diff options
| -rw-r--r-- | src/net_processing.cpp | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 7fced41d4f..b5e37722df 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -61,6 +61,14 @@ static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUAR static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; // SHA256("main address relay")[0:8] +/// Age after which a stale block will no longer be served if requested as +/// protection against fingerprinting. Set to one month, denominated in seconds. +static const int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60; + +/// Age after which a block is considered historical for purposes of rate +/// limiting block relay. Set to one week, denominated in seconds. +static const int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60; + // Internal stuff namespace { /** Number of nodes with fSyncStarted. */ @@ -706,6 +714,17 @@ void Misbehaving(NodeId pnode, int howmuch) // blockchain -> download logic notification // +// To prevent fingerprinting attacks, only send blocks/headers outside of the +// active chain if they are no more than a month older (both in time, and in +// best equivalent proof of work) than the best header chain we know about. +static bool StaleBlockRequestAllowed(const CBlockIndex* pindex, const Consensus::Params& consensusParams) +{ + AssertLockHeld(cs_main); + return (pindexBestHeader != nullptr) && + (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) && + (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, consensusParams) < STALE_RELAY_AGE_LIMIT); +} + PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanIn) { // Initialize global variables that cannot be constructed at startup. recentRejects.reset(new CRollingBloomFilter(120000, 0.000001)); @@ -983,13 +1002,8 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam if (chainActive.Contains(mi->second)) { send = true; } else { - static const int nOneMonth = 30 * 24 * 60 * 60; - // To prevent fingerprinting attacks, only send blocks outside of the active - // chain if they are valid, and no more than a month older (both in time, and in - // best equivalent proof of work) than the best header chain we know about. - send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != nullptr) && - (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() < nOneMonth) && - (GetBlockProofEquivalentTime(*pindexBestHeader, *mi->second, *pindexBestHeader, consensusParams) < nOneMonth); + send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) && + StaleBlockRequestAllowed(mi->second, consensusParams); if (!send) { LogPrintf("%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId()); } @@ -997,8 +1011,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam } // disconnect node in case we have reached the outbound limit for serving historical blocks // never disconnect whitelisted nodes - static const int nOneWeek = 7 * 24 * 60 * 60; // assume > 1 week = historical - if (send && connman->OutboundTargetReached(true) && ( ((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted) + if (send && connman->OutboundTargetReached(true) && ( ((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted) { LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId()); @@ -1723,6 +1736,12 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (mi == mapBlockIndex.end()) return true; pindex = (*mi).second; + + if (!chainActive.Contains(pindex) && + !StaleBlockRequestAllowed(pindex, chainparams.GetConsensus())) { + LogPrintf("%s: ignoring request from peer=%i for old block header that isn't in the main chain\n", __func__, pfrom->GetId()); + return true; + } } else { |