Add GUI to import private keys

Addresses GH #1808.

There are several possible future improvements:

 * add a new icon for key import

 * reduce duplication of code between the RPC private key importer and
 the GUI private key importer

 * improving error messages for various error states

1 files changed, 164 insertions, 0 deletions

diff --git a/src/qt/importkeysdialog.cpp b/src/qt/importkeysdialog.cpp
new file mode 100644
index 000000000..743a61d8b
--- /dev/null
+++ b/src/qt/importkeysdialog.cpp
@@ -0,0 +1,164 @@
+// Copyright (c) 2021 The Dogecoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#if defined(HAVE_CONFIG_H)
+#include "config/bitcoin-config.h"
+#endif
+
+#include "importkeysdialog.h"
+#include "ui_importkeysdialog.h"
+
+#include "base58.h"
+#include "guiutil.h"
+#include "platformstyle.h"
+#include "validation.h"
+#include "wallet/wallet.h"
+#include "walletmodel.h"
+#include "util.h"
+
+#include <QThread>
+#include <QDebug>
+
+/* Object for executing key import commands in a separate thread.
+*/
+class ImportKeyExecutor : public QObject
+{
+    Q_OBJECT
+
+public Q_SLOTS:
+    void rescan(CWallet*, CBlockIndex*);
+
+Q_SIGNALS:
+    void rescanWallet(CWallet*, CBlockIndex*);
+};
+
+#include "importkeysdialog.moc"
+
+void ImportKeyExecutor::rescan(CWallet* pwallet, CBlockIndex* genesisBlock)
+{
+    qWarning() << "started import key thread";
+    pwallet->UpdateTimeFirstKey(1);
+    pwallet->ScanForWalletTransactions(genesisBlock, true);
+    qWarning() << "quitting import key thread";
+    QObject::thread()->quit();
+}
+
+ImportKeysDialog::ImportKeysDialog(const PlatformStyle *_platformStyle, QWidget *parent) :
+    QDialog(parent),
+    ui(new Ui::ImportKeysDialog),
+    platformStyle(_platformStyle)
+{
+    ui->setupUi(this);
+
+    /* Main elements init */
+    if (fPruneMode) {
+        ui->rescanCheckBox->setEnabled(false);
+    }
+}
+
+ImportKeysDialog::~ImportKeysDialog()
+{
+    thread.wait();
+    delete ui;
+}
+
+void ImportKeysDialog::on_okButton_clicked()
+{
+    if (importKey()) {
+        resetDialogValues();
+        accept();
+    };
+}
+
+void ImportKeysDialog::on_cancelButton_clicked()
+{
+    reject();
+}
+
+void ImportKeysDialog::on_resetButton_clicked()
+{
+    resetDialogValues();
+}
+
+bool ImportKeysDialog::importKey()
+{
+    const QString privateKey      = ui->privateKey->text();
+    const QString privateKeyLabel = ui->privateKeyLabel->text();
+    const bool rescan             = ui->rescanCheckBox->isChecked();
+
+    resetDialogValues();
+
+    CBitcoinSecret vchSecret;
+    bool fGood = vchSecret.SetString(privateKey.toStdString());
+    if (!fGood) {
+        vchSecret.SetString("");
+        ui->privateKeyImportTextMessage->setText(tr("Invalid private key; please check and try again!"));
+        return false;
+    }
+
+    CKey key = vchSecret.GetKey();
+    if (!key.IsValid()) {
+        vchSecret.SetString("");
+        ui->privateKeyImportTextMessage->setText(tr("Invalid private key; please check and try again!"));
+        return false;
+    }
+
+    CPubKey pubkey = key.GetPubKey();
+    assert(key.VerifyPubKey(pubkey));
+    CKeyID vchAddress = pubkey.GetID();
+
+    pwalletMain->MarkDirty();
+    pwalletMain->SetAddressBook(vchAddress, privateKeyLabel.toStdString(), "receive");
+
+    if (pwalletMain->HaveKey(vchAddress)) {
+        vchSecret.SetString("");
+        ui->privateKeyImportTextMessage->setText(
+            tr("Invalid address generated from private key; please check and try again!"
+        ));
+        return false;
+    }
+
+    pwalletMain->mapKeyMetadata[vchAddress].nCreateTime = 1;
+
+    if (!pwalletMain->AddKeyPubKey(key, pubkey)) {
+        vchSecret.SetString("");
+        ui->privateKeyImportTextMessage->setText(tr("Failed to add private key."));
+        return false;
+    }
+
+    pwalletMain->UpdateTimeFirstKey(1);
+
+    if (rescan) {
+        ImportKeyExecutor *executor = new ImportKeyExecutor();
+        executor->moveToThread(&thread);
+        connect(this, SIGNAL(rescanWallet(CWallet*, CBlockIndex*)), executor, SLOT(rescan(CWallet*, CBlockIndex*)));
+
+        // On stopExecutor signal
+        // - quit the Qt event loop in the execution thread
+        connect(this, SIGNAL(stopExecutor()), &thread, SLOT(quit()));
+        // - queue executor for deletion (in execution thread)
+        connect(&thread, SIGNAL(finished()), executor, SLOT(deleteLater()), Qt::DirectConnection);
+
+        // Default implementation of QThread::run() simply spins up an event loop in the thread,
+        // which is what we want.
+        thread.start();
+        ui->privateKeyImportTextMessage->setText(tr("Rescanning..."));
+        Q_EMIT rescanWallet(pwalletMain, chainActive.Genesis());
+    }
+
+    vchSecret.SetString("");
+    return true;
+}
+
+void ImportKeysDialog::resetDialogValues()
+{
+    ui->privateKey->clear();
+    ui->privateKeyLabel->clear();
+    ui->rescanCheckBox->setCheckState(Qt::Unchecked);
+}
+
+void ImportKeysDialog::setOkButtonState(bool fState)
+{
+    ui->okButton->setEnabled(fState);
+}