src/checkpoints.cpp

   1 // Copyright (c) 2009-2012 The Bitcoin developers
   2 // Distributed under the MIT/X11 software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include <boost/assign/list_of.hpp> // for 'map_list_of()'
   6 #include <boost/foreach.hpp>
   7
   8 #include "checkpoints.h"
   9
  10 #include "txdb.h"
  11 #include "main.h"
  12 #include "uint256.h"
  13
  14 namespace Checkpoints
  15 {
  16     typedef std::map<int, std::pair<uint256, unsigned int> > MapCheckpoints;
  17
  18     //
  19     // What makes a good checkpoint block?
  20     // + Is surrounded by blocks with reasonable timestamps
  21     //   (no blocks before with a timestamp after, none after with
  22     //    timestamp before)
  23     // + Contains no strange transactions
  24     //
  25     static MapCheckpoints mapCheckpoints =
  26         boost::assign::map_list_of
  27         ( 0,     std::make_pair(hashGenesisBlock, 1360105017) )
  28         ( 9690,  std::make_pair(uint256("0x00000000026561450859c46868099e0df6068a538f038cb18988fd8d47dcdaf5"), 1362791423) )
  29         ( 13560, std::make_pair(uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052) )
  30         ( 37092, std::make_pair(uint256("0x0000000000a38c2f98556f46793b453e92d8fab2d31c0b93fd08bcf78e56099d"), 1376677203) )
  31         ( 44200, std::make_pair(uint256("0xc9bda7232a18b9c1f5ff974a9e5566b2d1879ceb8fc0e9e61fba9038a25b8447"), 1380145962) )
  32         ( 65000, std::make_pair(uint256("0xfb2b51a2fd65062c98a7a6053cde46aeaefebb95ba2f680e85a29ee25b1dcf05"), 1388526385) )
  33         ( 68600, std::make_pair(uint256("0xb646b0562080ab9411f85d4b2a1ca8b197c67ae170c5e328406871b44233cb06"), 1389867276) )
  34         ( 92161, std::make_pair(uint256("0x000000000079090eb31e7fa55487e4e666466253e68b213f44b7977ea7a2eeec"), 1398919969) )
  35         ( 98661, std::make_pair(uint256("0x48328dfc0eaffc659723739c6202854d1624449340193bdea3e71ece4ccdd43f"), 1401469019) )
  36     ;
  37
  38     // TestNet has no checkpoints
  39     static MapCheckpoints mapCheckpointsTestnet =
  40         boost::assign::map_list_of
  41         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  42         ;
  43
  44     bool CheckHardened(int nHeight, const uint256& hash)
  45     {
  46         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  47
  48         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  49         if (i == checkpoints.end()) return true;
  50         return hash == i->second.first;
  51     }
  52
  53     int GetTotalBlocksEstimate()
  54     {
  55         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  56
  57         return checkpoints.rbegin()->first;
  58     }
  59
  60     int GetLastCheckpointTime()
  61     {
  62         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  63
  64         return checkpoints.rbegin()->second.second;
  65     }
  66
  67     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  68     {
  69         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  70
  71         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  72         {
  73             const uint256& hash = i.second.first;
  74             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  75             if (t != mapBlockIndex.end())
  76                 return t->second;
  77         }
  78         return NULL;
  79     }
  80
  81     // ppcoin: synchronized checkpoint (centrally broadcasted)
  82     uint256 hashSyncCheckpoint = 0;
  83     uint256 hashPendingCheckpoint = 0;
  84     CSyncCheckpoint checkpointMessage;
  85     CSyncCheckpoint checkpointMessagePending;
  86     uint256 hashInvalidCheckpoint = 0;
  87     CCriticalSection cs_hashSyncCheckpoint;
  88
  89     // ppcoin: get last synchronized checkpoint
  90     CBlockIndex* GetLastSyncCheckpoint()
  91     {
  92         LOCK(cs_hashSyncCheckpoint);
  93         if (!mapBlockIndex.count(hashSyncCheckpoint))
  94             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
  95         else
  96             return mapBlockIndex[hashSyncCheckpoint];
  97         return NULL;
  98     }
  99
 100     // ppcoin: only descendant of current sync-checkpoint is allowed
 101     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 102     {
 103         if (!mapBlockIndex.count(hashSyncCheckpoint))
 104             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 105         if (!mapBlockIndex.count(hashCheckpoint))
 106             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 107
 108         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 109         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 110
 111         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 112         {
 113             // Received an older checkpoint, trace back from current checkpoint
 114             // to the same height of the received checkpoint to verify
 115             // that current checkpoint should be a descendant block
 116             CBlockIndex* pindex = pindexSyncCheckpoint;
 117             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 118                 if (!(pindex = pindex->pprev))
 119                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 120             if (pindex->GetBlockHash() != hashCheckpoint)
 121             {
 122                 hashInvalidCheckpoint = hashCheckpoint;
 123                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 124             }
 125             return false; // ignore older checkpoint
 126         }
 127
 128         // Received checkpoint should be a descendant block of the current
 129         // checkpoint. Trace back to the same height of current checkpoint
 130         // to verify.
