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 #include <algorithm>
   8
   9 #include "checkpoints.h"
  10
  11 #include "txdb.h"
  12 #include "main.h"
  13 #include "uint256.h"
  14
  15 namespace Checkpoints
  16 {
  17     typedef std::map<int, std::pair<uint256, unsigned int> > MapCheckpoints;
  18     typedef std::list<uint256> ListBannedBlocks;
  19
  20     //
  21     // What makes a good checkpoint block?
  22     // + Is surrounded by blocks with reasonable timestamps
  23     //   (no blocks before with a timestamp after, none after with
  24     //    timestamp before)
  25     // + Contains no strange transactions
  26     //
  27     static MapCheckpoints mapCheckpoints =
  28         boost::assign::map_list_of
  29         ( 0,      std::make_pair(hashGenesisBlock, 1360105017) )
  30         ( 13560,  std::make_pair(uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052) )
  31         ( 143990, std::make_pair(uint256("0x00000000001ff5c3940a9f73ad4a990f64955179bde0f743c76dbf0031429efc"), 1418953493) )
  32         ( 149000, std::make_pair(uint256("0x7a24acfcadcf43054e7f7d9f273522c0dfc5791ba4006e0273e7521a8d36c525"), 1420872125) )
  33         ( 160000, std::make_pair(uint256("0x000000000001cb1133043d38d077c0e93f66c8b2566779f10f182137d1e34a68"), 1425150237) )
  34         ( 200000, std::make_pair(uint256("0x0000000000029f8bbf66e6ea6f3e5db55009404aae0fe395a53dd33142b2bff2"), 1441127233) )
  35         ( 221047, std::make_pair(uint256("0xa28aef712e7aa0c285bfe29351ca21ed416689139e3063ef770fc826a8b9e9da"), 1449431646) )
  36         ( 243100, std::make_pair(uint256("0x000000000006522d1ebc0734cb0e6b83f5d4da0c3cbc72bd91b82016f611c4f0"), 1458215793) )
  37         ( 532000, std::make_pair(uint256("0x0000000000018b7eba5e189c41605780c8a855f74144fa837fa05fa4c67b6ba9"), 1569359486) )
  38     ;
  39
  40     static ListBannedBlocks listBanned =
  41         boost::assign::list_of
  42         // Invalid block #221047 with future timestamp of 2016/02/23 09:24:17 UTC
  43         ( uint256("0x46223e5432ceffe650d5729b4bb8479dcdf0ca1e534fa8e69382dc87b42ea94b") )
  44     ;
  45
  46     // TestNet has no checkpoints
  47     static MapCheckpoints mapCheckpointsTestnet =
  48         boost::assign::map_list_of
  49         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  50         ;
  51
  52     bool CheckHardened(int nHeight, const uint256& hash)
  53     {
  54         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  55
  56         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  57         if (i == checkpoints.end()) return true;
  58         return hash == i->second.first;
  59     }
  60
  61     bool CheckBanned(const uint256 &nHash)
  62     {
  63         if (fTestNet) // Testnet has no banned blocks
  64             return true;
  65         ListBannedBlocks::const_iterator it = std::find(listBanned.begin(), listBanned.end(), nHash);
  66         return it == listBanned.end();
  67     }
  68
  69     int GetTotalBlocksEstimate()
  70     {
  71         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  72
  73         return checkpoints.rbegin()->first;
  74     }
  75
  76     unsigned int GetLastCheckpointTime()
  77     {
  78         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  79
  80         return checkpoints.rbegin()->second.second;
  81     }
  82
  83     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  84     {
  85         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  86
  87         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  88         {
  89             const uint256& hash = i.second.first;
  90             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  91             if (t != mapBlockIndex.end())
  92                 return t->second;
  93         }
  94         return NULL;
  95     }
  96
  97     // ppcoin: synchronized checkpoint (centrally broadcasted)
  98     uint256 hashSyncCheckpoint = 0;
  99     uint256 hashPendingCheckpoint = 0;
 100     CSyncCheckpoint checkpointMessage;
 101     CSyncCheckpoint checkpointMessagePending;
 102     uint256 hashInvalidCheckpoint = 0;
 103     CCriticalSection cs_hashSyncCheckpoint;
 104
 105     // ppcoin: get last synchronized checkpoint
 106     CBlockIndex* GetLastSyncCheckpoint()
 107     {
 108         LOCK(cs_hashSyncCheckpoint);
 109         if (!mapBlockIndex.count(hashSyncCheckpoint))
 110             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 111         else
 112             return mapBlockIndex[hashSyncCheckpoint];
 113         return NULL;
 114     }
 115
 116     // ppcoin: only descendant of current sync-checkpoint is allowed
 117     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 118     {
 119         if (!mapBlockIndex.count(hashSyncCheckpoint))
 120             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 121         if (!mapBlockIndex.count(hashCheckpoint))
 122             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 123
 124         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 125         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 126
 127         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 128         {
 129             // Received an older checkpoint, trace back from current checkpoint
 130             // to the same height of the received checkpoint to verify
 131             // that current checkpoint should be a descendant block
 132             CBlockIndex* pindex = pindexSyncCheckpoint;
 133             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 134                 if ((pindex = pindex->pprev) == NULL)
 135                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 136             if (pindex->GetBlockHash() != hashCheckpoint)
 137             {
 138                 hashInvalidCheckpoint = hashCheckpoint;
 139                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 140             }
 141             return false; // ignore older checkpoint
 142         }
 143
 144         // Received checkpoint should be a descendant block of the current
 145         // checkpoint. Trace back to the same height of current checkpoint
 146         // to verify.
