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     struct Checkpoint
  17     {
  18         uint256 hashCheckPoint;
  19         unsigned int nTime;
  20     };
  21
  22     typedef std::map<int, Checkpoint> MapCheckpoints;
  23
  24     Checkpoint initCheckpoint(uint256 hashCheckPoint, unsigned int nTime)
  25     {
  26         Checkpoint item;
  27         item.hashCheckPoint = hashCheckPoint;
  28         item.nTime = nTime;
  29
  30         return item;
  31     }
  32
  33     //
  34     // What makes a good checkpoint block?
  35     // + Is surrounded by blocks with reasonable timestamps
  36     //   (no blocks before with a timestamp after, none after with
  37     //    timestamp before)
  38     // + Contains no strange transactions
  39     //
  40     static MapCheckpoints mapCheckpoints =
  41         boost::assign::map_list_of
  42         ( 0, initCheckpoint(hashGenesisBlock, 1360105017) )
  43         ( 9690, initCheckpoint(uint256("0x00000000026561450859c46868099e0df6068a538f038cb18988fd8d47dcdaf5"), 1362791423) )
  44         ( 13560, initCheckpoint(uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052) )
  45         ( 37092, initCheckpoint(uint256("0x0000000000a38c2f98556f46793b453e92d8fab2d31c0b93fd08bcf78e56099d"), 1376677203) )
  46         ( 44200, initCheckpoint(uint256("0xc9bda7232a18b9c1f5ff974a9e5566b2d1879ceb8fc0e9e61fba9038a25b8447"), 1380145962) )
  47         ( 65000, initCheckpoint(uint256("0xfb2b51a2fd65062c98a7a6053cde46aeaefebb95ba2f680e85a29ee25b1dcf05"), 1388526385) )
  48     ;
  49
  50     // TestNet has no checkpoints
  51     static MapCheckpoints mapCheckpointsTestnet =
  52         boost::assign::map_list_of
  53         ( 0, initCheckpoint(hashGenesisBlockTestNet, 1360105017) )
  54         ;
  55
  56     bool CheckHardened(int nHeight, const uint256& hash)
  57     {
  58         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  59
  60         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  61         if (i == checkpoints.end()) return true;
  62         return hash == i->second.hashCheckPoint;
  63     }
  64
  65     int GetTotalBlocksEstimate()
  66     {
  67         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  68
  69         return checkpoints.rbegin()->first;
  70     }
  71
  72     int GetLastCheckpointTime()
  73     {
  74         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  75
  76         return checkpoints.rbegin()->second.nTime;
  77     }
  78
  79     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  80     {
  81         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  82
  83         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  84         {
  85             const uint256& hash = i.second.hashCheckPoint;
  86             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  87             if (t != mapBlockIndex.end())
  88                 return t->second;
  89         }
  90         return NULL;
  91     }
  92
  93     // ppcoin: synchronized checkpoint (centrally broadcasted)
  94     uint256 hashSyncCheckpoint = 0;
  95     uint256 hashPendingCheckpoint = 0;
  96     CSyncCheckpoint checkpointMessage;
  97     CSyncCheckpoint checkpointMessagePending;
  98     uint256 hashInvalidCheckpoint = 0;
  99     CCriticalSection cs_hashSyncCheckpoint;
 100
 101     // ppcoin: get last synchronized checkpoint
 102     CBlockIndex* GetLastSyncCheckpoint()
 103     {
 104         LOCK(cs_hashSyncCheckpoint);
 105         if (!mapBlockIndex.count(hashSyncCheckpoint))
 106             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 107         else
 108             return mapBlockIndex[hashSyncCheckpoint];
 109         return NULL;
 110     }
 111
 112     // ppcoin: only descendant of current sync-checkpoint is allowed
 113     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 114     {
 115         if (!mapBlockIndex.count(hashSyncCheckpoint))
 116             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 117         if (!mapBlockIndex.count(hashCheckpoint))
 118             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 119
 120         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 121         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 122
 123         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 124         {
 125             // Received an older checkpoint, trace back from current checkpoint
 126             // to the same height of the received checkpoint to verify
 127             // that current checkpoint should be a descendant block
 128             CBlockIndex* pindex = pindexSyncCheckpoint;
 129             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 130                 if (!(pindex = pindex->pprev))
 131                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 132             if (pindex->GetBlockHash() != hashCheckpoint)
 133             {
 134                 hashInvalidCheckpoint = hashCheckpoint;
 135                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 136             }
 137             return false; // ignore older checkpoint
 138         }
 139
 140         // Received checkpoint should be a descendant block of the current
 141         // checkpoint. Trace back to the same height of current checkpoint
 142         // to verify.