 131         CBlockIndex* pindex = pindexCheckpointRecv;
 132         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 133             if (!(pindex = pindex->pprev))
 134                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 135         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 136         {
 137             hashInvalidCheckpoint = hashCheckpoint;
 138             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 139         }
 140         return true;
 141     }
 142
 143     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 144     {
 145         CTxDB txdb;
 146         txdb.TxnBegin();
 147         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 148         {
 149             txdb.TxnAbort();
 150             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 151         }
 152         if (!txdb.TxnCommit())
 153             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 154
 155 #ifndef USE_LEVELDB
 156         txdb.Close();
 157 #endif
 158
 159         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 160         return true;
 161     }
 162
 163     bool AcceptPendingSyncCheckpoint()
 164     {
 165         LOCK(cs_hashSyncCheckpoint);
 166         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 167         {
 168             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 169             {
 170                 hashPendingCheckpoint = 0;
 171                 checkpointMessagePending.SetNull();
 172                 return false;
 173             }
 174
 175             CTxDB txdb;
 176             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 177             if (!pindexCheckpoint->IsInMainChain())
 178             {
 179                 CBlock block;
 180                 if (!block.ReadFromDisk(pindexCheckpoint))
 181                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 182                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 183                 {
 184                     hashInvalidCheckpoint = hashPendingCheckpoint;
 185                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 186                 }
 187             }
 188
 189 #ifndef USE_LEVELDB
 190             txdb.Close();
 191 #endif
 192             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 193                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 194             hashPendingCheckpoint = 0;
 195             checkpointMessage = checkpointMessagePending;
 196             checkpointMessagePending.SetNull();
 197             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 198             // relay the checkpoint
 199             if (!checkpointMessage.IsNull())
 200             {
 201                 BOOST_FOREACH(CNode* pnode, vNodes)
 202                     checkpointMessage.RelayTo(pnode);
 203             }
 204             return true;
 205         }
 206         return false;
 207     }
 208
 209     // Automatically select a suitable sync-checkpoint
 210     uint256 AutoSelectSyncCheckpoint()
 211     {
 212         const CBlockIndex *pindex = pindexBest;
 213         // Search backward for a block within max span and maturity window
 214         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 215             pindex = pindex->pprev;
 216         return pindex->GetBlockHash();
 217     }
 218
 219     // Check against synchronized checkpoint
 220     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 221     {
 222         if (fTestNet) return true; // Testnet has no checkpoints
 223         int nHeight = pindexPrev->nHeight + 1;
 224
 225         LOCK(cs_hashSyncCheckpoint);
 226         // sync-checkpoint should always be accepted block
 227         assert(mapBlockIndex.count(hashSyncCheckpoint));
 228         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 229
 230         if (nHeight > pindexSync->nHeight)
 231         {
 232             // trace back to same height as sync-checkpoint
 233             const CBlockIndex* pindex = pindexPrev;
 234             while (pindex->nHeight > pindexSync->nHeight)
 235                 if (!(pindex = pindex->pprev))
 236                     return error("CheckSync: pprev null - block index structure failure");
 237             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 238                 return false; // only descendant of sync-checkpoint can pass check
 239         }
 240         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 241             return false; // same height with sync-checkpoint
 242         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 243             return false; // lower height than sync-checkpoint
 244         return true;
 245     }
 246
 247     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 248     {
 249         LOCK(cs_hashSyncCheckpoint);
 250         if (hashPendingCheckpoint == 0)
 251             return false;
 252         if (hashBlock == hashPendingCheckpoint)
 253             return true;
 254         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 255             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 256             return true;
 257         return false;
 258     }
 259
 260     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 261     bool ResetSyncCheckpoint()
 262     {
 263         LOCK(cs_hashSyncCheckpoint);
 264         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 265         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 266         {
 267             // checkpoint block accepted but not yet in main chain
 268             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 269             CTxDB txdb;
 270             CBlock block;
 271             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 272                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 273             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 274             {
 275                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 276             }
 277
 278 #ifndef USE_LEVELDB
 279             txdb.Close();
 280 #endif
 281
 282         }
 283         else if(!mapBlockIndex.count(hash))
 284         {
 285             // checkpoint block not yet accepted
 286             hashPendingCheckpoint = hash;
 287             checkpointMessagePending.SetNull();
