diff --git a/bitcoin-qt.pro b/bitcoin-qt.pro index 7444ff4a..8fc177f7 100644 --- a/bitcoin-qt.pro +++ b/bitcoin-qt.pro @@ -88,6 +88,7 @@ HEADERS += src/qt/bitcoingui.h \ src/qt/bitcoinaddressvalidator.h \ src/base58.h \ src/bignum.h \ + src/checkpoints.h \ src/util.h \ src/uint256.h \ src/serialize.h \ @@ -152,6 +153,7 @@ SOURCES += src/qt/bitcoin.cpp src/qt/bitcoingui.cpp \ src/init.cpp \ src/net.cpp \ src/irc.cpp \ + src/checkpoints.cpp \ src/db.cpp \ src/json/json_spirit_writer.cpp \ src/json/json_spirit_value.cpp \ diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp new file mode 100644 index 00000000..c7e054df --- /dev/null +++ b/src/checkpoints.cpp @@ -0,0 +1,65 @@ +// Copyright (c) 2011 The Bitcoin developers +// Distributed under the MIT/X11 software license, see the accompanying +// file license.txt or http://www.opensource.org/licenses/mit-license.php. + +#include // for 'map_list_of()' +#include + +#include "headers.h" +#include "checkpoints.h" + +namespace Checkpoints +{ + typedef std::map MapCheckpoints; + + // + // What makes a good checkpoint block? + // + Is surrounded by blocks with reasonable timestamps + // (no blocks before with a timestamp after, none after with + // timestamp before) + // + Contains no strange transactions + // + static MapCheckpoints mapCheckpoints = + boost::assign::map_list_of + ( 11111, uint256("0x0000000069e244f73d78e8fd29ba2fd2ed618bd6fa2ee92559f542fdb26e7c1d")) + ( 33333, uint256("0x000000002dd5588a74784eaa7ab0507a18ad16a236e7b1ce69f00d7ddfb5d0a6")) + ( 68555, uint256("0x00000000001e1b4903550a0b96e9a9405c8a95f387162e4944e8d9fbe501cd6a")) + ( 70567, uint256("0x00000000006a49b14bcf27462068f1264c961f11fa2e0eddd2be0791e1d4124a")) + ( 74000, uint256("0x0000000000573993a3c9e41ce34471c079dcf5f52a0e824a81e7f953b8661a20")) + (105000, uint256("0x00000000000291ce28027faea320c8d2b054b2e0fe44a773f3eefb151d6bdc97")) + (118000, uint256("0x000000000000774a7f8a7a12dc906ddb9e17e75d684f15e00f8767f9e8f36553")) + (134444, uint256("0x00000000000005b12ffd4cd315cd34ffd4a594f430ac814c91184a0d42d2b0fe")) + (140700, uint256("0x000000000000033b512028abb90e1626d8b346fd0ed598ac0a3c371138dce2bd")) + ; + + bool CheckBlock(int nHeight, const uint256& hash) + { + if (fTestNet) return true; // Testnet has no checkpoints + + MapCheckpoints::const_iterator i = mapCheckpoints.find(nHeight); + if (i == mapCheckpoints.end()) return true; + return hash == i->second; + } + + int GetTotalBlocksEstimate() + { + if (fTestNet) return 0; + + return mapCheckpoints.rbegin()->first; + } + + CBlockIndex* GetLastCheckpoint(const std::map& mapBlockIndex) + { + if (fTestNet) return NULL; + + int64 nResult; + BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints) + { + const uint256& hash = i.second; + std::map::const_iterator t = mapBlockIndex.find(hash); + if (t != mapBlockIndex.end()) + return t->second; + } + return NULL; + } +} diff --git a/src/checkpoints.h b/src/checkpoints.h new file mode 100644 index 00000000..9d52da40 --- /dev/null +++ b/src/checkpoints.h @@ -0,0 +1,29 @@ +// Copyright (c) 2011 The Bitcoin developers +// Distributed under the MIT/X11 software license, see the accompanying +// file license.txt or http://www.opensource.org/licenses/mit-license.php. +#ifndef