QOpcUaKeyPair Class

QOpcUaKeyPair handles private and public key pairs. More...

Header:	#include <QOpcUaKeyPair>
qmake:	QT += opcua
Since:	Qt 5.14
Inherits:	QObject

• List of all members, including inherited members

Public Types

enum class	Cipher { Aes128Cbc, Unencrypted }
enum class	KeyType { Rsa, Empty, Unknown }
enum class	RsaKeyStrength { Bits1024, Bits2048, Bits4096 }

Public Functions

	QOpcUaKeyPair(QObject *parent = nullptr)
virtual	~QOpcUaKeyPair()
void	generateRsaKey(QOpcUaKeyPair::RsaKeyStrength strength)
bool	hasPrivateKey() const
bool	loadFromPemData(const QByteArray &data)
QByteArray	privateKeyToByteArray(QOpcUaKeyPair::Cipher cipher, const QString &password) const
QByteArray	publicKeyToByteArray() const
QOpcUaKeyPair::KeyType	type() const

Signals

void	passphraseNeeded(QString &passphrase, int maximumLength, bool writeOperation)

Detailed Description

This class is currently available as a Technology Preview, and therefore the API and functionality provided by the class may be subject to change at any time without prior notice.

It can generate, load and store keys for asymmetric encryption. Instances of this class have to be passed to functions which need a key.

Member Type Documentation

enum class QOpcUaKeyPair::Cipher

Ciphers for encryption of private keys.

Constant	Value	Description
QOpcUaKeyPair::Cipher::Aes128Cbc	0	Encrypting AES128 with CBC
QOpcUaKeyPair::Cipher::Unencrypted	1	The Key will not be encrypted.

enum class QOpcUaKeyPair::KeyType

This enum type specifies the type of a key.

Constant	Value	Description
QOpcUaKeyPair::KeyType::Rsa	0	An RSA key
QOpcUaKeyPair::KeyType::Empty	1	No key is available.
QOpcUaKeyPair::KeyType::Unknown	2	The type of key is not handled.

enum class QOpcUaKeyPair::RsaKeyStrength

This enum type specifies the strength of a RSA key.

Constant	Value	Description
QOpcUaKeyPair::RsaKeyStrength::Bits1024	1024	A key strength of 1024 bits.
QOpcUaKeyPair::RsaKeyStrength::Bits2048	2048	A key strength of 2048 bits.
QOpcUaKeyPair::RsaKeyStrength::Bits4096	4096	A key strength of 4096 bits.

Member Function Documentation

QOpcUaKeyPair::QOpcUaKeyPair(QObject *parent = nullptr)

Creates a new empty key pair with parent as the parent object.

[signal] void QOpcUaKeyPair::passphraseNeeded(QString &passphrase, int maximumLength, bool writeOperation)

This signal is emitted when a private key needs a passphrase for encryption or decryption.

writeOperation is true when the passphrase is needed for exporting a key, and is false when the passphrase is needed for importing a key.

maximumLength specifies the maximum length in bytes for the passphrase. All characters in passphrase exceeding this limit will be ignored.

In case you have use this signal crossing thread boundaries you have to connect it with Qt::BlockingQueuedConnection.

[virtual] QOpcUaKeyPair::~QOpcUaKeyPair()

Destroys the key pair.

void QOpcUaKeyPair::generateRsaKey(QOpcUaKeyPair::RsaKeyStrength strength)

Generates a new asymmetric RSA key pair.

The length of the key is specified by strength.

bool QOpcUaKeyPair::hasPrivateKey() const

Returns true if the current key contains a private key, otherwise false.

bool QOpcUaKeyPair::loadFromPemData(const QByteArray &data)

Loads a key from PEM encoded data in data. Returns true on success and false otherwise.

It detects from the PEM header if the data contains a private or public key. Loading encrypted keys is possible by connecting a function to the signal passphraseNeeded for provision of the passphrase.

QByteArray QOpcUaKeyPair::privateKeyToByteArray(QOpcUaKeyPair::Cipher cipher, const QString &password) const

Returns the PEM encoded private key. In case there is no private key, an empty byte array is returned.

The encryption of the key has to be specified using the parameters cipher and password. In order to store the key unencrypted the cipher Cipher::Unencrypted has to be used.

QByteArray QOpcUaKeyPair::publicKeyToByteArray() const

Returns the public key as a byte array.

QOpcUaKeyPair::KeyType QOpcUaKeyPair::type() const

Returns the type of the current key.