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         ( 13560, std::make_pair(uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052) )
  29         ( 143990, std::make_pair(uint256("0x00000000001ff5c3940a9f73ad4a990f64955179bde0f743c76dbf0031429efc"), 1418953493) )
  30         ( 149000, std::make_pair(uint256("0x7a24acfcadcf43054e7f7d9f273522c0dfc5791ba4006e0273e7521a8d36c525"), 1420872125) )
  31     ;
  32
  33     // TestNet has no checkpoints
  34     static MapCheckpoints mapCheckpointsTestnet =
  35         boost::assign::map_list_of
  36         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  37         ;
  38
  39     bool CheckHardened(int nHeight, const uint256& hash)
  40     {
  41         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  42
  43         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  44         if (i == checkpoints.end()) return true;
  45         return hash == i->second.first;
  46     }
  47
  48     int GetTotalBlocksEstimate()
  49     {
  50         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  51
  52         return checkpoints.rbegin()->first;
  53     }
  54
  55     unsigned int GetLastCheckpointTime()
  56     {
  57         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  58
  59         return checkpoints.rbegin()->second.second;
  60     }
  61
  62     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  63     {
  64         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  65
  66         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  67         {
  68             const uint256& hash = i.second.first;
  69             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  70             if (t != mapBlockIndex.end())
  71                 return t->second;
  72         }
  73         return NULL;
  74     }
  75
  76     // ppcoin: synchronized checkpoint (centrally broadcasted)
  77     uint256 hashSyncCheckpoint = 0;
  78     uint256 hashPendingCheckpoint = 0;
  79     CSyncCheckpoint checkpointMessage;
  80     CSyncCheckpoint checkpointMessagePending;
  81     uint256 hashInvalidCheckpoint = 0;
  82     CCriticalSection cs_hashSyncCheckpoint;
  83
  84     // ppcoin: get last synchronized checkpoint
  85     CBlockIndex* GetLastSyncCheckpoint()
  86     {
  87         LOCK(cs_hashSyncCheckpoint);
  88         if (!mapBlockIndex.count(hashSyncCheckpoint))
  89             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
  90         else
  91             return mapBlockIndex[hashSyncCheckpoint];
  92         return NULL;
  93     }
  94
  95     // ppcoin: only descendant of current sync-checkpoint is allowed
  96     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
  97     {
  98         if (!mapBlockIndex.count(hashSyncCheckpoint))
  99             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 100         if (!mapBlockIndex.count(hashCheckpoint))
 101             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 102
 103         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 104         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 105
 106         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 107         {
 108             // Received an older checkpoint, trace back from current checkpoint
 109             // to the same height of the received checkpoint to verify
 110             // that current checkpoint should be a descendant block
 111             CBlockIndex* pindex = pindexSyncCheckpoint;
 112             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 113                 if (!(pindex = pindex->pprev))
 114                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 115             if (pindex->GetBlockHash() != hashCheckpoint)
 116             {
 117                 hashInvalidCheckpoint = hashCheckpoint;
 118                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 119             }
 120             return false; // ignore older checkpoint
 121         }
 122
 123         // Received checkpoint should be a descendant block of the current
 124         // checkpoint. Trace back to the same height of current checkpoint
 125         // to verify.
 126         CBlockIndex* pindex = pindexCheckpointRecv;
 127         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 128             if (!(pindex = pindex->pprev))
 129                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 130         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 131         {
 132             hashInvalidCheckpoint = hashCheckpoint;
 133             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 134         }
 135         return true;
 136     }
 137
 138     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 139     {
 140         CTxDB txdb;
 141         txdb.TxnBegin();
 142         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 143         {
 144             txdb.TxnAbort();
 145             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 146         }
 147         if (!txdb.TxnCommit())
 148             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 149
 150 #ifndef USE_LEVELDB
 151         txdb.Close();
 152 #endif
 153
 154         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 155         return true;
 156     }
 157
 158     bool AcceptPendingSyncCheckpoint()
 159     {
 160         LOCK(cs_hashSyncCheckpoint);
 161         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 162         {
 163             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 164             {
 165                 hashPendingCheckpoint = 0;
 166                 checkpointMessagePending.SetNull();
 167                 return false;
 168             }
 169
 170             CTxDB txdb;
 171             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 172             if (!pindexCheckpoint->IsInMainChain())
 173             {
 174                 CBlock block;
 175                 if (!block.ReadFromDisk(pindexCheckpoint))
 176                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 177                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 178                 {
 179                     hashInvalidCheckpoint = hashPendingCheckpoint;
 180                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 181                 }
 182             }
 183
 184 #ifndef USE_LEVELDB
 185             txdb.Close();
 186 #endif
 187             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 188                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 189             hashPendingCheckpoint = 0;
 190             checkpointMessage = checkpointMessagePending;
 191             checkpointMessagePending.SetNull();
 192             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 193             // relay the checkpoint
 194             if (!checkpointMessage.IsNull())
 195             {
 196                 BOOST_FOREACH(CNode* pnode, vNodes)
 197                     checkpointMessage.RelayTo(pnode);
 198             }
 199             return true;
 200         }
 201         return false;
 202     }
 203
 204     // Automatically select a suitable sync-checkpoint
 205     uint256 AutoSelectSyncCheckpoint()
 206     {
 207         const CBlockIndex *pindex = pindexBest;
 208         // Search backward for a block within max span and maturity window
 209         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 210             pindex = pindex->pprev;
 211         return pindex->GetBlockHash();
 212     }
 213
 214     // Check against synchronized checkpoint
 215     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 216     {
 217         if (fTestNet) return true; // Testnet has no checkpoints
 218         int nHeight = pindexPrev->nHeight + 1;
 219
 220         LOCK(cs_hashSyncCheckpoint);
 221         // sync-checkpoint should always be accepted block
 222         assert(mapBlockIndex.count(hashSyncCheckpoint));
 223         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 224
 225         if (nHeight > pindexSync->nHeight)
 226         {
 227             // trace back to same height as sync-checkpoint
 228             const CBlockIndex* pindex = pindexPrev;
 229             while (pindex->nHeight > pindexSync->nHeight)
 230                 if (!(pindex = pindex->pprev))
 231                     return error("CheckSync: pprev null - block index structure failure");
