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         ( 143990, std::make_pair(uint256("0x00000000001ff5c3940a9f73ad4a990f64955179bde0f743c76dbf0031429efc"), 1418953493) )
  37     ;
  38
  39     // TestNet has no checkpoints
  40     static MapCheckpoints mapCheckpointsTestnet =
  41         boost::assign::map_list_of
  42         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  43         ;
  44
  45     bool CheckHardened(int nHeight, const uint256& hash)
  46     {
  47         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  48
  49         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  50         if (i == checkpoints.end()) return true;
  51         return hash == i->second.first;
  52     }
  53
  54     int GetTotalBlocksEstimate()
  55     {
  56         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  57
  58         return checkpoints.rbegin()->first;
  59     }
  60
  61     int GetLastCheckpointTime()
  62     {
  63         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  64
  65         return checkpoints.rbegin()->second.second;
  66     }
  67
  68     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  69     {
  70         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  71
  72         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  73         {
  74             const uint256& hash = i.second.first;
  75             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  76             if (t != mapBlockIndex.end())
  77                 return t->second;
  78         }
  79         return NULL;
  80     }
  81
  82     // ppcoin: synchronized checkpoint (centrally broadcasted)
  83     uint256 hashSyncCheckpoint = 0;
  84     uint256 hashPendingCheckpoint = 0;
  85     CSyncCheckpoint checkpointMessage;
  86     CSyncCheckpoint checkpointMessagePending;
  87     uint256 hashInvalidCheckpoint = 0;
  88     CCriticalSection cs_hashSyncCheckpoint;
  89
  90     // ppcoin: get last synchronized checkpoint
  91     CBlockIndex* GetLastSyncCheckpoint()
  92     {
  93         LOCK(cs_hashSyncCheckpoint);
  94         if (!mapBlockIndex.count(hashSyncCheckpoint))
  95             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
  96         else
  97             return mapBlockIndex[hashSyncCheckpoint];
  98         return NULL;
  99     }
 100
 101     // ppcoin: only descendant of current sync-checkpoint is allowed
 102     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 103     {
 104         if (!mapBlockIndex.count(hashSyncCheckpoint))
 105             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 106         if (!mapBlockIndex.count(hashCheckpoint))
 107             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 108
 109         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 110         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 111
 112         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 113         {
 114             // Received an older checkpoint, trace back from current checkpoint
 115             // to the same height of the received checkpoint to verify
 116             // that current checkpoint should be a descendant block
 117             CBlockIndex* pindex = pindexSyncCheckpoint;
 118             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 119                 if (!(pindex = pindex->pprev))
 120                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 121             if (pindex->GetBlockHash() != hashCheckpoint)
 122             {
 123                 hashInvalidCheckpoint = hashCheckpoint;
 124                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 125             }
 126             return false; // ignore older checkpoint
 127         }
 128
 129         // Received checkpoint should be a descendant block of the current
 130         // checkpoint. Trace back to the same height of current checkpoint
 131         // to verify.
 132         CBlockIndex* pindex = pindexCheckpointRecv;
 133         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 134             if (!(pindex = pindex->pprev))
 135                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 136         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 137         {
 138             hashInvalidCheckpoint = hashCheckpoint;
 139             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 140         }
 141         return true;
 142     }
 143
 144     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 145     {
 146         CTxDB txdb;
 147         txdb.TxnBegin();
 148         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 149         {
 150             txdb.TxnAbort();
 151             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 152         }
 153         if (!txdb.TxnCommit())
 154             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 155
 156 #ifndef USE_LEVELDB
 157         txdb.Close();
 158 #endif
 159
 160         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 161         return true;
 162     }
 163
 164     bool AcceptPendingSyncCheckpoint()
 165     {
 166         LOCK(cs_hashSyncCheckpoint);
 167         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 168         {
 169             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 170             {
 171                 hashPendingCheckpoint = 0;
 172                 checkpointMessagePending.SetNull();
 173                 return false;
 174             }
 175
 176             CTxDB txdb;
 177             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 178             if (!pindexCheckpoint->IsInMainChain())
 179             {
 180                 CBlock block;
 181                 if (!block.ReadFromDisk(pindexCheckpoint))
 182                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 183                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 184                 {
 185                     hashInvalidCheckpoint = hashPendingCheckpoint;
 186                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 187                 }
 188             }
 189
 190 #ifndef USE_LEVELDB
 191             txdb.Close();
 192 #endif
 193             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 194                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 195             hashPendingCheckpoint = 0;
 196             checkpointMessage = checkpointMessagePending;
 197             checkpointMessagePending.SetNull();
 198             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 199             // relay the checkpoint
 200             if (!checkpointMessage.IsNull())
 201             {
 202                 BOOST_FOREACH(CNode* pnode, vNodes)
 203                     checkpointMessage.RelayTo(pnode);
 204             }
 205             return true;
 206         }
 207         return false;
 208     }
 209
 210     // Automatically select a suitable sync-checkpoint
 211     uint256 AutoSelectSyncCheckpoint()
 212     {
 213         const CBlockIndex *pindex = pindexBest;
 214         // Search backward for a block within max span and maturity window
 215         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 216             pindex = pindex->pprev;
 217         return pindex->GetBlockHash();
 218     }
 219
 220     // Check against synchronized checkpoint
 221     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 222     {
 223         if (fTestNet) return true; // Testnet has no checkpoints
 224         int nHeight = pindexPrev->nHeight + 1;
 225
 226         LOCK(cs_hashSyncCheckpoint);
 227         // sync-checkpoint should always be accepted block
 228         assert(mapBlockIndex.count(hashSyncCheckpoint));
 229         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 230
 231         if (nHeight > pindexSync->nHeight)
 232         {
 233             // trace back to same height as sync-checkpoint
 234             const CBlockIndex* pindex = pindexPrev;
 235             while (pindex->nHeight > pindexSync->nHeight)
 236                 if (!(pindex = pindex->pprev))
 237                     return error("CheckSync: pprev null - block index structure failure");
 238             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 239                 return false; // only descendant of sync-checkpoint can pass check
