Merge branch 'bip16_0.4.x' into 0.4.x

1 files changed, 202 insertions, 82 deletions

diff --git a/src/main.cpp b/src/main.cpp
index ebf51ae146..759e514ca8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -374,15 +374,6 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
     if ((int64)nLockTime > INT_MAX)
         return error("AcceptToMemoryPool() : not accepting nLockTime beyond 2038 yet");
 
-    // Safety limits
-    unsigned int nSize = ::GetSerializeSize(*this, SER_NETWORK);
-    // Checking ECDSA signatures is a CPU bottleneck, so to avoid denial-of-service
-    // attacks disallow transactions with more than one SigOp per 34 bytes.
-    // 34 bytes because a TxOut is:
-    //   20-byte address + 8 byte bitcoin amount + 5 bytes of ops + 1 byte script length
-    if (GetSigOpCount() > nSize / 34 || nSize < 100)
-        return error("AcceptToMemoryPool() : nonstandard transaction");
-
     // Rather not work on nonstandard transactions (unless -testnet)
     if (!fTestNet && !IsStandard())
         return error("AcceptToMemoryPool() : nonstandard transaction type");
@@ -426,17 +417,29 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
 
     if (fCheckInputs)
     {
-        // Check against previous transactions
+        MapPrevTx mapInputs;
         map<uint256, CTxIndex> mapUnused;
-        int64 nFees = 0;
         bool fInvalid = false;
-        if (!ConnectInputs(txdb, mapUnused, CDiskTxPos(1,1,1), pindexBest, nFees, false, false, 0, fInvalid))
+        if (!FetchInputs(txdb, mapUnused, false, false, mapInputs, fInvalid))
         {
             if (fInvalid)
                 return error("AcceptToMemoryPool() : FetchInputs found invalid tx %s", hash.ToString().substr(0,10).c_str());
-            return error("AcceptToMemoryPool() : ConnectInputs failed %s", hash.ToString().substr(0,10).c_str());
+            if (pfMissingInputs)
+                *pfMissingInputs = true;
+            return error("AcceptToMemoryPool() : FetchInputs failed %s", hash.ToString().substr(0,10).c_str());
         }
 
+        // Safety limits
+        unsigned int nSize = ::GetSerializeSize(*this, SER_NETWORK);
+        // Checking ECDSA signatures is a CPU bottleneck, so to avoid denial-of-service
+        // attacks disallow transactions with more than one SigOp per 34 bytes.
+        // 34 bytes because a TxOut is:
+        //   20-byte address + 8 byte bitcoin amount + 5 bytes of ops + 1 byte script length
+        if (GetSigOpCount() > nSize / 34 || nSize < 100)
+            return error("AcceptToMemoryPool() : nonstandard transaction");
+
+        int64 nFees = GetValueIn(mapInputs)-GetValueOut();
+
         // Don't accept it if it can't get into a block
         if (nFees < GetMinFee(1000, true, true))
             return error("AcceptToMemoryPool() : not enough fees");
@@ -465,6 +468,13 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
                 dFreeCount += nSize;
             }
         }
+
+        // Check against previous transactions
+        // This is done last to help prevent CPU exhaustion denial-of-service attacks.
+        if (!ConnectInputs(mapInputs, mapUnused, CDiskTxPos(1,1,1), pindexBest, false, false))
+        {
+            return error("AcceptToMemoryPool() : ConnectInputs failed %s", hash.ToString().substr(0,10).c_str());
+        }
     }
 
     // Store transaction in memory
@@ -862,9 +872,8 @@ bool CTransaction::DisconnectInputs(CTxDB& txdb)
 }
 
 
-bool CTransaction::ConnectInputs(CTxDB& txdb, map<uint256, CTxIndex>& mapTestPool, CDiskTxPos posThisTx,
-                                 CBlockIndex* pindexBlock, int64& nFees, bool fBlock, bool fMiner, int64 nMinFee,
-                                 bool& fInvalid)
+bool CTransaction::FetchInputs(CTxDB& txdb, const map<uint256, CTxIndex>& mapTestPool,
+                               bool fBlock, bool fMiner, MapPrevTx& inputsRet, bool& fInvalid)
 {
     // FetchInputs can return false either because we just haven't seen some inputs
     // (in which case the transaction should be stored as an orphan)
@@ -872,70 +881,143 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, map<uint256, CTxIndex>& mapTestPoo
     // be dropped).  If tx is definitely invalid, fInvalid will be set to true.
     fInvalid = false;
 
