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.
5 #include "checkpoints.h"
7 #include "txdb-leveldb.h"
14 typedef std::map<int, std::pair<uint256, unsigned int> > MapCheckpoints;
15 typedef std::list<uint256> ListBannedBlocks;
18 // What makes a good checkpoint block?
19 // + Is surrounded by blocks with reasonable timestamps
20 // (no blocks before with a timestamp after, none after with
22 // + Contains no strange transactions
24 static MapCheckpoints mapCheckpoints =
26 { 0, {hashGenesisBlock, 1360105017} },
27 { 13560, {uint256("0xa1591a0fcbf11f282d671581edb9f0aadcd06fee69761081e0a3245914c13729"), 1364674052} },
28 { 143990, {uint256("0x00000000001ff5c3940a9f73ad4a990f64955179bde0f743c76dbf0031429efc"), 1418953493} },
29 { 149000, {uint256("0x7a24acfcadcf43054e7f7d9f273522c0dfc5791ba4006e0273e7521a8d36c525"), 1420872125} },
30 { 160000, {uint256("0x000000000001cb1133043d38d077c0e93f66c8b2566779f10f182137d1e34a68"), 1425150237} },
31 { 200000, {uint256("0x0000000000029f8bbf66e6ea6f3e5db55009404aae0fe395a53dd33142b2bff2"), 1441127233} },
32 { 221047, {uint256("0xa28aef712e7aa0c285bfe29351ca21ed416689139e3063ef770fc826a8b9e9da"), 1449431646} },
33 { 243100, {uint256("0x000000000006522d1ebc0734cb0e6b83f5d4da0c3cbc72bd91b82016f611c4f0"), 1458215793} },
34 { 532000, {uint256("0x0000000000018b7eba5e189c41605780c8a855f74144fa837fa05fa4c67b6ba9"), 1569359486} },
35 { 561108, {uint256("0x2f3cf523ae1022300b4f40073e506d15ef0d6e208f123aed5b93016f81a10e1e"), 1580943827} },
36 { 712891, {uint256("0xaaafebcb23c1b8ab49f7517b7a34bcc420cc6f284d9ffc672c1f47b5af2b0088"), 1640557462} }
39 static ListBannedBlocks listBanned =
41 // Invalid block #221047 with future timestamp of 2016/02/23 09:24:17 UTC
42 uint256("0x46223e5432ceffe650d5729b4bb8479dcdf0ca1e534fa8e69382dc87b42ea94b")
45 // TestNet has no checkpoints
46 static MapCheckpoints mapCheckpointsTestnet =
48 { 0, { hashGenesisBlockTestNet, 1360105017 } }
51 bool CheckHardened(int nHeight, const uint256& hash)
53 MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
55 MapCheckpoints::const_iterator i = checkpoints.find(nHeight);
56 if (i == checkpoints.end()) return true;
57 return hash == i->second.first;
60 bool CheckBanned(const uint256 &nHash)
62 if (fTestNet) // Testnet has no banned blocks
64 ListBannedBlocks::const_iterator it = std::find(listBanned.begin(), listBanned.end(), nHash);
65 return it == listBanned.end();
68 int GetTotalBlocksEstimate()
70 MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
72 return checkpoints.rbegin()->first;
75 unsigned int GetLastCheckpointTime()
77 MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
79 return checkpoints.rbegin()->second.second;
82 CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
84 MapCheckpoints& checkpoints = (fTestNet ? mapCheckpointsTestnet : mapCheckpoints);
86 for(auto it = checkpoints.rbegin(); it != checkpoints.rend(); ++it)
88 const uint256& hash = it->second.first;
89 auto t = mapBlockIndex.find(hash);
90 if (t != mapBlockIndex.end())
96 // ppcoin: synchronized checkpoint (centrally broadcasted)
97 uint256 hashSyncCheckpoint = 0;
98 uint256 hashPendingCheckpoint = 0;
99 CSyncCheckpoint checkpointMessage;
100 CSyncCheckpoint checkpointMessagePending;
101 uint256 hashInvalidCheckpoint = 0;
102 CCriticalSection cs_hashSyncCheckpoint;
104 // ppcoin: get last synchronized checkpoint
105 CBlockIndex* GetLastSyncCheckpoint()
107 LOCK(cs_hashSyncCheckpoint);
108 if (!mapBlockIndex.count(hashSyncCheckpoint))
109 error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
111 return mapBlockIndex[hashSyncCheckpoint];
115 // ppcoin: only descendant of current sync-checkpoint is allowed
116 bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
118 if (!mapBlockIndex.count(hashSyncCheckpoint))
119 return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
120 if (!mapBlockIndex.count(hashCheckpoint))
121 return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
123 CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
124 CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
126 if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
128 // Received an older checkpoint, trace back from current checkpoint
129 // to the same height of the received checkpoint to verify
130 // that current checkpoint should be a descendant block
131 CBlockIndex* pindex = pindexSyncCheckpoint;
132 while (pindex->nHeight > pindexCheckpointRecv->nHeight)
133 if ((pindex = pindex->pprev) == NULL)
134 return error("ValidateSyncCheckpoint: pprev null - block index structure failure");
135 if (pindex->GetBlockHash() != hashCheckpoint)
137 hashInvalidCheckpoint = hashCheckpoint;
138 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
140 return false; // ignore older checkpoint
143 // Received checkpoint should be a descendant block of the current
144 // checkpoint. Trace back to the same height of current checkpoint
146 CBlockIndex* pindex = pindexCheckpointRecv;
147 while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
148 if ((pindex = pindex->pprev) == NULL)
