QFile

QString Hashes::MD5(QFile *fileStream)
    {
        QString md5;

        QByteArray hashData = QCryptographicHash::hash(fileStream->readAll(), QCryptographicHash::Md5);
        md5.append(hashData.toHex());
        fileStream->close();

        return md5;
    }

1.
#include <QtCore/QCoreApplication>

#include <QCryptographicHash>

#include <iostream>

int main(int argc, char *argv[])

{

 QCoreApplication a(argc, argv);

 QString pwd="abcdef";

 QString md5;

 QByteArray ba,bb;

 QCryptographicHash md(QCryptographicHash::Md5);

 ba.append(pwd);

 md.addData(ba);

 bb = md.result();

 md5.append(bb.toHex());

 std::cout<<md5.toStdString()<<std::endl;

 return a.exec();

}

2.
#include <QtCore/QCoreApplication>

#include <QCryptographicHash>

#include <iostream>

int main(int argc, char *argv[])

{

    QCoreApplication a(argc, argv);

    QString md5;

    QString pwd="abcdef";

    QByteArray bb;

    bb = QCryptographicHash::hash(pwd.toAscii(),QCryptographicHash::Md5 );

    md5.append(bb.toHex());

    std::cout<<md5.toStdString()<<std::endl;

    return a.exec();

}