pow_tests.cpp
1 // Copyright (c) 2015-2022 The Bitcoin Core developers 2 // Distributed under the MIT software license, see the accompanying 3 // file COPYING or http://www.opensource.org/licenses/mit-license.php. 4 5 #include <chain.h> 6 #include <chainparams.h> 7 #include <pow.h> 8 #include <test/util/random.h> 9 #include <test/util/setup_common.h> 10 #include <util/chaintype.h> 11 12 #include <boost/test/unit_test.hpp> 13 14 BOOST_FIXTURE_TEST_SUITE(pow_tests, BasicTestingSetup) 15 16 /* Test calculation of next difficulty target with no constraints applying */ 17 BOOST_AUTO_TEST_CASE(get_next_work) 18 { 19 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN); 20 int64_t nLastRetargetTime = 1261130161; // Block #30240 21 CBlockIndex pindexLast; 22 pindexLast.nHeight = 32255; 23 pindexLast.nTime = 1262152739; // Block #32255 24 pindexLast.nBits = 0x1d00ffff; 25 26 // Here (and below): expected_nbits is calculated in 27 // CalculateNextWorkRequired(); redoing the calculation here would be just 28 // reimplementing the same code that is written in pow.cpp. Rather than 29 // copy that code, we just hardcode the expected result. 30 unsigned int expected_nbits = 0x1d00d86aU; 31 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits); 32 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits)); 33 } 34 35 /* Test the constraint on the upper bound for next work */ 36 BOOST_AUTO_TEST_CASE(get_next_work_pow_limit) 37 { 38 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN); 39 int64_t nLastRetargetTime = 1231006505; // Block #0 40 CBlockIndex pindexLast; 41 pindexLast.nHeight = 2015; 42 pindexLast.nTime = 1233061996; // Block #2015 43 pindexLast.nBits = 0x1d00ffff; 44 unsigned int expected_nbits = 0x1d00ffffU; 45 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits); 46 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits)); 47 } 48 49 /* Test the constraint on the lower bound for actual time taken */ 50 BOOST_AUTO_TEST_CASE(get_next_work_lower_limit_actual) 51 { 52 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN); 53 int64_t nLastRetargetTime = 1279008237; // Block #66528 54 CBlockIndex pindexLast; 55 pindexLast.nHeight = 68543; 56 pindexLast.nTime = 1279297671; // Block #68543 57 pindexLast.nBits = 0x1c05a3f4; 58 unsigned int expected_nbits = 0x1c0168fdU; 59 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits); 60 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits)); 61 // Test that reducing nbits further would not be a PermittedDifficultyTransition. 62 unsigned int invalid_nbits = expected_nbits-1; 63 BOOST_CHECK(!PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, invalid_nbits)); 64 } 65 66 /* Test the constraint on the upper bound for actual time taken */ 67 BOOST_AUTO_TEST_CASE(get_next_work_upper_limit_actual) 68 { 69 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN); 70 int64_t nLastRetargetTime = 1263163443; // NOTE: Not an actual block time 71 CBlockIndex pindexLast; 72 pindexLast.nHeight = 46367; 73 pindexLast.nTime = 1269211443; // Block #46367 74 pindexLast.nBits = 0x1c387f6f; 75 unsigned int expected_nbits = 0x1d00e1fdU; 76 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits); 77 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits)); 78 // Test that increasing nbits further would not be a PermittedDifficultyTransition. 79 unsigned int invalid_nbits = expected_nbits+1; 80 BOOST_CHECK(!PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, invalid_nbits)); 81 } 82 83 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_negative_target) 84 { 85 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus(); 86 uint256 hash; 87 unsigned int nBits; 88 nBits = UintToArith256(consensus.powLimit).GetCompact(true); 89 hash = uint256{1}; 90 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus)); 91 } 92 93 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_overflow_target) 94 { 95 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus(); 96 uint256 hash; 97 unsigned int nBits{~0x00800000U}; 98 hash = uint256{1}; 99 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus)); 