Bitcoin Core 29.99.0
P2P Digital Currency
coinselection.cpp
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1// Copyright (c) 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 <policy/feerate.h>
6#include <policy/policy.h>
9#include <test/fuzz/fuzz.h>
10#include <test/fuzz/util.h>
13
14#include <numeric>
15#include <span>
16#include <vector>
17
18namespace wallet {
19
20static void AddCoin(const CAmount& value, int n_input, int n_input_bytes, int locktime, std::vector<COutput>& coins, CFeeRate fee_rate)
21{
23 tx.vout.resize(n_input + 1);
24 tx.vout[n_input].nValue = value;
25 tx.nLockTime = locktime; // all transactions get different hashes
26 coins.emplace_back(COutPoint(tx.GetHash(), n_input), tx.vout.at(n_input), /*depth=*/0, n_input_bytes, /*spendable=*/true, /*solvable=*/true, /*safe=*/true, /*time=*/0, /*from_me=*/true, fee_rate);
27}
28
29// Randomly distribute coins to instances of OutputGroup
30static void GroupCoins(FuzzedDataProvider& fuzzed_data_provider, const std::vector<COutput>& coins, const CoinSelectionParams& coin_params, bool positive_only, std::vector<OutputGroup>& output_groups)
31{
32 auto output_group = OutputGroup(coin_params);
33 bool valid_outputgroup{false};
34 for (auto& coin : coins) {
35 if (!positive_only || (positive_only && coin.GetEffectiveValue() > 0)) {
36 output_group.Insert(std::make_shared<COutput>(coin), /*ancestors=*/0, /*descendants=*/0);
37 }
38 // If positive_only was specified, nothing was inserted, leading to an empty output group
39 // that would be invalid for the BnB algorithm
40 valid_outputgroup = !positive_only || output_group.GetSelectionAmount() > 0;
41 if (valid_outputgroup && fuzzed_data_provider.ConsumeBool()) {
42 output_groups.push_back(output_group);
43 output_group = OutputGroup(coin_params);
44 valid_outputgroup = false;
45 }
46 }
47 if (valid_outputgroup) output_groups.push_back(output_group);
48}
49
50static CAmount CreateCoins(FuzzedDataProvider& fuzzed_data_provider, std::vector<COutput>& utxo_pool, CoinSelectionParams& coin_params, int& next_locktime)
51{
52 CAmount total_balance{0};
53 LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000)
54 {
55 const int n_input{fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 10)};
56 const int n_input_bytes{fuzzed_data_provider.ConsumeIntegralInRange<int>(41, 10000)};
57 const CAmount amount{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, MAX_MONEY)};
58 if (total_balance + amount >= MAX_MONEY) {
59 break;
60 }
61 AddCoin(amount, n_input, n_input_bytes, ++next_locktime, utxo_pool, coin_params.m_effective_feerate);
62 total_balance += amount;
63 }
64
65 return total_balance;
66}
67
68static SelectionResult ManualSelection(std::vector<COutput>& utxos, const CAmount& total_amount, const bool& subtract_fee_outputs)
69{
70 SelectionResult result(total_amount, SelectionAlgorithm::MANUAL);
71 std::set<std::shared_ptr<COutput>> utxo_pool;
72 for (const auto& utxo : utxos) {
73 utxo_pool.insert(std::make_shared<COutput>(utxo));
74 }
75 result.AddInputs(utxo_pool, subtract_fee_outputs);
76 return result;
77}
78
79// Returns true if the result contains an error and the message is not empty
80static bool HasErrorMsg(const util::Result<SelectionResult>& res) { return !util::ErrorString(res).empty(); }
81
82FUZZ_TARGET(coin_grinder)
83{
84 FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
85 std::vector<COutput> utxo_pool;
86
87 const CAmount target{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, MAX_MONEY)};
88
89 FastRandomContext fast_random_context{ConsumeUInt256(fuzzed_data_provider)};
90 CoinSelectionParams coin_params{fast_random_context};
91 coin_params.m_subtract_fee_outputs = fuzzed_data_provider.ConsumeBool();
92 coin_params.m_long_term_feerate = CFeeRate{ConsumeMoney(fuzzed_data_provider, /*max=*/COIN)};
