PPCoin: Release alert and checkpoint master public keys

[novacoin.git] / src / checkpoints.cpp

diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index abd72d4..0160649 100644 (file)
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -163,7 +163,7 @@ namespace Checkpoints
                 {
                     txdb.TxnAbort();
                     hashInvalidCheckpoint = hashPendingCheckpoint;
-                    return error("ProcessSyncCheckpoint: Reorganize failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
+                    return error("AcceptPendingSyncCheckpoint: Reorganize failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
                 }
             }
             txdb.Close();
@@ -185,11 +185,16 @@ namespace Checkpoints
         return false;
     }
 
+    // Automatically select a suitable sync-checkpoint 
     uint256 AutoSelectSyncCheckpoint()
     {
-        // select a block some time ago
-        CBlockIndex *pindex = mapBlockIndex[hashSyncCheckpoint];
-        while (pindex->pnext && pindex->pnext->GetBlockTime() + CHECKPOINT_MIN_SPAN <= GetAdjustedTime())
+        // Proof-of-work blocks are immediately checkpointed
+        // to defend against 51% attack which rejects other miners block 
+
+        // Select the last proof-of-work block
+        const CBlockIndex *pindex = GetLastBlockIndex(pindexBest, false);
+        // Search forward for a block within max span and maturity window
+        while (pindex->pnext && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN <= pindexBest->GetBlockTime() || pindex->nHeight + COINBASE_MATURITY - 20 <= pindexBest->nHeight))
             pindex = pindex->pnext;
         return pindex->GetBlockHash();
     }
@@ -282,10 +287,73 @@ namespace Checkpoints
         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
     }
+
+    bool SetCheckpointPrivKey(std::string strPrivKey)
+    {
+        // Test signing a sync-checkpoint with genesis block
+        CSyncCheckpoint checkpoint;
+        checkpoint.hashCheckpoint = hashGenesisBlock;
+        CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
+        sMsg << (CUnsignedSyncCheckpoint)checkpoint;
+        checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
+
+        std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
+        CKey key;
+        key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
+        if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
+            return false;
+
+        // Test signing successful, proceed
+        CSyncCheckpoint::strMasterPrivKey = strPrivKey;
+        return true;
+    }
+
+    bool SendSyncCheckpoint(uint256 hashCheckpoint)
+    {
+        CSyncCheckpoint checkpoint;
+        checkpoint.hashCheckpoint = hashCheckpoint;
+        CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
+        sMsg << (CUnsignedSyncCheckpoint)checkpoint;
+        checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
+
+        if (CSyncCheckpoint::strMasterPrivKey.empty())
+            return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
+        std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
+        CKey key;
+        key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
+        if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
+            return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
+
+        if(!checkpoint.ProcessSyncCheckpoint(NULL))
+        {
+            printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
+            return false;
+        }
+
+        // Relay checkpoint
+        {
+            LOCK(cs_vNodes);
+            BOOST_FOREACH(CNode* pnode, vNodes)
+                checkpoint.RelayTo(pnode);
+        }
+        return true;
+    }
+
+    // Is the sync-checkpoint outside maturity window?
+    bool IsMatureSyncCheckpoint()
+    {
+        LOCK(cs_hashSyncCheckpoint);
+        // sync-checkpoint should always be accepted block
+        assert(mapBlockIndex.count(hashSyncCheckpoint));
+        const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
+        return (nBestHeight >= pindexSync->nHeight + COINBASE_MATURITY);
+    }
 }
 
 // ppcoin: sync-checkpoint master key
-const std::string CSyncCheckpoint::strMasterPubKey = "0424f20205e5da98ba632bbd278a11a6499585f62bfb2c782377ef59f0251daab8085fc31471bcb8180bc75ed0fa41bb50c7c084511d54015a3a5241d645c7268a";
+const std::string CSyncCheckpoint::strMasterPubKey = "04c0c707c28533fd5c9f79d2d3a2d80dff259ad8f915241cd14608fb9bc07c74830efe8438f2b272a866b4af5e0c2cc2a9909972aefbd976937e39f46bb38c277c";
+
+std::string CSyncCheckpoint::strMasterPrivKey = "";
 
 // ppcoin: verify signature of sync-checkpoint message
 bool CSyncCheckpoint::CheckSignature()