encrypt decrypt json files using cryptopp

Blackzero

Can someone help me with my problem.

I'm trying to encrypt a file then the encrypted file is read and moved into a QbyteArray called buffer to be read by QJson but it always fails, the decrypt result always fails.

#include <iostream>
#include <string>
#include <cryptlib.h>
#include <aes.h>
#include <ccm.h>
#include <filters.h>
#include <files.h>
#include <osrng.h>
#include <hex.h>
#include <sha.h>
#include <secblock.h>
#include <QFile>
#include <QJsonDocument>
#include <QJsonObject>
#include <QCoreApplication>
using namespace CryptoPP;
using namespace std;

bool EncryptFile(const QString &inputFile, const QString &outputFile, const SecByteBlock &key, const SecByteBlock &iv)
{
    try
    {
        CBC_Mode<AES>::Encryption encryptor(key, key.size(), iv);

        FileSource(inputFile.toStdString().c_str(), true,
                   new StreamTransformationFilter(encryptor,
                                                  new FileSink(outputFile.toStdString().c_str())));

        return true;
    }
    catch (const Exception &e)
    {
        cerr << "encrypt failed" << e.what() << endl;
        return false;
    }
}

bool DecryptFileToBuffer(const QString &inputFile, QByteArray &outputBuffer, const SecByteBlock &key, const SecByteBlock &iv)
{
    try
    {
        CBC_Mode<AES>::Decryption decryptor(key, key.size(), iv);

        std::string decryptedData;
        FileSource(inputFile.toStdString().c_str(), true,
                   new StreamTransformationFilter(decryptor,
                                                  new StringSink(decryptedData)));

        outputBuffer = QByteArray::fromRawData(decryptedData.data(), decryptedData.size());

        return true;
    }
    catch (const Exception &e)
    {
        cerr << "decyrpt failed " << e.what() << endl;
        return false;
    }
}

bool loadJsonData(const QByteArray &jsonData, QJsonObject &jsonObject)
{
    QJsonParseError parseError;
    QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &parseError);
    if (jsonDoc.isNull()) {
        qDebug() << "Failed to parse JSON:" << parseError.errorString();
        return false;
    }

    if (!jsonDoc.isObject()) {
        qDebug() << "JSON document is not an object";
        return false;
    }

    jsonObject = jsonDoc.object();
    return true;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    AutoSeededRandomPool prng;
    SecByteBlock key(AES::DEFAULT_KEYLENGTH);
    SecByteBlock iv(AES::BLOCKSIZE);

    prng.GenerateBlock(key, key.size());
    prng.GenerateBlock(iv, iv.size());
    
    QString jsonFile = "db.json";
    QString encryptedFile = "encrypted_db.bin";

    // Enkripsi file JSON
    if (EncryptFile(jsonFile, encryptedFile, key, iv)) {
        qDebug() << "encrypt succes";
    } else {
        qDebug() << "encrypt failed";
        return -1;
    }

    QByteArray decryptedBuffer;
    if (DecryptFileToBuffer(encryptedFile, decryptedBuffer, key, iv)) {
        qDebug() << "decyrpt succes";
    } else {
        qDebug() << "decrypt failed";
        return -1;
    }

    QJsonObject jsonObject;
    if (loadJsonData(decryptedBuffer, jsonObject)) {
        qDebug() << "JSON data:" << QJsonDocument(jsonObject).toJson();
    } else {
        qDebug() << "failed read buffer json";
        return -1;
    }


    return a.exec();
}

output console:

encrypt succes
decyrpt succes

it does not output any data

Axel Spoerl

decryptedBuffer, an empty QByteArray, is passed as a second argument to EncryptFile. The method expects a file name as a second argument, which should probably be encryptedFile. Since the second argument is empty, there is nowhere to output anything.

Blackzero

This post is deleted!

Blackzero

This post is deleted!

Axel Spoerl

Please don’t delete topics. Mark them solved if they are.