93 coin_params.m_effective_feerate = CFeeRate{ConsumeMoney(fuzzed_data_provider, /*max=*/COIN)};
94 coin_params.change_output_size = fuzzed_data_provider.ConsumeIntegralInRange<int>(10, 1000);
95 coin_params.change_spend_size = fuzzed_data_provider.ConsumeIntegralInRange<int>(10, 1000);
96 coin_params.m_cost_of_change= coin_params.m_effective_feerate.GetFee(coin_params.change_output_size) + coin_params.m_long_term_feerate.GetFee(coin_params.change_spend_size);
97 coin_params.m_change_fee = coin_params.m_effective_feerate.GetFee(coin_params.change_output_size);
98 // For other results to be comparable to SRD, we must align the change_target with SRD’s hardcoded behavior
99 coin_params.m_min_change_target = CHANGE_LOWER + coin_params.m_change_fee;
100
101 // Create some coins
102 CAmount total_balance{0};
103 CAmount max_spendable{0};
104 int next_locktime{0};
105 LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000)
106 {
107 const int n_input{fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 10)};
108 const int n_input_bytes{fuzzed_data_provider.ConsumeIntegralInRange<int>(41, 10000)};
109 const CAmount amount{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, MAX_MONEY)};
110 if (total_balance + amount >= MAX_MONEY) {
111 break;
112 }
113 AddCoin(amount, n_input, n_input_bytes, ++next_locktime, utxo_pool, coin_params.m_effective_feerate);
114 total_balance += amount;
115 CAmount eff_value = amount - coin_params.m_effective_feerate.GetFee(n_input_bytes);
116 max_spendable += eff_value;
117 }
118
119 std::vector<OutputGroup> group_pos;
120 GroupCoins(fuzzed_data_provider, utxo_pool, coin_params, /*positive_only=*/true, group_pos);
121
122 // Run coinselection algorithms
123 auto result_cg = CoinGrinder(group_pos, target, coin_params.m_min_change_target, MAX_STANDARD_TX_WEIGHT);
124 if (target + coin_params.m_min_change_target > max_spendable || HasErrorMsg(result_cg)) return; // We only need to compare algorithms if CoinGrinder has a solution
125 assert(result_cg);
126 if (!result_cg->GetAlgoCompleted()) return; // Bail out if CoinGrinder solution is not optimal
127
128 auto result_srd = SelectCoinsSRD(group_pos, target, coin_params.m_change_fee, fast_random_context, MAX_STANDARD_TX_WEIGHT);
129 if (result_srd && result_srd->GetChange(CHANGE_LOWER, coin_params.m_change_fee) > 0) { // exclude any srd solutions that don’t have change, err on excluding
130 assert(result_srd->GetWeight() >= result_cg->GetWeight());
131 }
132
133 auto result_knapsack = KnapsackSolver(group_pos, target, coin_params.m_min_change_target, fast_random_context, MAX_STANDARD_TX_WEIGHT);
134 if (result_knapsack && result_knapsack->GetChange(CHANGE_LOWER, coin_params.m_change_fee) > 0) { // exclude any knapsack solutions that don’t have change, err on excluding
135 assert(result_knapsack->GetWeight() >= result_cg->GetWeight());
136 }
137}
138
139FUZZ_TARGET(coin_grinder_is_optimal)
140{
141 FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
142
143 FastRandomContext fast_random_context{ConsumeUInt256(fuzzed_data_provider)};
144 CoinSelectionParams coin_params{fast_random_context};
145 coin_params.m_subtract_fee_outputs = false;
146 // Set effective feerate up to MAX_MONEY sats per 1'000'000 vB (2'100'000'000 sat/vB = 21'000 BTC/kvB).
147 coin_params.m_effective_feerate = CFeeRate{ConsumeMoney(fuzzed_data_provider, MAX_MONEY), 1'000'000};
148 coin_params.m_min_change_target = ConsumeMoney(fuzzed_data_provider);
149
150 // Create some coins
151 CAmount max_spendable{0};
152 int next_locktime{0};
153 static constexpr unsigned max_output_groups{16};
154 std::vector<OutputGroup> group_pos;
155 LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), max_output_groups)
156 {
157 // With maximum m_effective_feerate and n_input_bytes = 1'000'000, input_fee <= MAX_MONEY.
