Check earlier for blocks with duplicate transactions. Fixes #1167

[novacoin.git] / src / main.cpp

diff --git a/src/main.cpp b/src/main.cpp
index 76e0783..e8cbc01 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1472,6 +1472,16 @@ bool CBlock::CheckBlock() const
         if (!tx.CheckTransaction())
             return error("CheckBlock() : CheckTransaction failed");
 
+    // Check for duplicate txids. This is caught by ConnectInputs(),
+    // but catching it earlier avoids a potential DoS attack:
+    set<uint256> uniqueTx;
+    BOOST_FOREACH(const CTransaction& tx, vtx)
+    {
+        uniqueTx.insert(tx.GetHash());
+    }
+    if (uniqueTx.size() != vtx.size())
+        return error("CheckBlock() : duplicate transaction");
+
     // Check that it's not full of nonstandard transactions
     if (GetSigOpCount() > MAX_BLOCK_SIGOPS)
         return error("CheckBlock() : out-of-bounds SigOpCount");
@@ -2618,7 +2628,7 @@ bool ProcessMessages(CNode* pfrom)
 
 bool SendMessages(CNode* pto, bool fSendTrickle)
 {
-    CRITICAL_BLOCK(cs_main)
+    TRY_CRITICAL_BLOCK(cs_main)
     {
         // Don't send anything until we get their version message
         if (pto->nVersion == 0)