scriptPubKey))
             && pcoin.first->GetHash() != txNew.vin[0].prevout.hash)
         {
+            int64 nTimeWeight = GetWeight((int64)pcoin.first->nTime, (int64)txNew.nTime);
+
             // Stop adding more inputs if already too many inputs
             if (txNew.vin.size() >= 100)
                 break;
@@ -1466,24 +1743,26 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
             if (pcoin.first->vout[pcoin.second].nValue > nCombineThreshold)
                 continue;
             // Do not add input that is still too young
-            if (pcoin.first->nTime + nStakeMaxAge > txNew.nTime)
+            if (nTimeWeight < nStakeMaxAge)
                 continue;
+
             txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
             nCredit += pcoin.first->vout[pcoin.second].nValue;
             vwtxPrev.push_back(pcoin.first);
         }
     }
+
     // Calculate coin age reward
     {
         uint64 nCoinAge;
         CTxDB txdb("r");
         if (!txNew.GetCoinAge(txdb, nCoinAge))
             return error("CreateCoinStake : failed to calculate coin age");
-        nCredit += GetProofOfStakeReward(nCoinAge);
+        nCredit += GetProofOfStakeReward(nCoinAge, nBits, txNew.nTime);
     }
 
     int64 nMinFee = 0;
-    loop
+    while (true)
     {
         // Set output amount
         if (txNew.vout.size() == 3)
@@ -1761,7 +2040,7 @@ bool CWallet::NewKeyPool()
     return true;
 }
 
-bool CWallet::TopUpKeyPool()
+bool CWallet::TopUpKeyPool(unsigned int nSize)
 {
     {
         LOCK(cs_wallet);
@@ -1772,7 +2051,12 @@ bool CWallet::TopUpKeyPool()
         CWalletDB walletdb(strWalletFile);
 
         // Top up key pool
-        unsigned int nTargetSize = max(GetArg("-keypool", 100), 0LL);
+        unsigned int nTargetSize;
+        if (nSize > 0)
+            nTargetSize = nSize;
+        else
+            nTargetSize = max(GetArg("-keypool", 100), 0LL);
+
         while (setKeyPool.size() < (nTargetSize + 1))
         {
             int64 nEnd = 1;
@@ -1838,7 +2122,8 @@ void CWallet::KeepKey(int64 nIndex)
         CWalletDB walletdb(strWalletFile);
         walletdb.ErasePool(nIndex);
     }
-    printf("keypool keep %"PRI64d"\n", nIndex);
+    if(fDebug)
+        printf("keypool keep %"PRI64d"\n", nIndex);
 }
 
 void CWallet::ReturnKey(int64 nIndex)
@@ -1848,7 +2133,8 @@ void CWallet::ReturnKey(int64 nIndex)
         LOCK(cs_wallet);
         setKeyPool.insert(nIndex);
     }
-    printf("keypool return %"PRI64d"\n", nIndex);
+    if(fDebug)
+        printf("keypool return %"PRI64d"\n", nIndex);
 }
 
 bool CWallet::GetKeyFromPool(CPubKey& result, bool fAllowReuse)
@@ -2115,7 +2401,7 @@ void CReserveKey::ReturnKey()
     vchPubKey = CPubKey();
 }
 
-void CWallet::GetAllReserveKeys(set<CKeyID>& setAddress)
+void CWallet::GetAllReserveKeys(set<CKeyID>& setAddress) const
 {
     setAddress.clear();
 
@@ -2145,3 +2431,54 @@ void CWallet::UpdatedTransaction(const uint256 &hashTx)
             NotifyTransactionChanged(this, hashTx, CT_UPDATED);
     }
 }
+
+void CWallet::GetKeyBirthTimes(std::map<CKeyID, int64> &mapKeyBirth) const {
+    mapKeyBirth.clear();
+
+    // get birth times for keys with metadata
+    for (std::map<CKeyID, CKeyMetadata>::const_iterator it = mapKeyMetadata.begin(); it != mapKeyMetadata.end(); it++)
+        if (it->second.nCreateTime)
+            mapKeyBirth[it->first] = it->second.nCreateTime;
+
+    // map in which we'll infer heights of other keys
+    CBlockIndex *pindexMax = FindBlockByHeight(std::max(0, nBestHeight - 144)); // the tip can be reorganised; use a 144-block safety margin
+    std::map<CKeyID, CBlockIndex*> mapKeyFirstBlock;
+    std::set<CKeyID> setKeys;
+    GetKeys(setKeys);
+    BOOST_FOREACH(const CKeyID &keyid, setKeys) {
+        if (mapKeyBirth.count(keyid) == 0)
+            mapKeyFirstBlock[keyid] = pindexMax;
+    }
+    setKeys.clear();
+
+    // if there are no such keys, we're done
+    if (mapKeyFirstBlock.empty())
+        return;
+
+    // find first block that affects those keys, if there are any left
+    std::vector<CKeyID> vAffected;
+    for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); it++) {
+        // iterate over all wallet transactions...
+        const CWalletTx &wtx = (*it).second;
+        std::map<uint256, CBlockIndex*>::const_iterator blit = mapBlockIndex.find(wtx.hashBlock);
+        if (blit != mapBlockIndex.end() && blit->second->IsInMainChain()) {
+            // ... which are already in a block
+            int nHeight = blit->second->nHeight;
+            BOOST_FOREACH(const CTxOut &txout, wtx.vout) {
+                // iterate over all their outputs
+                ::ExtractAffectedKeys(*this, txout.scriptPubKey, vAffected);
+                BOOST_FOREACH(const CKeyID &keyid, vAffected) {
+                    // ... and all their affected keys
+                    std::map<CKeyID, CBlockIndex*>::iterator rit = mapKeyFirstBlock.find(keyid);
+                    if (rit != mapKeyFirstBlock.end() && nHeight < rit->second->nHeight)
+                        rit->second = blit->second;
+                }
+                vAffected.clear();
+            }
+        }
+    }
+
+    // Extract block timestamps for those keys
+    for (std::map<CKeyID, CBlockIndex*>::const_iterator it = mapKeyFirstBlock.begin(); it != mapKeyFirstBlock.end(); it++)
+        mapKeyBirth[it->first] = it->second->nTime - 7200; // block times can be 2h off
+}