+    if (IsCoinBase())
+        return true; // Coinbase transactions have no inputs to fetch.
+
+    for (int i = 0; i < vin.size(); i++)
+    {
+        COutPoint prevout = vin[i].prevout;
+        if (inputsRet.count(prevout.hash))
+            continue; // Got it already
+
+        // Read txindex
+        CTxIndex& txindex = inputsRet[prevout.hash].first;
+        bool fFound = true;
+        if ((fBlock || fMiner) && mapTestPool.count(prevout.hash))
+        {
+            // Get txindex from current proposed changes
+            txindex = mapTestPool.find(prevout.hash)->second;
+        }
+        else
+        {
+            // Read txindex from txdb
+            fFound = txdb.ReadTxIndex(prevout.hash, txindex);
+        }
+        if (!fFound && (fBlock || fMiner))
+            return fMiner ? false : error("FetchInputs() : %s prev tx %s index entry not found", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
+
+        // Read txPrev
+        CTransaction& txPrev = inputsRet[prevout.hash].second;
+        if (!fFound || txindex.pos == CDiskTxPos(1,1,1))
+        {
+            // Get prev tx from single transactions in memory
+            CRITICAL_BLOCK(cs_mapTransactions)
+            {
+                if (!mapTransactions.count(prevout.hash))
+                    return error("FetchInputs() : %s mapTransactions prev not found %s", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
+                txPrev = mapTransactions[prevout.hash];
+            }
+            if (!fFound)
+                txindex.vSpent.resize(txPrev.vout.size());
+        }
+        else
+        {
+            // Get prev tx from disk
+            if (!txPrev.ReadFromDisk(txindex.pos))
+                return error("FetchInputs() : %s ReadFromDisk prev tx %s failed", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
+        }
+    }
+
+    // Make sure all prevout.n's are valid:
+    for (int i = 0; i < vin.size(); i++)
+    {
+        const COutPoint prevout = vin[i].prevout;
+        assert(inputsRet.count(prevout.hash) != 0);
+        const CTxIndex& txindex = inputsRet[prevout.hash].first;
+        const CTransaction& txPrev = inputsRet[prevout.hash].second;
+        if (prevout.n >= txPrev.vout.size() || prevout.n >= txindex.vSpent.size())
+        {
+            // Revisit this if/when transaction replacement is implemented and allows
+            // adding inputs:
+            fInvalid = true;
+            return error("FetchInputs() : %s prevout.n out of range %d %d %d prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str());
+        }
+    }
+
+    return true;
+}
+
+const CTxOut& CTransaction::GetOutputFor(const CTxIn& input, const MapPrevTx& inputs) const
+{
+    MapPrevTx::const_iterator mi = inputs.find(input.prevout.hash);
+    if (mi == inputs.end())
+        throw std::runtime_error("CTransaction::GetOutputFor() : prevout.hash not found");
+
+    const CTransaction& txPrev = (mi->second).second;
+    if (input.prevout.n >= txPrev.vout.size())
+        throw std::runtime_error("CTransaction::GetOutputFor() : prevout.n out of range");
+
+    return txPrev.vout[input.prevout.n];
+}
+
+int64 CTransaction::GetValueIn(const MapPrevTx& inputs) const
+{
+    if (IsCoinBase())
+        return 0;
+
+    int64 nResult = 0;
+    for (int i = 0; i < vin.size(); i++)
+    {
+        nResult += GetOutputFor(vin[i], inputs).nValue;
+    }
+    return nResult;
+
+}
+
+int CTransaction::GetP2SHSigOpCount(const MapPrevTx& inputs) const
+{
+    if (IsCoinBase())
+        return 0;
+
+    int nSigOps = 0;
+    for (int i = 0; i < vin.size(); i++)
+    {
+        const CTxOut& prevout = GetOutputFor(vin[i], inputs);
+        if (prevout.scriptPubKey.IsPayToScriptHash())
+            nSigOps += prevout.scriptPubKey.GetSigOpCount(vin[i].scriptSig);
+    }
+    return nSigOps;
+}
+
+bool CTransaction::ConnectInputs(MapPrevTx inputs,
+                                 map<uint256, CTxIndex>& mapTestPool, const CDiskTxPos& posThisTx,
+                                 const CBlockIndex* pindexBlock, bool fBlock, bool fMiner, bool fStrictPayToScriptHash)
+{
     // Take over previous transactions' spent pointers
+    // fBlock is true when this is called from AcceptBlock when a new best-block is added to the blockchain
+    // fMiner is true when called from the internal bitcoin miner
+    // ... both are false when called from CTransaction::AcceptToMemoryPool
     if (!IsCoinBase())
     {
         int64 nValueIn = 0;
+        int64 nFees = 0;
         for (int i = 0; i < vin.size(); i++)
         {
             COutPoint prevout = vin[i].prevout;
-
-            // Read txindex
-            CTxIndex txindex;
-            bool fFound = true;
-            if ((fBlock || fMiner) && mapTestPool.count(prevout.hash))
-            {
-                // Get txindex from current proposed changes
-                txindex = mapTestPool[prevout.hash];
-            }
-            else
-            {
-                // Read txindex from txdb
-                fFound = txdb.ReadTxIndex(prevout.hash, txindex);
-            }
-            if (!fFound && (fBlock || fMiner))
-                return fMiner ? false : error("ConnectInputs() : %s prev tx %s index entry not found", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
-
-            // Read txPrev
-            CTransaction txPrev;
-            if (!fFound || txindex.pos == CDiskTxPos(1,1,1))
-            {
-                // Get prev tx from single transactions in memory
-                CRITICAL_BLOCK(cs_mapTransactions)
-                {
-                    if (!mapTransactions.count(prevout.hash))
-                        return error("ConnectInputs() : %s mapTransactions prev not found %s", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
-                    txPrev = mapTransactions[prevout.hash];
-                }
-                if (!fFound)
-                    txindex.vSpent.resize(txPrev.vout.size());
-            }
-            else
-            {
-                // Get prev tx from disk
-                if (!txPrev.ReadFromDisk(txindex.pos))
-                    return error("ConnectInputs() : %s ReadFromDisk prev tx %s failed", GetHash().ToString().substr(0,10).c_str(),  prevout.hash.ToString().substr(0,10).c_str());
-            }
+            assert(inputs.count(prevout.hash) > 0);
+            CTxIndex& txindex = inputs[prevout.hash].first;
+            CTransaction& txPrev = inputs[prevout.hash].second;
 
