1 files changed, 99 insertions, 31 deletions

diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 611f3584c3..c9bf757dfc 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -129,6 +129,8 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->customFee->SetAllowEmpty(false);
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
+
+    GUIUtil::ExceptionSafeConnect(ui->sendButton, &QPushButton::clicked, this, &SendCoinsDialog::sendButtonClicked);
 }
 
 void SendCoinsDialog::setClientModel(ClientModel *_clientModel)
@@ -171,15 +173,15 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         for (const int n : confTargets) {
             ui->confTargetSelector->addItem(tr("%1 (%2 blocks)").arg(GUIUtil::formatNiceTimeOffset(n*Params().GetConsensus().nPowTargetSpacing)).arg(n));
         }
-        connect(ui->confTargetSelector, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::updateSmartFeeLabel);
-        connect(ui->confTargetSelector, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::coinControlUpdateLabels);
+        connect(ui->confTargetSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::updateSmartFeeLabel);
+        connect(ui->confTargetSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::coinControlUpdateLabels);
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
         connect(ui->groupFee, &QButtonGroup::idClicked, this, &SendCoinsDialog::updateFeeSectionControls);
         connect(ui->groupFee, &QButtonGroup::idClicked, this, &SendCoinsDialog::coinControlUpdateLabels);
 #else
-        connect(ui->groupFee, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::updateFeeSectionControls);
-        connect(ui->groupFee, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::coinControlUpdateLabels);
+        connect(ui->groupFee, qOverload<int>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::updateFeeSectionControls);
+        connect(ui->groupFee, qOverload<int>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::coinControlUpdateLabels);
 #endif
 
         connect(ui->customFee, &BitcoinAmountField::valueChanged, this, &SendCoinsDialog::coinControlUpdateLabels);
@@ -197,7 +199,18 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         // set default rbf checkbox state
         ui->optInRBF->setCheckState(Qt::Checked);
 
-        if (model->wallet().privateKeysDisabled()) {
+        if (model->wallet().hasExternalSigner()) {
+            //: "device" usually means a hardware wallet
+            ui->sendButton->setText(tr("Sign on device"));
+            if (gArgs.GetArg("-signer", "") != "") {
+                ui->sendButton->setEnabled(true);
+                ui->sendButton->setToolTip(tr("Connect your hardware wallet first."));
+            } else {
+                ui->sendButton->setEnabled(false);
+                //: "External signer" means using devices such as hardware wallets.
+                ui->sendButton->setToolTip(tr("Set external signer script path in Options -> Wallet"));
+            }
+        } else if (model->wallet().privateKeysDisabled()) {
             ui->sendButton->setText(tr("Cr&eate Unsigned"));
             ui->sendButton->setToolTip(tr("Creates a Partially Signed Bitcoin Transaction (PSBT) for use with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(PACKAGE_NAME));
         }
@@ -266,10 +279,10 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
     }
 
     // prepare transaction for getting txFee earlier
-    m_current_transaction = MakeUnique<WalletModelTransaction>(recipients);
+    m_current_transaction = std::make_unique<WalletModelTransaction>(recipients);
     WalletModel::SendCoinsReturn prepareStatus;
 
-    updateCoinControlState(*m_coin_control);
+    updateCoinControlState();
 
     prepareStatus = model->prepareTransaction(*m_current_transaction, *m_coin_control);
 
@@ -311,14 +324,14 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
         formatted.append(recipientElement);
     }
 
-    if (model->wallet().privateKeysDisabled()) {
+    if (model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner()) {
         question_string.append(tr("Do you want to draft this transaction?"));
     } else {
         question_string.append(tr("Are you sure you want to send?"));
     }
 
     question_string.append("<br /><span style='font-size:10pt;'>");
-    if (model->wallet().privateKeysDisabled()) {
+    if (model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner()) {
         question_string.append(tr("Please, review your transaction proposal. This will produce a Partially Signed Bitcoin Transaction (PSBT) which you can save or copy and then sign with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(PACKAGE_NAME));
     } else {
         question_string.append(tr("Please, review your transaction."));
@@ -366,7 +379,7 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
 
     if (formatted.size() > 1) {
         question_string = question_string.arg("");
-        informative_text = tr("To review recipient list click \"Show Details...\"");
+        informative_text = tr("To review recipient list click \"Show Details…\"");
         detailed_text = formatted.join("\n\n");
     } else {
         question_string = question_string.arg("<br /><br />" + formatted.at(0));
@@ -375,7 +388,7 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
     return true;
 }
 
-void SendCoinsDialog::on_sendButton_clicked()
+void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
 {
     if(!model || !model->getOptionsModel())
         return;
@@ -384,8 +397,8 @@ void SendCoinsDialog::on_sendButton_clicked()
     if (!PrepareSendText(question_string, informative_text, detailed_text)) return;
     assert(m_current_transaction);
 
