QCA::PublicKey Class Reference
[QCA user API]

Generic public key. More...

#include <QtCrypto>

Inheritance diagram for QCA::PublicKey:

Public Member Functions
	PublicKey (const PublicKey &from)
	PublicKey (const QString &fileName)
	PublicKey (const PrivateKey &k)
	PublicKey ()
	~PublicKey ()
bool	canEncrypt () const
bool	canVerify () const
SecureArray	encrypt (const SecureArray &a, EncryptionAlgorithm alg)
int	maximumEncryptSize (EncryptionAlgorithm alg) const
PublicKey &	operator= (const PublicKey &from)
void	startVerify (SignatureAlgorithm alg, SignatureFormat format=DefaultFormat)
QByteArray	toDER () const
DHPublicKey	toDH () const
DSAPublicKey	toDSA () const
QString	toPEM () const
bool	toPEMFile (const QString &fileName) const
RSAPublicKey	toRSA () const
void	update (const MemoryRegion &a)
bool	validSignature (const QByteArray &sig)
bool	verifyMessage (const MemoryRegion &a, const QByteArray &sig, SignatureAlgorithm alg, SignatureFormat format=DefaultFormat)
Static Public Member Functions
static PublicKey	fromDER (const QByteArray &a, ConvertResult *result=0, const QString &provider=QString())
static PublicKey	fromPEM (const QString &s, ConvertResult *result=0, const QString &provider=QString())
static PublicKey	fromPEMFile (const QString &fileName, ConvertResult *result=0, const QString &provider=QString())
Protected Member Functions
	PublicKey (const QString &type, const QString &provider)

Detailed Description

Generic public key.

Definition at line 516 of file qca_publickey.h.

Constructor & Destructor Documentation

QCA::PublicKey::PublicKey ( )

Create an empty (null) public key.

Definition at line 753 of file qca_publickey.cpp.

QCA::PublicKey::PublicKey ( const PrivateKey & k )

Create a public key based on a specified private key.

Parameters:

k

the private key to extract the public key parts from

Definition at line 762 of file qca_publickey.cpp.

QCA::PublicKey::PublicKey ( const QString & fileName )

Import a public key from a PEM representation in a file.

Parameters:

fileName

the name of the file containing the public key

See also:: fromPEMFile for an alternative method

Definition at line 767 of file qca_publickey.cpp.

QCA::PublicKey::PublicKey ( const PublicKey & from )

Copy constructor.

Parameters:

from

the PublicKey to copy from

Definition at line 772 of file qca_publickey.cpp.

QCA::PublicKey::~PublicKey ( )

Definition at line 777 of file qca_publickey.cpp.

QCA::PublicKey::PublicKey	(	const QString &	type,
		const QString &	provider
	)			`[protected]`

Create a new key of a specified type.

Parameters:

	type	the type of key to create
	provider	the provider to use, if required

Definition at line 757 of file qca_publickey.cpp.

Member Function Documentation

bool QCA::PublicKey::canEncrypt ( ) const

Test if this key can be used for encryption.

Returns:: true if the key can be used for encryption

Definition at line 802 of file qca_publickey.cpp.

bool QCA::PublicKey::canVerify ( ) const

Test if the key can be used for verifying signatures.

Returns:: true of the key can be used for verification

Definition at line 807 of file qca_publickey.cpp.

SecureArray QCA::PublicKey::encrypt	(	const SecureArray &	a,
		EncryptionAlgorithm	alg
	)

Encrypt a message using a specified algorithm.

Parameters:

	a	the message to encrypt
	alg	the algorithm to use

Definition at line 817 of file qca_publickey.cpp.

PublicKey QCA::PublicKey::fromDER	(	const QByteArray &	a,
		ConvertResult *	result = `0`,
		const QString &	provider = `QString()`
	)			`[static]`

Import a key in Distinguished Encoding Rules (DER) format.

This function takes a binary array, which is assumed to contain a public key in DER encoding, and returns the key. Unless you don't care whether the import succeeded, you should test the result, as shown below.

QCA::ConvertResult conversionResult;
QCA::PublicKey publicKey = QCA::PublicKey::fromDER(keyArray, &conversionResult);
if (! QCA::ConvertGood == conversionResult)
{
    std::cout << "Public key read failed" << std::endl;
}

Parameters:

	a	the array containing a DER encoded key
	result	pointer to a variable, which returns whether the conversion succeeded (ConvertGood) or not
	provider	the name of the provider to use for the import.

Definition at line 893 of file qca_publickey.cpp.

PublicKey QCA::PublicKey::fromPEM	(	const QString &	s,
		ConvertResult *	result = `0`,
		const QString &	provider = `QString()`
	)			`[static]`

Import a key in Privacy Enhanced Mail (PEM) format.

This function takes a string, which is assumed to contain a public key in PEM encoding, and returns that key. Unless you don't care whether the import succeeded, you should test the result, as shown below.

QCA::ConvertResult conversionResult;
QCA::PublicKey publicKey = QCA::PublicKey::fromPEM(keyAsString, &conversionResult);
if (! QCA::ConvertGood == conversionResult)
{
    std::cout << "Public key read failed" << std::endl;
}

Parameters:

	s	the string containing a PEM encoded key
	result	pointer to a variable, which returns whether the conversion succeeded (ConvertGood) or not
	provider	the name of the provider to use for the import.

