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-leveldb.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         ( 532000, std::make_pair(uint256("0x0000000000018b7eba5e189c41605780c8a855f74144fa837fa05fa4c67b6ba9"), 1569359486) )
  38         ( 561108, std::make_pair(uint256("0x2f3cf523ae1022300b4f40073e506d15ef0d6e208f123aed5b93016f81a10e1e"), 1580943827) )
  39         ( 712891, std::make_pair(uint256("0xaaafebcb23c1b8ab49f7517b7a34bcc420cc6f284d9ffc672c1f47b5af2b0088"), 1640557462) )
  40     ;
  41
  42     static ListBannedBlocks listBanned =
  43         boost::assign::list_of
  44         // Invalid block #221047 with future timestamp of 2016/02/23 09:24:17 UTC
  45         ( uint256("0x46223e5432ceffe650d5729b4bb8479dcdf0ca1e534fa8e69382dc87b42ea94b") )
  46     ;
  47
  48     // TestNet has no checkpoints
  49     static MapCheckpoints mapCheckpointsTestnet =
  50         boost::assign::map_list_of
  51         ( 0, std::make_pair(hashGenesisBlockTestNet, 1360105017) )
  52         ;
  53
  54     bool CheckHardened(int nHeight, const uint256& hash)
  55     {
  56         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  57
  58         MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
  59         if (i == checkpoints.end()) return true;
  60         return hash == i->second.first;
  61     }
  62
  63     bool CheckBanned(const uint256 &nHash)
  64     {
  65         if (fTestNet) // Testnet has no banned blocks
  66             return true;
  67         ListBannedBlocks::const_iterator it = std::find(listBanned.begin(), listBanned.end(), nHash);
  68         return it == listBanned.end();
  69     }
  70
  71     int GetTotalBlocksEstimate()
  72     {
  73         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  74
  75         return checkpoints.rbegin()->first;
  76     }
  77
  78     unsigned int GetLastCheckpointTime()
  79     {
  80         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  81
  82         return checkpoints.rbegin()->second.second;
  83     }
  84
  85     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
  86     {
  87         MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
  88
  89         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)
  90         {
  91             const uint256& hash = i.second.first;
  92             std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
  93             if (t != mapBlockIndex.end())
  94                 return t->second;
  95         }
  96         return NULL;
  97     }
  98
  99     // ppcoin: synchronized checkpoint (centrally broadcasted)
 100     uint256 hashSyncCheckpoint = 0;
 101     uint256 hashPendingCheckpoint = 0;
 102     CSyncCheckpoint checkpointMessage;
 103     CSyncCheckpoint checkpointMessagePending;
 104     uint256 hashInvalidCheckpoint = 0;
 105     CCriticalSection cs_hashSyncCheckpoint;
 106
 107     // ppcoin: get last synchronized checkpoint
 108     CBlockIndex* GetLastSyncCheckpoint()
 109     {
 110         LOCK(cs_hashSyncCheckpoint);
 111         if (!mapBlockIndex.count(hashSyncCheckpoint))
 112             error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 113         else
 114             return mapBlockIndex[hashSyncCheckpoint];
 115         return NULL;
 116     }
 117
 118     // ppcoin: only descendant of current sync-checkpoint is allowed
 119     bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
 120     {
 121         if (!mapBlockIndex.count(hashSyncCheckpoint))
 122             return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
 123         if (!mapBlockIndex.count(hashCheckpoint))
 124             return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
 125
 126         CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
 127         CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
 128
 129         if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
 130         {
 131             // Received an older checkpoint, trace back from current checkpoint
 132             // to the same height of the received checkpoint to verify
 133             // that current checkpoint should be a descendant block
 134             CBlockIndex* pindex = pindexSyncCheckpoint;
 135             while (pindex->nHeight > pindexCheckpointRecv->nHeight)
 136                 if ((pindex = pindex->pprev) == NULL)
 137                     return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
 138             if (pindex->GetBlockHash() != hashCheckpoint)
 139             {
 140                 hashInvalidCheckpoint = hashCheckpoint;
 141                 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 142             }
 143             return false; // ignore older checkpoint
 144         }
 145
 146         // Received checkpoint should be a descendant block of the current
 147         // checkpoint. Trace back to the same height of current checkpoint
 148         // to verify.