-    const QString confirmation = model->wallet().privateKeysDisabled() ? tr("Confirm transaction proposal") : tr("Confirm send coins");
-    const QString confirmButtonText = model->wallet().privateKeysDisabled() ? tr("Create Unsigned") : tr("Send");
+    const QString confirmation = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner() ? tr("Confirm transaction proposal") : tr("Confirm send coins");
+    const QString confirmButtonText = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner() ? tr("Create Unsigned") : tr("Sign and send");
     SendConfirmationDialog confirmationDialog(confirmation, question_string, informative_text, detailed_text, SEND_CONFIRM_DELAY, confirmButtonText, this);
     confirmationDialog.exec();
     QMessageBox::StandardButton retval = static_cast<QMessageBox::StandardButton>(confirmationDialog.result());
@@ -401,9 +414,60 @@ void SendCoinsDialog::on_sendButton_clicked()
         CMutableTransaction mtx = CMutableTransaction{*(m_current_transaction->getWtx())};
         PartiallySignedTransaction psbtx(mtx);
         bool complete = false;
-        const TransactionError err = model->wallet().fillPSBT(SIGHASH_ALL, false /* sign */, true /* bip32derivs */, psbtx, complete, nullptr);
+        // Always fill without signing first. This prevents an external signer
+        // from being called prematurely and is not expensive.
+        TransactionError err = model->wallet().fillPSBT(SIGHASH_ALL, false /* sign */, true /* bip32derivs */, nullptr, psbtx, complete);
         assert(!complete);
         assert(err == TransactionError::OK);
+        if (model->wallet().hasExternalSigner()) {
+            try {
+                err = model->wallet().fillPSBT(SIGHASH_ALL, true /* sign */, true /* bip32derivs */, nullptr, psbtx, complete);
+            } catch (const std::runtime_error& e) {
+                QMessageBox::critical(nullptr, tr("Sign failed"), e.what());
+                send_failure = true;
+                return;
+            }
+            if (err == TransactionError::EXTERNAL_SIGNER_NOT_FOUND) {
+                //: "External signer" means using devices such as hardware wallets.
+                QMessageBox::critical(nullptr, tr("External signer not found"), "External signer not found");
+                send_failure = true;
+                return;
+            }
+            if (err == TransactionError::EXTERNAL_SIGNER_FAILED) {
+                //: "External signer" means using devices such as hardware wallets.
+                QMessageBox::critical(nullptr, tr("External signer failure"), "External signer failure");
+                send_failure = true;
+                return;
+            }
+            if (err != TransactionError::OK) {
+                tfm::format(std::cerr, "Failed to sign PSBT");
+                processSendCoinsReturn(WalletModel::TransactionCreationFailed);
+                send_failure = true;
+                return;
+            }
+            // fillPSBT does not always properly finalize
+            complete = FinalizeAndExtractPSBT(psbtx, mtx);
+        }
+
+        // Broadcast transaction if complete (even with an external signer this
+        // is not always the case, e.g. in a multisig wallet).
+        if (complete) {
+            const CTransactionRef tx = MakeTransactionRef(mtx);
+            m_current_transaction->setWtx(tx);
+            WalletModel::SendCoinsReturn sendStatus = model->sendCoins(*m_current_transaction);
+            // process sendStatus and on error generate message shown to user
+            processSendCoinsReturn(sendStatus);
+
+            if (sendStatus.status == WalletModel::OK) {
+                Q_EMIT coinsSent(m_current_transaction->getWtx()->GetHash());
+            } else {
+                send_failure = true;
+            }
+            return;
+        }
+
+        // Copy PSBT to clipboard and offer to save
+        assert(!complete);
         // Serialize the PSBT
         CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
         ssTx << psbtx;
@@ -430,11 +494,12 @@ void SendCoinsDialog::on_sendButton_clicked()
             fileNameSuggestion.append(".psbt");
             QString filename = GUIUtil::getSaveFileName(this,
                 tr("Save Transaction Data"), fileNameSuggestion,
-                tr("Partially Signed Transaction (Binary) (*.psbt)"), &selectedFilter);
+                //: Expanded name of the binary PSBT file format. See: BIP 174.
+                tr("Partially Signed Transaction (Binary)") + QLatin1String(" (*.psbt)"), &selectedFilter);
             if (filename.isEmpty()) {
                 return;
             }
-            std::ofstream out(filename.toLocal8Bit().data());
+            std::ofstream out(filename.toLocal8Bit().data(), std::ofstream::out | std::ofstream::binary);
             out << ssTx.str();
             out.close();
             Q_EMIT message(tr("PSBT saved"), "PSBT saved to disk", CClientUIInterface::MSG_INFORMATION);
@@ -444,7 +509,7 @@ void SendCoinsDialog::on_sendButton_clicked()
             break;
         default:
             assert(false);
-        }
+        } // msgBox.exec()
     } else {
         // now send the prepared transaction
         WalletModel::SendCoinsReturn sendStatus = model->sendCoins(*m_current_transaction);
@@ -611,7 +676,9 @@ void SendCoinsDialog::setBalance(const interfaces::WalletBalances& balances)
     if(model && model->getOptionsModel())
     {
         CAmount balance = balances.balance;
-        if (model->wallet().privateKeysDisabled()) {
+        if (model->wallet().hasExternalSigner()) {
+            ui->labelBalanceName->setText(tr("External balance:"));
+        } else if (model->wallet().privateKeysDisabled()) {
             balance = balances.watch_only_balance;
             ui->labelBalanceName->setText(tr("Watch-only balance:"));
         }
@@ -695,7 +762,7 @@ void SendCoinsDialog::on_buttonMinimizeFee_clicked()
 void SendCoinsDialog::useAvailableBalance(SendCoinsEntry* entry)
 {
     // Include watch-only for wallets without private key
-    m_coin_control->fAllowWatchOnly = model->wallet().privateKeysDisabled();
+    m_coin_control->fAllowWatchOnly = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner();
 
