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         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 168         return true;
 169     }
 170
 171     bool AcceptPendingSyncCheckpoint()
 172     {
 173         LOCK(cs_hashSyncCheckpoint);
 174         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 175         {
 176             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 177             {
 178                 hashPendingCheckpoint = 0;
 179                 checkpointMessagePending.SetNull();
 180                 return false;
 181             }
 182
 183             CTxDB txdb;
 184             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 185             if (!pindexCheckpoint->IsInMainChain())
 186             {
 187                 CBlock block;
 188                 if (!block.ReadFromDisk(pindexCheckpoint))
 189                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 190                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 191                 {
 192                     hashInvalidCheckpoint = hashPendingCheckpoint;
 193                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 194                 }
 195             }
 196
 197             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 198                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 199             hashPendingCheckpoint = 0;
 200             checkpointMessage = checkpointMessagePending;
 201             checkpointMessagePending.SetNull();
 202             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 203             // relay the checkpoint
 204             if (!checkpointMessage.IsNull())
 205             {
 206                 BOOST_FOREACH(CNode* pnode, vNodes)
 207                     checkpointMessage.RelayTo(pnode);
 208             }
 209             return true;
 210         }
 211         return false;
 212     }
 213
 214     // Automatically select a suitable sync-checkpoint
 215     uint256 AutoSelectSyncCheckpoint()
 216     {
 217         const CBlockIndex *pindex = pindexBest;
 218         // Search backward for a block within max span and maturity window
 219         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 220             pindex = pindex->pprev;
 221         return pindex->GetBlockHash();
 222     }
 223
 224     // Check against synchronized checkpoint
 225     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 226     {
 227         if (fTestNet) return true; // Testnet has no checkpoints
 228         int nHeight = pindexPrev->nHeight + 1;
 229
 230         LOCK(cs_hashSyncCheckpoint);
 231         // sync-checkpoint should always be accepted block
 232         assert(mapBlockIndex.count(hashSyncCheckpoint));
 233         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 234
 235         if (nHeight > pindexSync->nHeight)
 236         {
 237             // trace back to same height as sync-checkpoint
 238             const CBlockIndex* pindex = pindexPrev;
 239             while (pindex->nHeight > pindexSync->nHeight)
 240                 if (!(pindex = pindex->pprev))
 241                     return error("CheckSync: pprev null - block index structure failure");
 242             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 243                 return false; // only descendant of sync-checkpoint can pass check
 244         }
 245         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 246             return false; // same height with sync-checkpoint
 247         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 248             return false; // lower height than sync-checkpoint
 249         return true;
 250     }
 251
 252     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 253     {
 254         LOCK(cs_hashSyncCheckpoint);
 255         if (hashPendingCheckpoint == 0)
 256             return false;
 257         if (hashBlock == hashPendingCheckpoint)
 258             return true;
 259         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 260             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 261             return true;
 262         return false;
 263     }
 264
 265     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 266     bool ResetSyncCheckpoint()
 267     {
 268         LOCK(cs_hashSyncCheckpoint);
 269         const uint256& hash = mapCheckpoints.rbegin()->second.hashCheckPoint;
 270         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 271         {
 272             // checkpoint block accepted but not yet in main chain
 273             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 274             CTxDB txdb;
 275             CBlock block;
 276             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 277                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 278             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 279             {
 280                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 281             }
 282         }
 283         else if(!mapBlockIndex.count(hash))
 284         {
 285             // checkpoint block not yet accepted
 286             hashPendingCheckpoint = hash;
 287             checkpointMessagePending.SetNull();
 288             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 289         }
 290
 291         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 292         {
 293             const uint256& hash = i.second.hashCheckPoint;
 294             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 295             {
 296                 if (!WriteSyncCheckpoint(hash))
 297                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 298                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 299                 return true;
 300             }
 301         }
 302
 303         return false;
 304     }
 305
 306     void AskForPendingSyncCheckpoint(CNode* pfrom)
 307     {
 308         LOCK(cs_hashSyncCheckpoint);