BITCOIN_CHECKPOINT_H +#define BITCOIN_CHECKPOINT_H + +#include +#include "util.h" + +class uint256; +class CBlockIndex; + +// +// Block-chain checkpoints are compiled-in sanity checks. +// They are updated every release or three. +// +namespace Checkpoints +{ + // Returns true if block passes checkpoint checks + bool CheckBlock(int nHeight, const uint256& hash); + + // Return conservative estimate of total number of blocks, 0 if unknown + int GetTotalBlocksEstimate(); + + // Returns last CBlockIndex* in mapBlockIndex that is a checkpoint + CBlockIndex* GetLastCheckpoint(const std::map& mapBlockIndex); +} + +#endif diff --git a/src/main.cpp b/src/main.cpp index 47f10907..a7871fcc 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -3,6 +3,7 @@ // Distributed under the MIT/X11 software license, see the accompanying // file license.txt or http://www.opensource.org/licenses/mit-license.php. #include "headers.h" +#include "checkpoints.h" #include "db.h" #include "net.h" #include "init.h" @@ -29,7 +30,6 @@ map mapNextTx; map mapBlockIndex; uint256 hashGenesisBlock("0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"); static CBigNum bnProofOfWorkLimit(~uint256(0) >> 32); -const int nTotalBlocksEstimate = 140700; // Conservative estimate of total nr of blocks on main chain const int nInitialBlockThreshold = 120; // Regard blocks up until N-threshold as "initial download" CBlockIndex* pindexGenesisBlock = NULL; int nBestHeight = -1; @@ -659,11 +659,32 @@ int64 static GetBlockValue(int nHeight, int64 nFees) return nSubsidy + nFees; } +static const int64 nTargetTimespan = 14 * 24 * 60 * 60; // two weeks +static const int64 nTargetSpacing = 10 * 60; +static const int64 nInterval = nTargetTimespan / nTargetSpacing; + +// +// minimum amount of work that could possibly be required nTime after +// minimum work required was nBase +// +unsigned int ComputeMinWork(unsigned int nBase, int64 nTime) +{ + CBigNum bnResult; + bnResult.SetCompact(nBase); + while (nTime > 0 && bnResult < bnProofOfWorkLimit) + { + // Maximum 400% adjustment... + bnResult *= 4; + // ... in best-case exactly 4-times-normal target time + nTime -= nTargetTimespan*4; + } + if (bnResult > bnProofOfWorkLimit) + bnResult = bnProofOfWorkLimit; + return bnResult.GetCompact(); +} + unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast) { - const int64 nTargetTimespan = 14 * 24 * 60 * 60; // two weeks - const int64 nTargetSpacing = 10 * 60; - const int64 nInterval = nTargetTimespan / nTargetSpacing; // Genesis block if (pindexLast == NULL) @@ -721,28 +742,15 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits) return true; } -// Return conservative estimate of total number of blocks, 0 if unknown -int GetTotalBlocksEstimate() -{ - if(fTestNet) - { - return 0; - } - else - { - return nTotalBlocksEstimate; - } -} - // Return maximum amount of blocks that other nodes claim to have int GetNumBlocksOfPeers() { - return std::max(cPeerBlockCounts.median(), GetTotalBlocksEstimate()); + return std::max(cPeerBlockCounts.median(), Checkpoints::GetTotalBlocksEstimate()); } bool IsInitialBlockDownload() { - if (pindexBest == NULL || nBestHeight < (GetTotalBlocksEstimate()-nInitialBlockThreshold)) + if (pindexBest == NULL || nBestHeight < (Checkpoints::GetTotalBlocksEstimate()-nInitialBlockThreshold)) return true; static int64 nLastUpdate; static CBlockIndex* pindexLastBest; @@ -1317,17 +1325,8 @@ bool CBlock::AcceptBlock() return DoS(10, error("AcceptBlock() : contains a non-final transaction")); // Check that the block chain matches the known block chain up to a checkpoint - if (!fTestNet) - if ((nHeight == 11111 && hash != uint256("0x0000000069e244f73d78e8fd29ba2fd2ed618bd6fa2ee92559f542fdb26e7c1d")) || - (nHeight == 33333 && hash != uint256("0x000000002dd5588a74784eaa7ab0507a18ad16a236e7b1ce69f00d7ddfb5d0a6")) || - (nHeight == 68555 && hash != uint256("0x00000000001e1b4903550a0b96e9a9405c8a95f387162e4944e8d9fbe501cd6a")) || - (nHeight == 70567 && hash != uint256("0x00000000006a49b14bcf27462068f1264c961f11fa2e0eddd2be0791e1d4124a")) || - (nHeight == 74000 && hash != uint256("0x0000000000573993a3c9e41ce34471c079dcf5f52a0e824a81e7f953b8661a20")) || - (nHeight == 105000 && hash != uint256("0x00000000000291ce28027faea320c8d2b054b2e0fe44a773f3eefb151d6bdc97")) || - (nHeight == 118000 && hash != uint256("0x000000000000774a7f8a7a12dc906ddb9e17e75d684f15e00f8767f9e8f36553")) || - (nHeight == 134444 && hash != uint256("0x00000000000005b12ffd4cd315cd34ffd4a594f430ac814c91184a0d42d2b0fe")) || - (nHeight == 140700 && hash != uint256("0x000000000000033b512028abb90e1626d8b346fd0ed598ac0a3c371138dce2bd"))) - return DoS(100, error("AcceptBlock() : rejected by checkpoint lockin at %d", nHeight)); + if (!Checkpoints::CheckBlock(nHeight, hash)) + return DoS(100, error("AcceptBlock() : rejected by checkpoint lockin at %d", nHeight)); // Write block to history file if (!CheckDiskSpace(::GetSerializeSize(*this, SER_DISK))) @@ -1362,6 +1361,28 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock) if (!pblock->CheckBlock()) return error("ProcessBlock() : CheckBlock FAILED"); + CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(mapBlockIndex); + if (pcheckpoint && pblock->hashPrevBlock != hashBestChain) + { + // Extra checks to prevent "fill up memory by spamming with bogus blocks" + int64 deltaTime = pblock->GetBlockTime() - pcheckpoint->nTime; + if (deltaTime < 0) + { + pfrom->Misbehaving(100); + return error("ProcessBlock() : block with timestamp before last checkpoint"); + } + CBigNum bnNewBlock; + bnNewBlock.SetCompact(pblock->nBits); + CBigNum bnRequired; + bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime)); + if (bnNewBlock > bnRequired) + { + pfrom->Misbehaving(100); + return error("ProcessBlock() : block with too little proof-of-work"); + } + } + + // If don't already have its previous block, shunt it off to holding area until we get it if (!mapBlockIndex.count(pblock->hashPrevBlock)) { diff --git a/src/main.h b/src/main.h index 60ca3183..3870cee8 100644 --- a/src/main.h +++ b/src/main.h @@ -99,7 +99,7 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1); bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey); bool CheckProofOfWork(uint256 hash, unsigned int nBits); -int GetTotalBlocksEstimate(); +unsigned int ComputeMinWork(unsigned int nBase, int64 nTime); int GetNumBlocksOfPeers(); bool IsInitialBlockDownload(); std::string GetWarnings(std::string strFor); diff --git a/src/makefile.linux-mingw b/src/makefile.linux-mingw