     // Calculate available amount to send.
     CAmount amount = model->wallet().getAvailableBalance(*m_coin_control);
@@ -734,23 +801,23 @@ void SendCoinsDialog::updateFeeMinimizedLabel()
     if (ui->radioSmartFee->isChecked())
         ui->labelFeeMinimized->setText(ui->labelSmartFee->text());
     else {
-        ui->labelFeeMinimized->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), ui->customFee->value()) + "/kB");
+        ui->labelFeeMinimized->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), ui->customFee->value()) + "/kvB");
     }
 }
 
-void SendCoinsDialog::updateCoinControlState(CCoinControl& ctrl)
+void SendCoinsDialog::updateCoinControlState()
 {
     if (ui->radioCustomFee->isChecked()) {
-        ctrl.m_feerate = CFeeRate(ui->customFee->value());
+        m_coin_control->m_feerate = CFeeRate(ui->customFee->value());
     } else {
-        ctrl.m_feerate.reset();
+        m_coin_control->m_feerate.reset();
     }
     // Avoid using global defaults when sending money from the GUI
     // Either custom fee will be used or if not selected, the confirmation target from dropdown box
-    ctrl.m_confirm_target = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
-    ctrl.m_signal_bip125_rbf = ui->optInRBF->isChecked();
+    m_coin_control->m_confirm_target = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
+    m_coin_control->m_signal_bip125_rbf = ui->optInRBF->isChecked();
     // Include watch-only for wallets without private key
-    ctrl.fAllowWatchOnly = model->wallet().privateKeysDisabled();
+    m_coin_control->fAllowWatchOnly = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner();
 }
 
 void SendCoinsDialog::updateNumberOfBlocks(int count, const QDateTime& blockDate, double nVerificationProgress, bool headers, SynchronizationState sync_state) {
@@ -763,13 +830,13 @@ void SendCoinsDialog::updateSmartFeeLabel()
 {
     if(!model || !model->getOptionsModel())
         return;
-    updateCoinControlState(*m_coin_control);
+    updateCoinControlState();
     m_coin_control->m_feerate.reset(); // Explicitly use only fee estimation rate for smart fee labels
     int returned_target;
     FeeReason reason;
     CFeeRate feeRate = CFeeRate(model->wallet().getMinimumFee(1000, *m_coin_control, &returned_target, &reason));
 
-    ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
+    ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kvB");
 
     if (reason == FeeReason::FALLBACK) {
         ui->labelSmartFee2->show(); // (Smart fee not initialized yet. This usually takes a few blocks...)
@@ -837,8 +904,9 @@ void SendCoinsDialog::coinControlFeatureChanged(bool checked)
 {
     ui->frameCoinControl->setVisible(checked);
 
-    if (!checked && model) // coin control features disabled
-        m_coin_control->SetNull();
+    if (!checked && model) { // coin control features disabled
+        m_coin_control = std::make_unique<CCoinControl>();
+    }
 
     coinControlUpdateLabels();
 }
@@ -926,7 +994,7 @@ void SendCoinsDialog::coinControlUpdateLabels()
     if (!model || !model->getOptionsModel())
         return;
 
-    updateCoinControlState(*m_coin_control);
+    updateCoinControlState();
 
     // set pay amounts
     CoinControlDialog::payAmounts.clear();