AES + Base64 return unknown symbols

[Limer]

-------------------encryption codes:

const QByteArray MQTT_SERVER_USER_PASSWORD_KEY = "23d655b75684433f1l525ed23826eb19";

// encryption 
m_password = m_passwordLineEdit->text();
QByteArray encodedPassword = AESEncryption::Crypt(AESEncryption::AES_256, AESEncryption::ECB, 
                                                  m_password.toLatin1(), MQTT_SERVER_USER_PASSWORD_KEY);
QString base64Password = encodedPassword.toBase64().data();
cJSON_AddStringToObject(root, "password", base64Password.toUtf8().data()); // cJSON library

// save to local file
char* data = cJSON_Print(root);
if (data)
{
    std::ofstream outfile;
    outfile.open("setting.json");
    if (outfile.is_open())
    {
        outfile << data;
        outfile.close();
    }
}
free(data);
cJSON_Delete(root);

---------------------- decryption codes:

// read from local file
std::ifstream infile;
infile.open("setting.json");
std::stringstream stream;
stream << infile.rdbuf();
std::string str = stream.str();
cJSON* root = cJSON_Parse(str.c_str());

// decryption
cJSON* passwordItem = cJSON_GetObjectItem(root , "password");
if (passwordItem)
{
    QByteArray encodedPassword = QString::fromUtf8(passwordItem->valuestring).toLatin1();
    QByteArray plainPassword = AESEncryption::Decrypt(AESEncryption::AES_256, AESEncryption::ECB, 
                                                      QByteArray::fromBase64(encodedPassword), MQTT_SERVER_USER_PASSWORD_KEY);
    m_pwdLineEdit->setText(plainPassword.data());
    m_password = plainPassword.data();
}

I use Qt-AES for encryption and decryption.

I need to save some information to local setting profile, when next time, users open the software, he/she can see the information. But for private informations, such as password, we should encrypt them, that is why I use AES algorithm. Because cJSON and C++ std:: use utf8, so I need to transfer to utf8, and then write to file.

Here is the result,

Why a redundant ? character? I guess it's the encoding problem, but I can't find the real reason, could someone give me any advice? THanks in advance.

[Kent-Dorfman]

I have a suspicion, but find out what the value of the unwanted character is and post it, please. I think somewhere in your data entry, save to sjon, or read from json, you are adding a newline or null character.

[Limer]

@kent-dorfman \n or `\0, but when added it? It's very strange.

[SGaist]

Hi,

Why are you making these transformations when putting the password in a QByteArray ?

[Limer]

@sgaist You mean the m_password.toLatin1() in encryption QByteArray encodedPassword = AESEncryption::Crypt(AESEncryption::AES_256, AESEncryption::ECB, m_password.toLatin1(), MQTT_SERVER_USER_PASSWORD_KEY); ?