158 const int n_input_bytes{fuzzed_data_provider.ConsumeIntegralInRange<int>(1, 1'000'000)};
159 // Only make UTXOs with positive effective value
160 const CAmount input_fee = coin_params.m_effective_feerate.GetFee(n_input_bytes);
161 // Ensure that each UTXO has at least an effective value of 1 sat
162 const CAmount eff_value{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, MAX_MONEY + group_pos.size() - max_spendable - max_output_groups)};
163 const CAmount amount{eff_value + input_fee};
164 std::vector<COutput> temp_utxo_pool;
165
166 AddCoin(amount, /*n_input=*/0, n_input_bytes, ++next_locktime, temp_utxo_pool, coin_params.m_effective_feerate);
167 max_spendable += eff_value;
168
169 auto output_group = OutputGroup(coin_params);
170 output_group.Insert(std::make_shared<COutput>(temp_utxo_pool.at(0)), /*ancestors=*/0, /*descendants=*/0);
171 group_pos.push_back(output_group);
172 }
173 size_t num_groups = group_pos.size();
174 assert(num_groups <= max_output_groups);
175
176 // Only choose targets below max_spendable
177 const CAmount target{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, std::max(CAmount{1}, max_spendable - coin_params.m_min_change_target))};
178
179 // Brute force optimal solution
180 CAmount best_amount{MAX_MONEY};
181 int best_weight{std::numeric_limits<int>::max()};
182 for (uint32_t pattern = 1; (pattern >> num_groups) == 0; ++pattern) {
183 CAmount subset_amount{0};
184 int subset_weight{0};
185 for (unsigned i = 0; i < num_groups; ++i) {
186 if ((pattern >> i) & 1) {
187 subset_amount += group_pos[i].GetSelectionAmount();
188 subset_weight += group_pos[i].m_weight;
189 }
190 }
191 if ((subset_amount >= target + coin_params.m_min_change_target) && (subset_weight < best_weight || (subset_weight == best_weight && subset_amount < best_amount))) {
192 best_weight = subset_weight;
193 best_amount = subset_amount;
194 }
195 }
196
197 if (best_weight < std::numeric_limits<int>::max()) {
198 // Sufficient funds and acceptable weight: CoinGrinder should find at least one solution
199 int high_max_selection_weight = fuzzed_data_provider.ConsumeIntegralInRange<int>(best_weight, std::numeric_limits<int>::max());
200
201 auto result_cg = CoinGrinder(group_pos, target, coin_params.m_min_change_target, high_max_selection_weight);
202 assert(result_cg);
203 assert(result_cg->GetWeight() <= high_max_selection_weight);
204 assert(result_cg->GetSelectedEffectiveValue() >= target + coin_params.m_min_change_target);
205 assert(best_weight < result_cg->GetWeight() || (best_weight == result_cg->GetWeight() && best_amount <= result_cg->GetSelectedEffectiveValue()));
206 if (result_cg->GetAlgoCompleted()) {
207 // If CoinGrinder exhausted the search space, it must return the optimal solution
208 assert(best_weight == result_cg->GetWeight());
209 assert(best_amount == result_cg->GetSelectedEffectiveValue());
210 }
211 }
212
213 // CoinGrinder cannot ever find a better solution than the brute-forced best, or there is none in the first place
214 int low_max_selection_weight = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, best_weight - 1);
215 auto result_cg = CoinGrinder(group_pos, target, coin_params.m_min_change_target, low_max_selection_weight);
216 // Max_weight should have been exceeded, or there were insufficient funds
217 assert(!result_cg);
218}
219
221 BNB,
222 SRD,
223 KNAPSACK,
224};
225
226template<CoinSelectionAlgorithm Algorithm>
227void FuzzCoinSelectionAlgorithm(std::span<const uint8_t> buffer) {
229 FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
230 std::vector<COutput> utxo_pool;
231
232 const CFeeRate long_term_fee_rate{ConsumeMoney(fuzzed_data_provider, /*max=*/COIN)};
233 const CFeeRate effective_fee_rate{ConsumeMoney(fuzzed_data_provider, /*max=*/COIN)};
234 // Discard feerate must be at least dust relay feerate
235 const CFeeRate discard_fee_rate{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(DUST_RELAY_TX_FEE, COIN)};
