pow_tests.cpp raw
1 // Copyright (c) 2015-present 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/common.h>
10 #include <test/util/setup_common.h>
11 #include <util/chaintype.h>
12
13 #include <boost/test/unit_test.hpp>
14
15 BOOST_FIXTURE_TEST_SUITE(pow_tests, BasicTestingSetup)
16
17 /* Test calculation of next difficulty target with no constraints applying */
18 BOOST_AUTO_TEST_CASE(get_next_work)
19 {
20 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN);
21 int64_t nLastRetargetTime = 1261130161; // Block #30240
22 CBlockIndex pindexLast;
23 pindexLast.nHeight = 32255;
24 pindexLast.nTime = 1262152739; // Block #32255
25 pindexLast.nBits = 0x1d00ffff;
26
27 // Here (and below): expected_nbits is calculated in
28 // CalculateNextWorkRequired(); redoing the calculation here would be just
29 // reimplementing the same code that is written in pow.cpp. Rather than
30 // copy that code, we just hardcode the expected result.
31 unsigned int expected_nbits = 0x1d00d86aU;
32 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits);
33 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits));
34 }
35
36 /* Test the constraint on the upper bound for next work */
37 BOOST_AUTO_TEST_CASE(get_next_work_pow_limit)
38 {
39 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN);
40 int64_t nLastRetargetTime = 1231006505; // Block #0
41 CBlockIndex pindexLast;
42 pindexLast.nHeight = 2015;
43 pindexLast.nTime = 1233061996; // Block #2015
44 pindexLast.nBits = 0x1d00ffff;
45 unsigned int expected_nbits = 0x1d00ffffU;
46 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits);
47 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits));
48 }
49
50 /* Test the constraint on the lower bound for actual time taken */
51 BOOST_AUTO_TEST_CASE(get_next_work_lower_limit_actual)
52 {
53 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN);
54 int64_t nLastRetargetTime = 1279008237; // Block #66528
55 CBlockIndex pindexLast;
56 pindexLast.nHeight = 68543;
57 pindexLast.nTime = 1279297671; // Block #68543
58 pindexLast.nBits = 0x1c05a3f4;
59 unsigned int expected_nbits = 0x1c0168fdU;
60 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits);
61 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits));
62 // Test that reducing nbits further would not be a PermittedDifficultyTransition.
63 unsigned int invalid_nbits = expected_nbits-1;
64 BOOST_CHECK(!PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, invalid_nbits));
65 }
66
67 /* Test the constraint on the upper bound for actual time taken */
68 BOOST_AUTO_TEST_CASE(get_next_work_upper_limit_actual)
69 {
70 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN);
71 int64_t nLastRetargetTime = 1263163443; // NOTE: Not an actual block time
72 CBlockIndex pindexLast;
73 pindexLast.nHeight = 46367;
74 pindexLast.nTime = 1269211443; // Block #46367
75 pindexLast.nBits = 0x1c387f6f;
76 unsigned int expected_nbits = 0x1d00e1fdU;
77 BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, chainParams->GetConsensus()), expected_nbits);
78 BOOST_CHECK(PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, expected_nbits));
79 // Test that increasing nbits further would not be a PermittedDifficultyTransition.
