Update transaction verification protocol

* CheckBlock() refactoring: move headers checking code to new CheckBlockHeader() and coinbase value checking code to ConnectBlock();
* Fix minimum stake fee at CENT.

diff --git a/src/main.cpp b/src/main.cpp
index 5f6577a..26aabe8 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1112,7 +1112,7 @@ CBigNum inline GetProofOfStakeLimit(int nHeight, unsigned int nTime)
 }
 
 // miner's coin base reward based on nBits
-int64 GetProofOfWorkReward(unsigned int nBits)
+int64 GetProofOfWorkReward(unsigned int nBits, int64 nFees)
 {
     CBigNum bnSubsidyLimit = MAX_MINT_PROOF_OF_WORK;
 
@@ -1145,9 +1145,9 @@ int64 GetProofOfWorkReward(unsigned int nBits)
 
     nSubsidy = (nSubsidy / CENT) * CENT;
     if (fDebug && GetBoolArg("-printcreation"))
-        printf("GetProofOfWorkReward() : create=%s nBits=0x%08x nSubsidy=%"PRI64d"\n", FormatMoney(nSubsidy).c_str(), nBits, nSubsidy);
+        printf("GetProofOfWorkReward() : create=%s nBits=0x%08x nSubsidy=%"PRI64d" nFees=%"PRI64d"\n", FormatMoney(nSubsidy).c_str(), nBits, nSubsidy, nFees);
 
-    return min(nSubsidy, MAX_MINT_PROOF_OF_WORK);
+    return min(nSubsidy + nFees, MAX_MINT_PROOF_OF_WORK);
 }
 
 // miner's coin stake reward based on nBits and coin age spent (coin-days)
@@ -1571,7 +1571,7 @@ bool CTransaction::CheckInputs(CCoinsViewCache &inputs, enum CheckSig_mode csmod
             if (!GetCoinAge(nCoinAge))
                 return error("CheckInputs() : %s unable to get coin age for coinstake", GetHash().ToString().substr(0,10).c_str());
 
-            unsigned int nTxSize = (nTime > STAKEFEE_SWITCH_TIME || fTestNet) ? GetSerializeSize(SER_NETWORK, PROTOCOL_VERSION) : 0;
+            unsigned int nTxSize = (nTime > VALIDATION_SWITCH_TIME || fTestNet) ? GetSerializeSize(SER_NETWORK, PROTOCOL_VERSION) : 0;
             int64 nReward = GetValueOut() - nValueIn;
             int64 nCalculatedReward = GetProofOfStakeReward(nCoinAge, pblock->nBits, nTime) - GetMinFee(1, false, GMF_BLOCK, nTxSize, CENT) + CENT;
 
@@ -1839,6 +1839,17 @@ bool CBlock::ConnectBlock(CBlockIndex* pindex, CCoinsViewCache &view, bool fJust
             blockundo.vtxundo.push_back(txundo);
     }
 
+    if (IsProofOfWork())
+    {
+        int64 nBlockReward = GetProofOfWorkReward(nBits, VALIDATION_SWITCH_TIME < nTime ? nFees : 0);
+
+        // Check coinbase reward
+        if (vtx[0].GetValueOut() > nBlockReward)
+            return error("ConnectBlock() : coinbase reward exceeded (actual=%"PRI64d" vs calculated=%"PRI64d")",
+                   vtx[0].GetValueOut(),
+                   nBlockReward);
+    }
+
     pindex->nMint = nValueOut - nValueIn + nFees;
     pindex->nMoneySupply = (pindex->pprev? pindex->pprev->nMoneySupply : 0) + nValueOut - nValueIn;
 
@@ -2261,6 +2272,37 @@ bool FindUndoPos(int nFile, CDiskBlockPos &pos, unsigned int nAddSize)
     return true;
 }
 