             if (prevout.n >= txPrev.vout.size() || prevout.n >= txindex.vSpent.size())
-            {
-                // Revisit this if/when transaction replacement is implemented and allows
-                // adding inputs:
-                fInvalid = true;
                 return error("ConnectInputs() : %s prevout.n out of range %d %d %d prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str());
-            }
 
             // If prev is coinbase, check that it's matured
             if (txPrev.IsCoinBase())
-                for (CBlockIndex* pindex = pindexBlock; pindex && pindexBlock->nHeight - pindex->nHeight < COINBASE_MATURITY; pindex = pindex->pprev)
+                for (const CBlockIndex* pindex = pindexBlock; pindex && pindexBlock->nHeight - pindex->nHeight < COINBASE_MATURITY; pindex = pindex->pprev)
                     if (pindex->nBlockPos == txindex.pos.nBlockPos && pindex->nFile == txindex.pos.nFile)
                         return error("ConnectInputs() : tried to spend coinbase at depth %d", pindexBlock->nHeight - pindex->nHeight);
 
-            // Verify signature
-            if (!VerifySignature(txPrev, *this, i))
-                return error("ConnectInputs() : %s VerifySignature failed", GetHash().ToString().substr(0,10).c_str());
-
-            // Check for conflicts
+            // Check for conflicts (double-spend)
             if (!txindex.vSpent[prevout.n].IsNull())
                 return fMiner ? false : error("ConnectInputs() : %s prev tx already used at %s", GetHash().ToString().substr(0,10).c_str(), txindex.vSpent[prevout.n].ToString().c_str());
 
@@ -944,6 +1026,10 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, map<uint256, CTxIndex>& mapTestPoo
             if (!MoneyRange(txPrev.vout[prevout.n].nValue) || !MoneyRange(nValueIn))
                 return error("ConnectInputs() : txin values out of range");
 
+            // Verify signature
+            if (!VerifySignature(txPrev, *this, i, fStrictPayToScriptHash, 0))
+                return error("ConnectInputs() : %s VerifySignature failed", GetHash().ToString().substr(0,10).c_str());
+
             // Mark outpoints as spent
             txindex.vSpent[prevout.n] = posThisTx;
 
@@ -961,24 +1047,11 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, map<uint256, CTxIndex>& mapTestPoo
         int64 nTxFee = nValueIn - GetValueOut();
         if (nTxFee < 0)
             return error("ConnectInputs() : %s nTxFee < 0", GetHash().ToString().substr(0,10).c_str());
-        if (nTxFee < nMinFee)
-            return false;
         nFees += nTxFee;
         if (!MoneyRange(nFees))
             return error("ConnectInputs() : nFees out of range");
     }
 
-    if (fBlock)
-    {
-        // Add transaction to changes
-        mapTestPool[GetHash()] = CTxIndex(posThisTx, vout.size());
-    }
-    else if (fMiner)
-    {
-        // Add transaction to test pool
-        mapTestPool[GetHash()] = CTxIndex(CDiskTxPos(1,1,1), vout.size());
-    }
-
     return true;
 }
 
@@ -1004,7 +1077,7 @@ bool CTransaction::ClientConnectInputs()
                 return false;
 
             // Verify signature
-            if (!VerifySignature(txPrev, *this, i))
+            if (!VerifySignature(txPrev, *this, i, true, 0))
                 return error("ConnectInputs() : VerifySignature failed");
 
