implement CScript => string extraction, check username constraits, improve username hash

src/bitcoinrpc.cpp

@@ -176,10 +176,10 @@ Value stop(const Array& params, bool fHelp)
     if (fHelp || params.size() > 1)
         throw runtime_error(
             "stop\n"
-            "Stop Bitcoin server.");
+            "Stop Twister server.");
     // Shutdown will take long enough that the response should get back
     StartShutdown();
-    return "Bitcoin server stopping";
+    return "Twister server stopping";
 }
 
 

src/core.cpp

@@ -80,7 +80,12 @@ uint256 CTransaction::GetHash() const
 
 uint256 CTransaction::GetUsernameHash() const
 {
-    return SerializeHash(userName);
+    if(userName.IsSmallString()) {
+        return SerializeHash(userName.ExtractSmallString());
+    }
+    // [MF] TODO: remove this assert later, it will fail for spammessage.
+    assert(!"username not small string");
+    return uint256();
 }
 
 

src/main.cpp

@@ -408,7 +408,9 @@ int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
     CBlock blockTmp;
 
     if (pblock == NULL) {
-        CCoins coins;
+      /* [MF] FIXME: Use GetTransaction to obtain block? */
+      /*
+      CCoins coins;
         if (pcoinsTip->GetCoins(GetUsernameHash(), coins)) {
             CBlockIndex *pindex = FindBlockByHeight(coins.nHeight);
             if (pindex) {
@@ -417,6 +419,8 @@ int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
                 pblock = &blockTmp;
             }
         }
+       */
+      return 0;
     }
 
     if (pblock) {
@@ -452,7 +456,26 @@ int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
 
 
 
-
+bool CheckUsername(const std::string &userName, CValidationState &state)
+{
+    if (!userName.size() || userName.size() > 16 )
+        return state.DoS(10, error("CheckUsername() : username size out of limits"));
+    BOOST_FOREACH(char c, userName) {
+        if( isalpha(c) ) {
+          if( !islower(c) )
+            return state.DoS(10, error("CheckUsername() : username must be lowercase"));
+        } else if( isdigit(c) ) {
+            // digit ok
+        } else if( isspace(c) ) {
+            return state.DoS(10, error("CheckUsername() : username spaces not allowed"));
+        } else if( c == '_' ) {
+            // underscore ok
+        } else {
+            return state.DoS(10, error("CheckUsername() : invalid username character"));
+        }
+    }
+    return true;
+}
 
 
 // [MF] check tx consistency and pow, not duplicated id.
@@ -467,10 +490,12 @@ bool CheckTransaction(const CTransaction& tx, CValidationState &state)
     } else {
       if (tx.userName.empty())
           return state.DoS(10, error("CheckTransaction() : username empty"));
-      if (tx.userName.size() > MAX_USERNAME_SIZE)
-          return state.DoS(100, error("CheckTransaction() : username too big"));
       if (tx.pubKey.empty())
           return state.DoS(10, error("CheckTransaction() : pubKey empty"));
+      if (!tx.userName.IsSmallString())
+          return state.DoS(10, error("CheckTransaction() : username not smallstring"));
+      if (!CheckUsername( tx.userName.ExtractSmallString(), state ))
+          return state.DoS(10, error("CheckTransaction() : username check failed"));
     }
     // Size limits
     if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
@@ -574,7 +599,7 @@ bool CTxMemPool::addUnchecked(const uint256& userhash, CTransaction &tx)
 bool CTxMemPool::remove(const CTransaction &tx, bool fRecursive)
 {
     // Remove transaction from memory pool
-    {
+    if( !tx.IsSpamMessage() ){
         LOCK(cs);
         uint256 hash = tx.GetUsernameHash();
         if (mapTx.count(hash))
@@ -1095,7 +1120,7 @@ bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, C
     }
 
     // Do not allow blocks that contain transactions which 'overwrite' older transactions,
-    for (unsigned int i = 0; i < block.vtx.size(); i++) {
+    for (unsigned int i = 1; i < block.vtx.size(); i++) {
         if( pblocktree->HaveTxIndex(block.vtx[i].GetUsernameHash()) )
           return state.DoS(100, error("ConnectBlock() : tried to overwrite transaction"));
 
@@ -1110,16 +1135,16 @@ bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, C
     int64 nStart = GetTimeMicros();
     CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
     std::vector<std::pair<uint256, CDiskTxPos> > vPos;
-    vPos.reserve(block.vtx.size());
+    vPos.reserve(block.vtx.size()-1);
     for (unsigned int i = 0; i < block.vtx.size(); i++)
     {
         const CTransaction &tx = block.vtx[i];
 
