// Copyright (c) 2021 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #include #include #include #include #include #include #include #include namespace wallet { BOOST_FIXTURE_TEST_SUITE(spend_tests, WalletTestingSetup) BOOST_FIXTURE_TEST_CASE(SubtractFee, TestChain100Setup) { CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey())); auto wallet = CreateSyncedWallet(*m_node.chain, WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain()), m_args, coinbaseKey); // Check that a subtract-from-recipient transaction slightly less than the // coinbase input amount does not create a change output (because it would // be uneconomical to add and spend the output), and make sure it pays the // leftover input amount which would have been change to the recipient // instead of the miner. auto check_tx = [&wallet](CAmount leftover_input_amount) { CRecipient recipient{GetScriptForRawPubKey({}), 50 * COIN - leftover_input_amount, /*subtract_fee=*/true}; constexpr int RANDOM_CHANGE_POSITION = -1; CCoinControl coin_control; coin_control.m_feerate.emplace(10000); coin_control.fOverrideFeeRate = true; // We need to use a change type with high cost of change so that the leftover amount will be dropped to fee instead of added as a change output coin_control.m_change_type = OutputType::LEGACY; auto res = CreateTransaction(*wallet, {recipient}, RANDOM_CHANGE_POSITION, coin_control); BOOST_CHECK(res); const auto& txr = *res; BOOST_CHECK_EQUAL(txr.tx->vout.size(), 1); BOOST_CHECK_EQUAL(txr.tx->vout[0].nValue, recipient.nAmount + leftover_input_amount - txr.fee); BOOST_CHECK_GT(txr.fee, 0); return txr.fee; }; // Send full input amount to recipient, check that only nonzero fee is // subtracted (to_reduce == fee). const CAmount fee{check_tx(0)}; // Send slightly less than full input amount to recipient, check leftover // input amount is paid to recipient not the miner (to_reduce == fee - 123) BOOST_CHECK_EQUAL(fee, check_tx(123)); // Send full input minus fee amount to recipient, check leftover input // amount is paid to recipient not the miner (to_reduce == 0) BOOST_CHECK_EQUAL(fee, check_tx(fee)); // Send full input minus more than the fee amount to recipient, check // leftover input amount is paid to recipient not the miner (to_reduce == // -123). This overpays the recipient instead of overpaying the miner more // than double the necessary fee. BOOST_CHECK_EQUAL(fee, check_tx(fee + 123)); } static void TestFillInputToWeight(int64_t additional_weight, std::vector expected_stack_sizes) { static const int64_t EMPTY_INPUT_WEIGHT = GetTransactionInputWeight(CTxIn()); CTxIn input; int64_t target_weight = EMPTY_INPUT_WEIGHT + additional_weight; BOOST_CHECK(FillInputToWeight(input, target_weight)); BOOST_CHECK_EQUAL(GetTransactionInputWeight(input), target_weight); BOOST_CHECK_EQUAL(input.scriptWitness.stack.size(), expected_stack_sizes.size()); for (unsigned int i = 0; i < expected_stack_sizes.size(); ++i) { BOOST_CHECK_EQUAL(input.scriptWitness.stack[i].size(), expected_stack_sizes[i]); } } BOOST_FIXTURE_TEST_CASE(FillInputToWeightTest, BasicTestingSetup) { { // Less than or equal minimum of 165 should not add any witness data CTxIn input; BOOST_CHECK(!FillInputToWeight(input, -1)); BOOST_CHECK_EQUAL(GetTransactionInputWeight(input), 165); BOOST_CHECK_EQUAL(input.scriptWitness.stack.size(), 0); BOOST_CHECK(!FillInputToWeight(input, 0)); BOOST_CHECK_EQUAL(GetTransactionInputWeight(input), 165); BOOST_CHECK_EQUAL(input.scriptWitness.stack.size(), 0); BOOST_CHECK(!FillInputToWeight(input, 164)); BOOST_CHECK_EQUAL(GetTransactionInputWeight(input), 165); BOOST_CHECK_EQUAL(input.scriptWitness.stack.size(), 0); BOOST_CHECK(FillInputToWeight(input, 165)); BOOST_CHECK_EQUAL(GetTransactionInputWeight(input), 165); BOOST_CHECK_EQUAL(input.scriptWitness.stack.size(), 0); } // Make sure we can add at least one weight TestFillInputToWeight(1, {0}); // 1 byte compact size uint boundary TestFillInputToWeight(252, {251}); TestFillInputToWeight(253, {83, 168}); TestFillInputToWeight(262, {86, 174}); TestFillInputToWeight(263, {260}); // 3 byte compact size uint boundary TestFillInputToWeight(65535, {65532}); TestFillInputToWeight(65536, {21842, 43688}); TestFillInputToWeight(65545, {21845, 43694}); TestFillInputToWeight(65546, {65541}); // Note: We don't test the next boundary because of memory allocation constraints. } BOOST_FIXTURE_TEST_CASE(wallet_duplicated_preset_inputs_test, TestChain100Setup) { // Verify that the wallet's Coin Selection process does not include pre-selected inputs twice in a transaction. // Add 4 spendable UTXO, 50 BTC each, to the wallet (total balance 200 BTC) for (int i = 0; i < 4; i++) CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey())); auto wallet = CreateSyncedWallet(*m_node.chain, WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return m_node.chainman->ActiveChain()), m_args, coinbaseKey); LOCK(wallet->cs_wallet); auto available_coins = AvailableCoins(*wallet); std::vector coins = available_coins.All(); // Preselect the first 3 UTXO (150 BTC total) std::set preset_inputs = {coins[0].outpoint, coins[1].outpoint, coins[2].outpoint}; // Try to create a tx that spends more than what preset inputs + wallet selected inputs are covering for. // The wallet can cover up to 200 BTC, and the tx target is 299 BTC. std::vector recipients = {{GetScriptForDestination(*Assert(wallet->GetNewDestination(OutputType::BECH32, "dummy"))), /*nAmount=*/299 * COIN, /*fSubtractFeeFromAmount=*/true}}; CCoinControl coin_control; coin_control.m_allow_other_inputs = true; for (const auto& outpoint : preset_inputs) { coin_control.Select(outpoint); } // Attempt to send 299 BTC from a wallet that only has 200 BTC. The wallet should exclude // the preset inputs from the pool of available coins, realize that there is not enough // money to fund the 299 BTC payment, and fail with "Insufficient funds". // // Even with SFFO, the wallet can only afford to send 200 BTC. // If the wallet does not properly exclude preset inputs from the pool of available coins // prior to coin selection, it may create a transaction that does not fund the full payment // amount or, through SFFO, incorrectly reduce the recipient's amount by the difference // between the original target and the wrongly counted inputs (in this case 99 BTC) // so that the recipient's amount is no longer equal to the user's selected target of 299 BTC. // First case, use 'subtract_fee_from_outputs=true' util::Result res_tx = CreateTransaction(*wallet, recipients, /*change_pos*/-1, coin_control); BOOST_CHECK(!res_tx.has_value()); // Second case, don't use 'subtract_fee_from_outputs'. recipients[0].fSubtractFeeFromAmount = false; res_tx = CreateTransaction(*wallet, recipients, /*change_pos*/-1, coin_control); BOOST_CHECK(!res_tx.has_value()); } BOOST_AUTO_TEST_SUITE_END() } // namespace wallet