 232             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 233                 return false; // only descendant of sync-checkpoint can pass check
 234         }
 235         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 236             return false; // same height with sync-checkpoint
 237         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 238             return false; // lower height than sync-checkpoint
 239         return true;
 240     }
 241
 242     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 243     {
 244         LOCK(cs_hashSyncCheckpoint);
 245         if (hashPendingCheckpoint == 0)
 246             return false;
 247         if (hashBlock == hashPendingCheckpoint)
 248             return true;
 249         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 250             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 251             return true;
 252         return false;
 253     }
 254
 255     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 256     bool ResetSyncCheckpoint()
 257     {
 258         LOCK(cs_hashSyncCheckpoint);
 259         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 260         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 261         {
 262             // checkpoint block accepted but not yet in main chain
 263             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 264             CTxDB txdb;
 265             CBlock block;
 266             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 267                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 268             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 269             {
 270                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 271             }
 272
 273 #ifndef USE_LEVELDB
 274             txdb.Close();
 275 #endif
 276
 277         }
 278         else if(!mapBlockIndex.count(hash))
 279         {
 280             // checkpoint block not yet accepted
 281             hashPendingCheckpoint = hash;
 282             checkpointMessagePending.SetNull();
 283             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 284         }
 285
 286         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 287         {
 288             const uint256& hash = i.second.first;
 289             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 290             {
 291                 if (!WriteSyncCheckpoint(hash))
 292                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 293                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 294                 return true;
 295             }
 296         }
 297
 298         return false;
 299     }
 300
 301     void AskForPendingSyncCheckpoint(CNode* pfrom)
 302     {
 303         LOCK(cs_hashSyncCheckpoint);
 304         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 305             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 306     }
 307
 308     bool SetCheckpointPrivKey(std::string strPrivKey)
 309     {
 310         // Test signing a sync-checkpoint with genesis block
 311         CSyncCheckpoint checkpoint;
 312         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 313         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 314         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 315         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 316
 317         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 318         CKey key;
 319         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 320         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 321             return false;
 322
 323         // Test signing successful, proceed
 324         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 325         return true;
 326     }
 327
 328     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 329     {
 330         CSyncCheckpoint checkpoint;
 331         checkpoint.hashCheckpoint = hashCheckpoint;
 332         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 333         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 334         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 335
 336         if (CSyncCheckpoint::strMasterPrivKey.empty())
 337             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 338         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 339         CKey key;
 340         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 341         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 342             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 343
 344         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 345         {
 346             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 347             return false;
 348         }
 349
 350         // Relay checkpoint
 351         {
 352             LOCK(cs_vNodes);
 353             BOOST_FOREACH(CNode* pnode, vNodes)
 354                 checkpoint.RelayTo(pnode);
 355         }
 356         return true;
 357     }
 358
 359     // Is the sync-checkpoint outside maturity window?
 360     bool IsMatureSyncCheckpoint()
 361     {
 362         LOCK(cs_hashSyncCheckpoint);
 363         // sync-checkpoint should always be accepted block
 364         assert(mapBlockIndex.count(hashSyncCheckpoint));
 365         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 366         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 367                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 368     }
 369 }
 370
 371 // ppcoin: sync-checkpoint master key
 372 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 373
 374 std::string CSyncCheckpoint::strMasterPrivKey = "";
 375
 376 // ppcoin: verify signature of sync-checkpoint message
 377 bool CSyncCheckpoint::CheckSignature()
 378 {
 379     CKey key;
 380     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 381         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 382     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 383         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 384
 385     // Now unserialize the data
 386     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 387     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 388     return true;
 389 }
 390
 391 // process synchronized checkpoint
 392 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 393 {
 394     if (!CheckSignature())
 395         return false;
 396
 397     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 398     if (!mapBlockIndex.count(hashCheckpoint))
 399     {
 400         // We haven't received the checkpoint chain, keep the checkpoint as pending
 401         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 402         Checkpoints::checkpointMessagePending = *this;
 403         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 404         // Ask this guy to fill in what we're missing
 405         if (pfrom)
 406         {
 407             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 408             // ask directly as well in case rejected earlier by duplicate
 409             // proof-of-stake because getblocks may not get it this time
 410             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 411         }
 412         return false;
 413     }
 414
 415     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 416         return false;
 417
 418     CTxDB txdb;
 419     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 420     if (!pindexCheckpoint->IsInMainChain())
 421     {
 422         // checkpoint chain received but not yet main chain
 423         CBlock block;
 424         if (!block.ReadFromDisk(pindexCheckpoint))
 425             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 426         if (!block.SetBestChain(txdb, pindexCheckpoint))
 427         {
 428             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 429             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 430         }
 431     }
 432
 433 #ifndef USE_LEVELDB
 434     txdb.Close();
 435 #endif
 436
 437     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 438         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 439     Checkpoints::checkpointMessage = *this;
 440     Checkpoints::hashPendingCheckpoint = 0;
 441     Checkpoints::checkpointMessagePending.SetNull();
 442     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 443     return true;
 444 }