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     ;
  38
  39     static ListBannedBlocks listBanned =
  40         boost::assign::list_of
  41         // Invalid block #221047 with future timestamp of 2016/02/23 09:24:17 UTC
  42         ( uint256("0x46223e5432ceffe650d5729b4bb8479dcdf0ca1e534fa8e69382dc87b42ea94b") )
  43     ;
  44
  45     // TestNet has no checkpoints
  46     static MapCheckpoints mapCheckpointsTestnet =
  47         boost::assign::map_list_of
  48         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  49         ;
  50
  51     bool CheckHardened(int nHeight, const uint256& hash)
  52     {
  53         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  54
  55         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  56         if (i == checkpoints.end()) return true;
  57         return hash == i->second.first;
  58     }
  59
  60     bool CheckBanned(const uint256 &nHash)
  61     {
  62         if (fTestNet) // Testnet has no banned blocks
  63             return true;
  64         ListBannedBlocks::const_iterator it = std::find(listBanned.begin(), listBanned.end(), nHash);
  65         return it == listBanned.end();
  66     }
  67
  68     int GetTotalBlocksEstimate()
  69     {
  70         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  71
  72         return checkpoints.rbegin()->first;
  73     }
  74
  75     unsigned int GetLastCheckpointTime()
  76     {
  77         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  78
  79         return checkpoints.rbegin()->second.second;
  80     }
  81
  82     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  83     {
  84         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  85
  86         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  87         {
  88             const uint256& hash = i.second.first;
  89             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  90             if (t != mapBlockIndex.end())
  91                 return t->second;
  92         }
  93         return NULL;
  94     }
  95
  96     // ppcoin: synchronized checkpoint (centrally broadcasted)
  97     uint256 hashSyncCheckpoint = 0;
  98     uint256 hashPendingCheckpoint = 0;
  99     CSyncCheckpoint checkpointMessage;
 100     CSyncCheckpoint checkpointMessagePending;
 101     uint256 hashInvalidCheckpoint = 0;
 102     CCriticalSection cs_hashSyncCheckpoint;
 103
 104     // ppcoin: get last synchronized checkpoint
 105     CBlockIndex* GetLastSyncCheckpoint()
 106     {
 107         LOCK(cs_hashSyncCheckpoint);
 108         if (!mapBlockIndex.count(hashSyncCheckpoint))
 109             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 110         else
 111             return mapBlockIndex[hashSyncCheckpoint];
 112         return NULL;
 113     }
 114
 115     // ppcoin: only descendant of current sync-checkpoint is allowed
 116     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 117     {
 118         if (!mapBlockIndex.count(hashSyncCheckpoint))
 119             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 120         if (!mapBlockIndex.count(hashCheckpoint))
 121             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 122
 123         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 124         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 125
 126         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 127         {
 128             // Received an older checkpoint, trace back from current checkpoint
 129             // to the same height of the received checkpoint to verify
 130             // that current checkpoint should be a descendant block
 131             CBlockIndex* pindex = pindexSyncCheckpoint;
 132             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 133                 if ((pindex = pindex->pprev) == NULL)
 134                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 135             if (pindex->GetBlockHash() != hashCheckpoint)
 136             {
 137                 hashInvalidCheckpoint = hashCheckpoint;
 138                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 139             }
 140             return false; // ignore older checkpoint
 141         }
 142
 143         // Received checkpoint should be a descendant block of the current
 144         // checkpoint. Trace back to the same height of current checkpoint
 145         // to verify.