index 29b433f8..61f8d488 100644 --- a/src/makefile.linux-mingw +++ b/src/makefile.linux-mingw @@ -32,6 +32,7 @@ CFLAGS=-O2 -w -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(INCLUDEPATH HEADERS = \ base58.h \ bignum.h \ + checkpoints.h \ crypter.h \ db.h \ headers.h \ @@ -61,6 +62,7 @@ endif LIBS += -l mingwthrd -l kernel32 -l user32 -l gdi32 -l comdlg32 -l winspool -l winmm -l shell32 -l comctl32 -l ole32 -l oleaut32 -l uuid -l rpcrt4 -l advapi32 -l ws2_32 -l shlwapi OBJS= \ + obj/checkpoints.o \ obj/crypter.o \ obj/db.o \ obj/init.o \ diff --git a/src/makefile.mingw b/src/makefile.mingw index 95d09f87..2cb78d97 100644 --- a/src/makefile.mingw +++ b/src/makefile.mingw @@ -29,6 +29,7 @@ CFLAGS=-mthreads -O2 -w -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(I HEADERS = \ base58.h \ bignum.h \ + checkpoints.h \ crypter.h \ db.h \ headers.h \ @@ -58,6 +59,7 @@ endif LIBS += -l kernel32 -l user32 -l gdi32 -l comdlg32 -l winspool -l winmm -l shell32 -l comctl32 -l ole32 -l oleaut32 -l uuid -l rpcrt4 -l advapi32 -l ws2_32 -l shlwapi OBJS= \ + obj/checkpoints.o \ obj/crypter.o \ obj/db.o \ obj/init.o \ diff --git a/src/makefile.osx b/src/makefile.osx index 7830f3ba..de718879 100644 --- a/src/makefile.osx +++ b/src/makefile.osx @@ -49,6 +49,7 @@ CFLAGS=-mmacosx-version-min=10.5 -arch i386 -O3 -Wno-invalid-offsetof -Wformat $ HEADERS = \ base58.h \ bignum.h \ + checkpoints.h \ crypter.h \ db.h \ headers.h \ @@ -69,6 +70,7 @@ HEADERS = \ wallet.h OBJS= \ + obj/checkpoints.o \ obj/crypter.o \ obj/db.o \ obj/init.o \ diff --git a/src/makefile.unix b/src/makefile.unix index 5f841ea0..6c481995 100644 --- a/src/makefile.unix +++ b/src/makefile.unix @@ -87,6 +87,7 @@ xCXXFLAGS=-pthread -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(HARDEN HEADERS = \ base58.h \ bignum.h \ + checkpoints.h \ crypter.h \ db.h \ headers.h \ @@ -107,6 +108,7 @@ HEADERS = \ wallet.h OBJS= \ + obj/checkpoints.o \ obj/crypter.o \ obj/db.o \ obj/init.o \ diff --git a/src/makefile.vc b/src/makefile.vc index c7e8578a..60f1e096 100644 --- a/src/makefile.vc +++ b/src/makefile.vc @@ -43,6 +43,7 @@ CFLAGS=/MD /c /nologo /EHsc /GR /Zm300 $(DEBUGFLAGS) $(DEFS) $(INCLUDEPATHS) HEADERS = \ base58.h \ bignum.h \ + checkpoints.h \ crypter.h \ db.h \ headers.h \ @@ -65,6 +66,7 @@ HEADERS = \ wallet.h OBJS= \ + obj\checkpoints.o \ obj\crypter.o \ obj\db.o \ obj\init.o \ @@ -87,6 +89,8 @@ all: bitcoind.exe .cpp{obj}.obj: cl $(CFLAGS) /DGUI /Fo$@ %s +obj\checkpoints.obj: $(HEADERS) + obj\util.obj: $(HEADERS) obj\script.obj: $(HEADERS) @@ -116,6 +120,8 @@ obj\uibase.obj: $(HEADERS) .cpp{obj\nogui}.obj: cl $(CFLAGS) /Fo$@ %s +obj\nogui\checkpoints.obj: $(HEADERS) + obj\nogui\util.obj: $(HEADERS) obj\nogui\script.obj: $(HEADERS) diff --git a/src/test/Checkpoints_tests.cpp b/src/test/Checkpoints_tests.cpp new file mode 100644 index 00000000..0d8a366d --- /dev/null +++ b/src/test/Checkpoints_tests.cpp @@ -0,0 +1,34 @@ +// +// Unit tests for block-chain checkpoints +// +#include // for 'map_list_of()' +#include +#include + +#include "../checkpoints.h" +#include "../util.h" + +using namespace std; + +BOOST_AUTO_TEST_SUITE(Checkpoints_tests) + +BOOST_AUTO_TEST_CASE(sanity) +{ + uint256 p11111 = uint256("0x0000000069e244f73d78e8fd29ba2fd2ed618bd6fa2ee92559f542fdb26e7c1d"); + uint256 p140700 = uint256("0x000000000000033b512028abb90e1626d8b346fd0ed598ac0a3c371138dce2bd"); + BOOST_CHECK(Checkpoints::CheckBlock(11111, p11111)); + BOOST_CHECK(Checkpoints::CheckBlock(140700, p140700)); + + + // Wrong hashes at checkpoints should fail: + BOOST_CHECK(!Checkpoints::CheckBlock(11111, p140700)); + BOOST_CHECK(!Checkpoints::CheckBlock(140700, p11111)); + + // ... but any hash not at a checkpoint should succeed: + BOOST_CHECK(Checkpoints::CheckBlock(11111+1, p140700)); + BOOST_CHECK(Checkpoints::CheckBlock(140700+1, p11111)); + + BOOST_CHECK(Checkpoints::GetTotalBlocksEstimate() >= 140700); +} + +BOOST_AUTO_TEST_SUITE_END() diff --git a/src/test/DoS_tests.cpp b/src/test/DoS_tests.cpp index e60bb742..01e66912 100644 --- a/src/test/DoS_tests.cpp +++ b/src/test/DoS_tests.cpp @@ -1,6 +1,7 @@ // // Unit tests for denial-of-service detection/prevention code // +#include // for 'map_list_of()' #include #include @@ -64,5 +65,54 @@ BOOST_AUTO_TEST_CASE(DoS_bantime) BOOST_CHECK(!CNode::IsBanned(addr.ip)); } +static bool CheckNBits(unsigned int nbits1, int64 time1, unsigned int nbits2, int64 time2) +{ + if (time1 > time2) + return CheckNBits(nbits2, time2, nbits1, time1); + int64 deltaTime = time2-time1; + + CBigNum required; + required.SetCompact(ComputeMinWork(nbits1, deltaTime)); + CBigNum have; + have.SetCompact(nbits2); + return (have <= required); +} + +BOOST_AUTO_TEST_CASE(DoS_checknbits) +{ + using namespace boost::assign; // for 'map_list_of()' + + // Timestamps,nBits from the bitcoin blockchain. + // These are the block-chain checkpoint blocks + typedef std::map BlockData; + BlockData chainData = + map_list_of(1239852051,486604799)(1262749024,486594666) + (1279305360,469854461)(1280200847,469830746)(1281678674,469809688) + (1296207707,453179945)(1302624061,453036989)(1309640330,437004818) + (1313172719,436789733); + + // Make sure CheckNBits considers every combination of block-chain-lock-in-points + // "sane": + BOOST_FOREACH(const BlockData::value_type& i, chainData) + { + BOOST_FOREACH(const BlockData::value_type& j, chainData) + { + BOOST_CHECK(CheckNBits(i.second, i.first, j.second, j.first)); + } + } + + // Test a couple of insane combinations: + BlockData::value_type firstcheck = *(chainData.begin()); + BlockData::value_type lastcheck = *(chainData.rbegin()); + + // First checkpoint difficulty at or a while after the last checkpoint time should fail when + // compared to last checkpoint + BOOST_CHECK(!CheckNBits(firstcheck.second, lastcheck.first+60*10, lastcheck.second, lastcheck.first)); + BOOST_CHECK(!CheckNBits(firstcheck.second, lastcheck.first+60*60*24*14, lastcheck.second, lastcheck.first)); + + // ... but OK if enough time passed for difficulty to adjust downward: + BOOST_CHECK(CheckNBits(firstcheck.second, lastcheck.first+60*60*24*365*4, lastcheck.second, lastcheck.first)); + +} BOOST_AUTO_TEST_SUITE_END() diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp index 8863aad4..39a7c88e 100644 --- a/src/test/test_bitcoin.cpp +++ b/src/test/test_bitcoin.cpp @@ -13,6 +13,7 @@ #include "util_tests.cpp" #include "base58_tests.cpp" #include "miner_tests.cpp" +#include "Checkpoints_tests.cpp" CWallet* pwalletMain;