 240         }
 241         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 242             return false; // same height with sync-checkpoint
 243         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 244             return false; // lower height than sync-checkpoint
 245         return true;
 246     }
 247
 248     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 249     {
 250         LOCK(cs_hashSyncCheckpoint);
 251         if (hashPendingCheckpoint == 0)
 252             return false;
 253         if (hashBlock == hashPendingCheckpoint)
 254             return true;
 255         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 256             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 257             return true;
 258         return false;
 259     }
 260
 261     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 262     bool ResetSyncCheckpoint()
 263     {
 264         LOCK(cs_hashSyncCheckpoint);
 265         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 266         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 267         {
 268             // checkpoint block accepted but not yet in main chain
 269             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 270             CTxDB txdb;
 271             CBlock block;
 272             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 273                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 274             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 275             {
 276                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 277             }
 278
 279 #ifndef USE_LEVELDB
 280             txdb.Close();
 281 #endif
 282
 283         }
 284         else if(!mapBlockIndex.count(hash))
 285         {
 286             // checkpoint block not yet accepted
 287             hashPendingCheckpoint = hash;
 288             checkpointMessagePending.SetNull();
 289             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 290         }
 291
 292         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 293         {
 294             const uint256& hash = i.second.first;
 295             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 296             {
 297                 if (!WriteSyncCheckpoint(hash))
 298                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 299                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 300                 return true;
 301             }
 302         }
 303
 304         return false;
 305     }
 306
 307     void AskForPendingSyncCheckpoint(CNode* pfrom)
 308     {
 309         LOCK(cs_hashSyncCheckpoint);
 310         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 311             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 312     }
 313
 314     bool SetCheckpointPrivKey(std::string strPrivKey)
 315     {
 316         // Test signing a sync-checkpoint with genesis block
 317         CSyncCheckpoint checkpoint;
 318         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 319         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 320         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 321         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 322
 323         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 324         CKey key;
 325         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 326         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 327             return false;
 328
 329         // Test signing successful, proceed
 330         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 331         return true;
 332     }
 333
 334     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 335     {
 336         CSyncCheckpoint checkpoint;
 337         checkpoint.hashCheckpoint = hashCheckpoint;
 338         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 339         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 340         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 341
 342         if (CSyncCheckpoint::strMasterPrivKey.empty())
 343             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 344         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 345         CKey key;
 346         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 347         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 348             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 349
 350         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 351         {
 352             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 353             return false;
 354         }
 355
 356         // Relay checkpoint
 357         {
 358             LOCK(cs_vNodes);
 359             BOOST_FOREACH(CNode* pnode, vNodes)
 360                 checkpoint.RelayTo(pnode);
 361         }
 362         return true;
 363     }
 364
 365     // Is the sync-checkpoint outside maturity window?
 366     bool IsMatureSyncCheckpoint()
 367     {
 368         LOCK(cs_hashSyncCheckpoint);
 369         // sync-checkpoint should always be accepted block
 370         assert(mapBlockIndex.count(hashSyncCheckpoint));
 371         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 372         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 373                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 374     }
 375 }
 376
 377 // ppcoin: sync-checkpoint master key
 378 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 379
 380 std::string CSyncCheckpoint::strMasterPrivKey = "";
 381
 382 // ppcoin: verify signature of sync-checkpoint message
 383 bool CSyncCheckpoint::CheckSignature()
 384 {
 385     CKey key;
 386     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 387         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 388     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 389         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 390
 391     // Now unserialize the data
 392     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 393     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 394     return true;
 395 }
 396
 397 // process synchronized checkpoint
 398 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 399 {
 400     if (!CheckSignature())
 401         return false;
 402
 403     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 404     if (!mapBlockIndex.count(hashCheckpoint))
 405     {
 406         // We haven't received the checkpoint chain, keep the checkpoint as pending
 407         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 408         Checkpoints::checkpointMessagePending = *this;
 409         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 410         // Ask this guy to fill in what we're missing
 411         if (pfrom)
 412         {
 413             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 414             // ask directly as well in case rejected earlier by duplicate
 415             // proof-of-stake because getblocks may not get it this time
 416             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 417         }
 418         return false;
 419     }
 420
 421     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 422         return false;
 423
 424     CTxDB txdb;
 425     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 426     if (!pindexCheckpoint->IsInMainChain())
 427     {
 428         // checkpoint chain received but not yet main chain
 429         CBlock block;
 430         if (!block.ReadFromDisk(pindexCheckpoint))
 431             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 432         if (!block.SetBestChain(txdb, pindexCheckpoint))
 433         {
 434             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 435             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 436         }
 437     }
 438
 439 #ifndef USE_LEVELDB
 440     txdb.Close();
 441 #endif
 442
 443     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 444         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 445     Checkpoints::checkpointMessage = *this;
 446     Checkpoints::hashPendingCheckpoint = 0;
 447     Checkpoints::checkpointMessagePending.SetNull();
 448     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 449     return true;
 450 }