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         ( 9690,  std::make_pair(uint256("0x00000000026561450859c46868099e0df6068a538f038cb18988fd8d47dcdaf5"), 1362791423) )
  29         ( 13560, std::make_pair(uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052) )
  30         ( 37092, std::make_pair(uint256("0x0000000000a38c2f98556f46793b453e92d8fab2d31c0b93fd08bcf78e56099d"), 1376677203) )
  31         ( 44200, std::make_pair(uint256("0xc9bda7232a18b9c1f5ff974a9e5566b2d1879ceb8fc0e9e61fba9038a25b8447"), 1380145962) )
  32         ( 65000, std::make_pair(uint256("0xfb2b51a2fd65062c98a7a6053cde46aeaefebb95ba2f680e85a29ee25b1dcf05"), 1388526385) )
  33         ( 68600, std::make_pair(uint256("0xb646b0562080ab9411f85d4b2a1ca8b197c67ae170c5e328406871b44233cb06"), 1389867276) )
  34         ( 92161, std::make_pair(uint256("0x000000000079090eb31e7fa55487e4e666466253e68b213f44b7977ea7a2eeec"), 1398919969) )
  35         ( 98661, std::make_pair(uint256("0x48328dfc0eaffc659723739c6202854d1624449340193bdea3e71ece4ccdd43f"), 1401469019) )
  36     ;
  37
  38     // TestNet has no checkpoints
  39     static MapCheckpoints mapCheckpointsTestnet =
  40         boost::assign::map_list_of
  41         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  42         ;
  43
  44     bool CheckHardened(int nHeight, const uint256& hash)
  45     {
  46         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  47
  48         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  49         if (i == checkpoints.end()) return true;
  50         return hash == i->second.first;
  51     }
  52
  53     int GetTotalBlocksEstimate()
  54     {
  55         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  56
  57         return checkpoints.rbegin()->first;
  58     }
  59
  60     int GetLastCheckpointTime()
  61     {
  62         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  63
  64         return checkpoints.rbegin()->second.second;
  65     }
  66
  67     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  68     {
  69         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  70
  71         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  72         {
  73             const uint256& hash = i.second.first;
  74             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  75             if (t != mapBlockIndex.end())
  76                 return t->second;
  77         }
  78         return NULL;
  79     }
  80
  81     // ppcoin: synchronized checkpoint (centrally broadcasted)
  82     uint256 hashSyncCheckpoint = 0;
  83     uint256 hashPendingCheckpoint = 0;
  84     CSyncCheckpoint checkpointMessage;
  85     CSyncCheckpoint checkpointMessagePending;
  86     uint256 hashInvalidCheckpoint = 0;
  87     CCriticalSection cs_hashSyncCheckpoint;
  88
  89     // ppcoin: get last synchronized checkpoint
  90     CBlockIndex* GetLastSyncCheckpoint()
  91     {
  92         LOCK(cs_hashSyncCheckpoint);
  93         if (!mapBlockIndex.count(hashSyncCheckpoint))
  94             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
  95         else
  96             return mapBlockIndex[hashSyncCheckpoint];
  97         return NULL;
  98     }
  99
 100     // ppcoin: only descendant of current sync-checkpoint is allowed
 101     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 102     {
 103         if (!mapBlockIndex.count(hashSyncCheckpoint))
 104             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 105         if (!mapBlockIndex.count(hashCheckpoint))
 106             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 107
 108         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 109         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 110
 111         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 112         {
 113             // Received an older checkpoint, trace back from current checkpoint
 114             // to the same height of the received checkpoint to verify
 115             // that current checkpoint should be a descendant block
 116             CBlockIndex* pindex = pindexSyncCheckpoint;
 117             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 118                 if (!(pindex = pindex->pprev))
 119                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 120             if (pindex->GetBlockHash() != hashCheckpoint)
 121             {
 122                 hashInvalidCheckpoint = hashCheckpoint;
 123                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 124             }
 125             return false; // ignore older checkpoint
 126         }
 127
 128         // Received checkpoint should be a descendant block of the current
 129         // checkpoint. Trace back to the same height of current checkpoint
 130         // to verify.
