Qt 4.8: QSslCertificate Class Reference

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# QSslCertificate Class Reference

The QSslCertificate class provides a convenient API for an X509 certificate. More...

     #include <QSslCertificate>

Note: All functions in this class are reentrant.

This class was introduced in Qt 4.3.

- List of all members, including inherited members

## Public Types

enum | SubjectInfo { Organization, CommonName, LocalityName, OrganizationalUnitName, CountryName, StateOrProvinceName }

## Public Functions

| QSslCertificate ( QIODevice * device, QSsl::EncodingFormat format = QSsl::Pem )
| QSslCertificate ( const QByteArray & data = QByteArray(), QSsl::EncodingFormat format = QSsl::Pem )
| QSslCertificate ( const QSslCertificate & other )
| ~QSslCertificate ()
QMultiMap<QSsl::AlternateNameEntryType, QString> | alternateSubjectNames () const
void | clear ()
QByteArray | digest ( QCryptographicHash::Algorithm algorithm = QCryptographicHash::Md5 ) const
QDateTime | effectiveDate () const
QDateTime | expiryDate () const
Qt::HANDLE | handle () const
bool | isNull () const
bool | isValid () const
QString | issuerInfo ( SubjectInfo subject ) const
QString | issuerInfo ( const QByteArray & tag ) const
QSslKey | publicKey () const
QByteArray | serialNumber () const
QString | subjectInfo ( SubjectInfo subject ) const
QString | subjectInfo ( const QByteArray & tag ) const
QByteArray | toDer () const
QByteArray | toPem () const
QByteArray | version () const
bool | operator!= ( const QSslCertificate & other ) const
QSslCertificate & | operator= ( const QSslCertificate & other )
bool | operator== ( const QSslCertificate & other ) const

## Static Public Members

QList<QSslCertificate> | fromData ( const QByteArray & data, QSsl::EncodingFormat format = QSsl::Pem )
QList<QSslCertificate> | fromDevice ( QIODevice * device, QSsl::EncodingFormat format = QSsl::Pem )
QList<QSslCertificate> | fromPath ( const QString & path, QSsl::EncodingFormat format = QSsl::Pem, QRegExp::PatternSyntax syntax = QRegExp::FixedString )

## Detailed Description

The QSslCertificate class provides a convenient API for an X509 certificate.

QSslCertificate stores an X509 certificate, and is commonly used to verify the identity and store information about the local host, a remotely connected peer, or a trusted third party Certificate Authority.

There are many ways to construct a QSslCertificate. The most common way is to call QSslSocket::peerCertificate(), which returns a QSslCertificate object, or QSslSocket::peerCertificateChain(), which returns a list of them. You can also load certificates from a DER (binary) or PEM (Base64) encoded bundle, typically stored as one or more local files, or in a Qt Resource.

You can call isNull() to check if your certificate is null. By default, QSslCertificate constructs a null certificate. To check if the certificate is valid, call isValid(). A null certificate is invalid, but an invalid certificate is not necessarily null. If you want to reset all contents in a certificate, call clear().

After loading a certificate, you can find information about the certificate, its subject, and its issuer, by calling one of the many accessor functions, including version(), serialNumber(), issuerInfo() and subjectInfo(). You can call effectiveDate() and expiryDate() to check when the certificate starts being effective and when it expires. The publicKey() function returns the certificate subject's public key as a QSslKey. You can call issuerInfo() or subjectInfo() to get detailed information about the certificate issuer and its subject.

Internally, QSslCertificate is stored as an X509 structure. You can access this handle by calling handle(), but the results are likely to not be portable.

See also QSslSocket, QSslKey, QSslCipher, and QSslError.

## Member Type Documentation

### enum QSslCertificate::SubjectInfo

Describes keys that you can pass to QSslCertificate::issuerInfo() or QSslCertificate::subjectInfo() to get information about the certificate issuer or subject.

Constant | Value | Description
--- | --- | ---
`QSslCertificate::Organization` | `0` | "O" The name of the organization.
`QSslCertificate::CommonName` | `1` | "CN" The common name; most often this is used to store the host name.
`QSslCertificate::LocalityName` | `2` | "L" The locality.
`QSslCertificate::OrganizationalUnitName` | `3` | "OU" The organizational unit name.
`QSslCertificate::CountryName` | `4` | "C" The country.
`QSslCertificate::StateOrProvinceName` | `5` | "ST" The state or province.

## Member Function Documentation

### QSslCertificate::QSslCertificate ( QIODevice * device, QSsl::EncodingFormat format = QSsl::Pem )

Constructs a QSslCertificate by reading format encoded data from device and using the first certificate found. You can later call isNull() to see if device contained a certificate, and if this certificate was loaded successfully.

### QSslCertificate::QSslCertificate ( const QByteArray & data = QByteArray(), QSsl::EncodingFormat format = QSsl::Pem )

Constructs a QSslCertificate by parsing the format encoded data and using the first available certificate found. You can later call isNull() to see if data contained a certificate, and if this certificate was loaded successfully.

### QSslCertificate::QSslCertificate ( const QSslCertificate & other )

Constructs an identical copy of other.