 309         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 310             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 311     }
 312
 313     bool SetCheckpointPrivKey(std::string strPrivKey)
 314     {
 315         // Test signing a sync-checkpoint with genesis block
 316         CSyncCheckpoint checkpoint;
 317         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 318         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 319         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 320         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 321
 322         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 323         CKey key;
 324         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 325         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 326             return false;
 327
 328         // Test signing successful, proceed
 329         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 330         return true;
 331     }
 332
 333     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 334     {
 335         CSyncCheckpoint checkpoint;
 336         checkpoint.hashCheckpoint = hashCheckpoint;
 337         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 338         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 339         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 340
 341         if (CSyncCheckpoint::strMasterPrivKey.empty())
 342             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 343         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 344         CKey key;
 345         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 346         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 347             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 348
 349         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 350         {
 351             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 352             return false;
 353         }
 354
 355         // Relay checkpoint
 356         {
 357             LOCK(cs_vNodes);
 358             BOOST_FOREACH(CNode* pnode, vNodes)
 359                 checkpoint.RelayTo(pnode);
 360         }
 361         return true;
 362     }
 363
 364     // Is the sync-checkpoint outside maturity window?
 365     bool IsMatureSyncCheckpoint()
 366     {
 367         LOCK(cs_hashSyncCheckpoint);
 368         // sync-checkpoint should always be accepted block
 369         assert(mapBlockIndex.count(hashSyncCheckpoint));
 370         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 371         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 372                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 373     }
 374
 375     // Is the sync-checkpoint too old?
 376     bool IsSyncCheckpointTooOld(unsigned int nSeconds)
 377     {
 378         LOCK(cs_hashSyncCheckpoint);
 379         // sync-checkpoint should always be accepted block
 380         assert(mapBlockIndex.count(hashSyncCheckpoint));
 381         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 382         return (pindexSync->GetBlockTime() + nSeconds < GetAdjustedTime());
 383     }
 384 }
 385
 386 // ppcoin: sync-checkpoint master key
 387 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 388
 389 std::string CSyncCheckpoint::strMasterPrivKey = "";
 390
 391 // ppcoin: verify signature of sync-checkpoint message
 392 bool CSyncCheckpoint::CheckSignature()
 393 {
 394     CKey key;
 395     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 396         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 397     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 398         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 399
 400     // Now unserialize the data
 401     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 402     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 403     return true;
 404 }
 405
 406 // ppcoin: process synchronized checkpoint
 407 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 408 {
 409     if (!CheckSignature())
 410         return false;
 411
 412     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 413     if (!mapBlockIndex.count(hashCheckpoint))
 414     {
 415         // We haven't received the checkpoint chain, keep the checkpoint as pending
 416         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 417         Checkpoints::checkpointMessagePending = *this;
 418         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 419         // Ask this guy to fill in what we're missing
 420         if (pfrom)
 421         {
 422             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 423             // ask directly as well in case rejected earlier by duplicate
 424             // proof-of-stake because getblocks may not get it this time
 425             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 426         }
 427         return false;
 428     }
 429
 430     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 431         return false;
 432
 433     CTxDB txdb;
 434     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 435     if (!pindexCheckpoint->IsInMainChain())
 436     {
 437         // checkpoint chain received but not yet main chain
 438         CBlock block;
 439         if (!block.ReadFromDisk(pindexCheckpoint))
 440             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 441         if (!block.SetBestChain(txdb, pindexCheckpoint))
 442         {
 443             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 444             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 445         }
 446     }
 447
 448     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 449         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 450     Checkpoints::checkpointMessage = *this;
 451     Checkpoints::hashPendingCheckpoint = 0;
 452     Checkpoints::checkpointMessagePending.SetNull();
 453     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 454     return true;
 455 }