 131         CBlockIndex* pindex = pindexCheckpointRecv;
 132         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 133             if (!(pindex = pindex->pprev))
 134                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 135         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 136         {
 137             hashInvalidCheckpoint = hashCheckpoint;
 138             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 139         }
 140         return true;
 141     }
 142
 143     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 144     {
 145         CTxDB txdb;
 146         txdb.TxnBegin();
 147         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 148         {
 149             txdb.TxnAbort();
 150             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 151         }
 152         if (!txdb.TxnCommit())
 153             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 154
 155         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 156         return true;
 157     }
 158
 159     bool AcceptPendingSyncCheckpoint()
 160     {
 161         LOCK(cs_hashSyncCheckpoint);
 162         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 163         {
 164             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 165             {
 166                 hashPendingCheckpoint = 0;
 167                 checkpointMessagePending.SetNull();
 168                 return false;
 169             }
 170
 171             CTxDB txdb;
 172             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 173             if (!pindexCheckpoint->IsInMainChain())
 174             {
 175                 CBlock block;
 176                 if (!block.ReadFromDisk(pindexCheckpoint))
 177                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 178                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 179                 {
 180                     hashInvalidCheckpoint = hashPendingCheckpoint;
 181                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 182                 }
 183             }
 184
 185             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 186                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 187             hashPendingCheckpoint = 0;
 188             checkpointMessage = checkpointMessagePending;
 189             checkpointMessagePending.SetNull();
 190             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 191             // relay the checkpoint
 192             if (!checkpointMessage.IsNull())
 193             {
 194                 BOOST_FOREACH(CNode* pnode, vNodes)
 195                     checkpointMessage.RelayTo(pnode);
 196             }
 197             return true;
 198         }
 199         return false;
 200     }
 201
 202     // Automatically select a suitable sync-checkpoint
 203     uint256 AutoSelectSyncCheckpoint()
 204     {
 205         const CBlockIndex *pindex = pindexBest;
 206         // Search backward for a block within max span and maturity window
 207         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 208             pindex = pindex->pprev;
 209         return pindex->GetBlockHash();
 210     }
 211
 212     // Check against synchronized checkpoint
 213     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 214     {
 215         if (fTestNet) return true; // Testnet has no checkpoints
 216         int nHeight = pindexPrev->nHeight + 1;
 217
 218         LOCK(cs_hashSyncCheckpoint);
 219         // sync-checkpoint should always be accepted block
 220         assert(mapBlockIndex.count(hashSyncCheckpoint));
 221         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 222
 223         if (nHeight > pindexSync->nHeight)
 224         {
 225             // trace back to same height as sync-checkpoint
 226             const CBlockIndex* pindex = pindexPrev;
 227             while (pindex->nHeight > pindexSync->nHeight)
 228                 if (!(pindex = pindex->pprev))
 229                     return error("CheckSync: pprev null - block index structure failure");
 230             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 231                 return false; // only descendant of sync-checkpoint can pass check
 232         }
 233         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 234             return false; // same height with sync-checkpoint
 235         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 236             return false; // lower height than sync-checkpoint
 237         return true;
 238     }
 239
 240     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 241     {
 242         LOCK(cs_hashSyncCheckpoint);
 243         if (hashPendingCheckpoint == 0)
 244             return false;
 245         if (hashBlock == hashPendingCheckpoint)
 246             return true;
 247         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 248             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 249             return true;
 250         return false;
 251     }
 252
 253     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 254     bool ResetSyncCheckpoint()
 255     {
 256         LOCK(cs_hashSyncCheckpoint);
 257         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 258         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 259         {
 260             // checkpoint block accepted but not yet in main chain
 261             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 262             CTxDB txdb;
 263             CBlock block;
 264             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 265                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 266             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 267             {
 268                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 269             }
 270         }
 271         else if(!mapBlockIndex.count(hash))
 272         {
 273             // checkpoint block not yet accepted
 274             hashPendingCheckpoint = hash;
 275             checkpointMessagePending.SetNull();
 276             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 277         }
 278
