Botan用PKCS8加密解密密钥，如何保存rng /设置种子？

Question

我尝试用Botan加密RSA私钥，但是，似乎无法为Botan随机生成器设置种子或保存它。

因此，当我尝试解密密钥（通过重新运行程序）时，结果会有所不同。

有一些代码：

std::unique_ptr<Botan::RandomNumberGenerator> rng(new Botan::System_RNG());
Botan::RSA_PrivateKey key(*rng.get(), 2048);

// We need to don't use a totally random rng in order to be able to decrypt the key.
QFile priv_key(QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation) + "/priv_key.rsa");

// If the private key does not exist, create it.
if (!priv_key.exists()) {


    Botan::RSA_PublicKey keyPub(key);
    auto encoded_key = Botan::PKCS8::BER_encode(key, *rng.get(), QSysInfo::machineUniqueId().toStdString());

    qDebug() << encoded_key.size();
    QByteArray arr(reinterpret_cast<char*>(encoded_key.data()), encoded_key.size());
    priv_key.open(QFile::WriteOnly | QFile::Truncate);
    priv_key.write(arr);
    priv_key.flush();
    priv_key.close();
}


else
    qDebug() << "already has a private key";

qDebug() << "filename: " << priv_key.fileName();

try {
    auto decoded_key = Botan::PKCS8::load_key(priv_key.fileName().toStdString(),
                           *rng.get(),
                           QSysInfo::machineUniqueId().toStdString());

    qDebug() << (decoded_key->private_key_bits() == key.private_key_bits());

} catch (std::exception& e) {
    qDebug() << e.what();
}