QCryptographicHash模块提供了计算加密哈希值的一些算法，包括MD5，SHA-1，SHA-256等，可以分段提供源数据，也可以将源数据封装为一个QIODevice，然后传入给QCryptographicHash。

The QCryptographicHash class provides a way to generate cryptographic hashes.

QCryptographicHash can be used to generate cryptographic hashes of binary or text data.

Currently MD4, MD5, SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 are supported.

示例代码如下：

#include <QCoreApplication>
#include <QtCore>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QFile hf("C:/Qt/Projects/016_QCryptographicHash/main.cpp");
    hf.open(QIODevice::ReadOnly);
    QCryptographicHash hs(QCryptographicHash::Md5);
    hs.addData(&hf);
    auto result=hs.result();
    qDebug() << result.toHex();
    hs.reset();
    return a.exec();
}

参考资料：

http://qt-project.org/doc/qt-5/QCryptographicHash.html