 146         CBlockIndex* pindex = pindexCheckpointRecv;
 147         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 148             if ((pindex = pindex->pprev) == NULL)
 149                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 150         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 151         {
 152             hashInvalidCheckpoint = hashCheckpoint;
 153             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 154         }
 155         return true;
 156     }
 157
 158     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 159     {
 160         CTxDB txdb;
 161         txdb.TxnBegin();
 162         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 163         {
 164             txdb.TxnAbort();
 165             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 166         }
 167         if (!txdb.TxnCommit())
 168             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 169
 170 #ifndef USE_LEVELDB
 171         txdb.Close();
 172 #endif
 173
 174         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 175         return true;
 176     }
 177
 178     bool AcceptPendingSyncCheckpoint()
 179     {
 180         LOCK(cs_hashSyncCheckpoint);
 181         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 182         {
 183             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 184             {
 185                 hashPendingCheckpoint = 0;
 186                 checkpointMessagePending.SetNull();
 187                 return false;
 188             }
 189
 190             CTxDB txdb;
 191             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 192             if (!pindexCheckpoint->IsInMainChain())
 193             {
 194                 CBlock block;
 195                 if (!block.ReadFromDisk(pindexCheckpoint))
 196                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 197                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 198                 {
 199                     hashInvalidCheckpoint = hashPendingCheckpoint;
 200                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 201                 }
 202             }
 203
 204 #ifndef USE_LEVELDB
 205             txdb.Close();
 206 #endif
 207             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 208                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 209             hashPendingCheckpoint = 0;
 210             checkpointMessage = checkpointMessagePending;
 211             checkpointMessagePending.SetNull();
 212             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 213             // relay the checkpoint
 214             if (!checkpointMessage.IsNull())
 215             {
 216                 BOOST_FOREACH(CNode* pnode, vNodes)
 217                     checkpointMessage.RelayTo(pnode);
 218             }
 219             return true;
 220         }
 221         return false;
 222     }
 223
 224     // Automatically select a suitable sync-checkpoint
 225     uint256 AutoSelectSyncCheckpoint()
 226     {
 227         const CBlockIndex *pindex = pindexBest;
 228         // Search backward for a block within max span and maturity window
 229         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 230             pindex = pindex->pprev;
 231         return pindex->GetBlockHash();
 232     }
 233
 234     // Check against synchronized checkpoint
 235     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 236     {
 237         if (fTestNet) return true; // Testnet has no checkpoints
 238         int nHeight = pindexPrev->nHeight + 1;
 239
 240         LOCK(cs_hashSyncCheckpoint);
 241         // sync-checkpoint should always be accepted block
 242         assert(mapBlockIndex.count(hashSyncCheckpoint));
 243         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 244
 245         if (nHeight > pindexSync->nHeight)
 246         {
 247             // trace back to same height as sync-checkpoint
 248             const CBlockIndex* pindex = pindexPrev;
 249             while (pindex->nHeight > pindexSync->nHeight)
 250                 if ((pindex = pindex->pprev) == NULL)
 251                     return error("CheckSync: pprev null - block index structure failure");
 252             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 253                 return false; // only descendant of sync-checkpoint can pass check
 254         }
 255         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 256             return false; // same height with sync-checkpoint
 257         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 258             return false; // lower height than sync-checkpoint
 259         return true;
 260     }
 261
 262     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 263     {
 264         LOCK(cs_hashSyncCheckpoint);
 265         if (hashPendingCheckpoint == 0)
 266             return false;
 267         if (hashBlock == hashPendingCheckpoint)
 268             return true;
 269         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 270             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 271             return true;
 272         return false;
 273     }
 274
 275     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 276     bool ResetSyncCheckpoint()
 277     {
 278         LOCK(cs_hashSyncCheckpoint);
 279         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 280         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 281         {
 282             // checkpoint block accepted but not yet in main chain
 283             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 284             CTxDB txdb;
 285             CBlock block;
 286             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 287                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 288             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 289             {
 290                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 291             }
 292
 293 #ifndef USE_LEVELDB
 294             txdb.Close();
 295 #endif
 296
 297         }
 298         else if(!mapBlockIndex.count(hash))
 299         {
 300             // checkpoint block not yet accepted
 301             hashPendingCheckpoint = hash;
 302             checkpointMessagePending.SetNull();