149 return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
150 if (pindex->GetBlockHash() != hashSyncCheckpoint)
152 hashInvalidCheckpoint = hashCheckpoint;
153 return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
158 bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
162 if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
165 return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
167 if (!txdb.TxnCommit())
168 return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
170 Checkpoints::hashSyncCheckpoint = hashCheckpoint;
174 bool AcceptPendingSyncCheckpoint()
176 LOCK(cs_hashSyncCheckpoint);
177 if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
179 if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
181 hashPendingCheckpoint = 0;
182 checkpointMessagePending.SetNull();
187 CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
188 if (!pindexCheckpoint->IsInMainChain())
191 if (!block.ReadFromDisk(pindexCheckpoint))
192 return error("AcceptPendingSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
193 if (!block.SetBestChain(txdb, pindexCheckpoint))
195 hashInvalidCheckpoint = hashPendingCheckpoint;
196 return error("AcceptPendingSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
200 if (!WriteSyncCheckpoint(hashPendingCheckpoint))
201 return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
202 hashPendingCheckpoint = 0;
203 checkpointMessage = checkpointMessagePending;
204 checkpointMessagePending.SetNull();
205 printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
206 // relay the checkpoint
207 if (!checkpointMessage.IsNull())
209 for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
210 checkpointMessage.RelayTo(*it);
217 // Automatically select a suitable sync-checkpoint
218 uint256 AutoSelectSyncCheckpoint()
220 const CBlockIndex *pindex = pindexBest;
221 // Search backward for a block within max span and maturity window
222 while (pindex->pprev && (pindex->GetBlockTime() + CHECKPOINT_MAX_SPAN > pindexBest->GetBlockTime() || pindex->nHeight + 8 > pindexBest->nHeight))
223 pindex = pindex->pprev;
224 return pindex->GetBlockHash();
227 // Check against synchronized checkpoint
228 bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
230 if (fTestNet) return true; // Testnet has no checkpoints
231 int nHeight = pindexPrev->nHeight + 1;
233 LOCK(cs_hashSyncCheckpoint);
234 // sync-checkpoint should always be accepted block
235 assert(mapBlockIndex.count(hashSyncCheckpoint));
236 const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
238 if (nHeight > pindexSync->nHeight)
240 // trace back to same height as sync-checkpoint
241 const CBlockIndex* pindex = pindexPrev;
242 while (pindex->nHeight > pindexSync->nHeight)
243 if ((pindex = pindex->pprev) == NULL)
244 return error("CheckSync: pprev null - block index structure failure");
245 if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
246 return false; // only descendant of sync-checkpoint can pass check
248 if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
249 return false; // same height with sync-checkpoint
250 if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
251 return false; // lower height than sync-checkpoint
255 bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
257 LOCK(cs_hashSyncCheckpoint);
258 if (hashPendingCheckpoint == 0)
260 if (hashBlock == hashPendingCheckpoint)
262 if (mapOrphanBlocks.count(hashPendingCheckpoint)
263 && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
268 // ppcoin: reset synchronized checkpoint to last hardened checkpoint
269 bool ResetSyncCheckpoint()
271 LOCK(cs_hashSyncCheckpoint);
272 const uint256& hash = mapCheckpoints.rbegin()->second.first;
273 if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
275 // checkpoint block accepted but not yet in main chain
276 printf("ResetSyncCheckpoint: SetBestChain to hardened checkpoint %s\n", hash.ToString().c_str());
279 if (!block.ReadFromDisk(mapBlockIndex[hash]))
280 return error("ResetSyncCheckpoint: ReadFromDisk failed for hardened checkpoint %s", hash.ToString().c_str());
281 if (!block.SetBestChain(txdb, mapBlockIndex[hash]))
283 return error("ResetSyncCheckpoint: SetBestChain failed for hardened checkpoint %s", hash.ToString().c_str());
286 else if(!mapBlockIndex.count(hash))
288 // checkpoint block not yet accepted
289 hashPendingCheckpoint = hash;
290 checkpointMessagePending.SetNull();
291 printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
294 for(auto it = mapCheckpoints.rbegin(); it != mapCheckpoints.rend(); ++it)
296 const uint256& hash = it->second.first;
297 if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
299 if (!WriteSyncCheckpoint(hash))
300 return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
301 printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
309 void AskForPendingSyncCheckpoint(CNode* pfrom)
311 LOCK(cs_hashSyncCheckpoint);
312 if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
313 pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
316 bool SetCheckpointPrivKey(std::string strPrivKey)