 288             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 289         }
 290
 291         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 292         {
 293             const uint256& hash = i.second.first;
 294             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 295             {
 296                 if (!WriteSyncCheckpoint(hash))
 297                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 298                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 299                 return true;
 300             }
 301         }
 302
 303         return false;
 304     }
 305
 306     void AskForPendingSyncCheckpoint(CNode* pfrom)
 307     {
 308         LOCK(cs_hashSyncCheckpoint);
 309         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 310             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 311     }
 312
 313     bool SetCheckpointPrivKey(std::string strPrivKey)
 314     {
 315         // Test signing a sync-checkpoint with genesis block
 316         CSyncCheckpoint checkpoint;
 317         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 318         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 319         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 320         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 321
 322         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 323         CKey key;
 324         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 325         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 326             return false;
 327
 328         // Test signing successful, proceed
 329         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 330         return true;
 331     }
 332
 333     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 334     {
 335         CSyncCheckpoint checkpoint;
 336         checkpoint.hashCheckpoint = hashCheckpoint;
 337         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 338         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 339         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 340
 341         if (CSyncCheckpoint::strMasterPrivKey.empty())
 342             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 343         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 344         CKey key;
 345         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 346         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 347             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 348
 349         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 350         {
 351             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 352             return false;
 353         }
 354
 355         // Relay checkpoint
 356         {
 357             LOCK(cs_vNodes);
 358             BOOST_FOREACH(CNode* pnode, vNodes)
 359                 checkpoint.RelayTo(pnode);
 360         }
 361         return true;
 362     }
 363
 364     // Is the sync-checkpoint outside maturity window?
 365     bool IsMatureSyncCheckpoint()
 366     {
 367         LOCK(cs_hashSyncCheckpoint);
 368         // sync-checkpoint should always be accepted block
 369         assert(mapBlockIndex.count(hashSyncCheckpoint));
 370         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 371         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 372                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 373     }
 374 }
 375
 376 // ppcoin: sync-checkpoint master key
 377 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 378
 379 std::string CSyncCheckpoint::strMasterPrivKey = "";
 380
 381 // ppcoin: verify signature of sync-checkpoint message
 382 bool CSyncCheckpoint::CheckSignature()
 383 {
 384     CKey key;
 385     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 386         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 387     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 388         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 389
 390     // Now unserialize the data
 391     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 392     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 393     return true;
 394 }
 395
 396 // process synchronized checkpoint
 397 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 398 {
 399     if (!CheckSignature())
 400         return false;
 401
 402     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 403     if (!mapBlockIndex.count(hashCheckpoint))
 404     {
 405         // We haven't received the checkpoint chain, keep the checkpoint as pending
 406         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 407         Checkpoints::checkpointMessagePending = *this;
 408         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 409         // Ask this guy to fill in what we're missing
 410         if (pfrom)
 411         {
 412             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 413             // ask directly as well in case rejected earlier by duplicate
 414             // proof-of-stake because getblocks may not get it this time
 415             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 416         }
 417         return false;
 418     }
 419
 420     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 421         return false;
 422
 423     CTxDB txdb;
 424     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 425     if (!pindexCheckpoint->IsInMainChain())
 426     {
 427         // checkpoint chain received but not yet main chain
 428         CBlock block;
 429         if (!block.ReadFromDisk(pindexCheckpoint))
 430             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 431         if (!block.SetBestChain(txdb, pindexCheckpoint))
 432         {
 433             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 434             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 435         }
 436     }
 437
 438 #ifndef USE_LEVELDB
 439     txdb.Close();
 440 #endif
 441
 442     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 443         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 444     Checkpoints::checkpointMessage = *this;
 445     Checkpoints::hashPendingCheckpoint = 0;
 446     Checkpoints::checkpointMessagePending.SetNull();
 447     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 448     return true;
 449 }