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     ;
  37
  38     static ListBannedBlocks listBanned =
  39         boost::assign::list_of
  40         // Invalid block #221047 with future timestamp of 2016/02/23 09:24:17 UTC
  41         ( uint256("0x46223e5432ceffe650d5729b4bb8479dcdf0ca1e534fa8e69382dc87b42ea94b") )
  42     ;
  43
  44     // TestNet has no checkpoints
  45     static MapCheckpoints mapCheckpointsTestnet =
  46         boost::assign::map_list_of
  47         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  48         ;
  49
  50     bool CheckHardened(int nHeight, const uint256& hash)
  51     {
  52         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  53
  54         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  55         if (i == checkpoints.end()) return true;
  56         return hash == i->second.first;
  57     }
  58
  59     bool CheckBanned(const uint256 &nHash)
  60     {
  61         if (fTestNet) // Testnet has no banned blocks
  62             return true;
  63         ListBannedBlocks::const_iterator it = std::find(listBanned.begin(), listBanned.end(), nHash);
  64         return it == listBanned.end();
  65     }
  66
  67     int GetTotalBlocksEstimate()
  68     {
  69         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  70
  71         return checkpoints.rbegin()->first;
  72     }
  73
  74     unsigned int GetLastCheckpointTime()
  75     {
  76         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  77
  78         return checkpoints.rbegin()->second.second;
  79     }
  80
  81     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  82     {
  83         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  84
  85         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  86         {
  87             const uint256& hash = i.second.first;
  88             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  89             if (t != mapBlockIndex.end())
  90                 return t->second;
  91         }
  92         return NULL;
  93     }
  94
  95     // ppcoin: synchronized checkpoint (centrally broadcasted)
  96     uint256 hashSyncCheckpoint = 0;
  97     uint256 hashPendingCheckpoint = 0;
  98     CSyncCheckpoint checkpointMessage;
  99     CSyncCheckpoint checkpointMessagePending;
 100     uint256 hashInvalidCheckpoint = 0;
 101     CCriticalSection cs_hashSyncCheckpoint;
 102
 103     // ppcoin: get last synchronized checkpoint
 104     CBlockIndex* GetLastSyncCheckpoint()
 105     {
 106         LOCK(cs_hashSyncCheckpoint);
 107         if (!mapBlockIndex.count(hashSyncCheckpoint))
 108             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 109         else
 110             return mapBlockIndex[hashSyncCheckpoint];
 111         return NULL;
 112     }
 113
 114     // ppcoin: only descendant of current sync-checkpoint is allowed
 115     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 116     {
 117         if (!mapBlockIndex.count(hashSyncCheckpoint))
 118             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 119         if (!mapBlockIndex.count(hashCheckpoint))
 120             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 121
 122         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 123         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 124
 125         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 126         {
 127             // Received an older checkpoint, trace back from current checkpoint
 128             // to the same height of the received checkpoint to verify
 129             // that current checkpoint should be a descendant block
 130             CBlockIndex* pindex = pindexSyncCheckpoint;
 131             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 132                 if (!(pindex = pindex->pprev))
 133                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 134             if (pindex->GetBlockHash() != hashCheckpoint)
 135             {
 136                 hashInvalidCheckpoint = hashCheckpoint;
 137                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 138             }
 139             return false; // ignore older checkpoint
 140         }
 141
 142         // Received checkpoint should be a descendant block of the current
 143         // checkpoint. Trace back to the same height of current checkpoint
 144         // to verify.
 145         CBlockIndex* pindex = pindexCheckpointRecv;
 146         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 147             if (!(pindex = pindex->pprev))
 148                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 149         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 150         {
 151             hashInvalidCheckpoint = hashCheckpoint;
 152             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 153         }
 154         return true;
 155     }
 156
 157     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 158     {
 159         CTxDB txdb;
 160         txdb.TxnBegin();
 161         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 162         {
 163             txdb.TxnAbort();
 164             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 165         }
 166         if (!txdb.TxnCommit())
 167             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 168
 169 #ifndef USE_LEVELDB
 170         txdb.Close();
 171 #endif
 172
 173         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 174         return true;
 175     }
 176
 177     bool AcceptPendingSyncCheckpoint()
 178     {
 179         LOCK(cs_hashSyncCheckpoint);
 180         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 181         {
 182             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 183             {
 184                 hashPendingCheckpoint = 0;
 185                 checkpointMessagePending.SetNull();
 186                 return false;
 187             }
 188
 189             CTxDB txdb;
 190             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 191             if (!pindexCheckpoint->IsInMainChain())
 192             {
 193                 CBlock block;
 194                 if (!block.ReadFromDisk(pindexCheckpoint))
 195                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 196                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 197                 {
 198                     hashInvalidCheckpoint = hashPendingCheckpoint;
 199                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 200                 }
 201             }
 202
 203 #ifndef USE_LEVELDB
 204             txdb.Close();
 205 #endif
 206             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 207                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 208             hashPendingCheckpoint = 0;
 209             checkpointMessage = checkpointMessagePending;
 210             checkpointMessagePending.SetNull();
 211             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 212             // relay the checkpoint
 213             if (!checkpointMessage.IsNull())
 214             {
 215                 BOOST_FOREACH(CNode* pnode, vNodes)
 216                     checkpointMessage.RelayTo(pnode);
 217             }
 218             return true;
 219         }
 220         return false;
