Branch data Line data Source code
1 : : // Copyright (c) 2020 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 <chainparams.h>
6 : : #include <consensus/consensus.h>
7 : : #include <consensus/merkle.h>
8 : : #include <kernel/coinstats.h>
9 : : #include <node/miner.h>
10 : : #include <script/interpreter.h>
11 : : #include <streams.h>
12 : : #include <test/fuzz/FuzzedDataProvider.h>
13 : : #include <test/fuzz/fuzz.h>
14 : : #include <test/fuzz/util.h>
15 : : #include <test/util/mining.h>
16 : : #include <test/util/setup_common.h>
17 : : #include <util/chaintype.h>
18 : : #include <validation.h>
19 : :
20 [ # # ]: 0 : FUZZ_TARGET(utxo_total_supply)
21 : : {
22 : : /** The testing setup that creates a chainman only (no chainstate) */
23 : 0 : ChainTestingSetup test_setup{
24 : : ChainType::REGTEST,
25 : : {
26 : : .extra_args = {"-testactivationheight=bip34@2"},
27 : : },
28 [ # # # # ]: 0 : };
29 : : // Create chainstate
30 [ # # ]: 0 : test_setup.LoadVerifyActivateChainstate();
31 : 0 : auto& node{test_setup.m_node};
32 [ # # # # ]: 0 : auto& chainman{*Assert(test_setup.m_node.chainman)};
33 [ # # ]: 0 : FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
34 : :
35 : 0 : const auto ActiveHeight = [&]() {
36 : 0 : LOCK(chainman.GetMutex());
37 [ # # # # ]: 0 : return chainman.ActiveHeight();
38 : 0 : };
39 : 0 : const auto PrepareNextBlock = [&]() {
40 : : // Use OP_FALSE to avoid BIP30 check from hitting early
41 [ # # # # ]: 0 : auto block = PrepareBlock(node, CScript{} << OP_FALSE);
42 : : // Replace OP_FALSE with OP_TRUE
43 : 0 : {
44 [ # # ]: 0 : CMutableTransaction tx{*block->vtx.back()};
45 [ # # # # ]: 0 : tx.vout.at(0).scriptPubKey = CScript{} << OP_TRUE;
46 [ # # # # ]: 0 : block->vtx.back() = MakeTransactionRef(tx);
47 : 0 : }
48 : 0 : return block;
49 : 0 : };
50 : :
51 : : /** The block template this fuzzer is working on */
52 [ # # ]: 0 : auto current_block = PrepareNextBlock();
53 : : /** Append-only set of tx outpoints, entries are not removed when spent */
54 : 0 : std::vector<std::pair<COutPoint, CTxOut>> txos;
55 : : /** The utxo stats at the chain tip */
56 : 0 : kernel::CCoinsStats utxo_stats;
57 : : /** The total amount of coins in the utxo set */
58 : 0 : CAmount circulation{0};
59 : :
60 : :
61 : : // Store the tx out in the txo map
62 : 0 : const auto StoreLastTxo = [&]() {
63 : : // get last tx
64 : 0 : const CTransaction& tx = *current_block->vtx.back();
65 : : // get last out
66 : 0 : const uint32_t i = tx.vout.size() - 1;
67 : : // store it
68 : 0 : txos.emplace_back(COutPoint{tx.GetHash(), i}, tx.vout.at(i));
69 [ # # # # : 0 : if (current_block->vtx.size() == 1 && tx.vout.at(i).scriptPubKey[0] == OP_RETURN) {
# # ]
70 : : // also store coinbase
71 : 0 : const uint32_t i = tx.vout.size() - 2;
72 : 0 : txos.emplace_back(COutPoint{tx.GetHash(), i}, tx.vout.at(i));
73 : : }
74 : 0 : };
75 : 0 : const auto AppendRandomTxo = [&](CMutableTransaction& tx) {
76 : 0 : const auto& txo = txos.at(fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, txos.size() - 1));
77 : 0 : tx.vin.emplace_back(txo.first);
78 : 0 : tx.vout.emplace_back(txo.second.nValue, txo.second.scriptPubKey); // "Forward" coin with no fee
79 : 0 : };
80 : 0 : const auto UpdateUtxoStats = [&]() {
81 : 0 : LOCK(chainman.GetMutex());
82 [ # # # # ]: 0 : chainman.ActiveChainstate().ForceFlushStateToDisk();
83 [ # # ]: 0 : utxo_stats = std::move(
84 [ # # # # : 0 : *Assert(kernel::ComputeUTXOStats(kernel::CoinStatsHashType::NONE, &chainman.ActiveChainstate().CoinsDB(), chainman.m_blockman, {})));
# # # # ]
85 : : // Check that miner can't print more money than they are allowed to
86 [ # # # # ]: 0 : assert(circulation == utxo_stats.total_amount);
87 : 0 : };
88 : :
89 : :
90 : : // Update internal state to chain tip
91 [ # # ]: 0 : StoreLastTxo();
92 [ # # ]: 0 : UpdateUtxoStats();
93 [ # # # # ]: 0 : assert(ActiveHeight() == 0);
94 : : // Get at which height we duplicate the coinbase
95 : : // Assuming that the fuzzer will mine relatively short chains (less than 200 blocks), we want the duplicate coinbase to be not too high.