 147         CBlockIndex* pindex = pindexCheckpointRecv;
 148         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 149             if ((pindex = pindex->pprev) == NULL)
 150                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 151         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 152         {
 153             hashInvalidCheckpoint = hashCheckpoint;
 154             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 155         }
 156         return true;
 157     }
 158
 159     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 160     {
 161         CTxDB txdb;
 162         txdb.TxnBegin();
 163         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 164         {
 165             txdb.TxnAbort();
 166             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 167         }
 168         if (!txdb.TxnCommit())
 169             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 170
 171 #ifndef USE_LEVELDB
 172         txdb.Close();
 173 #endif
 174
 175         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 176         return true;
 177     }
 178
 179     bool AcceptPendingSyncCheckpoint()
 180     {
 181         LOCK(cs_hashSyncCheckpoint);
 182         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 183         {
 184             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 185             {
 186                 hashPendingCheckpoint = 0;
 187                 checkpointMessagePending.SetNull();
 188                 return false;
 189             }
 190
 191             CTxDB txdb;
 192             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 193             if (!pindexCheckpoint->IsInMainChain())
 194             {
 195                 CBlock block;
 196                 if (!block.ReadFromDisk(pindexCheckpoint))
 197                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 198                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 199                 {
 200                     hashInvalidCheckpoint = hashPendingCheckpoint;
 201                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 202                 }
 203             }
 204
 205 #ifndef USE_LEVELDB
 206             txdb.Close();
 207 #endif
 208             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 209                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 210             hashPendingCheckpoint = 0;
 211             checkpointMessage = checkpointMessagePending;
 212             checkpointMessagePending.SetNull();
 213             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 214             // relay the checkpoint
 215             if (!checkpointMessage.IsNull())
 216             {
 217                 for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
 218                     checkpointMessage.RelayTo(*it);
 219             }
 220             return true;
 221         }
 222         return false;
 223     }
 224
 225     // Automatically select a suitable sync-checkpoint
 226     uint256 AutoSelectSyncCheckpoint()
 227     {
 228         const CBlockIndex *pindex = pindexBest;
 229         // Search backward for a block within max span and maturity window
 230         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 231             pindex = pindex->pprev;
 232         return pindex->GetBlockHash();
 233     }
 234
 235     // Check against synchronized checkpoint
 236     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 237     {
 238         if (fTestNet) return true; // Testnet has no checkpoints
 239         int nHeight = pindexPrev->nHeight + 1;
 240
 241         LOCK(cs_hashSyncCheckpoint);
 242         // sync-checkpoint should always be accepted block
 243         assert(mapBlockIndex.count(hashSyncCheckpoint));
 244         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 245
 246         if (nHeight > pindexSync->nHeight)
 247         {
 248             // trace back to same height as sync-checkpoint
 249             const CBlockIndex* pindex = pindexPrev;
 250             while (pindex->nHeight > pindexSync->nHeight)
 251                 if ((pindex = pindex->pprev) == NULL)
 252                     return error("CheckSync: pprev null - block index structure failure");
 253             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 254                 return false; // only descendant of sync-checkpoint can pass check
 255         }
 256         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 257             return false; // same height with sync-checkpoint
 258         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 259             return false; // lower height than sync-checkpoint
 260         return true;
 261     }
 262
 263     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 264     {
 265         LOCK(cs_hashSyncCheckpoint);
 266         if (hashPendingCheckpoint == 0)
 267             return false;
 268         if (hashBlock == hashPendingCheckpoint)
 269             return true;
 270         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 271             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 272             return true;
 273         return false;
 274     }
 275
 276     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 277     bool ResetSyncCheckpoint()
 278     {
 279         LOCK(cs_hashSyncCheckpoint);
 280         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 281         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 282         {
 283             // checkpoint block accepted but not yet in main chain
 284             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 285             CTxDB txdb;
 286             CBlock block;
 287             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 288                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 289             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 290             {
 291                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 292             }
 293
 294 #ifndef USE_LEVELDB
 295             txdb.Close();
 296 #endif
 297
 298         }
 299         else if(!mapBlockIndex.count(hash))
 300         {
 301             // checkpoint block not yet accepted
