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