         CTxUndo txundo;
-        if (!tx.IsSpamMessage())
+        if (!tx.IsSpamMessage()) {
             blockundo.vtxundo.push_back(txundo);
-
-        vPos.push_back(std::make_pair(tx.GetUsernameHash(), pos));
+            vPos.push_back(std::make_pair(tx.GetUsernameHash(), pos));
+        }
         pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
     }
     int64 nTime = GetTimeMicros() - nStart;

src/main.h

@@ -270,6 +270,8 @@ inline bool AllowFree(double dPriority)
     return dPriority > COIN * 144 / 250;
 }
 
+bool CheckUsername(const std::string &userName, CValidationState &state);
+
 // Context-independent validity checks
 bool CheckTransaction(const CTransaction& tx, CValidationState& state);
 

src/rpcblockchain.cpp

@@ -55,9 +55,22 @@ Object blockToJSON(const CBlock& block, const CBlockIndex* blockindex)
     result.push_back(Pair("version", block.nVersion));
     result.push_back(Pair("merkleroot", block.hashMerkleRoot.GetHex()));
     Array txs;
-    BOOST_FOREACH(const CTransaction&tx, block.vtx)
+    Array txuserhashes;
+    Array usernames;
+    std::string spamMessage;
+    BOOST_FOREACH(const CTransaction&tx, block.vtx) {
         txs.push_back(tx.GetHash().GetHex());
+        if( tx.IsSpamMessage() ) {
+          spamMessage = tx.message.ExtractPushDataString(0);
+        } else {
+          txuserhashes.push_back(tx.GetUsernameHash().GetHex());
+          usernames.push_back(tx.userName.ExtractSmallString());
+        }
+    }
     result.push_back(Pair("tx", txs));
+    result.push_back(Pair("spamMessage", spamMessage));
+    result.push_back(Pair("userhashes", txuserhashes));
+    result.push_back(Pair("usernames", usernames));
     result.push_back(Pair("time", (boost::int64_t)block.GetBlockTime()));
     result.push_back(Pair("nonce", (boost::uint64_t)block.nNonce));
     result.push_back(Pair("bits", HexBits(block.nBits)));

src/rpcwallet.cpp

@@ -1304,7 +1304,7 @@ Value encryptwallet(const Array& params, bool fHelp)
     // slack space in .dat files; that is bad if the old data is
     // unencrypted private keys. So:
     StartShutdown();
-    return "wallet encrypted; Bitcoin server stopping, restart to run with encrypted wallet. The keypool has been flushed, you need to make a new backup.";
+    return "wallet encrypted; Twister server stopping, restart to run with encrypted wallet. The keypool has been flushed, you need to make a new backup.";
 }
 
 class DescribeAddressVisitor : public boost::static_visitor<Object>

src/script.cpp

@@ -1777,6 +1777,16 @@ bool CScript::IsPayToScriptHash() const
             this->at(22) == OP_EQUAL);
 }
 
+bool CScript::IsSmallString() const
+{
+    if( !size() || this->at(0) >= OP_PUSHDATA1 )
+        return false;
+    unsigned int opSize = this->at(0);
+    if( this->size() != opSize + 1 )
+        return false;
+    return true;
+}
+
 class CScriptVisitor : public boost::static_visitor<bool>
 {
 private:

src/script.h

@@ -533,6 +533,8 @@ public:
 
     bool IsPayToScriptHash() const;
 
+    bool IsSmallString() const;
+
     // Called by IsStandardTx
     bool IsPushOnly() const
     {
@@ -548,6 +550,43 @@ public:
         return true;
     }
 
+    bool ExtractPushData( std::vector< std::vector<unsigned char> > &vData) const
+    {
+        vData.clear();
+        const_iterator pc = begin();
+        while (pc < end())
+        {
+            opcodetype opcode;
+            std::vector<unsigned char> vch;
+            if (!GetOp(pc, opcode, vch))
+                return false;
+            if (opcode > OP_16)
+                return false;
+            vData.push_back(vch);
+        }
+        return true;
+    }
+
+    // only for username
+    std::string ExtractSmallString() const
+    {
+        if( !IsSmallString() )
+          return std::string();
+
+        unsigned int opSize = this->at(0);
+        return std::string((const char*)&(this[1]), opSize);
+    }
+
+    std::string ExtractPushDataString(int n) const
+    {
+        std::vector< std::vector<unsigned char> > vData;
+        if( ExtractPushData(vData) && vData.size() >= n+1 ) {
+          std::string str((const char*)vData[n].data(), vData[n].size());
+          return str;
+        }
+        return std::string();
+    }
+
 
     void SetDestination(const CTxDestination& address);
     void SetMultisig(int nRequired, const std::vector<CPubKey>& keys);