318 // Test signing a sync-checkpoint with genesis block
319 CSyncCheckpoint checkpoint;
320 checkpoint.hashCheckpoint = !fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet;
321 CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
322 sMsg << (CUnsignedSyncCheckpoint)checkpoint;
323 checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
325 std::vector<unsigned char> vchPrivKey = ParseHex(strPrivKey);
327 key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
328 if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
331 // Test signing successful, proceed
332 CSyncCheckpoint::strMasterPrivKey = strPrivKey;
336 bool SendSyncCheckpoint(uint256 hashCheckpoint)
338 CSyncCheckpoint checkpoint;
339 checkpoint.hashCheckpoint = hashCheckpoint;
340 CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
341 sMsg << (CUnsignedSyncCheckpoint)checkpoint;
342 checkpoint.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());
344 if (CSyncCheckpoint::strMasterPrivKey.empty())
345 return error("SendSyncCheckpoint: Checkpoint master key unavailable.");
346 std::vector<unsigned char> vchPrivKey = ParseHex(CSyncCheckpoint::strMasterPrivKey);
348 key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end())); // if key is not correct openssl may crash
349 if (!key.Sign(Hash(checkpoint.vchMsg.begin(), checkpoint.vchMsg.end()), checkpoint.vchSig))
350 return error("SendSyncCheckpoint: Unable to sign checkpoint, check private key?");
352 if(!checkpoint.ProcessSyncCheckpoint(NULL))
354 printf("WARNING: SendSyncCheckpoint: Failed to process checkpoint.\n");
361 for (std::vector<CNode*>::iterator it = vNodes.begin(); it != vNodes.end(); ++it)
362 checkpoint.RelayTo(*it);
367 // Is the sync-checkpoint outside maturity window?
368 bool IsMatureSyncCheckpoint()
370 LOCK(cs_hashSyncCheckpoint);
371 // sync-checkpoint should always be accepted block
372 assert(mapBlockIndex.count(hashSyncCheckpoint));
373 const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
374 return (nBestHeight >= pindexSync->nHeight + nCoinbaseMaturity ||
375 pindexSync->GetBlockTime() + nStakeMinAge < GetAdjustedTime());
379 // ppcoin: sync-checkpoint master key
380 const std::string CSyncCheckpoint::strMasterPubKey = "04a51b735f816de4ec3f891d5b38bbc91e1f7245c7c08d17990760b86b4d8fc3910a850ffecf73bfa8886f01739a0c4c4322201282d07b6e48ce931cc92af94850";
382 std::string CSyncCheckpoint::strMasterPrivKey = "";
384 // ppcoin: verify signature of sync-checkpoint message
385 CSyncCheckpoint::CSyncCheckpoint()
390 void CSyncCheckpoint::SetNull()
392 CUnsignedSyncCheckpoint::SetNull();
397 bool CSyncCheckpoint::IsNull() const
399 return (hashCheckpoint == 0);
402 uint256 CSyncCheckpoint::GetHash() const
404 return SerializeHash(*this);
407 bool CSyncCheckpoint::RelayTo(CNode *pnode) const
409 // returns true if wasn't already sent
410 if (pnode->hashCheckpointKnown != hashCheckpoint)
412 pnode->hashCheckpointKnown = hashCheckpoint;
413 pnode->PushMessage("checkpoint", *this);
419 bool CSyncCheckpoint::CheckSignature()
421 CPubKey key(ParseHex(CSyncCheckpoint::strMasterPubKey));
422 if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
423 return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
425 // Now unserialize the data
426 CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
427 sMsg >> *(CUnsignedSyncCheckpoint*)this;
431 // process synchronized checkpoint
432 bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
434 if (!CheckSignature())
437 LOCK(Checkpoints::cs_hashSyncCheckpoint);
438 if (!mapBlockIndex.count(hashCheckpoint))
440 // We haven't received the checkpoint chain, keep the checkpoint as pending
441 Checkpoints::hashPendingCheckpoint = hashCheckpoint;
442 Checkpoints::checkpointMessagePending = *this;
443 printf("ProcessSyncCheckpoint: pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
444 // Ask this guy to fill in what we're missing
447 pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
448 // ask directly as well in case rejected earlier by duplicate
449 // proof-of-stake because getblocks may not get it this time
450 pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
455 if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
459 CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
460 if (!pindexCheckpoint->IsInMainChain())
462 // checkpoint chain received but not yet main chain
464 if (!block.ReadFromDisk(pindexCheckpoint))
465 return error("ProcessSyncCheckpoint: ReadFromDisk failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
466 if (!block.SetBestChain(txdb, pindexCheckpoint))
468 Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
469 return error("ProcessSyncCheckpoint: SetBestChain failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
473 if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
474 return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
475 Checkpoints::checkpointMessage = *this;
476 Checkpoints::hashPendingCheckpoint = 0;
477 Checkpoints::checkpointMessagePending.SetNull();
478 printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());