236 const CAmount target{fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(1, MAX_MONEY)};
237 const bool subtract_fee_outputs{fuzzed_data_provider.ConsumeBool()};
238
239 FastRandomContext fast_random_context{ConsumeUInt256(fuzzed_data_provider)};
240 CoinSelectionParams coin_params{fast_random_context};
241 coin_params.m_subtract_fee_outputs = subtract_fee_outputs;
242 coin_params.m_long_term_feerate = long_term_fee_rate;
243 coin_params.m_effective_feerate = effective_fee_rate;
244 coin_params.change_output_size = fuzzed_data_provider.ConsumeIntegralInRange(1, MAX_SCRIPT_SIZE);
245 coin_params.m_change_fee = effective_fee_rate.GetFee(coin_params.change_output_size);
246 coin_params.m_discard_feerate = discard_fee_rate;
247 coin_params.change_spend_size = fuzzed_data_provider.ConsumeIntegralInRange<int>(41, 1000);
248 const auto change_spend_fee{coin_params.m_discard_feerate.GetFee(coin_params.change_spend_size)};
249 coin_params.m_cost_of_change = coin_params.m_change_fee + change_spend_fee;
250 CScript change_out_script = CScript() << std::vector<unsigned char>(coin_params.change_output_size, OP_TRUE);
251 const auto dust{GetDustThreshold(CTxOut{/*nValueIn=*/0, change_out_script}, coin_params.m_discard_feerate)};
252 coin_params.min_viable_change = std::max(change_spend_fee + 1, dust);
253
254 int next_locktime{0};
255 CAmount total_balance{CreateCoins(fuzzed_data_provider, utxo_pool, coin_params, next_locktime)};
256
257 std::vector<OutputGroup> group_pos;
258 GroupCoins(fuzzed_data_provider, utxo_pool, coin_params, /*positive_only=*/true, group_pos);
259
260 int max_selection_weight = fuzzed_data_provider.ConsumeIntegralInRange<int>(0, std::numeric_limits<int>::max());
261
262 std::optional<SelectionResult> result;
263
264 if constexpr (Algorithm == CoinSelectionAlgorithm::BNB) {
265 if (!coin_params.m_subtract_fee_outputs) {
266 auto result_bnb = SelectCoinsBnB(group_pos, target, coin_params.m_cost_of_change, max_selection_weight);
267 if (result_bnb) {
268 result = *result_bnb;
269 assert(result_bnb->GetChange(coin_params.min_viable_change, coin_params.m_change_fee) == 0);
270 assert(result_bnb->GetSelectedValue() >= target);
271 assert(result_bnb->GetWeight() <= max_selection_weight);
272 (void)result_bnb->GetShuffledInputVector();
273 (void)result_bnb->GetInputSet();
274 }
275 }
276 }
277
278 if constexpr (Algorithm == CoinSelectionAlgorithm::SRD) {
279 auto result_srd = SelectCoinsSRD(group_pos, target, coin_params.m_change_fee, fast_random_context, max_selection_weight);
280 if (result_srd) {
281 result = *result_srd;
282 assert(result_srd->GetSelectedValue() >= target);
283 assert(result_srd->GetChange(CHANGE_LOWER, coin_params.m_change_fee) > 0);
284 assert(result_srd->GetWeight() <= max_selection_weight);
285 result_srd->RecalculateWaste(coin_params.min_viable_change, coin_params.m_cost_of_change, coin_params.m_change_fee);
286 (void)result_srd->GetShuffledInputVector();
287 (void)result_srd->GetInputSet();
288 }
289 }
290
291 if constexpr (Algorithm == CoinSelectionAlgorithm::KNAPSACK) {
292 std::vector<OutputGroup> group_all;
293 GroupCoins(fuzzed_data_provider, utxo_pool, coin_params, /*positive_only=*/false, group_all);
294
295 for (const OutputGroup& group : group_all) {
296 const CoinEligibilityFilter filter{fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeIntegral<uint64_t>()};
297 (void)group.EligibleForSpending(filter);
298 }
299
300 CAmount change_target{GenerateChangeTarget(target, coin_params.m_change_fee, fast_random_context)};
301 auto result_knapsack = KnapsackSolver(group_all, target, change_target, fast_random_context, max_selection_weight);
302 // If the total balance is sufficient for the target and we are not using
303 // effective values, Knapsack should always find a solution (unless the selection exceeded the max tx weight).
