QCA::PublicKey Class Reference

Generic public key. More...

#include <QtCrypto>

Inheritance diagram for QCA::PublicKey:

QCA::PKey QCA::Algorithm QCA::DHPublicKey QCA::DSAPublicKey QCA::RSAPublicKey Collaboration diagram for QCA::PublicKey:

Collaboration graph
[legend]
List of all members.

Public Member Functions

 PublicKey ()
 PublicKey (const PrivateKey &k)
 PublicKey (const QString &fileName)
 PublicKey (const PublicKey &from)
PublicKeyoperator= (const PublicKey &from)
RSAPublicKey toRSA () const
DSAPublicKey toDSA () const
DHPublicKey toDH () const
bool canEncrypt () const
bool canVerify () const
int maximumEncryptSize (EncryptionAlgorithm alg) const
SecureArray encrypt (const SecureArray &a, EncryptionAlgorithm alg)
void startVerify (SignatureAlgorithm alg, SignatureFormat format=DefaultFormat)
void update (const MemoryRegion &a)
bool validSignature (const QByteArray &sig)
bool verifyMessage (const MemoryRegion &a, const QByteArray &sig, SignatureAlgorithm alg, SignatureFormat format=DefaultFormat)
QByteArray toDER () const
QString toPEM () const
bool toPEMFile (const QString &fileName) const

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.
Examples:

rsatest.cpp.


Constructor & Destructor Documentation

QCA::PublicKey::PublicKey  ) 
 

Create an empty (null) public key.

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

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

QCA::PublicKey::PublicKey const PublicKey from  ) 
 

Copy constructor.

Parameters:
from the PublicKey to copy from

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


Member Function Documentation

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

Assignment operator.

Parameters:
from the PublicKey to copy from

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.

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.

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.

bool QCA::PublicKey::canEncrypt  )  const
 

Test if this key can be used for encryption.

Returns:
true if the key can be used for encryption
Examples:
rsatest.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

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

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

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

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

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

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

QByteArray QCA::PublicKey::toDER  )  const
 

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

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

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

static 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.

static 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.

static 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


The documentation for this class was generated from the following file:
Generated on Fri Jul 6 12:15:18 2007 for Qt Cryptographic Architecture by  doxygen 1.4.6