80 unsigned int invalid_nbits = expected_nbits+1;
81 BOOST_CHECK(!PermittedDifficultyTransition(chainParams->GetConsensus(), pindexLast.nHeight+1, pindexLast.nBits, invalid_nbits));
82 }
83
84 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_negative_target)
85 {
86 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus();
87 uint256 hash;
88 unsigned int nBits;
89 nBits = UintToArith256(consensus.powLimit).GetCompact(true);
90 hash = uint256{1};
91 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus));
92 }
93
94 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_overflow_target)
95 {
96 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus();
97 uint256 hash;
98 unsigned int nBits{~0x00800000U};
99 hash = uint256{1};
100 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus));
101 }
102
103 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_too_easy_target)
104 {
105 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus();
106 uint256 hash;
107 unsigned int nBits;
108 arith_uint256 nBits_arith = UintToArith256(consensus.powLimit);
109 nBits_arith *= 2;
110 nBits = nBits_arith.GetCompact();
111 hash = uint256{1};
112 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus));
113 }
114
115 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_biger_hash_than_target)
116 {
117 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus();
118 uint256 hash;
119 unsigned int nBits;
120 arith_uint256 hash_arith = UintToArith256(consensus.powLimit);
121 nBits = hash_arith.GetCompact();
122 hash_arith *= 2; // hash > nBits
123 hash = ArithToUint256(hash_arith);
124 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus));
125 }
126
127 BOOST_AUTO_TEST_CASE(CheckProofOfWork_test_zero_target)
128 {
129 const auto consensus = CreateChainParams(*m_node.args, ChainType::MAIN)->GetConsensus();
130 uint256 hash;
131 unsigned int nBits;
132 arith_uint256 hash_arith{0};
133 nBits = hash_arith.GetCompact();
134 hash = ArithToUint256(hash_arith);
135 BOOST_CHECK(!CheckProofOfWork(hash, nBits, consensus));
136 }
137
138 BOOST_AUTO_TEST_CASE(GetBlockProofEquivalentTime_test)
139 {
140 const auto chainParams = CreateChainParams(*m_node.args, ChainType::MAIN);
141 std::vector<CBlockIndex> blocks(10000);
142 for (int i = 0; i < 10000; i++) {
143 blocks[i].pprev = i ? &blocks[i - 1] : nullptr;
144 blocks[i].nHeight = i;
145 blocks[i].nTime = 1269211443 + i * chainParams->GetConsensus().nPowTargetSpacing;
146 blocks[i].nBits = 0x207fffff; /* target 0x7fffff000... */
147 blocks[i].nChainWork = i ? blocks[i - 1].nChainWork + GetBlockProof(blocks[i - 1]) : arith_uint256(0);
148 }
149
150 for (int j = 0; j < 1000; j++) {
151 CBlockIndex *p1 = &blocks[m_rng.randrange(10000)];
152 CBlockIndex *p2 = &blocks[m_rng.randrange(10000)];
153 CBlockIndex *p3 = &blocks[m_rng.randrange(10000)];
154
155 int64_t tdiff = GetBlockProofEquivalentTime(*p1, *p2, *p3, chainParams->GetConsensus());
156 BOOST_CHECK_EQUAL(tdiff, p1->GetBlockTime() - p2->GetBlockTime());
157 }
158 }
159
160 void sanity_check_chainparams(const ArgsManager& args, ChainType chain_type)
161 {
162 const auto chainParams = CreateChainParams(args, chain_type);
163 const auto consensus = chainParams->GetConsensus();
164
165 // hash genesis is correct
166 BOOST_CHECK_EQUAL(consensus.hashGenesisBlock, chainParams->GenesisBlock().GetHash());
167
168 // target timespan is an even multiple of spacing
169 BOOST_CHECK_EQUAL(consensus.nPowTargetTimespan % consensus.nPowTargetSpacing, 0);
170
171 // genesis nBits is positive, doesn't overflow and is lower than powLimit
172 arith_uint256 pow_compact;
173 bool neg, over;
174 pow_compact.SetCompact(chainParams->GenesisBlock().nBits, &neg, &over);
175 BOOST_CHECK(!neg && pow_compact != 0);
176 BOOST_CHECK(!over);
177 BOOST_CHECK(UintToArith256(consensus.powLimit) >= pow_compact);
178
179 // check max target * 4*nPowTargetTimespan doesn't overflow -- see pow.cpp:CalculateNextWorkRequired()
180 if (!consensus.fPowNoRetargeting) {
181 arith_uint256 targ_max{UintToArith256(uint256{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"})};
182 targ_max /= consensus.nPowTargetTimespan*4;
183 BOOST_CHECK(UintToArith256(consensus.powLimit) < targ_max);
184 }
185 }
186
187 BOOST_AUTO_TEST_CASE(ChainParams_MAIN_sanity)
188 {
189 sanity_check_chainparams(*m_node.args, ChainType::MAIN);
190 }
191
192 BOOST_AUTO_TEST_CASE(ChainParams_REGTEST_sanity)
193 {
194 sanity_check_chainparams(*m_node.args, ChainType::REGTEST);
195 }
196
197 BOOST_AUTO_TEST_CASE(ChainParams_TESTNET_sanity)
198 {
199 sanity_check_chainparams(*m_node.args, ChainType::TESTNET);
200 }
201
202 BOOST_AUTO_TEST_CASE(ChainParams_TESTNET4_sanity)
203 {
204 sanity_check_chainparams(*m_node.args, ChainType::TESTNET4);
205 }
206
207 BOOST_AUTO_TEST_CASE(ChainParams_SIGNET_sanity)
208 {
209 sanity_check_chainparams(*m_node.args, ChainType::SIGNET);
210 }
211
212 BOOST_AUTO_TEST_SUITE_END()
213