 302             hashPendingCheckpoint = hash;
 303             checkpointMessagePending.SetNull();
 304             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 305         }
 306
 307         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 308         {
 309             const uint256& hash = i.second.first;
 310             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 311             {
 312                 if (!WriteSyncCheckpoint(hash))
 313                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 314                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 315                 return true;
 316             }
 317         }
 318
 319         return false;
 320     }
 321
 322     void AskForPendingSyncCheckpoint(CNode* pfrom)
 323     {
 324         LOCK(cs_hashSyncCheckpoint);
 325         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 326             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 327     }
 328
 329     bool SetCheckpointPrivKey(std::string strPrivKey)
 330     {
 331         // Test signing a sync-checkpoint with genesis block
 332         CSyncCheckpoint checkpoint;
 333         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 334         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 335         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 336         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 337
 338         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 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 false;
 343
 344         // Test signing successful, proceed
 345         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 346         return true;
 347     }
 348
 349     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 350     {
 351         CSyncCheckpoint checkpoint;
 352         checkpoint.hashCheckpoint = hashCheckpoint;
 353         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 354         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 355         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 356
 357         if (CSyncCheckpoint::strMasterPrivKey.empty())
 358             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 359         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 360         CKey key;
 361         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 362         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 363             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 364
 365         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 366         {
 367             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 368             return false;
 369         }
 370
 371         // Relay checkpoint
 372         {
 373             LOCK(cs_vNodes);
 374             for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
 375                 checkpoint.RelayTo(*it);
 376         }
 377         return true;
 378     }
 379
 380     // Is the sync-checkpoint outside maturity window?
 381     bool IsMatureSyncCheckpoint()
 382     {
 383         LOCK(cs_hashSyncCheckpoint);
 384         // sync-checkpoint should always be accepted block
 385         assert(mapBlockIndex.count(hashSyncCheckpoint));
 386         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 387         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 388                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 389     }
 390 }
 391
 392 // ppcoin: sync-checkpoint master key
 393 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 394
 395 std::string CSyncCheckpoint::strMasterPrivKey = "";
 396
 397 // ppcoin: verify signature of sync-checkpoint message
 398 bool CSyncCheckpoint::CheckSignature()
 399 {
 400     CPubKey key(ParseHex(CSyncCheckpoint::strMasterPubKey));
 401     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 402         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 403
 404     // Now unserialize the data
 405     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 406     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 407     return true;
 408 }
 409
 410 // process synchronized checkpoint
 411 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 412 {
 413     if (!CheckSignature())
 414         return false;
 415
 416     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 417     if (!mapBlockIndex.count(hashCheckpoint))
 418     {
 419         // We haven't received the checkpoint chain, keep the checkpoint as pending
 420         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 421         Checkpoints::checkpointMessagePending = *this;
 422         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 423         // Ask this guy to fill in what we're missing
 424         if (pfrom)
 425         {
 426             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 427             // ask directly as well in case rejected earlier by duplicate
 428             // proof-of-stake because getblocks may not get it this time
 429             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 430         }
 431         return false;
 432     }
 433
 434     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 435         return false;
 436
 437     CTxDB txdb;
 438     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 439     if (!pindexCheckpoint->IsInMainChain())
 440     {
 441         // checkpoint chain received but not yet main chain
 442         CBlock block;
 443         if (!block.ReadFromDisk(pindexCheckpoint))
 444             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 445         if (!block.SetBestChain(txdb, pindexCheckpoint))
 446         {
 447             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 448             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 449         }
 450     }
 451
 452 #ifndef USE_LEVELDB
 453     txdb.Close();
 454 #endif
 455
 456     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 457         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 458     Checkpoints::checkpointMessage = *this;
 459     Checkpoints::hashPendingCheckpoint = 0;
 460     Checkpoints::checkpointMessagePending.SetNull();
 461     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 462     return true;
 463 }