 143         CBlockIndex* pindex = pindexCheckpointRecv;
 144         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 145             if (!(pindex = pindex->pprev))
 146                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 147         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 148         {
 149             hashInvalidCheckpoint = hashCheckpoint;
 150             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 151         }
 152         return true;
 153     }
 154
 155     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 156     {
 157         CTxDB txdb;
 158         txdb.TxnBegin();
 159         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 160         {
 161             txdb.TxnAbort();
 162             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 163         }
 164         if (!txdb.TxnCommit())
 165             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 166
 167 #ifndef USE_LEVELDB
 168         txdb.Close();
 169 #endif
 170
 171         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 172         return true;
 173     }
 174
 175     bool AcceptPendingSyncCheckpoint()
 176     {
 177         LOCK(cs_hashSyncCheckpoint);
 178         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 179         {
 180             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 181             {
 182                 hashPendingCheckpoint = 0;
 183                 checkpointMessagePending.SetNull();
 184                 return false;
 185             }
 186
 187             CTxDB txdb;
 188             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 189             if (!pindexCheckpoint->IsInMainChain())
 190             {
 191                 CBlock block;
 192                 if (!block.ReadFromDisk(pindexCheckpoint))
 193                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 194                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 195                 {
 196                     hashInvalidCheckpoint = hashPendingCheckpoint;
 197                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 198                 }
 199             }
 200
 201 #ifndef USE_LEVELDB
 202             txdb.Close();
 203 #endif
 204             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 205                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 206             hashPendingCheckpoint = 0;
 207             checkpointMessage = checkpointMessagePending;
 208             checkpointMessagePending.SetNull();
 209             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 210             // relay the checkpoint
 211             if (!checkpointMessage.IsNull())
 212             {
 213                 BOOST_FOREACH(CNode* pnode, vNodes)
 214                     checkpointMessage.RelayTo(pnode);
 215             }
 216             return true;
 217         }
 218         return false;
 219     }
 220
 221     // Automatically select a suitable sync-checkpoint
 222     uint256 AutoSelectSyncCheckpoint()
 223     {
 224         const CBlockIndex *pindex = pindexBest;
 225         // Search backward for a block within max span and maturity window
 226         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 227             pindex = pindex->pprev;
 228         return pindex->GetBlockHash();
 229     }
 230
 231     // Check against synchronized checkpoint
 232     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 233     {
 234         if (fTestNet) return true; // Testnet has no checkpoints
 235         int nHeight = pindexPrev->nHeight + 1;
 236
 237         LOCK(cs_hashSyncCheckpoint);
 238         // sync-checkpoint should always be accepted block
 239         assert(mapBlockIndex.count(hashSyncCheckpoint));
 240         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 241
 242         if (nHeight > pindexSync->nHeight)
 243         {
 244             // trace back to same height as sync-checkpoint
 245             const CBlockIndex* pindex = pindexPrev;
 246             while (pindex->nHeight > pindexSync->nHeight)
 247                 if (!(pindex = pindex->pprev))
 248                     return error("CheckSync: pprev null - block index structure failure");
 249             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 250                 return false; // only descendant of sync-checkpoint can pass check
 251         }
 252         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 253             return false; // same height with sync-checkpoint
 254         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 255             return false; // lower height than sync-checkpoint
 256         return true;
 257     }
 258
 259     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 260     {
 261         LOCK(cs_hashSyncCheckpoint);
 262         if (hashPendingCheckpoint == 0)
 263             return false;
 264         if (hashBlock == hashPendingCheckpoint)
 265             return true;
 266         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 267             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 268             return true;
 269         return false;
 270     }
 271
 272     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 273     bool ResetSyncCheckpoint()
 274     {
 275         LOCK(cs_hashSyncCheckpoint);
 276         const uint256& hash = mapCheckpoints.rbegin()->second.hashCheckPoint;
 277         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 278         {
 279             // checkpoint block accepted but not yet in main chain
 280             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 281             CTxDB txdb;
 282             CBlock block;
 283             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 284                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 285             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 286             {
 287                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 288             }
 289
 290 #ifndef USE_LEVELDB
 291             txdb.Close();
 292 #endif
 293
 294         }
 295         else if(!mapBlockIndex.count(hash))
 296         {
 297             // checkpoint block not yet accepted
 298             hashPendingCheckpoint = hash;
 299             checkpointMessagePending.SetNull();
 300             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 301         }
 302
 303         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 304         {
 305             const uint256& hash = i.second.hashCheckPoint;