+bool CBlock::CheckBlockHeader(bool fCheckPoW, bool fCheckSig) const
+{
+    // Check timestamp
+    if (GetBlockTime() > GetAdjustedTime() + 2 * 60 * 60)
+        return error("CheckBlockHeader() : block timestamp too far in the future");
+
+    if (IsProofOfWork())
+    {
+        // Check proof of work matches claimed amount
+        if (fCheckPoW && !CheckProofOfWork(GetHash(), nBits))
+            return DoS(50, error("CheckBlockHeader() : proof of work failed"));
+
+        // Should we check proof-of-work block signature or not?
+        //
+        // * Always skip on TestNet
+        // * Perform checking for the first 9689 blocks
+        // * Perform checking since last checkpoint until 20 Sep 2013 (will be removed after)
+
+        if(!fTestNet && fCheckSig)
+        {
+            bool checkEntropySig = (GetBlockTime() < ENTROPY_SWITCH_TIME);
+
+            // check legacy proof-of-work block signature
+            if (checkEntropySig && !CheckLegacySignature())
+                return DoS(100, error("CheckBlockHeader() : bad proof-of-work block signature"));
+        }
+    }
+
+    return true;
+}
+
 bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) const
 {
     // These are checks that are independent of context
@@ -2270,20 +2312,12 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) c
     if (vtx.empty() || vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
         return DoS(100, error("CheckBlock() : size limits failed"));
 
-    // Check proof of work matches claimed amount
-    if (fCheckPOW && IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
-        return DoS(50, error("CheckBlock() : proof of work failed"));
-
-    // Check timestamp
-    if (GetBlockTime() > GetAdjustedTime() + 2 * 60 * 60)
-        return error("CheckBlock() : block timestamp too far in the future");
+    if (!CheckBlockHeader(fCheckPOW, fCheckSig))
+        return false;
 
-    // First transaction must be coinbase, the rest must not be
-    if (vtx.empty() || !vtx[0].IsCoinBase())
+    // First transaction must be coinbase
+    if (!vtx[0].IsCoinBase())
         return DoS(100, error("CheckBlock() : first tx is not coinbase"));
-    for (unsigned int i = 1; i < vtx.size(); i++)
-        if (vtx[i].IsCoinBase())
-            return DoS(100, error("CheckBlock() : more than one coinbase"));
 
     // Check coinbase timestamp
     if (GetBlockTime() > FutureDrift((int64)vtx[0].nTime))
@@ -2295,54 +2329,35 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) c
         if (vtx[0].vout.size() != 1 || !vtx[0].vout[0].IsEmpty())
             return DoS(100, error("CheckBlock() : coinbase output not empty for proof-of-stake block"));
 
-        // Second transaction must be coinstake, the rest must not be
-        if (vtx.empty() || !vtx[1].IsCoinStake())
+        // Second transaction must be coinstake
+        if (!vtx[1].IsCoinStake())
             return DoS(100, error("CheckBlock() : second tx is not coinstake"));
-        for (unsigned int i = 2; i < vtx.size(); i++)
-            if (vtx[i].IsCoinStake())
-                return DoS(100, error("CheckBlock() : more than one coinstake"));
 
         // Check coinstake timestamp
         if (!CheckCoinStakeTimestamp(GetBlockTime(), (int64)vtx[1].nTime))
             return DoS(50, error("CheckBlock() : coinstake timestamp violation nTimeBlock=%"PRI64d" nTimeTx=%u", GetBlockTime(), vtx[1].nTime));
     }
-    else
-    {
-        int64 nReward = GetProofOfWorkReward(nBits);
-        // Check coinbase reward
-        if (vtx[0].GetValueOut() > nReward)
-            return DoS(50, error("CheckBlock() : coinbase reward exceeded (actual=%"PRI64d" vs calculated=%"PRI64d")",
-                   vtx[0].GetValueOut(),
-                   nReward));
-
-        // Should we check proof-of-work block signature or not?
-        //
-        // * Always skip on TestNet
-        // * Perform checking for the first 9689 blocks
-        // * Perform checking since last checkpoint until 20 Sep 2013 (will be removed after)
-
-        if(!fTestNet && fCheckSig)
-        {
-            bool checkEntropySig = (GetBlockTime() < ENTROPY_SWITCH_TIME);
-
-            // check legacy proof-of-work block signature
-            if (checkEntropySig && !CheckLegacySignature())
-                return DoS(100, error("CheckBlock() : bad proof-of-work block signature"));
-        }
-    }
-
 
     // Check transactions
-    BOOST_FOREACH(const CTransaction& tx, vtx)
+    for (unsigned int i = 0; i < vtx.size(); i++)
     {
-        if (!tx.CheckTransaction())
-            return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed"));
+        const CTransaction& tx = vtx[i];
 