100 } 101 102 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_too_easy_target) 103 { 104 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus(); 105 uint256 hash; 106 unsigned int nBits; 107 arith_uint256 nBits_arith = UintToArith256(consensus.powLimit); 108 nBits_arith *= 2; 109 nBits = nBits_arith.GetCompact(); 110 hash = uint256{1}; 111 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus)); 112 } 113 114 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_biger_hash_than_target) 115 { 116 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus(); 117 uint256 hash; 118 unsigned int nBits; 119 arith_uint256 hash_arith = UintToArith256(consensus.powLimit); 120 nBits = hash_arith.GetCompact(); 121 hash_arith *= 2; // hash > nBits 122 hash = ArithToUint256(hash_arith); 123 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus)); 124 } 125 126 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_zero_target) 127 { 128 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus(); 129 uint256 hash; 130 unsigned int nBits; 131 arith_uint256 hash_arith{0}; 132 nBits = hash_arith.GetCompact(); 133 hash = ArithToUint256(hash_arith); 134 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus)); 135 } 136 137 BOOST_AUTO_TEST_CASE(GetBlockProofEquivalentTime_test) 138 { 139 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN); 140 std::vector<CBlockIndex> blocks(10000); 141 for (int i = 0; i < 10000; i++) { 142 blocks[i].pprev = i ? &blocks[i - 1] : nullptr; 143 blocks[i].nHeight = i; 144 blocks[i].nTime = 1269211443 + i * chainParams->GetConsensus().nPowTargetSpacing; 145 blocks[i].nBits = 0x207fffff; /* target 0x7fffff000... */ 146 blocks[i].nChainWork = i ? blocks[i - 1].nChainWork + GetBlockProof(blocks[i - 1]) : arith_uint256(0); 147 } 148 149 for (int j = 0; j < 1000; j++) { 150 CBlockIndex *p1 = &blocks[m_rng.randrange(10000)]; 151 CBlockIndex *p2 = &blocks[m_rng.randrange(10000)]; 152 CBlockIndex *p3 = &blocks[m_rng.randrange(10000)]; 153 154 int64_t tdiff = GetBlockProofEquivalentTime(*p1, *p2, *p3, chainParams->GetConsensus()); 155 BOOST_CHECK_EQUAL(tdiff, p1->GetBlockTime() - p2->GetBlockTime()); 156 } 157 } 158 159 void sanity_check_chainparams(const ArgsManager& args, ChainType chain_type) 160 { 161 const auto chainParams = CreateChainParams(args, chain_type); 162 const auto consensus = chainParams->GetConsensus(); 163 164 // hash genesis is correct 165 BOOST_CHECK_EQUAL(consensus.hashGenesisBlock, chainParams->GenesisBlock().GetHash()); 166 167 // target timespan is an even multiple of spacing 168 BOOST_CHECK_EQUAL(consensus.nPowTargetTimespan % consensus.nPowTargetSpacing, 0); 169 170 // genesis nBits is positive, doesn't overflow and is lower than powLimit 171 arith_uint256 pow_compact; 172 bool neg, over; 173 pow_compact.SetCompact(chainParams->GenesisBlock().nBits, &neg, &over); 174 BOOST_CHECK(!neg && pow_compact != 0); 175 BOOST_CHECK(!over); 176 BOOST_CHECK(UintToArith256(consensus.powLimit) >= pow_compact); 177 178 // check max target * 4*nPowTargetTimespan doesn't overflow -- see pow.cpp:CalculateNextWorkRequired() 179 if (!consensus.fPowNoRetargeting) { 180 arith_uint256 targ_max{UintToArith256(uint256{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"})}; 181 targ_max /= consensus.nPowTargetTimespan*4; 182 BOOST_CHECK(UintToArith256(consensus.powLimit) < targ_max); 183 } 184 } 185 186 BOOST_AUTO_TEST_CASE(ChainParams_MAIN_sanity) 187 { 188 sanity_check_chainparams(*m_node.args, ChainType::MAIN); 189 } 190 191 BOOST_AUTO_TEST_CASE(ChainParams_REGTEST_sanity) 192 { 193 sanity_check_chainparams(*m_node.args, ChainType::REGTEST); 194 } 195 196 BOOST_AUTO_TEST_CASE(ChainParams_TESTNET_sanity) 197 { 198 sanity_check_chainparams(*m_node.args, ChainType::TESTNET); 199 } 200 201 BOOST_AUTO_TEST_CASE(ChainParams_TESTNET4_sanity) 202 { 203 sanity_check_chainparams(*m_node.args, ChainType::TESTNET4); 204 } 205 206 BOOST_AUTO_TEST_CASE(ChainParams_SIGNET_sanity) 207 { 208 sanity_check_chainparams(*m_node.args, ChainType::SIGNET); 209 } 210 211 BOOST_AUTO_TEST_SUITE_END()