 221     }
 222
 223     // Automatically select a suitable sync-checkpoint
 224     uint256 AutoSelectSyncCheckpoint()
 225     {
 226         const CBlockIndex *pindex = pindexBest;
 227         // Search backward for a block within max span and maturity window
 228         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 229             pindex = pindex->pprev;
 230         return pindex->GetBlockHash();
 231     }
 232
 233     // Check against synchronized checkpoint
 234     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 235     {
 236         if (fTestNet) return true; // Testnet has no checkpoints
 237         int nHeight = pindexPrev->nHeight + 1;
 238
 239         LOCK(cs_hashSyncCheckpoint);
 240         // sync-checkpoint should always be accepted block
 241         assert(mapBlockIndex.count(hashSyncCheckpoint));
 242         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 243
 244         if (nHeight > pindexSync->nHeight)
 245         {
 246             // trace back to same height as sync-checkpoint
 247             const CBlockIndex* pindex = pindexPrev;
 248             while (pindex->nHeight > pindexSync->nHeight)
 249                 if (!(pindex = pindex->pprev))
 250                     return error("CheckSync: pprev null - block index structure failure");
 251             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 252                 return false; // only descendant of sync-checkpoint can pass check
 253         }
 254         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 255             return false; // same height with sync-checkpoint
 256         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 257             return false; // lower height than sync-checkpoint
 258         return true;
 259     }
 260
 261     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 262     {
 263         LOCK(cs_hashSyncCheckpoint);
 264         if (hashPendingCheckpoint == 0)
 265             return false;
 266         if (hashBlock == hashPendingCheckpoint)
 267             return true;
 268         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 269             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 270             return true;
 271         return false;
 272     }
 273
 274     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 275     bool ResetSyncCheckpoint()
 276     {
 277         LOCK(cs_hashSyncCheckpoint);
 278         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 279         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 280         {
 281             // checkpoint block accepted but not yet in main chain
 282             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 283             CTxDB txdb;
 284             CBlock block;
 285             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 286                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 287             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 288             {
 289                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 290             }
 291
 292 #ifndef USE_LEVELDB
 293             txdb.Close();
 294 #endif
 295
 296         }
 297         else if(!mapBlockIndex.count(hash))
 298         {
 299             // checkpoint block not yet accepted
 300             hashPendingCheckpoint = hash;
 301             checkpointMessagePending.SetNull();
 302             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 303         }
 304
 305         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 306         {
 307             const uint256& hash = i.second.first;
 308             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 309             {
 310                 if (!WriteSyncCheckpoint(hash))
 311                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 312                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 313                 return true;
 314             }
 315         }
 316
 317         return false;
 318     }
 319
 320     void AskForPendingSyncCheckpoint(CNode* pfrom)
 321     {
 322         LOCK(cs_hashSyncCheckpoint);
 323         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 324             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 325     }
 326
 327     bool SetCheckpointPrivKey(std::string strPrivKey)
 328     {
 329         // Test signing a sync-checkpoint with genesis block
 330         CSyncCheckpoint checkpoint;
 331         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 332         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 333         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 334         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 335
 336         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 337         CKey key;
 338         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 339         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 340             return false;
 341
 342         // Test signing successful, proceed
 343         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 344         return true;
 345     }
 346
 347     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 348     {
 349         CSyncCheckpoint checkpoint;
 350         checkpoint.hashCheckpoint = hashCheckpoint;
 351         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 352         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 353         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 354
 355         if (CSyncCheckpoint::strMasterPrivKey.empty())
 356             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 357         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 358         CKey key;
 359         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 360         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 361             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 362
 363         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 364         {
 365             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 366             return false;
 367         }
 368
 369         // Relay checkpoint
 370         {
 371             LOCK(cs_vNodes);
 372             BOOST_FOREACH(CNode* pnode, vNodes)
 373                 checkpoint.RelayTo(pnode);
 374         }
 375         return true;
 376     }
 377
 378     // Is the sync-checkpoint outside maturity window?
 379     bool IsMatureSyncCheckpoint()
 380     {
 381         LOCK(cs_hashSyncCheckpoint);
 382         // sync-checkpoint should always be accepted block
 383         assert(mapBlockIndex.count(hashSyncCheckpoint));
 384         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 385         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 386                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 387     }
 388 }
 389
 390 // ppcoin: sync-checkpoint master key
 391 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 392
 393 std::string CSyncCheckpoint::strMasterPrivKey = "";
 394
 395 // ppcoin: verify signature of sync-checkpoint message
 396 bool CSyncCheckpoint::CheckSignature()
 397 {
 398     CKey key;
 399     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 400         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 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 }