### QSslCertificate::~QSslCertificate ()

Destroys the QSslCertificate.

### QMultiMap<QSsl::AlternateNameEntryType, QString> QSslCertificate::alternateSubjectNames () const

Returns the list of alternative subject names for this certificate. The alternate subject names typically contain host names, optionally with wildcards, that are valid for this certificate.

These names are tested against the connected peer's host name, if either the subject information for CommonName doesn't define a valid host name, or the subject info name doesn't match the peer's host name.

See also subjectInfo().

### void QSslCertificate::clear ()

Clears the contents of this certificate, making it a null certificate.

See also isNull().

### QByteArray QSslCertificate::digest ( QCryptographicHash::Algorithm algorithm = QCryptographicHash::Md5 ) const

Returns a cryptographic digest of this certificate. By default, an MD5 digest will be generated, but you can also specify a custom algorithm.

### QDateTime QSslCertificate::effectiveDate () const

Returns the date-time that the certificate becomes valid, or an empty QDateTime if this is a null certificate.

See also expiryDate().

### QDateTime QSslCertificate::expiryDate () const

Returns the date-time that the certificate expires, or an empty QDateTime if this is a null certificate.

See also effectiveDate().

### QList<QSslCertificate> QSslCertificate::fromData ( const QByteArray & data, QSsl::EncodingFormat format = QSsl::Pem )`[static]`

Searches for and parses all certificates in data that are encoded in the specified format and returns them in a list of certificates.

See also fromDevice().

### QList<QSslCertificate> QSslCertificate::fromDevice ( QIODevice * device, QSsl::EncodingFormat format = QSsl::Pem )`[static]`

Searches for and parses all certificates in device that are encoded in the specified format and returns them in a list of certificates.

See also fromData().

### QList<QSslCertificate> QSslCertificate::fromPath ( const QString & path, QSsl::EncodingFormat format = QSsl::Pem, QRegExp::PatternSyntax syntax = QRegExp::FixedString )`[static]`

Searches all files in the path for certificates encoded in the specified format and returns them in a list. must be a file or a pattern matching one or more files, as specified by syntax.

Example:

     foreach (const QSslCertificate &cert, QSslCertificate::fromPath("C:/ssl/certificate.*.pem", QSsl::Pem,
                                                              QRegExp::Wildcard)) {
         qDebug() << cert.issuerInfo(QSslCertificate::Organization);
     }

See also fromData().

### Qt::HANDLE QSslCertificate::handle () const

Returns a pointer to the native certificate handle, if there is one, or a null pointer otherwise.

You can use this handle, together with the native API, to access extended information about the certificate.

Warning: Use of this function has a high probability of being non-portable, and its return value may vary from platform to platform or change from minor release to minor release.

### bool QSslCertificate::isNull () const

Returns true if this is a null certificate (i.e., a certificate with no contents); otherwise returns false.

By default, QSslCertificate constructs a null certificate.

See also isValid() and clear().

### bool QSslCertificate::isValid () const

Returns true if this certificate is valid; otherwise returns false.

Note: Currently, this function checks that the current data-time is within the date-time range during which the certificate is considered valid, and checks that the certificate is not in a blacklist of fraudulent certificates.

See also isNull().

### QString QSslCertificate::issuerInfo ( SubjectInfo subject ) const

Returns the issuer information for the subject from the certificate, or an empty string if there is no information for subject in the certificate.

See also subjectInfo().

### QString QSslCertificate::issuerInfo ( const QByteArray & tag ) const

Returns the issuer information for tag from the certificate, or an empty string if there is no information for tag in the certificate.

See also subjectInfo().

### QSslKey QSslCertificate::publicKey () const

Returns the certificate subject's public key.

### QByteArray QSslCertificate::serialNumber () const

Returns the certificate's serial number string in decimal format. In case the serial number cannot be converted to decimal format (i.e. if it is bigger than 4294967295, which means it does not fit into 4 bytes), its hexadecimal version is returned.

### QString QSslCertificate::subjectInfo ( SubjectInfo subject ) const

Returns the information for the subject, or an empty string if there is no information for subject in the certificate.

See also issuerInfo().

### QString QSslCertificate::subjectInfo ( const QByteArray & tag ) const

Returns the subject information for tag, or an empty string if there is no information for tag in the certificate.

See also issuerInfo().

### QByteArray QSslCertificate::toDer () const

Returns this certificate converted to a DER (binary) encoded representation.

### QByteArray QSslCertificate::toPem () const

Returns this certificate converted to a PEM (Base64) encoded representation.

### QByteArray QSslCertificate::version () const

Returns the certificate's version string.

### bool QSslCertificate::operator!= ( const QSslCertificate & other ) const

Returns true if this certificate is not the same as other; otherwise returns false.

### QSslCertificate & QSslCertificate::operator= ( const QSslCertificate & other )

Copies the contents of other into this certificate, making the two certificates identical.

### bool QSslCertificate::operator== ( const QSslCertificate & other ) const

Returns true if this certificate is the same as other; otherwise returns false.