See also:: toPEM, which provides an inverse of fromPEM(); fromPEMFile, which provides an import direct from a file.

Definition at line 898 of file qca_publickey.cpp.

PublicKey QCA::PublicKey::fromPEMFile	(	const QString &	fileName,
		ConvertResult *	result = `0`,
		const QString &	provider = `QString()`
	)			`[static]`

Import a key in Privacy Enhanced Mail (PEM) format from a file.

This function takes the name of a file, which is assumed to contain a public key in PEM encoding, and returns that key. Unless you don't care whether the import succeeded, you should test the result, as shown below.

QCA::ConvertResult conversionResult;
QCA::PublicKey publicKey = QCA::PublicKey::fromPEMFile(fileName, &conversionResult);
if (! QCA::ConvertGood == conversionResult)
{
    std::cout << "Public key read failed" << std::endl;
}

Parameters:

	fileName	a string containing the name of the file
	result	pointer to a variable, which returns whether the conversion succeeded (ConvertGood) or not
	provider	the name of the provider to use for the import.

See also:: toPEMFile, which provides an inverse of fromPEMFile(); fromPEM, which provides an import from a string

Note:: there is also a constructor form that can import from a file

Definition at line 903 of file qca_publickey.cpp.

int QCA::PublicKey::maximumEncryptSize ( EncryptionAlgorithm alg ) const

The maximum message size that can be encrypted with a specified algorithm.

Parameters:

alg

the algorithm to check

Definition at line 812 of file qca_publickey.cpp.

PublicKey & QCA::PublicKey::operator= ( const PublicKey & from )

Assignment operator.

Parameters:

from

the PublicKey to copy from

Reimplemented from QCA::PKey.

Definition at line 781 of file qca_publickey.cpp.

void QCA::PublicKey::startVerify	(	SignatureAlgorithm	alg,
		SignatureFormat	format = `DefaultFormat`
	)

Initialise the signature verification process.

Parameters:

	alg	the algorithm to use for signing
	format	the specific format to use, for DSA

Definition at line 822 of file qca_publickey.cpp.

QByteArray QCA::PublicKey::toDER ( ) const

Export the key in Distinguished Encoding Rules (DER) format.

Definition at line 846 of file qca_publickey.cpp.

DHPublicKey QCA::PublicKey::toDH ( ) const

Convenience method to convert this key to a DHPublicKey.

Note that if the key is not an DH key (eg it is DSA or RSA), then this will produce a null key.

Definition at line 797 of file qca_publickey.cpp.

DSAPublicKey QCA::PublicKey::toDSA ( ) const

Convenience method to convert this key to a DSAPublicKey.

Note that if the key is not an DSA key (eg it is RSA or DH), then this will produce a null key.

Definition at line 792 of file qca_publickey.cpp.

QString QCA::PublicKey::toPEM ( ) const

Export the key in Privacy Enhanced Mail (PEM) format.

See also:: toPEMFile provides a convenient way to save the PEM encoded key to a file; fromPEM provides an inverse of toPEM, converting the PEM encoded key back to a PublicKey

Definition at line 867 of file qca_publickey.cpp.

bool QCA::PublicKey::toPEMFile ( const QString & fileName ) const

Export the key in Privacy Enhanced Mail (PEM) to a file.

Parameters:

fileName

the name (and path, if necessary) of the file to save the PEM encoded key to.

See also:: toPEM for a version that exports to a QString, which may be useful if you need to do more sophisticated handling; fromPEMFile provides an inverse of toPEMFile, reading a PEM encoded key from a file

Definition at line 888 of file qca_publickey.cpp.

RSAPublicKey QCA::PublicKey::toRSA ( ) const

Convenience method to convert this key to an RSAPublicKey.

Note that if the key is not an RSA key (eg it is DSA or DH), then this will produce a null key.

Definition at line 787 of file qca_publickey.cpp.

void QCA::PublicKey::update ( const MemoryRegion & a )

Update the signature verification process with more data.

Parameters:

a

the array containing the data that should be added to the signature

Definition at line 829 of file qca_publickey.cpp.

bool QCA::PublicKey::validSignature ( const QByteArray & sig )

Check the signature is valid for the message.

The process to check that a signature is correct is shown below:

// note that pubkey is a PublicKey
if( pubkey.canVerify() )
{
    pubkey.startVerify( QCA::EMSA3_MD5 );
    pubkey.update( theMessage ); // might be called multiple times
    if ( pubkey.validSignature( theSignature ) )
    {
        // then signature is valid
    }
    else
    {
        // then signature is invalid
    }
}

Parameters:

sig

the signature to check

Returns:: true if the signature is correct

Definition at line 834 of file qca_publickey.cpp.

bool QCA::PublicKey::verifyMessage	(	const MemoryRegion &	a,
		const QByteArray &	sig,
		SignatureAlgorithm	alg,
		SignatureFormat	format = `DefaultFormat`
	)

Single step message verification.

If you have the whole message to be verified, then this offers a more convenient approach to verification.

Parameters:

	a	the message to check the signature on
	sig	the signature to be checked
	alg	the algorithm to use
	format	the signature format to use, for DSA

Returns:: true if the signature is valid for the message

Definition at line 839 of file qca_publickey.cpp.

The documentation for this class was generated from the following files:

qca

QCA::PublicKey Class Reference [QCA user API]

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

qca

KDE Support

QCA::PublicKey Class Reference
[QCA user API]