 279         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 280         {
 281             const uint256& hash = i.second.first;
 282             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 283             {
 284                 if (!WriteSyncCheckpoint(hash))
 285                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 286                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 287                 return true;
 288             }
 289         }
 290
 291         return false;
 292     }
 293
 294     void AskForPendingSyncCheckpoint(CNode* pfrom)
 295     {
 296         LOCK(cs_hashSyncCheckpoint);
 297         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 298             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 299     }
 300
 301     bool SetCheckpointPrivKey(std::string strPrivKey)
 302     {
 303         // Test signing a sync-checkpoint with genesis block
 304         CSyncCheckpoint checkpoint;
 305         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 306         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 307         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 308         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 309
 310         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 311         CKey key;
 312         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 313         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 314             return false;
 315
 316         // Test signing successful, proceed
 317         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 318         return true;
 319     }
 320
 321     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 322     {
 323         CSyncCheckpoint checkpoint;
 324         checkpoint.hashCheckpoint = hashCheckpoint;
 325         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 326         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 327         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 328
 329         if (CSyncCheckpoint::strMasterPrivKey.empty())
 330             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 331         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 332         CKey key;
 333         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 334         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 335             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 336
 337         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 338         {
 339             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 340             return false;
 341         }
 342
 343         // Relay checkpoint
 344         {
 345             LOCK(cs_vNodes);
 346             BOOST_FOREACH(CNode* pnode, vNodes)
 347                 checkpoint.RelayTo(pnode);
 348         }
 349         return true;
 350     }
 351
 352     // Is the sync-checkpoint outside maturity window?
 353     bool IsMatureSyncCheckpoint()
 354     {
 355         LOCK(cs_hashSyncCheckpoint);
 356         // sync-checkpoint should always be accepted block
 357         assert(mapBlockIndex.count(hashSyncCheckpoint));
 358         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 359         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 360                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 361     }
 362 }
 363
 364 // ppcoin: sync-checkpoint master key
 365 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 366
 367 std::string CSyncCheckpoint::strMasterPrivKey = "";
 368
 369 // ppcoin: verify signature of sync-checkpoint message
 370 bool CSyncCheckpoint::CheckSignature()
 371 {
 372     CKey key;
 373     if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
 374         return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
 375     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 376         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 377
 378     // Now unserialize the data
 379     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 380     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 381     return true;
 382 }
 383
 384 // ppcoin: process synchronized checkpoint
 385 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 386 {
 387     if (!CheckSignature())
 388         return false;
 389
 390     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 391     if (!mapBlockIndex.count(hashCheckpoint))
 392     {
 393         // We haven't received the checkpoint chain, keep the checkpoint as pending
 394         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 395         Checkpoints::checkpointMessagePending = *this;
 396         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 397         // Ask this guy to fill in what we're missing
 398         if (pfrom)
 399         {
 400             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 401             // ask directly as well in case rejected earlier by duplicate
 402             // proof-of-stake because getblocks may not get it this time
 403             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 404         }
 405         return false;
 406     }
 407
 408     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 409         return false;
 410
 411     CTxDB txdb;
 412     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 413     if (!pindexCheckpoint->IsInMainChain())
 414     {
 415         // checkpoint chain received but not yet main chain
 416         CBlock block;
 417         if (!block.ReadFromDisk(pindexCheckpoint))
 418             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 419         if (!block.SetBestChain(txdb, pindexCheckpoint))
 420         {
 421             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 422             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 423         }
 424     }
 425
 426     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 427         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 428     Checkpoints::checkpointMessage = *this;
 429     Checkpoints::hashPendingCheckpoint = 0;
 430     Checkpoints::checkpointMessagePending.SetNull();
 431     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 432     return true;
 433 }