 149         CBlockIndex* pindex = pindexCheckpointRecv;
 150         while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
 151             if ((pindex = pindex->pprev) == NULL)
 152                 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
 153         if (pindex->GetBlockHash() != hashSyncCheckpoint)
 154         {
 155             hashInvalidCheckpoint = hashCheckpoint;
 156             return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
 157         }
 158         return true;
 159     }
 160
 161     bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
 162     {
 163         CTxDB txdb;
 164         txdb.TxnBegin();
 165         if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
 166         {
 167             txdb.TxnAbort();
 168             return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 169         }
 170         if (!txdb.TxnCommit())
 171             return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
 172
 173         Checkpoints::hashSyncCheckpoint = hashCheckpoint;
 174         return true;
 175     }
 176
 177     bool AcceptPendingSyncCheckpoint()
 178     {
 179         LOCK(cs_hashSyncCheckpoint);
 180         if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
 181         {
 182             if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
 183             {
 184                 hashPendingCheckpoint = 0;
 185                 checkpointMessagePending.SetNull();
 186                 return false;
 187             }
 188
 189             CTxDB txdb;
 190             CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
 191             if (!pindexCheckpoint->IsInMainChain())
 192             {
 193                 CBlock block;
 194                 if (!block.ReadFromDisk(pindexCheckpoint))
 195                     return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 196                 if (!block.SetBestChain(txdb, pindexCheckpoint))
 197                 {
 198                     hashInvalidCheckpoint = hashPendingCheckpoint;
 199                     return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 200                 }
 201             }
 202
 203             if (!WriteSyncCheckpoint(hashPendingCheckpoint))
 204                 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
 205             hashPendingCheckpoint = 0;
 206             checkpointMessage = checkpointMessagePending;
 207             checkpointMessagePending.SetNull();
 208             printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
 209             // relay the checkpoint
 210             if (!checkpointMessage.IsNull())
 211             {
 212                 for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
 213                     checkpointMessage.RelayTo(*it);
 214             }
 215             return true;
 216         }
 217         return false;
 218     }
 219
 220     // Automatically select a suitable sync-checkpoint
 221     uint256 AutoSelectSyncCheckpoint()
 222     {
 223         const CBlockIndex *pindex = pindexBest;
 224         // Search backward for a block within max span and maturity window
 225         while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
 226             pindex = pindex->pprev;
 227         return pindex->GetBlockHash();
 228     }
 229
 230     // Check against synchronized checkpoint
 231     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
 232     {
 233         if (fTestNet) return true; // Testnet has no checkpoints
 234         int nHeight = pindexPrev->nHeight + 1;
 235
 236         LOCK(cs_hashSyncCheckpoint);
 237         // sync-checkpoint should always be accepted block
 238         assert(mapBlockIndex.count(hashSyncCheckpoint));
 239         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 240
 241         if (nHeight > pindexSync->nHeight)
 242         {
 243             // trace back to same height as sync-checkpoint
 244             const CBlockIndex* pindex = pindexPrev;
 245             while (pindex->nHeight > pindexSync->nHeight)
 246                 if ((pindex = pindex->pprev) == NULL)
 247                     return error("CheckSync: pprev null - block index structure failure");
 248             if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
 249                 return false; // only descendant of sync-checkpoint can pass check
 250         }
 251         if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
 252             return false; // same height with sync-checkpoint
 253         if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
 254             return false; // lower height than sync-checkpoint
 255         return true;
 256     }
 257
 258     bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
 259     {
 260         LOCK(cs_hashSyncCheckpoint);
 261         if (hashPendingCheckpoint == 0)
 262             return false;
 263         if (hashBlock == hashPendingCheckpoint)
 264             return true;
 265         if (mapOrphanBlocks.count(hashPendingCheckpoint)
 266             && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
 267             return true;
 268         return false;
 269     }
 270
 271     // ppcoin: reset synchronized checkpoint to last hardened checkpoint
 272     bool ResetSyncCheckpoint()
 273     {
 274         LOCK(cs_hashSyncCheckpoint);
 275         const uint256& hash = mapCheckpoints.rbegin()->second.first;
 276         if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
 277         {
 278             // checkpoint block accepted but not yet in main chain
 279             printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
 280             CTxDB txdb;
 281             CBlock block;
 282             if (!block.ReadFromDisk(mapBlockIndex[hash]))
 283                 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
 284             if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
 285             {
 286                 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
 287             }
 288         }
 289         else if(!mapBlockIndex.count(hash))
 290         {
 291             // checkpoint block not yet accepted
 292             hashPendingCheckpoint = hash;
 293             checkpointMessagePending.SetNull();
 294             printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
