QMessageAuthenticationCode 类

QMessageAuthenticationCode 类提供生成基于哈希的消息身份验证代码的办法。更多...

头：	#include <QMessageAuthenticationCode>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake:	QT += core

所有成员列表，包括继承成员

注意： 此类的所有函数可重入 .

公共函数

	QMessageAuthenticationCode (QCryptographicHash::Algorithm method , const QByteArray & key = QByteArray())
	~QMessageAuthenticationCode ()
void	addData (const char * data , qsizetype length )
void	addData (const QByteArray & data )
bool	addData (QIODevice * device )
void	reset ()
QByteArray	result () const
void	setKey (const QByteArray & key )

静态公共成员

QByteArray

hash (const QByteArray & message , const QByteArray & key , QCryptographicHash::Algorithm method )

详细描述

QMessageAuthenticationCode supports all cryptographic hashes which are supported by QCryptographicHash .

To generate message authentication code, pass hash algorithm QCryptographicHash::Algorithm to constructor, then set key and message by setKey () 和 addData () functions. Result can be acquired by result () 函数。

    QByteArray key = "key";
    QByteArray message = "The quick brown fox jumps over the lazy dog";
    ...
    QMessageAuthenticationCode code(QCryptographicHash::Sha256, key);
    code.addData(message);
    code.result().toHex(); // returns "f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8"

Alternatively, this effect can be achieved by providing message, key and method to hash () 方法。

    QMessageAuthenticationCode::hash(message, key, QCryptographicHash::Sha256).toHex();

另请参阅 QCryptographicHash .

成员函数文档编制

`[explicit]` QMessageAuthenticationCode:: QMessageAuthenticationCode ( QCryptographicHash::Algorithm method , const QByteArray & key = QByteArray())

Constructs an object that can be used to create a cryptographic hash from data using method method and key key .

QMessageAuthenticationCode:: ~QMessageAuthenticationCode ()

销毁对象。

void QMessageAuthenticationCode:: addData (const char * data , qsizetype length )

Adds the first length chars of data to the message.

void QMessageAuthenticationCode:: addData (const QByteArray & data )

此函数重载 addData()。

bool QMessageAuthenticationCode:: addData ( QIODevice * device )

读取数据，从打开 QIODevice device until it ends and adds it to message. Returns true 若读取是成功的。

注意： device must be already opened.

`[static]` QByteArray QMessageAuthenticationCode:: hash (const QByteArray & message , const QByteArray & key , QCryptographicHash::Algorithm method )

Returns the authentication code for the message message using the key key and the method method .

void QMessageAuthenticationCode:: reset ()

Resets message data. Calling this method doesn't affect the key.

QByteArray QMessageAuthenticationCode:: result () const

Returns the final authentication code.

另请参阅 QByteArray::toHex ().

void QMessageAuthenticationCode:: setKey (const QByteArray & key )

Sets secret key . Calling this method automatically resets the object state.

For optimal performance, call this method only to change the active key, not to set an initial key, as in

QMessageAuthenticationCode mac(method);
mac.setKey(key); // does extra work
use(mac);

Prefer to pass initial keys as the constructor argument:

QMessageAuthenticationCode mac(method, key); // OK, optimal
use(mac);

You can use std::optional to delay construction of a QMessageAuthenticationCode until you know the key:

std::optional<QMessageAuthenticationCode> mac;
~~~
key = ~~~;
mac.emplace(method, key);
use(*mac);