 306             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 307             {
 308                 if (!WriteSyncCheckpoint(hash))
 309                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 310                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 311                 return true;
 312             }
 313         }
 314
 315         return false;
 316     }
 317
 318     void AskForPendingSyncCheckpoint(CNode* pfrom)
 319     {
 320         LOCK(cs_hashSyncCheckpoint);
 321         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 322             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 323     }
 324
 325     bool SetCheckpointPrivKey(std::string strPrivKey)
 326     {
 327         // Test signing a sync-checkpoint with genesis block
 328         CSyncCheckpoint checkpoint;
 329         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 330         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 331         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 332         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 333
 334         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 335         CKey key;
 336         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 337         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 338             return false;
 339
 340         // Test signing successful, proceed
 341         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 342         return true;
 343     }
 344
 345     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 346     {
 347         CSyncCheckpoint checkpoint;
 348         checkpoint.hashCheckpoint = hashCheckpoint;
 349         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 350         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 351         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 352
 353         if (CSyncCheckpoint::strMasterPrivKey.empty())
 354             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 355         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 356         CKey key;
 357         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 358         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 359             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 360
 361         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 362         {
 363             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 364             return false;
 365         }
 366
 367         // Relay checkpoint
 368         {
 369             LOCK(cs_vNodes);
 370             BOOST_FOREACH(CNode* pnode, vNodes)
 371                 checkpoint.RelayTo(pnode);
 372         }
 373         return true;
 374     }
 375
 376     // Is the sync-checkpoint outside maturity window?
 377     bool IsMatureSyncCheckpoint()
 378     {
 379         LOCK(cs_hashSyncCheckpoint);
 380         // sync-checkpoint should always be accepted block
 381         assert(mapBlockIndex.count(hashSyncCheckpoint));
 382         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 383         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 384                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 385     }
 386
 387     // Is the sync-checkpoint too old?
 388     bool IsSyncCheckpointTooOld(unsigned int nSeconds)
 389     {
 390         LOCK(cs_hashSyncCheckpoint);
 391         // sync-checkpoint should always be accepted block
 392         assert(mapBlockIndex.count(hashSyncCheckpoint));
 393         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 394         return (pindexSync->GetBlockTime() + nSeconds < GetAdjustedTime());
 395     }
 396 }
 397
 398 // ppcoin: sync-checkpoint master key
 399 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 400
 401 std::string CSyncCheckpoint::strMasterPrivKey = "";
 402
 403 // ppcoin: verify signature of sync-checkpoint message
 404 bool CSyncCheckpoint::CheckSignature()
 405 {
 406     CKey key;
 407     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 408         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 409     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 410         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 411
 412     // Now unserialize the data
 413     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 414     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 415     return true;
 416 }
 417
 418 // ppcoin: process synchronized checkpoint
 419 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 420 {
 421     if (!CheckSignature())
 422         return false;
 423
 424     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 425     if (!mapBlockIndex.count(hashCheckpoint))
 426     {
 427         // We haven't received the checkpoint chain, keep the checkpoint as pending
 428         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 429         Checkpoints::checkpointMessagePending = *this;
 430         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 431         // Ask this guy to fill in what we're missing
 432         if (pfrom)
 433         {
 434             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 435             // ask directly as well in case rejected earlier by duplicate
 436             // proof-of-stake because getblocks may not get it this time
 437             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 438         }
 439         return false;
 440     }
 441
 442     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 443         return false;
 444
 445     CTxDB txdb;
 446     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 447     if (!pindexCheckpoint->IsInMainChain())
 448     {
 449         // checkpoint chain received but not yet main chain
 450         CBlock block;
 451         if (!block.ReadFromDisk(pindexCheckpoint))
 452             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 453         if (!block.SetBestChain(txdb, pindexCheckpoint))
 454         {
 455             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 456             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 457         }
 458     }
 459
 460 #ifndef USE_LEVELDB
 461     txdb.Close();
 462 #endif
 463
 464     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 465         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 466     Checkpoints::checkpointMessage = *this;
 467     Checkpoints::hashPendingCheckpoint = 0;
 468     Checkpoints::checkpointMessagePending.SetNull();
 469     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 470     return true;
 471 }