AskPassphraseDialog::~AskPassphraseDialog()
{
    // Attempt to overwrite text so that they do not linger around in memory
    // ui->passEdit1->setText(QString(" ").repeated(ui->passEdit1->text().size()));
    // ui->passEdit2->setText(QString(" ").repeated(ui->passEdit2->text().size()));
    // ui->passEdit3->setText(QString(" ").repeated(ui->passEdit3->text().size()));
    secureClearPassFields();
    delete ui;
}

void AskPassphraseDialog::accept()
{
    SecureString oldpass, newpass1, newpass2;
    if(!model)
        return;
    oldpass.reserve(MAX_PASSPHRASE_SIZE);
    newpass1.reserve(MAX_PASSPHRASE_SIZE);
    newpass2.reserve(MAX_PASSPHRASE_SIZE);
    // TODO: get rid of this .c_str() by implementing SecureString::operator=(std::string)
    // Alternately, find a way to make this input mlock()'d to begin with.
    oldpass.assign(ui->passEdit1->text().toStdString().c_str());
    newpass1.assign(ui->passEdit2->text().toStdString().c_str());
    newpass2.assign(ui->passEdit3->text().toStdString().c_str());

    secureClearPassFields();

    switch(mode)
    {
    case Encrypt: {
        if(newpass1.empty() || newpass2.empty())
        {
            // Cannot encrypt with empty passphrase
            break;
        }
        QMessageBox::StandardButton retval = QMessageBox::question(this, tr("Confirm wallet encryption"),
                 tr("Warning: If you encrypt your wallet and lose your passphrase, you will <b>LOSE ALL OF YOUR COINS</b>!") + "<br><br>" + tr("Are you sure you wish to encrypt your wallet?"),
                 QMessageBox::Yes|QMessageBox::Cancel,
                 QMessageBox::Cancel);
        if(retval == QMessageBox::Yes)
        {
            if(newpass1 == newpass2)
            {
                if(model->setWalletEncrypted(true, newpass1))
                {
                    QMessageBox::warning(this, tr("Wallet encrypted"),
                                         "<qt>" + 
                                         tr("PerfectCoin will close now to finish the encryption process. "
                                         "Remember that encrypting your wallet cannot fully protect "
                                         "your coins from being stolen by malware infecting your computer.") + 
                                         "<br><br><b>" + 
                                         tr("IMPORTANT: Any previous backups you have made of your wallet file "
                                         "should be replaced with the newly generated, encrypted wallet file. "
                                         "For security reasons, previous backups of the unencrypted wallet file "
                                         "will become useless as soon as you start using the new, encrypted wallet.") + 
                                         "</b></qt>");
                    QApplication::quit();
                }
                else
                {
                    QMessageBox::critical(this, tr("Wallet encryption failed"),
                                         tr("Wallet encryption failed due to an internal error. Your wallet was not encrypted."));
                }
                QDialog::accept(); // Success
            }
            else
            {
                QMessageBox::critical(this, tr("Wallet encryption failed"),
                                     tr("The supplied passphrases do not match."));
            }
        }
        else
        {
            QDialog::reject(); // Cancelled
        }
        } break;
    case UnlockStaking:
    case Unlock:
        if(!model->setWalletLocked(false, oldpass))
        {
            QMessageBox::critical(this, tr("Wallet unlock failed"),
                                  tr("The passphrase entered for the wallet decryption was incorrect."));
        }
        else
        {
            fWalletUnlockStakingOnly = ui->stakingCheckBox->isChecked();
            QDialog::accept(); // Success
        }
        break;
    case Decrypt:
        if(!model->setWalletEncrypted(false, oldpass))
        {
            QMessageBox::critical(this, tr("Wallet decryption failed"),
                                  tr("The passphrase entered for the wallet decryption was incorrect."));
        }
        else
        {
            QDialog::accept(); // Success
        }
        break;
    case ChangePass:
        if(newpass1 == newpass2)
        {
            if(model->changePassphrase(oldpass, newpass1))
            {
                QMessageBox::information(this, tr("Wallet encrypted"),
                                     tr("Wallet passphrase was successfully changed."));
                QDialog::accept(); // Success
            }
            else
            {
//.........这里部分代码省略.........