304 if (total_balance >= target && subtract_fee_outputs && !HasErrorMsg(result_knapsack)) {
305 assert(result_knapsack);
306 }
307 if (result_knapsack) {
308 result = *result_knapsack;
309 assert(result_knapsack->GetSelectedValue() >= target);
310 assert(result_knapsack->GetWeight() <= max_selection_weight);
311 result_knapsack->RecalculateWaste(coin_params.min_viable_change, coin_params.m_cost_of_change, coin_params.m_change_fee);
312 (void)result_knapsack->GetShuffledInputVector();
313 (void)result_knapsack->GetInputSet();
314 }
315 }
316
317 std::vector<COutput> utxos;
318 CAmount new_total_balance{CreateCoins(fuzzed_data_provider, utxos, coin_params, next_locktime)};
319 if (new_total_balance > 0) {
320 std::set<std::shared_ptr<COutput>> new_utxo_pool;
321 for (const auto& utxo : utxos) {
322 new_utxo_pool.insert(std::make_shared<COutput>(utxo));
323 }
324 if (result) {
325 const auto weight{result->GetWeight()};
326 result->AddInputs(new_utxo_pool, subtract_fee_outputs);
327 assert(result->GetWeight() > weight);
328 }
329 }
330
331 std::vector<COutput> manual_inputs;
332 CAmount manual_balance{CreateCoins(fuzzed_data_provider, manual_inputs, coin_params, next_locktime)};
333 if (manual_balance == 0) return;
334 auto manual_selection{ManualSelection(manual_inputs, manual_balance, coin_params.m_subtract_fee_outputs)};
335 if (result) {
336 const CAmount old_target{result->GetTarget()};
337 const std::set<std::shared_ptr<COutput>> input_set{result->GetInputSet()};
338 const int old_weight{result->GetWeight()};
339 result->Merge(manual_selection);
340 assert(result->GetInputSet().size() == input_set.size() + manual_inputs.size());
341 assert(result->GetTarget() == old_target + manual_selection.GetTarget());
342 assert(result->GetWeight() == old_weight + manual_selection.GetWeight());
343 }
344}
345
346FUZZ_TARGET(coinselection_bnb) {
347 FuzzCoinSelectionAlgorithm<CoinSelectionAlgorithm::BNB>(buffer);
348}
349
350FUZZ_TARGET(coinselection_srd) {
351 FuzzCoinSelectionAlgorithm<CoinSelectionAlgorithm::SRD>(buffer);
352}
353
354FUZZ_TARGET(coinselection_knapsack) {
355 FuzzCoinSelectionAlgorithm<CoinSelectionAlgorithm::KNAPSACK>(buffer);
356}
357
358} // namespace wallet
static constexpr CAmount MAX_MONEY
No amount larger than this (in satoshi) is valid.
Definition: amount.h:26
int64_t CAmount
Amount in satoshis (Can be negative)
Definition: amount.h:12
static constexpr CAmount COIN
The amount of satoshis in one BTC.
Definition: amount.h:15
Fee rate in satoshis per kilovirtualbyte: CAmount / kvB.
Definition: feerate.h:33
An outpoint - a combination of a transaction hash and an index n into its vout.
Definition: transaction.h:29
Serialized script, used inside transaction inputs and outputs.
Definition: script.h:415
An output of a transaction.
Definition: transaction.h:150
Fast randomness source.