         // check transaction timestamp
         if (GetBlockTime() < (int64)tx.nTime)
             return DoS(50, error("CheckBlock() : block timestamp earlier than transaction timestamp"));
+
+        if (i != 0 && tx.IsCoinBase())
+            return DoS(100, error("CheckBlock() : coinbase in wrong position"));
+
+        if (i != 1 && tx.IsCoinStake())
+            return DoS(100, error("CheckBlock() : coinstake in wrong position"));
+
+        if (!tx.CheckTransaction())
+            return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed"));
     }
 
+
     // Check for duplicate txids. This is caught by ConnectInputs(),
     // but catching it earlier avoids a potential DoS attack:
     BuildMerkleTree();

diff --git a/src/main.h b/src/main.h
index 9f43f51..2b9f15d 100644 (file)
--- a/src/main.h
+++ b/src/main.h
@@ -124,7 +124,7 @@ bool LoadExternalBlockFile(FILE* fileIn);
 
 bool CheckProofOfWork(uint256 hash, unsigned int nBits);
 unsigned int GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake);
-int64 GetProofOfWorkReward(unsigned int nBits);
+int64 GetProofOfWorkReward(unsigned int nBits, int64 nFees=0);
 int64 GetProofOfStakeReward(int64 nCoinAge, unsigned int nBits, unsigned int nTime, bool bCoinYearOnly=false);
 unsigned int ComputeMinWork(unsigned int nBase, int64 nTime);
 unsigned int ComputeMinStake(unsigned int nBase, int64 nTime, unsigned int nBlockTime);
@@ -1459,6 +1459,7 @@ public:
     bool AddToBlockIndex(const CDiskBlockPos &pos);
 
     // Context-independent validity checks
+    bool CheckBlockHeader(bool fCheckPoW=true, bool fCheckSig=false) const;
     bool CheckBlock(bool fCheckPOW=true, bool fCheckMerkleRoot=true, bool fCheckSig=false) const;
 
     // Store block on disk

diff --git a/src/miner.cpp b/src/miner.cpp
index 6a9adc6..7ee8525 100644 (file)
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -356,7 +356,7 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
             printf("CreateNewBlock(): total size %"PRI64u"\n", nBlockSize);
 
         if (!fProofOfStake)
-            pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
+            pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits, VALIDATION_SWITCH_TIME < pblock->nTime ? nFees : 0);
 
         // Fill in header
         pblock->hashPrevBlock  = pindexPrev->GetBlockHash();

diff --git a/src/timestamps.h b/src/timestamps.h
index 18dac1c..de8a6a6 100644 (file)
--- a/src/timestamps.h
+++ b/src/timestamps.h
@@ -6,7 +6,8 @@ static const unsigned int STAKE_SWITCH_TIME = 1371686400; // Thu, 20 Jun 2013 00
 static const unsigned int TARGETS_SWITCH_TIME = 1374278400; // Sat, 20 Jul 2013 00:00:00 GMT
 static const unsigned int CHAINCHECKS_SWITCH_TIME = 1379635200; // Fri, 20 Sep 2013 00:00:00 GMT
 static const unsigned int STAKECURVE_SWITCH_TIME = 1382227200; // Sun, 20 Oct 2013 00:00:00 GMT
-static const unsigned int FEE_SWITCH_TIME = 1404172800; // Tue, 01 Jul 2014 00:00:00 GMT
-static const unsigned int STAKEFEE_SWITCH_TIME = 1406851200; // Fri, 01 Aug 2014 00:00:00 GMT
+static const unsigned int FEE_SWITCH_TIME = 1405814400; // Sun, 20 Jul 2014 00:00:00 GMT
+
+static const unsigned int VALIDATION_SWITCH_TIME = 1408492800; // Wed, 20 Aug 2014 00:00:00 GMT
 
 #endif

diff --git a/src/util.h b/src/util.h
index 5117164..3e5beb9 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -63,7 +63,6 @@ static const int64 CENT = 10000;
 void LogStackTrace();
 #endif
 
-
 /* Format characters for (s)size_t and ptrdiff_t */
 #if defined(_MSC_VER) || defined(__MSVCRT__)
   /* (s)size_t and ptrdiff_t have the same size specifier in MSVC: