How to get encryption/decryption progress when encrypt big files with botan in Qt

Question

I have the code below to encrypt and decrypt file with botan in Qt. When encrypt big files it spend a lot of time, and i want to get the number of processed bytes when encrypting/decrypting big files. Is it possible?

   void AES::Encrypt(SymmetricKey key, InitializationVector iv, string inFilename,  string outFilename)
{
    std::ifstream in(inFilename.c_str(),std::ios::binary);
    std::ofstream out(outFilename.c_str(),std::ios::binary);

    Pipe pipe(get_cipher("AES-256/CBC", key, iv,ENCRYPTION),new DataSink_Stream(out));
    pipe.start_msg();
    in >> pipe;
    pipe.end_msg();

    out.flush();
    out.close();
    in.close();

    qDebug() << "Encrypted!";
}

void AES::Decrypt(SymmetricKey key, InitializationVector iv, string inFilename,  string outFilename)
{
    std::ifstream in(inFilename.c_str(),std::ios::binary);
    std::ofstream out(outFilename.c_str(),std::ios::binary);

    Pipe pipe(get_cipher("AES-256/CBC", key, iv,DECRYPTION),new DataSink_Stream(out));
    pipe.start_msg();
    in >> pipe;
    pipe.end_msg();

    out.flush();
    out.close();
    in.close();

    qDebug() << "Decrypted!";
}

score 0 · Accepted Answer · answered Dec 08 '12 at 17:24

If you look in the Botan documentation about Pipe/Filter Mechanisms, there's a discussion about handling of large files and bounding use of memory. At the end of that section, is a code snippet which shows handling of large files with a bounded buffer. By adding in some code there, I think you'll be able to keep the encryption operation from running out of memory as well as being able to fire Qt progress signals out of that loop.

How to get encryption/decryption progress when encrypt big files with botan in Qt

1 Answers1