 303             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 304         }
 305
 306         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 307         {
 308             const uint256& hash = i.second.first;
 309             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 310             {
 311                 if (!WriteSyncCheckpoint(hash))
 312                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 313                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 314                 return true;
 315             }
 316         }
 317
 318         return false;
 319     }
 320
 321     void AskForPendingSyncCheckpoint(CNode* pfrom)
 322     {
 323         LOCK(cs_hashSyncCheckpoint);
 324         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 325             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 326     }
 327
 328     bool SetCheckpointPrivKey(std::string strPrivKey)
 329     {
 330         // Test signing a sync-checkpoint with genesis block
 331         CSyncCheckpoint checkpoint;
 332         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 333         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 334         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 335         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 336
 337         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 338         CKey key;
 339         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 340         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 341             return false;
 342
 343         // Test signing successful, proceed
 344         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 345         return true;
 346     }
 347
 348     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 349     {
 350         CSyncCheckpoint checkpoint;
 351         checkpoint.hashCheckpoint = hashCheckpoint;
 352         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 353         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 354         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 355
 356         if (CSyncCheckpoint::strMasterPrivKey.empty())
 357             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 358         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 359         CKey key;
 360         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 361         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 362             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 363
 364         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 365         {
 366             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 367             return false;
 368         }
 369
 370         // Relay checkpoint
 371         {
 372             LOCK(cs_vNodes);
 373             BOOST_FOREACH(CNode* pnode, vNodes)
 374                 checkpoint.RelayTo(pnode);
 375         }
 376         return true;
 377     }
 378
 379     // Is the sync-checkpoint outside maturity window?
 380     bool IsMatureSyncCheckpoint()
 381     {
 382         LOCK(cs_hashSyncCheckpoint);
 383         // sync-checkpoint should always be accepted block
 384         assert(mapBlockIndex.count(hashSyncCheckpoint));
 385         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 386         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 387                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 388     }
 389 }
 390
 391 // ppcoin: sync-checkpoint master key
 392 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 393
 394 std::string CSyncCheckpoint::strMasterPrivKey = "";
 395
 396 // ppcoin: verify signature of sync-checkpoint message
 397 bool CSyncCheckpoint::CheckSignature()
 398 {
 399     CKey key;
 400     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 401         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 402     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 403         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 404
 405     // Now unserialize the data
 406     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 407     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 408     return true;
 409 }
 410
 411 // process synchronized checkpoint
 412 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 413 {
 414     if (!CheckSignature())
 415         return false;
 416
 417     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 418     if (!mapBlockIndex.count(hashCheckpoint))
 419     {
 420         // We haven't received the checkpoint chain, keep the checkpoint as pending
 421         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 422         Checkpoints::checkpointMessagePending = *this;
 423         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 424         // Ask this guy to fill in what we're missing
 425         if (pfrom)
 426         {
 427             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 428             // ask directly as well in case rejected earlier by duplicate
 429             // proof-of-stake because getblocks may not get it this time
 430             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 431         }
 432         return false;
 433     }
 434
 435     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 436         return false;
 437
 438     CTxDB txdb;
 439     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 440     if (!pindexCheckpoint->IsInMainChain())
 441     {
 442         // checkpoint chain received but not yet main chain
 443         CBlock block;
 444         if (!block.ReadFromDisk(pindexCheckpoint))
 445             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 446         if (!block.SetBestChain(txdb, pindexCheckpoint))
 447         {
 448             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 449             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 450         }
 451     }
 452
 453 #ifndef USE_LEVELDB
 454     txdb.Close();
 455 #endif
 456
 457     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 458         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 459     Checkpoints::checkpointMessage = *this;
 460     Checkpoints::hashPendingCheckpoint = 0;
 461     Checkpoints::checkpointMessagePending.SetNull();
 462     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 463     return true;
 464 }