             ///// this is redundant with the mapNextTx stuff, not sure which I want to get rid of
@@ -1077,20 +1150,51 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
                         return false;
         }
 
+    // P2SH didn't become active until Apr 1 2012 (Feb 15 on testnet)
+    int64 nEvalSwitchTime = fTestNet ? 1329264000 : 1333238400;
+    bool fStrictPayToScriptHash = (pindex->nTime >= nEvalSwitchTime);
+
     //// issue here: it doesn't know the version
     unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - 1 + GetSizeOfCompactSize(vtx.size());
 
     map<uint256, CTxIndex> mapQueuedChanges;
     int64 nFees = 0;
+    int nSigOps = 0;
     BOOST_FOREACH(CTransaction& tx, vtx)
     {
+        nSigOps += tx.GetSigOpCount();
+        if (nSigOps > MAX_BLOCK_SIGOPS)
+            return error("ConnectBlock() : too many sigops");
+
         CDiskTxPos posThisTx(pindex->nFile, pindex->nBlockPos, nTxPos);
         nTxPos += ::GetSerializeSize(tx, SER_DISK);
 
         bool fInvalid;
-        if (!tx.ConnectInputs(txdb, mapQueuedChanges, posThisTx, pindex, nFees, true, false, 0, fInvalid))
-            return false;
+        MapPrevTx mapInputs;
+        if (!tx.IsCoinBase())
+        {
+            if (!tx.FetchInputs(txdb, mapQueuedChanges, true, false, mapInputs, fInvalid))
+                return false;
+
+            if (fStrictPayToScriptHash)
+            {
+                // Add in sigops done by pay-to-script-hash inputs;
+                // this is to prevent a "rogue miner" from creating
+                // an incredibly-expensive-to-validate block.
+                nSigOps += tx.GetP2SHSigOpCount(mapInputs);
+                if (nSigOps > MAX_BLOCK_SIGOPS)
+                    return error("ConnectBlock() : too many sigops");
+            }
+
+            nFees += tx.GetValueIn(mapInputs)-tx.GetValueOut();
+
+            if (!tx.ConnectInputs(mapInputs, mapQueuedChanges, posThisTx, pindex, true, false, fStrictPayToScriptHash))
+                return false;
+        }
+
+        mapQueuedChanges[tx.GetHash()] = CTxIndex(posThisTx, tx.vout.size());
     }
+
     // Write queued txindex changes
     for (map<uint256, CTxIndex>::iterator mi = mapQueuedChanges.begin(); mi != mapQueuedChanges.end(); ++mi)
     {
@@ -1353,7 +1457,7 @@ bool CBlock::CheckBlock() const
 
     // Check that it's not full of nonstandard transactions
     if (GetSigOpCount() > MAX_BLOCK_SIGOPS)
-        return error("CheckBlock() : too many nonstandard transactions");
+        return error("CheckBlock() : out-of-bounds SigOpCount");
 
     // Check merkleroot
     if (hashMerkleRoot != BuildMerkleTree())
@@ -2863,6 +2967,8 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
             unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK);
             if (nBlockSize + nTxSize >= MAX_BLOCK_SIZE_GEN)
                 continue;
+
+            // Legacy limits on sigOps:
             int nTxSigOps = tx.GetSigOpCount();
             if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
                 continue;
@@ -2875,14 +2981,28 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
             // because we're already processing them in order of dependency
             map<uint256, CTxIndex> mapTestPoolTmp(mapTestPool);
             bool fInvalid;
-            if (!tx.ConnectInputs(txdb, mapTestPoolTmp, CDiskTxPos(1,1,1), pindexPrev, nFees, false, true, nMinFee, fInvalid))
+            MapPrevTx mapInputs;
+            if (!tx.FetchInputs(txdb, mapTestPoolTmp, false, true, mapInputs, fInvalid))
+                continue;
+
+            int64 nTxFees = tx.GetValueIn(mapInputs)-tx.GetValueOut();
+            if (nTxFees < nMinFee)
+                continue;
+
+            nTxSigOps += tx.GetP2SHSigOpCount(mapInputs);
+            if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
+                continue;
+
+            if (!tx.ConnectInputs(mapInputs, mapTestPoolTmp, CDiskTxPos(1,1,1), pindexPrev, false, true))
                 continue;
+            mapTestPoolTmp[tx.GetHash()] = CTxIndex(CDiskTxPos(1,1,1), tx.vout.size());
             swap(mapTestPool, mapTestPoolTmp);
 
             // Added
             pblock->vtx.push_back(tx);
             nBlockSize += nTxSize;
             nBlockSigOps += nTxSigOps;
+            nFees += nTxFees;
 
             // Add transactions that depend on this one to the priority queue
             uint256 hash = tx.GetHash();