96 : : // Up to 300 seems reasonable.
97 : 0 : int64_t duplicate_coinbase_height = fuzzed_data_provider.ConsumeIntegralInRange(0, 300);
98 : : // Always pad with OP_0 at the end to avoid bad-cb-length error
99 [ # # # # ]: 0 : const CScript duplicate_coinbase_script = CScript() << duplicate_coinbase_height << OP_0;
100 : : // Mine the first block with this duplicate
101 [ # # # # ]: 0 : current_block = PrepareNextBlock();
102 [ # # ]: 0 : StoreLastTxo();
103 : :
104 : 0 : {
105 : : // Create duplicate (CScript should match exact format as in CreateNewBlock)
106 [ # # ]: 0 : CMutableTransaction tx{*current_block->vtx.front()};
107 [ # # ]: 0 : tx.vin.at(0).scriptSig = duplicate_coinbase_script;
108 : :
109 : : // Mine block and create next block template
110 [ # # # # ]: 0 : current_block->vtx.front() = MakeTransactionRef(tx);
111 : 0 : }
112 [ # # ]: 0 : current_block->hashMerkleRoot = BlockMerkleRoot(*current_block);
113 [ # # # # ]: 0 : assert(!MineBlock(node, current_block).IsNull());
114 [ # # # # : 0 : circulation += GetBlockSubsidy(ActiveHeight(), Params().GetConsensus());
# # ]
115 : :
116 [ # # # # ]: 0 : assert(ActiveHeight() == 1);
117 [ # # ]: 0 : UpdateUtxoStats();
118 [ # # # # ]: 0 : current_block = PrepareNextBlock();
119 [ # # ]: 0 : StoreLastTxo();
120 : :
121 : : // Limit to avoid timeout, but enough to cover duplicate_coinbase_height
122 : : // and CVE-2018-17144.
123 [ # # # # ]: 0 : LIMITED_WHILE(fuzzed_data_provider.remaining_bytes(), 2'00)
124 : : {
125 [ # # ]: 0 : CallOneOf(
126 : : fuzzed_data_provider,
127 : 0 : [&] {
128 : : // Append an input-output pair to the last tx in the current block
129 : 0 : CMutableTransaction tx{*current_block->vtx.back()};
130 [ # # ]: 0 : AppendRandomTxo(tx);
131 [ # # # # ]: 0 : current_block->vtx.back() = MakeTransactionRef(tx);
132 [ # # ]: 0 : StoreLastTxo();
133 : 0 : },
134 : 0 : [&] {
135 : : // Append a tx to the list of txs in the current block
136 : 0 : CMutableTransaction tx{};
137 [ # # ]: 0 : AppendRandomTxo(tx);
138 [ # # # # : 0 : current_block->vtx.push_back(MakeTransactionRef(tx));
# # ]
139 [ # # ]: 0 : StoreLastTxo();
140 : 0 : },
141 : 0 : [&] {
142 : : // Append the current block to the active chain
143 : 0 : node::RegenerateCommitments(*current_block, chainman);
144 : 0 : const bool was_valid = !MineBlock(node, current_block).IsNull();
145 : :
146 : 0 : const auto prev_utxo_stats = utxo_stats;
147 [ # # ]: 0 : if (was_valid) {
148 [ # # ]: 0 : if (duplicate_coinbase_height == ActiveHeight()) {
149 : : // we mined the duplicate coinbase
150 [ # # ]: 0 : assert(current_block->vtx.at(0)->vin.at(0).scriptSig == duplicate_coinbase_script);
151 : : }
152 : :
153 : 0 : circulation += GetBlockSubsidy(ActiveHeight(), Params().GetConsensus());
154 : : }
155 : :
156 : 0 : UpdateUtxoStats();
157 : :
158 [ # # ]: 0 : if (!was_valid) {
159 : : // utxo stats must not change
160 [ # # ]: 0 : assert(prev_utxo_stats.hashSerialized == utxo_stats.hashSerialized);
161 : : }
162 : :
163 [ # # ]: 0 : current_block = PrepareNextBlock();
164 : 0 : StoreLastTxo();
165 : 0 : });
166 : : }
167 [ # # ]: 0 : }
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