Definition: random.h:377
T ConsumeIntegralInRange(T min, T max)
#define LIMITED_WHILE(condition, limit)
Can be used to limit a theoretically unbounded loop.
Definition: fuzz.h:22
bilingual_str ErrorString(const Result< T > &result)
Definition: result.h:93
static CAmount CreateCoins(FuzzedDataProvider &fuzzed_data_provider, std::vector< COutput > &utxo_pool, CoinSelectionParams &coin_params, int &next_locktime)
static void AddCoin(const CAmount &value, int n_input, int n_input_bytes, int locktime, std::vector< COutput > &coins, CFeeRate fee_rate)
static constexpr CAmount CHANGE_LOWER
lower bound for randomly-chosen target change amount
Definition: coinselection.h:23
util::Result< SelectionResult > SelectCoinsBnB(std::vector< OutputGroup > &utxo_pool, const CAmount &selection_target, const CAmount &cost_of_change, int max_selection_weight)
CAmount GenerateChangeTarget(const CAmount payment_value, const CAmount change_fee, FastRandomContext &rng)
Choose a random change target for each transaction to make it harder to fingerprint the Core wallet b...
util::Result< SelectionResult > CoinGrinder(std::vector< OutputGroup > &utxo_pool, const CAmount &selection_target, CAmount change_target, int max_selection_weight)
std::vector< OutputGroup > & GroupCoins(const std::vector< COutput > &available_coins, bool subtract_fee_outputs=false)
void FuzzCoinSelectionAlgorithm(std::span< const uint8_t > buffer)
util::Result< SelectionResult > KnapsackSolver(std::vector< OutputGroup > &groups, const CAmount &nTargetValue, CAmount change_target, FastRandomContext &rng, int max_selection_weight)
static SelectionResult ManualSelection(std::vector< COutput > &utxos, const CAmount &total_amount, const bool &subtract_fee_outputs)
FUZZ_TARGET(coin_grinder)
static bool HasErrorMsg(const util::Result< SelectionResult > &res)
Definition: spend.cpp:661
CoinSelectionAlgorithm
util::Result< SelectionResult > SelectCoinsSRD(const std::vector< OutputGroup > &utxo_pool, CAmount target_value, CAmount change_fee, FastRandomContext &rng, int max_selection_weight)
Select coins by Single Random Draw.
CAmount GetDustThreshold(const CTxOut &txout, const CFeeRate &dustRelayFeeIn)
Definition: policy.cpp:26
static constexpr unsigned int DUST_RELAY_TX_FEE
Min feerate for defining dust.
Definition: policy.h:62
static constexpr int32_t MAX_STANDARD_TX_WEIGHT
The maximum weight for transactions we're willing to relay/mine.
Definition: policy.h:34
static const int MAX_SCRIPT_SIZE
Definition: script.h:40
@ OP_TRUE
Definition: script.h:84
A mutable version of CTransaction.
Definition: transaction.h:378
std::vector< CTxOut > vout
Definition: transaction.h:380
Txid GetHash() const
Compute the hash of this CMutableTransaction.
Definition: transaction.cpp:69
bool empty() const
Definition: translation.h:35
Parameters for filtering which OutputGroups we may use in coin selection.
Parameters for one iteration of Coin Selection.
bool m_subtract_fee_outputs
Indicate that we are subtracting the fee from outputs.
CFeeRate m_effective_feerate
The targeted feerate of the transaction being built.
A group of UTXOs paid to the same output script.
CAmount GetTarget() const
void AddInputs(const std::set< std::shared_ptr< COutput > > &inputs, bool subtract_fee_outputs)
CAmount ConsumeMoney(FuzzedDataProvider &fuzzed_data_provider, const std::optional< CAmount > &max) noexcept
Definition: util.cpp:29
uint256 ConsumeUInt256(FuzzedDataProvider &fuzzed_data_provider) noexcept
Definition: util.h:171
void SeedRandomStateForTest(SeedRand seedtype)
Seed the global RNG state for testing and log the seed value.
Definition: random.cpp:19
@ ZEROS
Seed with a compile time constant of zeros.
assert(!tx.IsCoinBase())