 295         }
 296
 297         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
 298         {
 299             const uint256& hash = i.second.first;
 300             if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
 301             {
 302                 if (!WriteSyncCheckpoint(hash))
 303                     return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
 304                 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
 305                 return true;
 306             }
 307         }
 308
 309         return false;
 310     }
 311
 312     void AskForPendingSyncCheckpoint(CNode* pfrom)
 313     {
 314         LOCK(cs_hashSyncCheckpoint);
 315         if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
 316             pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
 317     }
 318
 319     bool SetCheckpointPrivKey(std::string strPrivKey)
 320     {
 321         // Test signing a sync-checkpoint with genesis block
 322         CSyncCheckpoint checkpoint;
 323         checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
 324         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 325         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 326         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 327
 328         std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
 329         CKey key;
 330         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 331         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 332             return false;
 333
 334         // Test signing successful, proceed
 335         CSyncCheckpoint::strMasterPrivKey = strPrivKey;
 336         return true;
 337     }
 338
 339     bool SendSyncCheckpoint(uint256 hashCheckpoint)
 340     {
 341         CSyncCheckpoint checkpoint;
 342         checkpoint.hashCheckpoint = hashCheckpoint;
 343         CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
 344         sMsg << (CUnsignedSyncCheckpoint)checkpoint;
 345         checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
 346
 347         if (CSyncCheckpoint::strMasterPrivKey.empty())
 348             return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
 349         std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
 350         CKey key;
 351         key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
 352         if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
 353             return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
 354
 355         if(!checkpoint.ProcessSyncCheckpoint(NULL))
 356         {
 357             printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
 358             return false;
 359         }
 360
 361         // Relay checkpoint
 362         {
 363             LOCK(cs_vNodes);
 364             for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
 365                 checkpoint.RelayTo(*it);
 366         }
 367         return true;
 368     }
 369
 370     // Is the sync-checkpoint outside maturity window?
 371     bool IsMatureSyncCheckpoint()
 372     {
 373         LOCK(cs_hashSyncCheckpoint);
 374         // sync-checkpoint should always be accepted block
 375         assert(mapBlockIndex.count(hashSyncCheckpoint));
 376         const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
 377         return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
 378                 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
 379     }
 380 }
 381
 382 // ppcoin: sync-checkpoint master key
 383 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
 384
 385 std::string CSyncCheckpoint::strMasterPrivKey = "";
 386
 387 // ppcoin: verify signature of sync-checkpoint message
 388 bool CSyncCheckpoint::CheckSignature()
 389 {
 390     CPubKey key(ParseHex(CSyncCheckpoint::strMasterPubKey));
 391     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 392         return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
 393
 394     // Now unserialize the data
 395     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 396     sMsg >> *(CUnsignedSyncCheckpoint*)this;
 397     return true;
 398 }
 399
 400 // process synchronized checkpoint
 401 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
 402 {
 403     if (!CheckSignature())
 404         return false;
 405
 406     LOCK(Checkpoints::cs_hashSyncCheckpoint);
 407     if (!mapBlockIndex.count(hashCheckpoint))
 408     {
 409         // We haven't received the checkpoint chain, keep the checkpoint as pending
 410         Checkpoints::hashPendingCheckpoint = hashCheckpoint;
 411         Checkpoints::checkpointMessagePending = *this;
 412         printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
 413         // Ask this guy to fill in what we're missing
 414         if (pfrom)
 415         {
 416             pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
 417             // ask directly as well in case rejected earlier by duplicate
 418             // proof-of-stake because getblocks may not get it this time
 419             pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
 420         }
 421         return false;
 422     }
 423
 424     if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
 425         return false;
 426
 427     CTxDB txdb;
 428     CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
 429     if (!pindexCheckpoint->IsInMainChain())
 430     {
 431         // checkpoint chain received but not yet main chain
 432         CBlock block;
 433         if (!block.ReadFromDisk(pindexCheckpoint))
 434             return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 435         if (!block.SetBestChain(txdb, pindexCheckpoint))
 436         {
 437             Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
 438             return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
 439         }
 440     }
 441
 442     if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
 443         return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
 444     Checkpoints::checkpointMessage = *this;
 445     Checkpoints::hashPendingCheckpoint = 0;
 446     Checkpoints::checkpointMessagePending.SetNull();
 447     printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
 448     return true;
 449 }